Absorbing Components Research Articles

Conducting Polymers and Thermosensitive Hydrogels for Green Electricity Generation

Sustainable strategies to generate electricity using natural resources, such as sunlight (photovoltaic cells) and wind (wind towers), have driven a significant change in our homes in terms of electricity consumption. Herein, a new alternative for green electricity supply using solar‐driven evaporators devices fabricated with hydrogels is described. The photothermal electricity production is promoted by alginate‐poly(N‐isopropylacrylamide) (ALG‐PNIPAAm) bio‐hydrogel, modified with acid‐doped conducting polymer (CP), as thermal absorber component, to minimize energy losses. Direct current and voltage monitoring are used during the solar irradiation experiments to evaluate the power density of the hydrogel thermal electricity generator, whereas electrochemical impedance spectroscopy is employed to approach the diffusion processes. Impedance measurements elucidate the ion diffusion dynamics within the hydrogel, directly correlating this behavior to enhanced power generation. Therefore, the highest power supply (64.4 μW·cm−2) and current stability (32–33 μA), over time, are obtained for ALG‐PNIPAAm‐PEDOT‐PSS hydrogel, demonstrating that hydrophilic groups (OH, SO3H), present in the CP backbone, promote the capillary flow of the electrolyte during the sunlight irradiation. The doped CP molecules facilitate a fast ion transport thanks to a good balance between the material hydrophilicity and the interconnected pores.

Impact behavior of the SCS panel with hybrid energy absorbing components: Experimental and analytical studies

A new steel-concrete-steel panel with front aluminum foam layer and rear energy absorbing connector (SCS-FL-EAC) was firstly developed. The dynamic behavior of SCS-FL-EAC was studied through conducting drop-weight impact tests. Three stages of impact process of SCS-FL-EAC were identified. The aluminum foam layer and energy absorbing connector were crushed under impact loading. The aluminum foam layer reached densification, and a local indention was observed beneath the projectile. Plastic hinges were also found at the corners of the pleated steel plate of the energy absorbing connector. The SCS panel exhibited the combination of bi-linear global flexural deformation and local deformation. Furthermore, the effects of aluminum foam layer on the impact resistant performances of SCS-FL-EAC were investigated. The results indicated that the inclusion of the aluminum foam layer effectively mitigated inertial effects and reduced the maximum impact force. Additionally, the SCS-FL-EAC demonstrated improved impact-resistant performances with an increased thickness of the aluminum foam layer. Furthermore, an analytical model was proposed to predict the force and displacement responses of SCS-FL-EAC subjected to impact load, and the predicted impact responses showed good agreement with experimental results.

In-situ chemically synthesized Fe3O4/K-geopolymer composite with microwave absorbency for additive manufacturing

In this work, we utilized an in-situ chemical synthesis method to fabricate a Fe3O4/K-geopolymer (KGP) composite to be applied in a microwave absorbent field. This material, as a type of ceramic precursor, is highly expected to be a 3D printing material to prepare microwave absorbing components with complex shapes. The investigation results demonstrate that the material possesses a large effective microwave absorbing bandwidth of 3.7 GHz with the minimum reflection loss reducing to −12.2 dB when the generated Fe3O4 percent reaches 12 wt% in the KGP composite. This microwave absorbent performance can be attributed to a synergistic effect between the eddy current loss caused by the improved electrical conductivity of magnetic nanoparticles and the interfacial polarization effect from the geopolymer matrix and magnetic medium interface. Also, we used direct ink writing technology to print two-dimensional components with desirable patterns. Thickness-dependent wave absorption evaluation results confirmed a maximum reflection loss of −25.9 dB at 15.2 Hz was obtained from the printed sample containing 9.0 wt% Fe3O4 for a layer thickness of 10 mm, indicating that wave consumption effectiveness was determined by porous microstructures, magnetic loss of Fe3O4 nanoparticles as well as suitable impedance matching. The preparation method and synthesized material pave the way for integrated manufacturing of 3D printing components with microwave absorbing performance.

