Mechanical Recycling of Carbon Fiber-Reinforced Polymer in a Circular Economy.

This review thoroughly investigates the mechanical recycling of carbon fiber-reinforced polymer composites (CFRPCs), a critical area for sustainable material management. With CFRPC widely used in high-performance areas like aerospace, transportation, and energy, developing effective recycling methods is essential for tackling environmental and economic issues. Mechanical recycling stands out for its low energy consumption and minimal environmental impact. This paper reviews current mechanical recycling techniques, highlighting their benefits in terms of energy efficiency and material recovery, but also points out their challenges, such as the degradation of mechanical properties due to fiber damage and difficulties in achieving strong interfacial adhesion in recycled composites. A novel part of this review is the use of finite element analysis (FEA) to predict the behavior of recycled CFRPCs, showing the potential of recycled fibers to preserve structural integrity and performance. This review also emphasizes the need for more research to develop standardized mechanical recycling protocols for CFRPCs that enhance material properties, optimize recycling processes, and assess environmental impacts thoroughly. By combining experimental and numerical studies, this review identifies knowledge gaps and suggests future research directions. It aims to advance the development of sustainable, efficient, and economically viable CFRPC recycling methods. The insights from this review could significantly benefit the circular economy by reducing waste and enabling the reuse of valuable carbon fibers in new composite materials.

The parapoxvirus Orf virus inhibits dsDNA-mediated type I IFN expression via STING-dependent and STING-independent signalling pathways.

Type I interferons (IFNs) are critical in the host defence against viruses. They induce hundreds of interferon-stimulated genes (ISGs) many of which have an antiviral role. Poxviruses induce IFNs via their pathogen-associated molecular patterns, in particular, their genomic DNA. In a majority of cell types, dsDNA is detected by a range of cytoplasmic DNA sensors that mediate type I IFN expression via stimulator of interferon genes (STING). Orf virus (ORFV) induces cutaneous pustular skin lesions and is the type species of the Parapoxvirus genus within the Poxviridae family. The aim of this study was to investigate whether ORFV modulates dsDNA-induced type I IFN expression via STING-dependent signalling pathways in human dermal fibroblasts (hNDF) and THP-1 cells. We showed that ORFV infection of these cell types treated with poly(dA:dT) resulted in strong inhibition of expression of IFN-ß. In hNDFs, we showed using siRNA knock-down that STING was essential for type I IFN induction. IFN-ß expression was further reduced when both STING and RIG-I were knocked down. In addition, HEK293 cells that do not express STING or Toll-like receptors also produce IFN-ß following stimulation with poly(dA:dT). The 5' triphosphate dsRNA produced by RNA polymerase III specifically results in the induction of type I IFNs through the RIG-I receptor. We showed that ORFV infection resulted in strong inhibition of IFN-ß expression in HEK293 cells stimulated with poly(dA:dT). Overall, this study shows that ORFV potently counteracts the STING-dependent and STING-independent IFN response by antagonizing dsDNA-activated IFN signalling pathways.

Pre-clinical efficacy of African medicinal plants used in the treatment of snakebite envenoming: A systematic review.

The World Health Organization has listed Snakebite Envenoming (SBE) as a priority neglected tropical disease, with a worldwide annual snakebite affecting 5.4 million people and injuring 2.7 million lives. In many parts of rural areas of Africa and Asia, medicinal plants have been used as alternatives to conventional antisnake venom (ASV) due in part to inaccessibility to hospitals. Systemic reviews (SR) of laboratory-based preclinical studies play an essential role in drug discovery. We conducted an SR to evaluate the relationship between interventional medicinal plants and their observed effects on venom-induced experiments. This SR was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The Modified collaborative approach to meta-analysis and review of animal data from experimental studies (CAMARADES) and SYRCLE's risk of bias tools were used to appraise the included studies. Data were searched online in Medline via PubMed, Embase via OVID, and Scopus. Studies reporting in vivo and in vitro pharmacological activities of African medicinal plants/extracts/constituents against venom-induced pathologies were identified and included for screening. Data from the included studies were extracted and synthesized. Ten studies reported statistically significant percentage protection (40-100%) of animals against venom-induced lethality compared with control groups that received no medicinal plant intervention. Sixteen studies reported significant effects (p ≤ 0.05) against venom-induced pathologies compared with the control group; these include hemolytic, histopathologic, necrotic, and anti-enzymatic effects. The plant family Fabaceae has the highest number of studies reporting its efficacy, followed by Annonaceae, Malvaceae, Combretaceae, Sterculiaceae, and Olacaceae. Some African medicinal plants are preclinically effective against venom-induced lethality, hematotoxicity, and cytotoxicity. The evidence was extracted from three in vitro studies, nine in vivo studies, and five studies that combined both in vivo and in vitro models. The effective plants belong to the Fabaceae family, followed by Malvaceae, and Annonaceae.

