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This research explores the innovative fabrication and characterization of recycled polypropylene composites that reinforced by natural fibers, specifically date palm micro fibers (DPF). Employed a twin-screw extruder for the mixing, and injection molding technique for the samples fabrication. DPF was incorporated at varying weight percentages (0, 2, 5, and 10 wt%). A comprehensive analysis, including thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), was conducted to assess thermal stability, chemical interactions and crystalline structure. Mechanical properties were evaluated through shore-D hardness and uniaxial tensile tests. Notably, the study revealed that an increased DPF filler content resulted in superior mechanical properties, such as enhanced shore-D hardness and tensile strength. This improvement was attributed to the alignment of DPF fillers and the recycled polypropylene matrix. The significance of this research lies in showcasing the promising potential of DPF as an eco-friendly reinforcement material in recycled polypropylene biocomposites, providing a sustainable and environmentally friendly alternative for various engineering applications. The work contributes to advancing greener solutions in material science and highlights the unique advantages of DPF in enhancing composite materials.

Washingtonia is a palm tree that enriched with lignocellulosic biomass, which provided it with the potentiality for various applications. In this study, different biomass from Washingtonia plant, i.e. leaf stalk (W-LS), trunk core (W-TC), and trunk spine (W-TS) fibers, were collectively investigated by characterization. Under scanning electron microscopy (SEM) examination, the spine-shape structure of W-TS fiber along with its small particle size might facilitate it for fabrication reactivity. From chemical and elemental composition analysis, both W-TC and W-TS fibers were found with high cellulose content, while with the closely similar residual elements, suggesting them from the same source of trunk segment. However, the low cellulose content of W-LS fiber with its high ash content had somehow reduced its crystallinity and thermal stability properties. From X-ray diffraction (XRD) analysis, the crystallinity was estimated the highest for W-TS (68.2%), and while with the lowest for W-LS fiber (57.3%), which in line with the detected functional groups by Fourier Transform Infrared-ray (FTIR) spectrophotometry. In thermogravimetry (TGA) analysis, all fibers possessed great thermal resistance with Tonset in the range of 307.4–328.1°C and Tpeak in the range of 352.4–347.9°C. Washingtonia fiber had a high potential to be applied as a bio-material for versatile applications in the future.

This study deals with the evaluation of the impact of three different olive tree residues: olive tree small branch (OTS), olive tree big brunch (OTB) and olive tree leaves (OTL) as a filler on thermal properties of olive/epoxy biocomposites. Olive residue-based epoxy composites were processed at 40% filler loading to fabricate biocomposites by hand lay-up techniques. The thermal stability was investigated by thermal gravimetric analysis (TGA) while dynamic mechanical properties and thermal expansion of fiber composites were analyzed by the dynamic mechanical analyzer (DMA) and thermomechanical analyzer (TMA). The OTL/epoxy composite showed improvement in thermal and DMA (storage modulus, loss modulus, and damping factor) as compared to OTB and OTS/epoxy composites. On the other hand, OTS filled epoxy matrix exhibited the greatest thermal degradation temperature while CTE was the lowest and greatest dynamic mechanical properties over all composites. DMA results revealed that the OTS/epoxy composite possesses the highest storage modulus in view of the strong fiber/matrix interfacial. It is evident from obtained results that the incorporation of olive biomass enhanced thermal, dimensional, and dynamic mechanical characterizations of epoxy composites and appropriate use for automotive or materials applications of building that mandate high-dimensional stability and dynamic mechanical characterizations.

The objective of this work is to determine the suitability of olive tree leaves powder (OTL) as reinforcement along with pineapple leaf fibre (PALF) in the epoxy composites. The parent and hybrid composites were fabricated using the hot press technique with the overall fibre loading at 40 wt% and OTL: PALF in the ratio of 50:50, 30:70 and 70:30, respectively. The fabricated composites were characterized using dynamic mechanical analysis (DMA), flexural and impact tests. As the proportion of PALF was increased in the hybrid composites, impact strength improved significantly. However, hybrid composites were not effective in withstanding the bending load where their bending strength and flexural modulus were lower than the parent composites. Hybrid composites outperformed parent composites with superior storage modulus, lower loss modulus and lower damping factor as per the DMA results.