XMM-Newton – NuSTAR monitoring campaign of the Seyfert 1 galaxy IC 4329A

We present the results of a joint XMM-Newton and NuSTAR campaign on the active galactic nucleus (AGN) IC 4329A, consisting of 9 × 20 ks XMM-Newton observations, and 5 × 20 ks NuSTAR observations within nine days, performed in August 2021. Within each observation, the AGN is not very variable, and the fractional variability never exceeds 5%. Flux variations are observed between the different observations on timescales of days, with a ratio of 30% of the minimum and maximum 2–10 keV flux. These variations follow the softer-when-brighter behavior typically observed in AGN. In all observations, a soft excess is clearly present. Consistently with previous observations, the X-ray spectra of the source exhibit a cutoff energy between 140 and 250 keV that is constant within the error in the different observations. We detected a prominent component of the 6.4 keV Fe Kα line consistent with being constant during the monitoring, consisting of an unresolved narrow core and a broader component likely originating in the inner accredion disk. We find that the reflection component is weak (Rmax = 0.009 ± 0.002) and most likely originates in distant neutral medium. We also found a warm absorber component together with an ultrafast outflow. Their energetics show that these outflows have enough mechanical power for significant feedback on the environment of the AGN.

Miura-ori based reconfigurable multilayer absorber for high-efficiency wide-angle absorption.

Radar stealth structures that can achieve high-efficiency wide-angle absorption are key components of future military equipment. However, it is difficult for both planar and three-dimensional (3D) absorbers to achieve efficient absorption in a large incidence angle range. The multilayer reconfigurable absorber component based on Miura origami provides a unique solution. First, the multilayer origami absorber is parameterized in the simulation software. Each origami structure is covered with resistive films that fit the panels. Geometric constraints are satisfied among the multilayer structures. They support reconfigurability in the range of continuous states (as opposed to discrete states), which is conducive to finding the folded state with a more efficient absorption rate within the frequency band. Secondly, the designed structure does not require a specialized mechanically supported multilayer origami absorber. In addition, the equivalent analogue circuit method is used to analyze the efficient absorption of multilayer origami under oblique incidence. Finally, our proposed absorber satisfies the requirements of multiple absorption metrics: broadband, high efficiency, wide incidence angle, and polarization insensitivity. As the validation, we simulated and fabricated a double-layer origami absorber. Our proposed origami absorber can maintain an absorption rate of more than 90% for both transverse electric (TE) and transverse magnetic (TM) polarizations in the operating frequency band (5-20 GHz) over a wide range of incidence angles (0°-70°). When the incidence angle qinc = 40°, the double-layer origami absorber (q1 = 90°, α1 = 60°, and a2 = 75°) can achieve at least 10 dB reflection reduction of -18 dB and -20 dB in TE and TM modes, respectively. The proposed origami absorber provides a reference for the design of other absorbers.

Characterization of the Components and Metabolites of Achyranthes Bidentata in the Plasma and Brain Tissue of Rats Based on Ultrahigh Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC-HR-MS).