Development of Hybrid Composite Utilizing Micro-Cellulose Fibers Extracted from Date Palm Rachis in the Najran Region.

Environmental effects can be reduced by using renewable resources in various applications. The date palm fibers (DPF) used in this study were extracted from waste date ranches of the Najran region by retting and manual peeling processes. The biocomposites were developed by reinforcing the silane-treated DPF (SDPF) at different wt.% in eugenol phthalonitrile (EPN) and difunctional benzoxazine (BA-a) copolymer. The impact strength, tensile, flexural, and dynamic mechanical properties and thermogravimetric analysis were evaluated to understand the mechanical, thermomechanical, and thermal properties. Results confirmed that 30 wt.% SDPF-reinforced poly (EPN/BA-a) composites produced the highest mechanical and thermomechanical properties, and were considered optimized SDPF reinforcement. Furthermore, hybrid composites with 30 wt.% SDPF and 15 wt.% silane-treated glass fibers (SGF) reinforcement having different lamination sequences were also studied. The lamination sequences showed a significant impact on the mechanical and thermomechanical properties, as properties were further enhanced by adding a core layer of SGF in hybrid composites. However, the thermal properties of SDPF/SGF laminates were higher than SDPF biocomposites, but the SGF lamination sequence did not produce any impact. According to the limiting oxygen and heat resistance indexes, the developed SDPF/SGF laminates are self-extinguishing materials and can be used in temperature-tolerant applications up to 230 °C.

Development of New Bio-Composite of PEO/Silk Fibroin Blends Loaded with Piezoelectric Material.

New bio-composite nanofibers composed of polyethylene oxide (PEO)/silk fibroin (SF)/barium titanate (BaTiO3) are introduced in this study. The SF solution was added to the PEO solution to form a PEO/SF blend with different weight percentages (5, 10, 15, 20 wt.%). The PEO/15 wt.% SF blend was selected to continue the experimental plan based on the optimum nanofiber morphology. Different wt.% of BaTiO3 particles (0.2, 0.4, 0.8, 1 wt.%) were added to the PEO/15 wt.% SF blend solution, and the suspensions obtained were introduced to an electrospinning device. The fabricated tissue was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The zeta potential of the solution and the piezoelectric performance of the fabricated tissue were characterized. A newly designed pizoTester was used to investigate piezoelectric properties. The results showed that a well-organized, smooth PEO/15 wt.% SF/0.2 wt.% BaTiO3 nanofiber composite with low bead contents was obtained. Improved properties and electrical coupling were achieved in the newly introduced material. Electrospun PEO/15 wt.% SF/0.2 wt.% BaTiO3 mats increased the output voltage (1150 mV) compared to pristine PEO and PEO/SF composite fibers (410 and 290 mV, respectively) upon applying 20 N force at 5 Hz frequency. The observed enhancement in piezoelectric properties suggests that the prepared composite could be a promising material in cardiac tissue engineering (CTE).

Effect of Accelerated Weathering on the Thermal, Tensile, and Morphological Characteristics of Polypropylene/Date Nanofiller Composites.

