Instability of Hyperthermia Temperature for Magnetic Nanoparticles of Low Anisotropy Constant Due to Nonlinear Characteristics.

Magnetic nanoparticles (MNPs) subjected to external alternating magnetic field can induce heat in MNPs due to hysteresis, which is usually employed for tumor hyperthermia. An effective hyperthermia treatment should selectively kill the tumor cells without damaging the ambient healthy tissue. Hence, it is important for hyperthermia to correctly control the alternating magnetic field-induced temperature of MNPs in the tumor. This work develops a thermal model to analyze various forms of temperature-rise with time in magnetic nanoparticles for tumor hyperthermia. Results show that there are horizontal, linear rise, square root, exponential decay and abrupt temperature-rise lines with time in MNPs. The horizontal, linear rise, and square root temperature lines with time are consistent with the available experimental data. It is worthily noted that the form of abrupt temperaturerise with time can result in harm to the normal cells or tissue. If the abrupt temperature-rise does not be controlled and predicted well.

Thermal Transport Model of Short-Pulse Laser Microscale Ablation for Poly(methyl methacrylate) and Acrylonitrile Butadiene Styrene/Polyvinyl Chloride.

This study analytically investigates the picosecond laser ablation of poly(methyl methacrylate) (PMMA) and acrylonitrile butadiene styrene (ABS)/polyvinyl chloride (PVC). Pulsed laser ablation is a well-established tool for polymers. However the ablation mechanism used in laser processing of polymers is not thoroughly understood. This study utilizes a thermal transport model to analyze the relationship between the ablation rate and laser fluence. This model considers the energy balance at the decomposition interface. The calculated variation of the ablation rate with the logarithm of the laser fluence agrees with the measured data. This study also validates that the variation of the ablation rate with the logarithm of the laser fluence obeys Beer's law.

Processing Characteristics and Parametric Effects on Picosecond Laser Nanoscaled Patterning of Poly(methyl methacrylate).

Characteristics of picosecond laser processing for poly(methyl methacrylate) (PMMA) are studied in this text. Poly(methyl methacrylate) (PMMA) can be applied to micro- or nano-scale electronic devices. Short-pulsed laser is usually used for noncontact processing of nanoscale patterning of poly(methyl methacrylate) (PMMA). This study considers optical energy of laser to be transferred into decomposition energy of poly(methyl methacrylate) (PMMA). Using the condition of the energy balance at the decomposition interface, the variation of the ablation rate with the logarithm of the laser fluence is calculated for poly(methyl methacrylate) (PMMA) and agrees with the measured data. This study also discusses parametric effects of poly(methyl methacrylate) (PMMA) on the variation of the ablation rate with the logarithm of the laser fluence.