Achyranthes bidentata (AR) is a traditional Chinese herb used for the treatment of hypertension and cerebral ischemia, but its pharmacological effects are not known. We aimed to detect and accurately identify the components and metabolites of AR in the plasma and brain tissue of Sprague Dawley rats. We employed ultrahigh performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HR-MS) to detect AR components in the plasma and brain tissue of rats. The absorption and metabolites in the plasma and brain tissue of normal control rats and rats that underwent middle cerebral artery occlusion (MCAO) were characterized and compared. A total of 281 compounds, including alkaloids, flavonoids, terpenoids, phenylpropanes, sugars and glycosides, steroids, triterpenes, amino acids, and peptides, was identified in samples of Achyranthes bidentata (TCM-AR). Four types of absorbable prototype components and 48 kinds of metabolites were identified in rats in the normal control plasma group which were given AR (AR plasma group), and five kinds of metabolites were identified in rats of the normal control brain tissue group which were given AR (AR brain group). Three absorbed prototype components and 13 metabolites were identified in the plasma of rats which underwent MCAO and were given AR (MCAO + AR plasma group). Six absorbed prototype components and two metabolites were identified in the brain tissue of rats who underwent MCAO and were administered AR (MCAO + AR brain group). These results showed that, after the oral administration of AR, the number of identified components in plasma was more than that in brain tissue. The number of prototype components in the AR plasma group was higher than that in the MCAO + AR plasma group, which may indicate that metabolite absorption in rats undergoing MCAO was worse. The number of prototype components in the MCAO + AR brain group was higher than that in the AR brain group, indicating that the blood-brain barrier was destroyed after MCAO, resulting in more compounds entering brain tissue. UHPLC-HR-MS was used to rapidly analyze the components and metabolites of AR in the blood and brain of rats under normal and pathologic conditions, and to comprehensively characterize the components of TCM-AR. We also analyzed and compared the absorbable components and metabolites of normal rats under cerebral ischemia-reperfusion injury to explore the potential mechanism of action. This method could be applied to various Chinese herbs and disease models, which could promote TCM modernization.

Is mesh pore size in polypropylene meshes associated with the outcome in Lichtenstein inguinal hernia repair: a registry-based analysis of 22,141 patients

IntroductionExperimental data show that large-pored meshes reduce foreign body reaction, inflammation and scar bridging and thus improve mesh integration. However, clinical data on the effect of mesh porosity on the outcome of hernioplasty are limited. This study investigated the relation of pore size in polypropylene meshes to the outcome of Lichtenstein inguinal hernioplasty using data from the Herniamed registry.MethodsThis analysis of data from the Herniamed registry evaluated perioperative and 1-year follow-up outcomes in patients undergoing elective, primary, unilateral Lichtenstein inguinal hernia repair using polypropylene meshes. Patients operated with a non-polypropylene mesh or a polypropylene mesh with absorbable components were excluded. Polypropylene meshes with a pore size of 1.0 × 1.0 mm or less were defined as small-pored meshes, while a pore size of more than 1.0 × 1.0 mm was considered large-pored.Unadjusted analyses and multivariable analyses were performed to investigate the relation of pore size of polypropylene meshes, patient and surgical characteristics to the outcome parameters.ResultsData from 22,141 patients were analyzed, of which 6853 (31%) were operated on with a small-pore polypropylene mesh and 15,288 (69%) with a large-pore polypropylene mesh. No association of mesh pore size with intraoperative, general or postoperative complications, recurrence rate or pain requiring treatment was found at 1-year follow-up. A lower risk of complication-related reoperation tended to be associated with small-pore size (p = 0.086). Furthermore, small-pore mesh repair was associated with a lower risk of pain at rest and pain on exertion at 1-year follow-up.ConclusionThe present study could not demonstrate an advantage of large-pore polypropylene meshes for the outcome of Lichtenstein inguinal hernioplasty.

Experimental and Numerical Investigation of Energy Absorption Characteristics of a E-Glass/Epoxy Crash Box

Crash boxes are energy absorbing components generally placed at the front end of cars to reduce the amount of damage at especially low impact velocities. The number of electric vehicles has been increasing recently, so weight reduction studies are. For this reason, lighter glass or carbon fiber reinforced composite crash boxes are preferred instead of steel ones. In the current study, the dynamic compression behavior of a rectangular cross-section thin-walled composite crash box was investigated both experimentally and numerically. The main aim of the study was to understand the effective damage modes and monitor the deformation sequence experimentally and numerically. Once the numerical model is verified then it can be further used to reveal the behavior at different impact velocities and geometries. The methodology followed in the study first started with the static mechanical characterization of the composite material. Within the scope of this study, 2×2 twill-woven glass fiber/epoxy crash boxes were produced using the vacuum bagging method. Quasi-static compression and tension tests were carried out in accordance with ASTM D3039 and ASTM D6641 standards. In the numerical part, Radioss finite element package was used with the material model of MAT 25 along with the failure option of Tsai-Wu. Experimental dynamic crushing tests of the crash box was carried out using a custom made drop-weight tester at impact velocity of 4.4 m/s and dropping mass with 450 kg. The material model constants were obtained once the coupon based static and dynamic tests were completed. From the dynamic crushing tests, maximum and mean force values of 225 and 65.0 kN were noted, respectively. There is close agreement between the experimental and numerical results both in terms of force and displacement values. This verified numerical model can further be used to investigate the crushing characteristics at different impact conditions.