The aging of polypropylene (PP) composites reinforced with date palm nanofiber (DNF) was investigated in this study in order to predict their long-term performance. To produce composites, date palm nanofibers in the range of 1-5 wt% loading were dry-melt-blended with polypropylene. These biocomposites were then subjected to UV exposure (Xenon arch source) for accelerated weathering for 250 and 500 h according to a standard method. The change in thermal properties before and after accelerated weathering was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA analysis shows that the maximum degradation temperature for sample at 1 wt% loading was 382.7 °C, which slightly decreased to 379.9 °C after 250 h and to 367.7 °C after 500 h of weathering. DSC analysis also revealed lower crystallinity of the same samples after exposure to accelerated weathering. Mechanical properties were also studied to identify the damage induced by accelerated weathering. The tensile strength of the highest loading (5 wt%) of the sample was found to occur at 34.83 MPa, which was slightly lowered to 31.64 after 500 h treatment. A minimal decrease in tensile strength, deterioration, and weathering-induced oxidation indicates the excellent stability of these composites. Therefore, our study provides insight into the aging behavior of such composites, which may be useful in dry conditions, as well as nonstructural automotive and other parts for which minimum tensile strength (~25 MPa) is specified.

Impact of Hybrid Fillers on the Properties of High Density Polyethylene Based Composites.

The main objective of this work is to develop a variety of hybrid high-density polyethylene (HDPE) micro- and nanocomposites and to investigate their thermal, mechanical, and morphological characteristics as a function of number of fillers and their contents percentage. In this study, 21 formulations of the composites were prepared using fillers with different sizes including micro fillers such as talc, calcium carbonate (CaCO3), as well as nano-filler (fumed silica (FS)) though the melt blending technique. The morphological, mechanical, and thermal properties of the composite samples were evaluated. The morphological study revealed negligible filler agglomerates, good matrix-filler interfacial bonding in case of combined both CaCO3 and FS into the composites. Sequentially, improvements in tensile, flexural and Izod impact strengths as a function of fillers loading in the HDPE matrix have been reported. The maximum enhancement (%) of tensile, flexural and impact strengths were 127%, 86% and 16.6%, respectively, for composites containing 25% CaCO3 and 1% FS without any inclusion of talc filler; this indicates that the types/nature, size, quantity and dispersion status of fillers are playing a major role in the mechanical properties of the prepared composites more than the number of the used fillers.

3D Co-Seismic Surface Displacements Measured by DInSAR and MAI of the 2017 Sarpol Zahab Earthquake, Mw7.3.

On 12 November 2017, an earthquake occurred in Sarpol Zahab city, located on the Iraq/Iran boundary, with a moment magnitude (Mw) of 7.3. Advanced Land Observing Satellite 2 (ALOS-2) L-band (23.6 cm wavelength) and C-band Sentinel-1A data (ascending and descending) were used to detect the co-seismic displacements maps caused by this earthquake. The ALOS-2 data was utilized to reconstruct the 3D co-seismic displacements maps, as well as estimate the fault-dip and slip distribution along the rupture. The results showed the maximum surface displacement in the north, east, and up directions to be 100, 50, and 100 cm, respectively. The best-fit faulting geometry had a strike of 337.5° and a dip of 11.2° toward the northeast, at a depth of 8 km. The predicted geodetic moment was 1.15 1020 Nm, which corresponds to a magnitude of Mw 7.31. There were two significant slip sources: one in the shallower depth range of 8.5-10 km, with a peak slip of 5 m, and another in the depth range of 10.5-20 km, with a peak slip of 5.3 m. Both controlled the principal deformation signals in geodetic images. The slip was concentrated, along with a strike distance of 20 to 40 km, at a depth of 10 to 20 km. The earthquake was caused by the Zagros Mountains Front Fault (ZMFF), based on the results of 3D co-seismic deformation, inferred slip, preliminary investigation, and interpretation of the mainshock, as well as aftershock distributions.

Influence of Carbon Micro- and Nano-Fillers on the Viscoelastic Properties of Polyethylene Terephthalate.