Lignocellulosic based nano-sized filler are effective substituent for switching from manmade nanofillers (i.e. carbon, glass etc.) to reinforce polymer composites owing to their lightweight, plentifulness, and fully compostable characteristics. The present study adapted a dry mechanical ball mill assisted downsizing process to produce nanoscale filler from waste date palm agro residue. Then, the melt mixing technique was used to fabricate biocomposites of polypropylene (PP) with 1–5 wt% loading of this nanofillers. To investigate the variations in dimensional stability of the composites, thermo-mechanical analysis (TMA) was used. The thermomechanical analysis indicated that these composites exhibits low coefficient of thermal expansion (CTE). The CTE values for the highest nanofiller loaded sample (i.e.5 wt%) was found to be 95 and 138 at 40 °C and 80 °C, respectively, when compared to neat PP (which is 80.4 and 125) at the same temperatures. Moreover, the viscoelastic parameters of the biocomposites, such as storage modulus (E’), loss modulus (E′′), and damping factor (tan δ) were examined by using dynamic mechanical analysis (DMA) in both solid and molten state. It is observed that the both E′ and E′′ decreases with temperature in all composites compared to the neat PP in the solid state. The storage modulus (E’) difference between the biocomposites and PP at −50 °C was found to be only 9 %. On the other hand, E′ and E′′ were found to increase with the entire angular frequency range in the molten state. The E’ at 0.1 rad/s of the neat PP is 732 Pa, while the sample with 1 wt% of nanofiller loading shows storage modulus 850 Pa. Overall, these composites demonstrated good dimensional stability in a given temperature range and frequency in the solid state, as well as typical viscoelastic behavior of entangled polymeric liquid in the molten state. Consequently, these analyses provided useful information for the development of natural fiber-based composites for long-term stability in outdoor applications.

Conocarpus is a buttonwood plant enriched with lignocellulosic biomass, which has high potential for various applications. In this study, different biomasses of the Conocarpus plant, such as, leaf fibers (CP–L), branches (CP–B) and trunk (CP–T), were examined collectively through characterization techniques. The chemical composition analysis showed that CP–T fibers have a higher cellulose content than CPL and CP–B fibers. Elementary analysis also detected versatile elements based on minerals such as Mg, Si, P, S, Cl, K and Ca in fiber with a high ash content. Based on the morphological analysis, the CP–T fiber with compact and striated characteristics can contribute more effectively to the reinforcement of composite materials. In addition, the particle size of the fibers increased with increasing crystallinity, which depends on the source of the fibers, being smaller in those obtained from leaves and greater in those obtained from the trunk. This finding showed that the size of the fiber is highly correlated with the stiffness of the fiber structure. In addition, all fibers regardless of their source have great thermal stability, with a high onset degradation temperature of 273.9–316.2 °C. In conclusion, Conocarpus biomass fibers, due to its advantageous properties, have a potential to be used as a bio-filler in polymer composites.

Thermal expansion and viscoelastic properties of the date palm fibre (DPF)/epoxy composites were influenced by the type of filler from different parts of the date palm tree. The variation in properties is mainly due to the difference in fibre composition between the DPF from leaf stalk, leaf sheath, fruit bunch stalk, and tree trunk. Among the investigated composites, composite reinforced with the tree trunk fibre displayed higher thermal stability as visible from the lower weight loss, higher onset and inflection temperatures and maximum residue % from the thermogravimetric analysis (TGA). Lower coefficient of linear thermal expansion (CLTE) obtained from thermomechanical analysis (TMA) further provided supportive evidence for dimensional stability at elevated temperature. Based on the dynamic mechanical analysis (DMA) results, the DPF/epoxy composites with fruit bunch stalk fillers displayed a better property by showing higher storage modulus and lesser tan delta values. Hence, composite from the tree trunk and fruit bunch stalk fibres of date palm is recommended for applications requiring superior thermal resistance.