Experimental and numerical investigation on the crashworthiness performance of double hat‐section Al‐CFRP beam subjected to quasi‐static bending test

AbstractNowadays, hybrid structures, which combine low‐density composites with low‐cost thin‐walled metals, have shown great effect in enhancing the performance of automotive body structures, especially the energy absorber components. This study focuses on the experimental and numerical investigation of the bending energy absorption behavior of CFRP/aluminum hybrid double hat‐section beams used in the side part of the car body. In the experimental section, two types of double hat‐section beams were fabricated: aluminum and Al/CFRP. These beams were then subjected to quasi‐static three‐point bending tests. The results demonstrated that the hybrid beam exhibited superior energy absorption capabilities compared to the single beam. Subsequently, a finite element model was developed using LS‐Dyna software and was validated by comparing the experimental and numerical load–displacement results. In‐depth numerical analyses were conducted to investigate the influence of various design parameters, including CFRP‐reinforcement configuration, numbers of CFRP layers, CFRP ply‐angle, CFRP reinforced length, and aluminum/CFRP mass, on crashworthiness indicators. The numerical findings indicate that the hybrid beam with , ply‐angles exhibited better crash force efficiency (CFE) and specific energy absorption (SEA) compared to other ply‐angles, respectively. Furthermore, increasing the number of CFRP layers within the total beam's mass improved its energy absorption capacity. It was also revealed that the CFRP length on the upper and lower hats could be considered as 42.5% of the total aluminum beam length, as opposed to the full CFRP length, providing enhanced energy absorption capabilities.Highlights Bending behavior of the Al and Al/CFRP double hat section beams. Effects of variable thickness and identical mass on the double hat section beam. Effects of variable ply angle and number of CFRP layers on the hybrid beams. Discrete effect of CFRP reinforcement configurations and inner CFRP lengths.

Tuning optical properties to optimize microwave absorbers

Microwave absorbing materials are critical for several components including bolometers and beam dumps. Profound knowledge of the material properties and the material-wave interactions is a necessity for both design and use of these components. With the strong focus of the ITER absorbing components on ceramic materials, a systematic study was performed to methodically investigate the optical properties of the aluminium oxide-titanium oxide material system.

Investigation of granular natural stone materials as photothermal absorbers for sustainable and environmentally friendly energy harvesting

The development of cost-effective and environmentally friendly solar thermal technologies that deliver high performance poses several challenges, where the collector and absorber components play a pivotal role. This research addresses these issues by investigating enhanced temperature generation using a 30 cm × 30 cm Fresnel lens collector under solar illumination from a xenon lamp. Natural stone materials (andesite, coal, and pumice), characterized by granular structures with an average diameter of 1.68-2.00 mm, were selected because of their abundance and eco-friendliness. This research is focused on evaluating the effect of Fresnel lens on temperature generation performance. Two types of temperature generation tests were carried out: wet tests (where the natural stone materials were immersed in distilled water) and dry tests (where the natural stone materials were used in dry conditions). The morphologies of the natural stone materials were examined using an optical microscope and scanning electron microscope. Furthermore, the optical properties of the natural stone materials were analyzed using an ultraviolet-visible (UV-VIS) spectrophotometer. The findings revealed that there were significant improvements in the photothermal absorber performance with the use of a Fresnel lens in dry tests, where the highest temperature was achieved for coal (103.25 °C), followed by andesite (89.00 °C) and pumice (73.00 °C). The impurities varied between the materials, where the impurities were most dominant for pumice while coal was more uniform. Further examination using scanning electron microscope showed that all materials had light-trapping structures in the form of rough surfaces, pores, and crack gaps. Andesite was dominated by rough surfaces, while coal and pumice were dominated by crack gaps and pores, respectively. However, based on the UV-VIS spectrophotometric results, there were no correlations between the optical properties (absorbance, reflectance, and transmittance) and temperature achieved by the photothermal absorber materials. This research demonstrates the potential of using natural stone materials as photothermal absorbers in combination with a Fresnel lens collector for low-to-medium temperature solar thermal applications.