In this research study, three carbon fillers of varying dimensionality in the form of graphite (3D), graphite nano-platelets (2D), and multiwall carbon nanotubes (1D) were incorporated into a matrix of poly (ethylene terephthalate), forming carbon-reinforced polymer composites. Melt compounding was followed by compression moulding and then a quenching process for some of the samples to inhibit crystallization. The samples were analysed using dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM), considering the dimensionality and loading of the carbon fillers. The dynamic mechanical analysis revealed a similar decline of storage moduli for all composites during the glassy to rubbery transition. However, storage moduli values at room temperature increased with higher loading of nano-fillers but only to a certain level; followed by a reduction attributed to the formation of agglomerates of nanotubes and/or rolled up of nano-platelets, as observed by SEM. Much greater reinforcement was observed for the carbon nanotubes compared to the graphite and or the graphite nano-platelets. The quenched PET samples showed significant changes in their dynamic mechanical properties due to both filler addition and to cold crystallization during the DMTA heating cycle. The magnitude of changes due to filler dimensionality was found to follow the order: 1D > 2D > 3D, this carbon filler with lower dimensionality have a more significant effect on the viscoelastic properties of polymer composite materials.

Experimental and Theoretical Analysis of Mechanical Properties of Graphite/Polyethylene Terephthalate Nanocomposites.

In this work, graphite nanoplatelets (GNP) were incorporated into poly (ethylene terephthalate) (PET) matrix to prepare PET-GNP nanocomposites using a melt compounding followed by compression moulding and then quenching process. Both static and dynamic mechanical properties of these quenched materials were characterized as a function of GNP contents using dynamic mechanical thermal analysis (DMTA) and tensile machine, respectively. The results demonstrated that the addition of GNP improved the stiffness of PET significantly. Additionally, the maximum increase in the storage modulus of 72% at 6 wt.% GNP. The incorporation of GNP beyond 6 wt.% into PET decreases the storage moduli, but they remain higher than pure PET. The observed reduction could be due to agglomeration, resulting in poorer dispersion and distribution of higher levels of GNP into the PET matrix. In contrast to the results for moduli, tensile strength and elongations at break reduce with increasing the GNP content. For example, tensile strength reduced from ∼46 MPa (neat PET) to ∼39 MPa (-15%) for the nanocomposites containing 2 wt.% GNP. This reduction is accompanied by a decline in elongation at break from ∼6.3 (neat PET) to ∼3.4 (-46%) for the same nanocomposites. Such reductions are followed by a gradual decrease in upon further addition of GNP. These reductions indicate that increasing GNP loadings, results in brittleness in nanocomposites. In addition, it was found that quenched PET and composite samples were not fully crystallized after processing and therefore (cold) crystallized during the first heating cycle DMTA, as indicated by a rise in storage moduli above the glass transition temperature during the DMTA first heat. Furthermore, mathematical models based on non-linear theories are developed to capture the experimental data. For this, a set of mechanical stress-strain data is used for model parameters' identification. Another set of data is used for the model validation that demonstrates good agreements with the experimental study.

Non-compartmental toxicokinetic studies of the Nigerian Naja nigricollis venom.