The objective of current work is to evaluate the density, void content, water absorption, thickness swelling and thermal expansion of non-woven bamboo mat (B)/ woven kenaf mat (K)/nanoclay/epoxy hybrid nanocomposites. The natural fibers based hybrid nanocomposites were prepared by incorporation of montmorillonite (MMT), halloysite nanotube (HNT) and organically modified montmorillonite (OMMT) at 1 wt.% loading, through hand lay-up technique. Water absorption was investigated by soaking the samples with distilled water at room temperature until saturation point and the thickness swelling was also measured as per standard. Thermomechanical analyser (TMA) was used to study the dimensional stability caused by temperature variation. Addition of nanoclay increase the density, reduced the void content and suppress water uptake in all hybrid nanocomposites. B/K/OMMT hybrid nanocomposites exhibit better dimensional stability with regards to water absorptions and thermal expansion as compare to B/K/MMT and B/K/HNT. The improvement can be attributed by the uniformly dispersed and strong interfacial adhesion bonding between the OMMT and epoxy matrix. The develop nanocomposites in this work can be utilized for building and automotive application which required high dimensional stability property.

In this study date palm stem fibers (DPF)/epoxy composites at different loading (40, 50 and 60 wt.%) were fabricated and their tensile, impact and morphological properties are characterized. The interfacial bonding in tensile fractured samples of composites was examined by scanning electron microscopy (SEM). Tensile and impact results revealed that increase in DPF loading until 50% improved the mechanical strength, modulus, impact strength and elongation at break with respect to pure epoxy resin. Tensile strength, modulus, impact strength and elongation at break of pure epoxy resin increases from 20.5 to 25.7657 MPa, 0.5123 to 1.546 GPa, 45.81 to 98.71 J/m and 0.91 to 1.412% respectively while, energy absorption decreases drastically from 50 to 32% with the incorporation of DPF filler. SEM microstructure displayed good interfacial bonding in 50% DPF epoxy however the addition of more DPF loading reduces the interfacial strength due to poor wettability. Overall test results declared that 50% DPF loading is ideal to enhance tensile, impact strengths and morphological properties of epoxy. Keywords: Date palm stem fiber, Epoxy resin, Polymer composites, Tensile properties, Impact strength, Morphological properties

Cured epoxy resins pretense a constraint for variety of advanced applications due to its notably poor thermal and dynamic (viscoelastic) properties, hence required to minimize their properties prior to their usage. The aim of the present study is to evaluate the effect of nano oil palm empty fruit bunch (OPEFB) fibers at different loadings (1%, 3% and 5%) on the dynamic mechanical properties through dynamic mechanical analysis (DMA) in terms of storage modulus E′, loss modulus E″ and glass transition temperature (Tg) of epoxy composites. Results explored that dynamic properties of the epoxy composites get improved remarkably by the incorporation of nano OPEFB to epoxy composites, while 3% loading displays marked decrease in damping factor with relative to pure epoxy composites and the rest. Overall we perceived that the 3% loading of nano OPEFB filler is the best and optimal to enhance dynamic mechanical properties and to modify the damping factor of the epoxy composites resulting in most promising light weight and thermally stable composite structural materials. Keywords: Oil palm fibers, Epoxy matrix, Nanocomposites, Glass transition temperature, Dynamic mechanical properties, Damping factor