Metallurgical Analysis in the Outer Tube Fault Area

In the automotive manufacturing industry, product failures are still found. In this study, one of the automotive components, namely the outer tube of the motorcycle front fork, was cracked. The outer tube is part of the shock absorber component which is also connected to the motorcycle steering system. Failure analysis aims to obtain some data or facts that can indicate the root cause of the failure or failure. Sample preparation which includes the process of selecting the cut area, cleaning and cutting for the fractography process. As for metallography, sample preparation is continued with the process of mounting, sanding, polishing and etching. Fractographic test showed that the fracture occurred in a brittle fracture mode, with no traces of plastic deformation. The morphology of the fracture surface also shows the presence of gas trapped in large quantities. In the metallographic test, the overall microstructure shows an eutectic phase with a uniform dendrite structure pattern, this indicates that metal solidification occurs quite quickly and can cause a lot of gas to be trapped in the metal characterized by the presence of multiple porosities. This can provide an indication of the relationship between the microstructure and the fracture surface morphology. Cracking and brittle fracture can be caused by the stress that occurs in the metal that exceeds the yield and plastic limits due to the large pressure of gas trapped in the metal.

Bioinspired Double-Broadband Switchable Microwave Absorbing Grid Structures with Inflatable Kresling Origami Actuators.

Tunable radar stealth structures are critical components for future military equipment because of their potential to further enhance the design space and performance. Some previous investigations have utilized simple origami structures as the basic adjusting components but failed to achieve the desired broadband microwave absorbing characteristic. Herein, a novel double-broadband switchable microwave absorbing grid structure has been developed with the actuators of inflatable Kresling origami structures. Geometric constraints are derived to endow a bistable feature with this origami configuration, and the stable states are switched by adjusting the internal pressure. An ultra-broadband microwave absorbing structure is proposed with a couple of complementary microwave stealth bands, and optimized by a particle swarm optimization algorithm. The superior electromagnetic performance results from the mode switch activating different absorbing components at corresponding frequencies. A digital adjusting strategy is applied, which effectively achieves a continuously adjusting effect. Further investigations showthat the proposed structure possesses superior robustness. In addition, minimal interactions are found between adjacent grid units, and the electromagnetic performance is mainly related to the duty ratio of the units in different states. They have enhanced the microwave absorbing performance of grid structures through a tunable design, a provided a feasible paradigm for other tunable absorbers.

Integrated device for multiscale series vibration reduction and energy harvesting

A multi-degree-of-freedom device is proposed, which can achieve efficient vibration reduction as the main objective and energy harvesting as the secondary purpose. The device comprises a multiscale nonlinear vibration absorber (NVA) and piezoelectric components. Energy conversion and energy measurement methods are used to evaluate the device performance from multiple perspectives. Research has shown that this device can efficiently transfer transient energy from the main structure and convert a portion of transient energy into electrical energy. Main resonance and higher-order resonance are the main reasons for efficient energy transfer. The device can maintain high vibration reduction performance even when the excitation amplitude changes over a large range. Compared with the single structures with and without precompression, the multiscale NVA-piezoelectric device offers significant vibration reduction advantages. In addition, there are significant differences in the parameter settings of the two substructures for vibration reduction and energy harvesting.

