Iranian Research Organization for Science and TechnologyJournal of Particle Science and Technology2423-408712120260601Extending the allowable exposure time of rotating X-ray anodes via an embedded lithium pulsating heat pipe: A 3D multiphase analysis120169110.22104/jpst.2026.8247.1291ENMohsenAminiDepartment of Mechanical Engineering, University of Sistan and Baluchestan, Zahedan, IranFaramarzSarhaddiDepartment of Mechanical Engineering, University of Sistan and Baluchestan, Zahedan, Iran0000-0002-5216-9823HassanAzarkishDepartment of Mechanical Engineering, University of Sistan and Baluchestan, Zahedan, IranJournal Article20260513Thermal management of high-power X-ray rotating anodes is strictly constrained by the intense, localized heat fluxes generated during brief exposure times. This study proposes the integration of a lithium-based rotating pulsating heat pipe (RPHP) into the anode and investigates its transient thermal-hydraulic performance using a volume of fluid (VOF) multiphase model, which is heavily influenced by both extreme centrifugal forces and the intense heat flux applied during the exposure time. The results reveal a fundamental thermodynamic trade-off governing the optimal rotational speed: while higher rotational speeds enhance internal fluid circulation as well as latent and sensible heat transport, they simultaneously generate massive hydrostatic pressures that cause a significant transient delay in the phase-change (boiling) process. Consequently, the maximum allowable exposure time exhibits a non-monotonic dependence on the rotational speed. A case study based on the RAD-14 X-ray tube was investigated with a heat input of 20 kW on a minimum focal spot size (0.3 mm). A critical temperature limit of 2200 K was defined to evaluate and compare the allowable exposure times across different configurations. Compared to a conventional solid anode (which is limited to an exposure time of 0.436 s), the RPHP integration at 8500 rpm achieves optimal thermal performance, extending the allowable exposure time to 0.706 s (a 62 % increment). However, further increasing the speed to 10000 rpm exacerbates the pressure-induced boiling retardation, leading to an exposure time of 0.619 s (a 42 % increment relative to the solid base, but a 12 % reduction compared to the 8500 rpm peak).https://jpst.irost.ir/article_1691_8303a79b1e19a194f1875981be5bdb6f.pdfIranian Research Organization for Science and TechnologyJournal of Particle Science and Technology2423-408712120260601Optimization and characterization of biosynthesized silver nanoparticles by the extract of the thyme plant2128174010.22104/jpst.2026.8413.1297ENAminBaghizadehDepartment of Biotechnology, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran0000-0001-5587-2621FereshtehFakhrabadipoorDepartment of Agricultural Biotechnology, Payame Noor University, Tehran, IranMohammadaliEbrahimiDepartment of Agricultural Biotechnology, Payame Noor University, Tehran, IranJournal Article20260711Nanotechnology is an attractive research field due to the production of nanoparticles in different sizes, shapes, chemical compositions, and distributions, and their many applications for humans. The fabrication, manipulation, and use of metallic nanoparticles are of great importance due to their reduced dimensions and, as a result, their unique thermal, optical, and electronic properties. Most nanoparticle synthesis techniques are inefficient considering material and energy consumption. In most chemical methods, dangerous chemical materials to humans and the environment are used. Accordingly, there is a demand for nanoparticle production using biological methods. Biological nanoparticle production methods have priority over physical and chemical methods considering energy cost, time reduction, and use of natural solvents. Currently, silver nanoparticles are one of the most commercial nanomaterials. In this research, silver nanoparticles were produced using thyme plant extract obtained using biological methods without any chemical materials. Various synthesis parameters such as temperature, pH, and synthesis time were optimized. The synthesized nanoparticles were characterized by various methods, including ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), and zeta potential. The synthesized nanoparticles are spherical, with a mean diameter of 38.9 ± 10.4 nm (range 20–60 nm) as measured by TEM. Results show that biosynthesis of silver nanoparticles using thyme extract is a successful, cost-effective, and time-efficient method.https://jpst.irost.ir/article_1740_54f5f4071faca32ad5285fef87b78646.pdf