Damietta University

UDC 517.53 By using beta-negative binomial distribution, we introduce two novel subclasses of spiral-like functions; namely, spiral-starlike functions and spiral-convex functions denoted by $S^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta)$ and $E^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta),$ respectively, and defined in the domain of open unit disk $\mathbb{D}=\{z \in \mathbb{C}\colon |z|<1\}.$ We establish sufficient conditions for functions to be members of families mentioned above. Further, the bounds of some initial coefficients and Fekete–Szegö functionals for the classes described above are obtained.

The effect of CuO on the structural, optical, dielectric, and radiation shielding properties of copper fluorobarioborate (CFBB) glasses synthesized by the melt-quench technique with a general composition xCuO–(50 − x)B2O₃–35BaO–15MgF₂ (0–0.5 mol%) was investigated. XRD measurements indicated that all the samples, except those with higher values of CuO, were amorphous in nature. FTIR studies exhibited stable BO₃, BO₄, and B–O–B units, indicating an insignificantly modified borate network. The UV–Vis spectral studies showed enhanced UV absorption with the increase in the concentration of CuO. The value of both the direct and indirect optical band gaps is found to be almost the same (3.48–3.60 eV). Dynamic measurements of dielectric properties showed strong frequency dispersion, characterized by decreased ε′ and ε′′ and conductivity behavior based on hopping mechanisms. The radiation shielding parameters show high attenuation at low photon energies and improved shielding for CFBB glasses with increased CuO content. Hence, CFBB glasses have sufficient promise for optical transparency coupled with stable dielectric behavior and effective γ-ray attenuation. The novelty of this study is in simultaneous investigations concerning optical clarity, dielectric stability, and shielding efficacy in low CuO-doped fluorobarioborates, emphasizing their potential usage in multiple ways due to their multifunctionality.

Developing multifunctional nanomaterials remains critical for sustainable crop protection and the mitigation of biotic stress. This study describes the green synthesis of a ternary reduced graphene oxide/silicon dioxide/zinc oxide (rGO/SiO₂/ZnO) nanocomposite, utilizing an aqueous extract of soybean (Glycine max) as a sustainable reducing and stabilizing agent. FTIR spectroscopy confirmed the reduction of graphene oxide (GO) to rGO. Transmission electron microscopy (TEM) revealed the successful anchoring of crystalline ZnO and SiO₂ nanoparticles, with an average diameter of 55 nm, onto the rGO matrix. The stability of the synthesized architecture was validated by a zeta potential of -30.9 mV, indicating high colloidal stability. Biological assays demonstrated significant broad-spectrum antimicrobial efficacy. The nanocomposite achieved a 3.5-fold increase in the inhibition zone against Escherichia coli compared to monometallic ZnO NPs and exhibited significant inhibitory efficacy against Fusarium oxysporum, Penicillium digitatum, Aspergillus niger, and Candida albicans. Time-kill kinetics demonstrated rapid, concentration-dependent microbicidal efficacy, while TEM ultrastructural analysis of treated F. oxysporum revealed cellular degradation, characterized by expanded vacuoles and lipid droplet accumulation. In seed nano-priming experiments, soybean seeds treated with rGO/SiO₂/ZnO (50–500 mg/L) exhibited improved germination percentages and reduced disease incidence. The 150 mg/L concentration was identified as the optimal treatment, yielding a 57% increase in fungicidal action against F. oxysporum relative to ZnO NPs alone. Furthermore, this treatment mitigated pathogen-induced damage, resulting in a 400% increase in germination rate over infected controls and a 197% increase in shoot fresh mass compared to healthy, unprimed controls. These findings indicate that the rGO/SiO2/ZnO nanocomposite exhibits a multifunctional profile, acting concurrently as a biostimulant and a protective agent. This suggests its potential as an integrated approach for managing fungal-induced biotic stress in soybean cultivation. This study provides a foundational step toward developing sustainable nanomaterials that may contribute to long-term crop resilience in agricultural systems.

Purpose Natural fibers are gaining attention as eco-friendly, cost-effective and high-performance materials. Pineapple leaf fiber stands out for its low density, light weight, affordability, biodegradability and renewability. The purpose of this study is to explore the production of fabrics from pineapple fibers, cotton and their blends to evaluate the potential of using pineapple fibers as a sustainable alternative to cotton. Design/methodology/approach Pineapple, cotton and pineapple blended with cotton using twill 3/1 and matt 2/2 weave structures were produced. The weight, air permeability and low-stress properties (tensile, shear, bending, compression and surface) of these samples were evaluated and compared by calculating the primary and total hand values (THVs) using the Kawabata evaluation system. Findings Results indicated that the produced fabrics were suitable for men’s jackets, women’s thin dresses and men’s suit applications, with an accepted THV ranging from average to excellent. The twill pineapple fabric reached the highest weight, air permeability and THV = 6.4 as a men’s suit; it was evaluated as excellent for this application. Research limitations/implications Only twill 3/1 and matt 2/2 weave structures were used, as they are common. In addition, the blending of cotton/pineapple comes from inserting one pineapple yarn and then one cotton yarn in the weft direction, as blending fibers were not reachable. Originality/value Original study of producing pineapple, cotton and a blend of them fabrics, ensuring replacing cotton fibers with pineapple fibers availability as a waste natural source for reaching eco-friendly products.

In current study, two novel polymers derived from original Chitosan is synthetized. Polymeric blends from Chitosan and the new polymers are used to fabricate spin coated thin films. The effect of UV irradiation on the optical properties of pristine Chitosan and two novel Chitosan derived polymers blends in form of thin film structure are studied. The optical parameters of the blends thin films such as the refractive index (n), extinction coefficient (k) and dielectric constants are determined by spectrophotometric technique in the spectral range 200–2500 nm. The energy gap values (Eg), dielectric constants at infinity (ε∞), lattice permittivity (εL) and dispersion parameters are calculated. Eg is found to be 5.14 eV for Chitosan film and it is reduced to 4.25 and 4 eV for the two polymeric blends. ε∞ is calculated to be 2.96 for Chitosan film which is reduced to 2.88 upon UV irradiation. The influence of exposing thin films to UV light demonstrates interesting modifications in linear and nonlinear optical properties (third order non-linear susceptibility and the non-linear refractive index) of Chitosan and its derivatives. The emission characteristics of the blends are also investigated. The fluorescence intensity of the polymeric films is decreased upon UV exposure. The obtained results propose that Chitosan and its derivatives are possible candidates for opto-electronic applications such as optical switching, optical limiters and OLED.