Energy and exergy evaluation of a novel baffled water photovoltaic/thermal system using integrated collector storage as thermal system: An experimental study

This study analyzes a new baffled photovoltaic/thermal (PV/T) collector consisting of a baffled integrated collector storage (ICS) system integrated with a polycrystalline silicon PV panel. ICS systems have a significant advantage: combining absorbing and storage components causes a simple, affordable structure; furthermore, to improve the convection mechanism, several baffles are installed in the ICS. The energy and exergy analyses were carried out experimentally to discuss the efficiency of the PV/T collector comprehensively. The reserved water stratifies in the tank during daytime, and its temperature obtains the maximum values of 47.2 °C and 38.1 °C at the top and bottom of the tank. Interestingly, the mean water temperature is lower than the ambient temperature in the morning due to radiative sky cooling at night. The thermal, electrical, and overall energy efficiencies of the PV/T system are high in the early morning, nearly 21.67%, 15.22%, and 65.09%; then, these energy efficiencies reduce due to increasing ambient heat losses and PV temperature. Thermal exergy efficiency reaches nearly 0.15%, while electrical exergy efficiency varies between 21% and 22% during daily hours. Therefore, the simple structure with high overall efficiency, nearly 65%, causes the new baffled PV/T collector to be an affordable, robust PV/T system.

Relativistic X-ray reflection and highly ionized absorption in the spectrum of NS LMXB 1A 1744−361

ABSTRACT We present the results from the spectral and timing analysis of the accreting neutron star (NS) 1A 1744−361 from the Nuclear Spectroscopic Telescope ARray observation performed in its 2022 outbursts. The unabsorbed bolometric X-ray luminosity during this observation in the energy band 0.1–100 keV is 3.9 × 1037 erg s−1, assuming a distance of 9 kpc. During this observation, the source was in the banana branch of the atoll track. The source spectrum exhibits relativistic disc reflection and clear absorption features when an absorbed blackbody and cut-off power-law model describes the continuum emission. The 3–50 keV source spectrum is well fitted using a model combination consisting of an absorbed single-temperature blackbody and a reflection model along with the addition of a warm absorber component. The inner-disc radius, Rin, obtained from the reflection fit is ∼(1.61–2.86)RISCO = (8.4–14.9)Rg (17.6–31.2 km for a 1.4 M⊙ NS). This measurement allowed us to further constrain the magnetic field strength to B ≲ 0.94 × 109 G. The strong absorption features ∼6.91 keV and ∼7.99 keV imply the presence of highly ionized absorbing material with a column density NH of ∼3 × 1022 cm−2, emanating from the accretion disc in the form of disc wind with an outflow velocity of vout ≃ 0.021c ≃ 6300 km s−1.

Time-dependent photoionization spectroscopy of the Seyfert galaxy NGC 3783

We present an investigation into the spectroscopic properties of non-equilibrium photoionization processes operating in a time-evolving mode. Through a quantitative comparison between equilibrium and time-evolving models, we find that the time-evolving model exhibits a broader distribution of charge states, accompanied by a slight shift in the peak ionization state depending on the source variability and gas density. The time-evolving code tpho in SPEX was successfully employed to analyze the spectral properties of warm absorbers in the Seyfert galaxy NGC 3783. The incorporation of variability in the tpho model improves the fits of the time-integrated spectra, providing more accurate descriptions of the average charge states of several elements, in particular Fe, which is peaked around Fe XIX. The inferred densities and distances of the relevant X-ray absorber components are estimated to be approximately a few times 1011 m−3 and ≤1 pc, respectively. Furthermore, the updated fit suggests a potential scenario in which the observed absorbers are being expelled from the central active galactic nucleus at the escape velocities. This implies that these absorbers might not play a significant role in the active galactic nucleus feedback mechanism.