Snakebite envenoming (SBE) is a neglected public health problem, especially in Asia, Latin America and Africa. There is inadequate knowledge of venom toxicokinetics especially from African snakes. To mimic a likely scenario of a snakebite envenoming, we used an enzyme-linked immunosorbent assay (ELISA) approach to study the toxicokinetic parameters in rabbits, following a single intramuscular (IM) administration of Northern Nigeria Naja nigricollis venom. We used a developed and validated non-compartmental approach in the R package PK to determine the toxicokinetic parameters of the venom and subsequently used pharmacometrics modelling to predict the movement of the toxin within biological systems. We found that N. nigricollis venom contained sixteen venom protein families following a mass spectrometric analysis of the whole venom. Most of these proteins belong to the three-finger toxins family (3FTx) and venom phospholipase A2 (PLA2) with molecular weight ranging from 3 to 16 kDa. Other venom protein families were in small proportions with higher molecular weights. The N. nigricollis venom was rapidly absorbed at 0.5 h, increased after 1 h and continued to decrease until the 16th hour (Tmax), where maximum concentration (Cmax) was observed. This was followed by a decrease in concentration at the 32nd hour. The venom of N. nigricollis was found to have high volume of distribution (1250 ± 245 mL) and low clearance (29.0 ± 2.5 mL/h) with an elimination half-life of 29 h. The area under the curve (AUC) showed that the venom remaining in the plasma over 32 h was 0.0392 ± 0.0025 mg h.L-1, and the mean residence time was 43.17 ± 8.04 h. The pharmacometrics simulation suggests that the venom toxins were instantly and rapidly absorbed into the extravascular compartment and slowly moved into the central compartment. Our study demonstrates that Nigerian N. nigricollis venom contains low molecular weight toxins that are well absorbed into the blood and deep tissues. The venom could be detected in rabbit blood 48 h after intramuscular envenoming.

Enhancing the Performance of a Metal-Free Self-Supported Carbon Felt-Based Supercapacitor with Facile Two-Step Electrochemical Activation.

Carbon felt (CF) is an inexpensive carbon-based material that is highly conductive and features extraordinary inherent surface area. Using such a metal-free, low-cost material for energy storage applications can benefit their practical implementation; however, only limited success has been achieved using metal-free CF for supercapacitor electrodes. This work thoroughly studies a cost-effective and simple method for activating metal-free self-supported carbon felt. As-received CF samples were first chemically modified with an acidic mixture, then put through a time optimization two-step electrochemical treatment in inorganic salts. The initial oxidative exfoliation process enhances the fiber's surface area and ultimately introduced oxygen functional groups to the surface, whereas the subsequent reduction process substantially improved the conductivity. We achieved a 205-fold enhancement of capacitance over the as-received CF, with a maximum specific capacitance of 205 Fg-1, while using a charging current density of 23 mAg-1. Additionally, we obtained a remarkable capacitance retention of 78% upon increasing the charging current from 0.4 to 1 Ag-1. Finally, the cyclic stability reached 87% capacitance retention after 2500 cycles. These results demonstrate the potential utility of electrochemically activated CF electrodes in supercapacitor devices.

The parapoxvirus Orf virus inhibits IFN-ß expression induced by dsRNA.

Orf virus (ORFV) is the type species of the Parapoxvirus genus that belongs to the Poxviridae family. Type I interferons (IFN) are critical in the host defence against viruses. They induce hundreds of interferon stimulated genes (ISGs) many of which have an antiviral role. The ability of ORFV to modulate type I IFN production was undertaken to investigate whether ORFV could inhibit IFN-ß expression via dsRNA dependant signalling pathways. HEK293 cells are known to lack DNA pattern-recognition receptors and Toll-like receptors however, they do express the cytosolic dsRNA receptors RIG-I and MDA5. HEK293 cells were shown to produce high levels of IFN-ß when cells were stimulated with poly(I:C) and this was shown to be predominantly via RIG-I-dependant signalling as confirmed by siRNA knock-down of RIG-I. Further we showed that HEK293 cells are permissive for ORFV and caused potent inhibition of IFN-ß transcription when cells were stimulated with poly(I:C) post-viral infection. Studies using heat inactivated ORFV suggested that de novo synthesis of early genes was required. In addition our findings showed that the ORFV encoded factor ORF020, that is known to bind dsRNA, is involved in antagonising IFN expression. Overall, this study has shown for first time the ability of ORFV to counteract type I IFN expression by antagonising dsRNA-activated RIG-I signalling.

The parapoxvirus Orf virus ORF116 gene encodes an antagonist of the interferon response.

