Tailoring tokamak error fields to control plasma instabilities and transport.

A tokamak relies on the axisymmetric magnetic fields to confine fusion plasmas and aims to deliver sustainable and clean energy. However, misalignments arise inevitably in the tokamak construction, leading to small asymmetries in the magnetic field known as error fields (EFs). The EFs have been a major concern in the tokamak approaches because small EFs, even less than 0.1%, can drive a plasma disruption. Meanwhile, the EFs in the tokamak can be favorably used for controlling plasma instabilities, such as edge-localized modes (ELMs). Here we show an optimization that tailors the EFs to maintain an edge 3D response for ELM control with a minimized core 3D response to avoid plasma disruption and unnecessary confinement degradation. We design and demonstrate such an edge-localized 3D response in the KSTAR facility, benefiting from its unique flexibility to change many degrees of freedom in the 3D coil space for the various fusion plasma regimes. This favorable control of the tokamak EF represents a notable advance for designing intrinsically 3D tokamaks to optimize stability and confinement for next-step fusion reactors.

The Association between Dental Implant Treatment Experience and Socioeconomic Factors in Korean Adults: A Cross-Sectional Survey Data Analysis.

Background: We examined the Korean adults' experience with dental implants and analyzed its association with various socioeconomic factors. Methods: This study was based on the participants enrolled in the 2013-2015 KNHANES. Using the variables associated with dental implant treatment experience and other socioeconomic factors, we evaluated the statistical significance and potential associations between the dental implant treatment experience and its related factors. The final analysis in this study was performed on adults aged 20 yr and over. It comprised 4,893 subjects in the year 2013, 4,431 subjects in 2014, and 4,430 subjects in 2015. Results: An increasing number of individuals had reported undergoing dental implant treatment. An older age was associated with a higher likelihood of undergoing dental implant treatment, particularly in adults aged ≥40 years. Additionally, the likelihood was higher in individuals with a greater income level, low-level of educational background, and married status. Factors that were observed to influence dental implant treatment experience included age, education level, income level, marital status. Conclusion: Our analysis confirmed the growing accessibility to dental implants among Korean adults and an association between dental implant treatment experience and socioeconomic factors. We recommend a healthcare policy on dental implants that considers relevant socioeconomic factors, in order to provide dental implant treatment to individuals who are in absolute need of treatment.

Diffusion in a two-dimensional anisotropic web map by extrinsic noise applied to the intrinsically perturbed quantity.

Diffusion by an extrinsic noise in a two-dimensional anisotropic web mapping is studied in the case where an extrinsic noise is applied to the intrinsically perturbed (intrinsically active) physical quantity and the intrinsic web diffusion is negligible. Contrary to the case where the extrinsic noise is applied to the other (intrinsically passive) physical quantity to yield a highly anisotropic diffusion scaling [Gunyoung Park and C. S. Chang, Phys. Rev. E 64, 026211 (2001)], the diffusion scaling in this case is found to be isotropic.

Oxidation of pharmaceuticals during ozonation and advanced oxidation processes.

This study investigates the oxidation of pharmaceuticals during conventional ozonation and advanced oxidation processes (AOPs) applied in drinking water treatment. In a first step, second-order rate constants for the reactions of selected pharmaceuticals with ozone (k(O3)) and OH radicals (k(OH)) were determined in bench-scale experiments (in brackets apparent k(O3) at pH 7 and T = 20 degrees C): bezafibrate (590 +/- 50 M(-1) s(-1)), carbamazepine (approximately 3 x 10(5) M(-1) s(-1)), diazepam (0.75 +/- 0.15 M(-1) s(-1)), diclofenac (approximately 1 x 10(6) M(-1) s(-1)), 17alpha-ethinylestradiol (approximately 3 x 10(6) M(-1) s(-1)), ibuprofen (9.6 +/- 1.0 M(-1) s(-1)), iopromide (<0.8 M(-1) s(-1)), sulfamethoxazole (approximately 2.5 x 10(6) M(-1) s(-1)), and roxithromycin (approximately 7 x 10(4) M(-1) s(-1)). For five of the pharmaceuticals the apparent k(O3) at pH 7 was >5 x 10(4) M(-1) s(-1), indicating that these compounds are completely transformed during ozonation processes. Values for k(OH) ranged from 3.3 to 9.8 x 10(9) M(-1) s(-1). Compared to other important micropollutants such as MTBE and atrazine, the selected pharmaceuticals reacted about two to three times faster with OH radicals. In the second part of the study, oxidation kinetics of the selected pharmaceuticals were investigated in ozonation experiments performed in different natural waters. It could be shown that the second-order rate constants determined in pure aqueous solution could be applied to predict the behavior of pharmaceuticals dissolved in natural waters. Overall it can be concluded that ozonation and AOPs are promising processes for an efficient removal of pharmaceuticals in drinking waters.