The aim of the present study is to improve the flexural, thermal stability and dynamic mechanical properties of epoxy composites by reinforcing date palm fibres (DPF) at different loading (40%, 50% and 60% by wt.) and to evaluate the best loading through hand lay-up technique. Three point bending dynamic properties in terms of storage modulus (E′), loss modulus (E″) damping factor, Cole–Cole plot and thermal properties were analyzed by dynamic mechanical and thermogravimetric analyser, respectively. Flexural test results show that loading of 50% DPF increases both the flexural strength and modulus of pure epoxy composites from 26.15 MPa to 32.64 MPa and 2.26 GPa to 3.28 GPa, respectively. TGA results revealed that reinforcement of DPF in epoxy composites also improves the thermal stability and residual content. The residual content of epoxy (9.58%), 40% DPF/epoxy (12.51%), 50% DPF/epoxy (19.8%) and for 60% DPF/epoxy composites (15.2%) was noted, revealing that 50% DPF/epoxy composites confers the best result. Incorporation of DPF into epoxy also improves the E′ and E″ but 50% DPF show more remarkable improvement compared to 40% and 60% DPF loading. Moreover, damping factor decreases considerably by the reinforcement of DPF and are found lowest for 50% DPF/epoxy composites among all composites. Drawn Cole–Cole plot also suggests the existence of certain heterogeneity in DPF/epoxy composites compared to homogenous nature of epoxy composites. We concluded that 50% DPF loading is the ideal loading to enhanced flexural, thermal stability and dynamic properties of epoxy composites. Keywords: Date palm fibres, Epoxy composites, Flexural strength, Thermal stability, Dynamic mechanical properties, Damping factor, Cole–Cole plot

Abstract Background Research has shown high rates of stress and dissatisfaction among allied health professionals, including physiotherapists, having an adverse impact on workforce retention rates. This study aimed to examine the job satisfaction and influential factors among physiotherapists working in private and government hospitals of Saudi Arabia with a focus on leadership style. Methods This was a cross-sectional observational study conducted among sixty-nine licensed physical therapists working in various health care settings in Riyadh. The Job Satisfaction Survey questionnaire was used to measure job satisfaction, and the Multifactor Leadership Questionnaire was used to measure perceptions of leadership style. Other data including demographic and work-related information were collected. Chi-square and Pearson’s correlation analysis were used to establish correlation among the variables. Results The respondents from government and private hospitals showed non-significant differences (p > 0.05) among them on job satisfaction score, which was considered “ambivalent”. Some of the respondents “slightly disagreed” in terms of pay, promotion, fringe benefits, contingent reward, operating conditions, and communication; however, rest of them “slightly agreed” for immediate supervision, co-workers, and the nature of work. Job satisfaction correlated significantly with female gender (p 0.05). Conclusions All the physiotherapists, whether working in government or private hospitals, were neither fully satisfied nor fully dissatisfied with their jobs. Female physiotherapists from musculoskeletal subspecialty of physiotherapy were more satisfied than male physiotherapists from other subspecialty of physiotherapy. Of course, leadership style does matter in the job satisfaction among physiotherapists in the kingdom of Saudi Arabia.

The capability of functional logic operations is highly intriguing, but far from being realized owing to limited recognition element (RE) and complex readout signals, which limit their applications. In this contribution, for a visual colorimetric sensor for melamine (MEL) we described the construction of two- and three-input AND logic gate by exploiting the intrinsic peroxidase (POD)-like activity of CeO2 nanorods (NRs) (~23.04% Ce3+ fraction and aspect ratio (RTEM) of 3.85 ± 0.18) as RE at acidic pH (4.5). Further ATP piloted catalytic tuning of POD-like activity in CeO2 NRs employed for a functional logic gate-controlled MEL sensing at neutral pH (7.4). AND logic circuit operated MEL sensing record colorimetric response time of 15 min to produce blue color proportionate to MEL concentration. The fabricated nanozyme (CeO2)-based logic gate sensor probe for MEL at pH 4.5 showed a linear response from 0.004 nM to 1.56 nM with a limit of detection (LOD) of 4 pM; while translation from acidic to neutral pH (at 7.4) sensor exhibited linear response ranging from 0.2 nM to 3.12 nM with a LOD value of 17 pM. Through CeO2 POD-like nanozyme behavior under acidic and neutral pH, the fabricated logic gate sensor showed high affinity for MEL, generating prominent visual output with picomolar sensitivity, good reproducibility, and stability with relative standard deviation (RSD)

The current review summarizes the known synthetic routes of fused imidazopyrazoles. This review is classified into two main categories based on the type of annulations, for example, annulation of the imidazole ring onto a pyrazole scaffold or annulation of the pyrazole ring onto an imidazole scaffold. Some medicinal applications of imidazopyrazoles are mentioned.