Orf virus (ORFV) is the type species of the Parapoxvirus genus of the Poxviridae family. Genetic and functional studies have revealed ORFV has multiple immunomodulatory genes that manipulate innate immune responses, during the early stage of infection. ORF116 is a novel gene of ORFV with hitherto unknown function. Characterization of an ORF116 deletion mutant showed that it replicated in primary lamb testis cells with reduced levels compared to the wild-type and produced a smaller plaque phenotype. ORF116 was shown to be expressed prior to DNA replication. The potential function of ORF116 was investigated by gene-expression microarray analysis in HeLa cells infected with wild-type ORFV or the ORF116 deletion mutant. The analysis of differential cellular gene expression revealed a number of interferon-stimulated genes (ISGs) differentially expressed at either 4 or 6 h post infection. IFI44 showed the greatest differential expression (4.17-fold) between wild-type and knockout virus. Other ISGs that were upregulated in the knockout included RIG-I, IFIT2, MDA5, OAS1, OASL, DDX60, ISG20 and IFIT1 and in addition the inflammatory cytokine IL-8. These findings were validated by infecting HeLa cells with an ORF116 revertant recombinant virus and analysis of transcript expression by quantitative real time-PCR (qRT-PCR). These observations suggested a role for the ORFV gene ORF116 in modulating the IFN response and inflammatory cytokines. This study represents the first functional analysis of ORF116.

Comprehensive Review of the Properties and Modifications of Carbon Fiber-Reinforced Thermoplastic Composites.

Carbon fiber-reinforced polymers are considered a promising composite for many industrial applications including in the automation, renewable energy, and aerospace industries. They exhibit exceptional properties such as a high strength-to-weight ratio and high wear resistance and stiffness, which give them an advantage over other conventional materials such as metals. Various polymers can be used as matrices such as thermosetting, thermoplastic, and elastomers polymers. This comprehensive review focuses on carbon fiber-reinforced thermoplastic polymers due to the advantages of thermoplastic compared to thermosetting and elastomer polymers. These advantages include recyclability, ease of processability, flexibility, and shorter production time. The related properties such as strength, modulus, thermal conductivity, and stability, as well as electrical conductivity, are discussed in depth. Additionally, the modification techniques of the surface of carbon fiber, including the chemical and physical methods, are thoroughly explored. Overall, this review represents and summarizes the future prospective and research developments carried out on carbon fiber-reinforced thermoplastic polymers.

Facile Synthesis of Hydrophilic Homo-Polyacrylamides via Cu(0)-Mediated Reversible Deactivation Radical Polymerization.

In this work, copper-mediated reversible deactivation radical polymerization (RDRP) of homo-polyacrylamides was conducted in aqueous solutions at 0.0 °C. Various degrees of polymerization (DP = 20, 40, 60, and 80) of well-defined water-soluble homopolymers were targeted. In the absence of any significant undesirable side reactions, the dispersity of polydiethylacrylamide (PDEA) and polydimethylacrylamide (PDMA) was narrow under controlled polymerization conditions. To accelerate the polymerization rate, disproportionation of copper bromide in the presence of a suitable ligand was performed prior to polymerization. Full conversion of the monomer was confirmed by nuclear magnetic resonance (NMR) analysis. Additionally, the linear evolution of the polymeric chains was established by narrow molecular weight distributions (MWDs). The values of theoretical and experimental number average molecular weights (Mn) were calculated, revealing a good matching and robustness of the system. The effect of decreasing the reaction temperature on the rate of polymerization was also investigated. At temperatures lower than 0.0 °C, the controlled polymerization and the rate of the process were not affected.

Improving pitting corrosion resistance of the commercial titanium through graphene oxide-titanium oxide composite.

Titanium oxide has been commonly used for wide range of applications due to excellent corrosion resistance. This study presents the impact of graphene oxide (GO) addition to titanium oxide as coating materials during titanium anodization process on the corrosion behaviour. The GO was prepared by electrochemical exfoliation using low voltage mode in a sodium sulphate electrolyte, which is easier and more environmentally friendly compared to the chemical approach. Raman and scanning electron microscope were used to examine the success of the exfoliation process. The surface morphologies and potentiodynamic polarization results indicate that the addition of GO significantly inhibit the pitting corrosion and stabilize passivation current densities over wide ranges of anodic potentials. The untreated titanium, however, noticeably displayed fluctuation of anodic current densities, confirming the presence of pitting corrosion. The results obtained by electrochemical impedance spectroscopy (EIS) also confirm that the addition of GO enhanced corrosion protection even at higher frequency ranges. The cyclic polarization scan results show a positive shift in the re-passivation potential Erep after the addition of GO. This work emphasizes that the addition of GO during anodization of titanium not only protect its surface from pitting corrosion but also provide a strong passive layer.