Compton Camera Arrangement With a Monolithic LaBr3(Ce) Scintillator and Pixelated GAGG Detector for Medical Imaging

The results presented in this manuscript are divided in two main parts. The aim of the presented work is to conduct feasibility tests on a Compton camera setup to be later scaled up and used for PET and triple coincidence γ-PET purposes. The first part is focused on laboratory characterization of a monolithic LaBr3(Ce) scintillator coupled to a 64-channel multi-anode photomultiplier (H8500C PMT from Hamamatsu) in combination with a well-established algorithm allowing to determine the interaction’s position resolution. The second part of the article is dedicated to the evaluation of a Compton camera detector arrangement in which the monolithic scintillator acts as an absorber, while a pixelated GAGG scintillator array, read out by a SiPM multi-pixel photon counter (MPPC), is used as a scatterer component. The accuracy achievable with this system for detecting γ rays from laboratory point sources is investigated. The Compton camera system has been tested with radioactive 137Cs and 60Co point sources. The signal readout and data acquisition system is based on individual spectroscopy electronics modules (NIM and VME), for the absorber and a customized electronics based on Anger logic for the GAGG scatter array. The raw data were analyzed to serve as input for the image reconstruction, performed using the MEGAlib toolkit software. With a spatial resolution of 1 mm for the scatterer and less than 3 mm for the absorber component, respectively, shifts of 2 mm of both radioactive sources (137Cs and 60Co) could be resolved with the whole Compton camera system.

Optical and Electrical Properties of Polystyrene/Poly‐methyl methacrylate Polymeric Blend Filled with Semiconductor and Insulator Nanofillers

The present study deals with the effect of adding different fillers (semiconductor and insulator) on a polystyrene (PS)/poly‐methyl methacrylate (PMMA) polymer blend using casting method. A constant content (1 wt%) of semiconductors [multiwalled carbon nanotubes (MWCNTs), polyaniline (PANI), zinc oxide nanoparticles (NPs), and titanium dioxide NPs] and insulator [silicon dioxide NPs] fillers is used. Transmission electron microscopy images for MWCNTs show that most nanotubes have an average diameter of 7–11 nm. Moreover, the average size of all metal nano‐oxides is almost 20 nm and confirmed by X‐ray diffraction. Fourier‐transform infrared spectroscopy confirms the formation and the interaction between PS/PMMA polymer blend and fillers. The structural, mechanical, optical, and dielectric properties of the prepared polymer nanocomposites are studied using different tools. Optical characteristics such as absorbance, reflection, bandgap energy (E g), and optical dielectric components (real and imaginary) are studied. These results reveal that pure 20PS/80PMMA film has E g(direct) = 4.46 eV, which drops as different fillers are incorporated into the blend. The addition of MWCNTs, PANI to the PS/PMMA blend improves the electrical conductivity due to the growth of conductive paths between the filler and the blending matrix.

Dynamic study through numerical simulations of MacPherson suspension and static analysis of shock absorber components

A suspension or shock absorber system is a mechanical device that is designed to attenuate or reduce the shock impulse and kinetic energy due to level differences or obstacles encountered by the car. In a vehicle structure, the shock absorber reduces the effect of driving on rough terrain, which automatically leads to improved driving quality and also increases passenger comfort.The purpose of this dynamic study by numerical simulations of the MacPherson strut suspension is to highlight the dynamic differences between the stock and heavy MacPherson suspension duty for the Volkswagen Jetta, because it is the most common type of suspension on vehicles, and it is not complex in terms of operation.The study was carried out only at the simulation stage in the MSC ADAMS program, for the dynamic analysis of the component parts, later the second phase of the research will propose the study on a real system.One of the specific objectives of the paper is to compare the two types of springs, the stock with which the car is equipped at the factory and the modified one, the heavy duty variant (package heavy roads).The second specific objective is to compare the two types of springs in relation to the two heights of the speed limiter and the two types of tires.The third objective of this paper is to perform a comparative analysis of the main components of a shock absorber assembly, statically through tests in the ABAQUS simulation program.Later, the results obtained after the analyzes indicated that the heavy duty type suspension has a higher degree of force attenuation. The end of the study was focused on the finite element analysis of the main components of a shock absorber in a suspension, analyzed from a static point of view.