2-Oxo-2H-chromene-3-carbohydrazide derivatives 2a,b react with 2-{[4-(substituted thiazol-2-yl)iminoethyl)-phenyl]hydrazono}-3-oxo-butyric acid ethyl esters 4a–c to give 3-methyl-1-[(2-oxo-2H-chromen-3-yl) carbonyl]-4-{[4-(substituted thiazol-2-yl)iminoethyl)-phenyl]hydrazono}]-2-pyrazolin-5-one derivatives 5a–f. A considerable increase in the reaction rate had been observed with better yield using microwave irradiation for the synthesis of compounds 2a, b, 3a–c, and 5a–f. The synthesized products were tested against B. subtilis, S. aureus, and E. coli as well as C. albicans compared with tetracycline and nystatin as reference drugs.

Three tricyclic ring system, pyridazino[6,1-b]quinazolin-10-ones, benzimidazolo-pyridazine thione, and 1,2,4-benzotriazino-pyridazinethione along with imidazo-[1,2-b]-pyridazinethione, 1,2,4-triazolo[4,3-b]pyridazine-thione derivatives were synthesized starting from 6-chloropyridazin3-(2H)-thione. Some disulfide and sulfide derivatives were also prepared. The antimicrobial activity of the synthesized compounds was tested. Some of these compounds possess a highly response against gram-positive and gram-negative bacteria as well as fungi.

Different series of high density Polyethylene/Ethylene Vinyl Acetate (HDPE/EVA) blends were prepared via melt blending in a corotating intermeshing twin screw extruder. The effects of VA percentage and EVA loading ratio on the thermal, rheological viscoelastic, mechanical, and fracture toughness of the blends were analyzed. The results showed that the addition of EVA to HDPE reduces the thermal, elastic, and viscoelastic properties of the blends. The microscopic examination of the fracture surface confirmed the ductile fracture of HDPE/EVA blends for all blend ratios and VA percentages. Increasing the EVA ratio and VA content caused a significant reduction in the blend crystallinity but had no significant effect on melting temperature. The complex viscosity increased with increasing the percentage of EVA due to the restriction of molecular mobility and reduction of free volume, induced by the addition of EVA. The storage modulus decreased with increasing the EVA ratio and temperature, while it increased with increasing the frequency. Young’s modulus, yield strength, and fracture strain decreased with increasing the EVA ratio. Similarly, the fracture toughness decreased proportional to the EVA percentage. Finally the results indicated that the VA content has significant effects on the mechanical, thermal, and dynamic properties of HDPE/EVA blends.

In this work, the fabricated polylactic acid (PLA) and hybrid natural fiber (NF) biocomposites via a melt extrusion method were investigated. NFs from locally grown plants were utilized as fillers. Polyethene glycol (PEG) was used as the plasticizer to improve the processability of the PLA. The effect of PLA/NF biocomposite processing was assessed by mechanical characterization (tensile, modulus, strain at break, and impact tests), and thermal properties (thermogravimetric analysis and differential scanning calorimetry [DSC] analysis). The dynamic mechanical analysis (DMA), and thermo-mechanical analysis (TMA) of the samples were also analyzed. The mechanical properties of PLA/NF biocomposites improved as compared with that of PLA. The DMA findings show that the storage modulus and loss modulus exhibited a slight reduction for PLA/NF biocomposites compared with the PLA sample. In opposite, the glass transition temperature ([T.sub.g]) from DSC thermogram results showed no obvious changes in values compared with the PLA sample. Furthermore, the findings of TMA showed a significant decrease in coefficient of thermal expansion values of PLA/NF biocomposites compared with those of PLA samples. The overall findings from this work indicated that PLA/NF biocomposites have the potential to make novel biocomposites and suitable for further application especially in biomedical applications due to its good stiffness, tensile strength, and dimensional stability. KEYWORDS mechanical properties, morphological properties, natural fibers, polylactic acid, thermal properties, orcid.org/0000-0002-9194-719X orcid.org/0000-0001-5348-5740 1 | INTRODUCTION The reinforcement of biofiber provides excellent characterizations and applications, and it offers lower cost in the present condition. In addition, biofiber composites are considered the [...]