Evaluation of the Infill Design on the Tensile Response of 3D Printed Polylactic Acid Polymer.

The current study explores the effects of geometrical shapes of the infills on the 3D printed polylactic acid (PLA) plastic on the tensile properties. For this purpose, by utilizing an accessible supply desktop printer, specimens of diamond, rectangular, and hexagonal infill patterns were produced using the fused filament fabrication (FFF) 3D printing technique. Additionally, solid samples were printed for comparison. The printed tensile test specimens were conducted at environmental temperature, Ta of 23 °C and crosshead speed, VC.H of 5 mm/min. Mainly, this study focuses on investigating the percentage infill with respect to the cross-sectional area of the investigated samples. The mechanical properties, i.e., modulus of toughness, ultimate tensile stress, yield stress, and percent elongation, were explored for each sample having a different geometrical infill design. The test outcomes for each pattern were systematically compared. To further validate the experimental results, a computer simulation using finite element analysis was also performed and contrasted with the experimental tensile tests. The experimental results mainly suggested a brittle behavior for solidly infilled specimen, while rectangular, diamond, and hexagonal infill patterns showed ductile-like behavior (fine size and texture of infills). This brittleness may be due to the relatively higher infill density results that led to the high bonding adhesion of the printed layers, and the size and thickness effects of the solid substrate. It made the solidly infilled specimen structure denser and brittle. Among all structures, hexagon geometrical infill showed relative improvement in the mechanical properties (highest ultimate tensile stress and modulus values 1759.4 MPa and 57.74 MPa, respectively) compared with other geometrical infills. Therefore, the geometrical infill effects play an important role in selecting the suitable mechanical property's values in industrial applications.

Development and validation of antisnake venom knowledge assessment tool (AKAT) for healthcare practitioners.

Antisnake venom (ASV) is the only specific and standard treatment for snakebite envenoming worldwide. The knowledge of antivenom dosage, mode of administration, availability, and logistics is essential to the healthcare practitioners (HCPs) in the management of snakebites. It is vital for the HCPs involved in the handling of ASVs to have its basic knowledge. The ASV contains proteins and can, therefore, easily get denatured if not handled appropriately, leading to poor therapeutic outcome. It is also essential for clinicians to be aware of the tendency of ASV to cause a severe life-threatening hypersensitivity reaction. There is currently no validated tool for assessing the knowledge of ASV among HCPs. Therefore, we developed and validated a tool for evaluating the HCPs knowledge of ASV. The items included in the tool were first generated from a comprehensive literature review. Face validity were conducted by presenting the drafted tool to ten experts on the subject matter. A validation study was conducted among doctors, pharmacists, nurses, pharmacy technicians, and the general public. The objectives of the study were to test the tool for content validity using the content validity index (CVI), construct validity using contrast group approach, difficulty index, readability, and reliability test using the test-retest method. We developed and validated a final tool containing thirty-three items. The tool was valid for face validity and had a scale-level (average) content validity (S-CVI/Ave) of 0.91. The ASV knowledge of pharmacists was higher than that of doctors, pharmacy technicians, nurses, and the general public (p < 0.001), thus, valid for construct validity. The readability of the tool using the Simple Measure of Gobbledygook (SMOG) was determined to be grade level 7. The test-retest analysis showed no significant difference between the mean knowledge scores measured at four weeks interval (p = 0.916), implying excellent reliability. The AKAT has demonstrated good psychometrical properties that would enable its application among a wide range of healthcare practitioners.