The circular loop antenna immersed in a dissipative medium

Investigations were made of the radiating and circuit properties of circular loop antennas when immersed in conducting media with various loss tangents. The following quantities were experimentally examined and compared with the available theoretical results. 1) Driving point admittanceY_{in}of circular loops as a function of the circumference per wavelength,2pib/lambda = betab. 2) Current amplitude and phase distributions. 3) Field patterns. In each case the loss tangentsigma/omegaepsilon_{r}epsilon_{0}of the medium (conductivitysigma, permittivityepsilon_{r}epsilon_{0}) is taken as a parameter. The experimental results are in good agreement with the theory. A comparison between the behavior of the loop in a conducting medium and those of a linear dipole was made wherever possible. It was discovered that there is a cut off size beyond which the driving point admittance of a linear dipole is the same whether or not its ends are connected to form a loop. This particular loss tangent is 1.06, and the cut off size islambda/2. A circular loop antenna withbetab= 1.0is excited predominantly in a dipole mode and its field pattern resembles that of a two element dipole array. A study was made to determine how this pattern becomes more like that of a monopole as the loss tangent of the solution is increased.     

Oxygen evolution reaction on transition metal borides

The oxygen evolution reaction on the transition metal borides (mainly Co_xB and Ni_xB) was investigated with various composition ratio of BMetal and sintering temperature. The activity of oxygen evolution reaction became maximum at the composition range of BCo =$\text{1}\text{3}$ and BNi ? $\text{1}\text{3}$, respectively. The sintering temperature also affected largely the activity of oxygen evolution reaction and the metal borides with the composition ratio BMetal = $\text{1}\text{3}$ gave the highest activity at the sintering temperature lower than 300°C for nickel borides and 400 ～ 500°C for cobalt borides. The oxygen evolution reaction on iron boride and lanthanum hexaboride was also briefly discussed, and the order of the activity of oxygen evolution reaction was as follows:

The Tafel slope of oxygen evolution reaction on metal borides was varied from ca. 40 mV for Ni (ca 70 mV for Co) to ca. 120 mV with the increase in the activity of oxygen evolution reaction. The oxide formation became easier with the increase in the activity of oxygen evolution reaction and the differential capacity of the oxide formation in the range more cathodic than the oxygen evolution increased with the decrease in the apparent activation energy of oxygen evolution reaction at 0.60 V (HgHgO).     

Characteristics of carbon-related materials deposited in electron-energy controlled CH4/H2 RF discharge plasmas

The influence of electron temperature T_e on the production of carbon-related materials was investigated in a hollow-type magnetron radio-frequency (RF) CH₄/H₂ plasma. Here, the electron temperature decreased along the plasma column. Since the dissociation of CH₄ is determined by the electron energy in plasmas, the density ratio of radicals CH₂/CH₃ can be varied by the electron temperature. Therefore, the change of the electron temperature is quite important for controlling the characteristics of carbon-related materials. In the experiment, the production of diamond microparticles in low T_e plasma was detected. On the other hand, thin carbon films consisting of graphitic carbons were observed in the high T_e plasma. Therefore, it is shown that control of the electron temperature in the plasma has a key effect on the film quality.     

Electrochemical detection of volatile organic compounds using a Na3Zr2Si2PO12/Bi2Cu0.1V0.9O5.35 heterojunction device

A fast sodium ion conductor, NASICON (Na₃Zr₂Si₂PO₁₂), has been widely used for gas sensor applications. In this study, we demonstrate that a device combining NASICON with an oxygen-ion conductor of BiCuVOx (Bi₂Cu_0.1V_0.9O_5.35) can electrochemically detect volatile organic compounds (VOCs), such as ethanol, formaldehyde, and toluene. The sensing electrode made of BiCuVOx was attached onto a sintered NASICON disk at high temperature to produce an interfacial layer that had a different morphology and composition from those of NASICON and BiCuVOx, as observed by scanning electron microscopy-energy dispersive X-ray spectroscopy analysis. The device in which NASICON was fitted with the BiCuVOx-based electrode was found to efficiently detect VOCs in ppm concentrations. The sensor signal (electromotive force) exceeded 100 mV in response to 10 ppm HCOH at 400 °C, demonstrating the high sensitivity of the device. It also exhibited a relatively quick response, reproducible and stable sensor signals, and high selectivity to VOCs. The sensor responses followed behavior typical for mixed-potential-type gas sensors based on oxygen-ion conductors. It was thus suggested that the electrochemical oxidation of VOCs with oxide ions took place at the interfacial oxygen ion-conductive layer that was formed by the reaction of NASICON with BiCuVOx.     

Chitin scaffolds in tissue engineering

Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine.     

Enhanced and Engineered d0 Ferromagnetism in Molecularly‐Thin Zinc Oxide Nanosheets

Molecularly‐thin nanosheets are ultimate two‐dimensional (2D) nanomaterials potentially giving unusual physical and chemical properties due to the strong 2D quantum and surface effects. Here, it is demonstrated that 1.5‐nm‐thick ZnO nanosheets exhibit greatly enhanced room‐temperature ferromagnetism. Saturation magnetization value of the nanosheets with intercalated dodecyl sulfate layers is approximately 100 times that of ZnO mesocrystals. Anion exchange with dodecyl phosphate layers strongly suppresses ferromagnetic ordering as a result of surface defect passivation while maintaining bulk‐like n‐type semiconducting properties, which reveals significance of interfacial states to engineer functional properties of nanosheet‐based hybrid materials.     

L/N-Type Calcium Channel Blocker Cilnidipine Added to Renin-Angiotensin Inhibition Improves Ambulatory Blood Pressure Profile and Suppresses Cardiac Hypertrophy in Hypertension with Chronic Kidney Disease

Ambulatory blood pressure (BP) and heart rate (HR) profile are proposed to be related to renal deterioration and cardiovascular complication in hypertension and chronic kidney disease (CKD). In this study, we examined the beneficial effects cilnidipine, a unique L/N-type calcium channel blocker (CCB), in addition to renin-angiotensin system inhibitors, on ambulatory BP and HR profile, as well as cardiorenal function in hypertensive CKD patients. Forty-five patients were randomly assigned to the cilnidipine replacement group (n = 21) or the control CCBs group (n = 24) during a 24-week active treatment period. Although clinical BP values were similar in the cilnidipine and control CCBs groups after the treatment period, the results of ambulatory BP monitoring showed that the 24-h and daytime systolic BP levels in the cilnidipine group were significantly lower compared with the control group after the study. Furthermore, the left ventricular mass index (LVMI) was significantly decreased in the cilnidipine group compared to the control group after the study (LVMI, 135.3 ± 26.4 versus 181.2 ± 88.4, p = 0.031), with a significant difference in the changes in the LVMI between the cilnidipine and control groups (change in LVMI, −12.4 ± 23.7 versus 26.2 ± 64.4, p = 0.007). These results indicate that cilnidipine is beneficial for the suppression of pathological cardiac remodeling, at least partly, via a superior improving effect on ambulatory BP profile compared with control CCBs in hypertensive CKD patients.     

Quality- and Dilution Losses in the Recycling of Ferrous Materials from End-of-Life Passenger Cars: Input-Output Analysis under Explicit Consideration of Scrap Quality

Metals can in theory be infinitely recycled in a closed-loop without any degradation in quality. In reality, however, open-loop recycling is more typical for metal scrap recovered from end-of-life (EoL) products because mixing of different metal species results in scrap quality that no longer matches the originals. Further losses occur when meeting the quality requirement of the target product requires dilution of the secondary material by adding high purity materials. Standard LCA usually does not address these losses. This paper presents a novel approach to quantifying quality- and dilution losses, by means of hybrid input-output analysis. We focus on the losses associated with the recycling of ferrous materials from end-of-life vehicle (ELV) due to the mixing of copper, a typical contaminant in steel recycling. Given the quality of scrap in terms of copper density, the model determines the ratio by which scrap needs to be diluted in an electric arc furnace (EAF), and the amount of demand for EAF steel including those quantities needed for dilution. Application to a high-resolution Japanese IO table supplemented with data on ferrous materials including different grades of scrap indicates that a nationwide avoidance of these losses could result in a significant reduction of CO(2) emissions.