Investigation of slider out-of-plane and in-plane vibrations during the track-seeking process

This paper employs the coupled air bearing model and modal order reduction (MOR) model of head stack assembly (HSA) to investigate the track-seeking process of a femto slider. Simulations indicate that the flying height and the pitch angle may increase or decrease significantly, depending on the track-seeking directions. For the slider studied in this paper, it is safer for sweeping from OD to ID, than sweeping from ID to OD. The most serious vibration is the off-track vibration, and it is highly related to the sweeping acceleration profile. A smooth acceleration profile is crucial to reduce all the vibrations of slider, especially the off-track vibration.     

Synthesis of optical quality ZnO nanowires utilizing ultrasonic spray pyrolysis

ZnO nanowires were grown by an ultrasonic spray pyrolysis technique. The aspect ratio and size of the wire were dependent mainly on the pH value of a precursor solution and the growth temperature. By high-resolution transmission electron microscopic analysis and photoluminescence measurements, it was confirmed that the nanowires are monocrystalline with good optical quality.     

Modeling laser heated thin film media for heat assisted magnetic recording

In the present study, we concern laser induced heat generation and its effect on lubricant depletion on the multilayer disk structure. A mathematical model is applied to explore the local laser heating from the point of view of the interaction between the disk media and the electromagnetic wave. The absorption rate of optical energy in each layer of disk structure is derived from the Maxwell equations, which is incorporated into the energy equation by a source term. We simulate the unsteady heat transfer and lubricant depletion processes on a multilayer disk structure. The effect of multi-cycle heating on the lubricant depletion is investigated. Comparison between the present results and those obtained by applying a heat flux boundary condition is also made. The present simulations provide useful information on the media structure design of hard disk drives in heat assisted magnetic recording.     

Back heating effect of media hot spot at nanoscale head–disk interface

Microsystem Technologies - Heat-assisted magnetic recording (HAMR) is one of prospective high density recording technologies in current hard disk industry due to its theoretical potential. In this...     

Sulfonated polyetherketone （SPEK-C） films investigated by positron annihilation lifetime spectroscopy and atomic force microscopy

The characterization of sulfonated polyetherketone （SPEK-C） films was investigated by using positron annihilation lifetime spectroscopy （PALS） and atomic force microscopy （AFM）. It was found that free volume radius and intensity depend on the variation of sulfonation degree and solvent evaporation time of the films. Pore size and distribution determined from PALS and AFM measurements showed reasonable agreement.     

Differences in traffic violations and at-fault crashes between license suspension and revocation

Upon conviction for particular traffic offenses, drivers can have their licenses revoked. Drivers who receive license revocation have an opportunity to apply for a sentence reduction, and some of those who apply receive a reduced sanction — license suspension. There may be differences between drivers whose license was revoked as originally sentenced and drivers who received the reduced sanction of license suspension with regard to traffic violations and crashes after driving privileges are restored. This study verified the differences during the follow-up periods of 6, 12, and 18 months using analysis of covariance and the t-test with stratified samples based on the police profiles of approximately 154,000 drivers in South Korea. The study found that drivers in the group whose license had been suspended committed traffic violations and caused traffic crashes less often for all time periods than those whose license had been revoked. However, omitted factors such as the attitude of suspended drivers and exposure to traffic violations and crashes (e.g., driving frequency after license reinstatement), are likely to affect the findings; thus, caution should be exercised when the findings are referenced for policy implications.     

A study of the characteristics of nuclear photographic materials used in activation autoradiography

The characteristics of nuclear photographic materials (MP and Kodak BioMax MR Film photographic films and MP photographic plates) were investigated. The dependence of their optical density on the β-particle fluence, their sensitivities versus the β-particle energy, and the relative error in measuring the average and local β-particle fluences were determined. It was shown that, though the MP-type domestic nuclear photographic materials are less sensitive to relativistic-energy β particles than the Kodak photographic materials, they assure a smaller relative error in measuring the β-particle fluence.     

Fuzzy <Emphasis Type="Italic">H</Emphasis><Subscript>∞</Subscript> FIR Filtering for T–S Fuzzy Systems with Quantization and Packet Dropout

This paper proposes a new fuzzy H_∞ finite impulse response (FIR) filter with quantization and packet dropout for Takagi–Sugeno (T–S) fuzzy systems with external disturbance. The measurements are quantized by a logarithmic quantizer and then transmitted from the plant to the filter imperfectly due to random packet loss described by the Bernoulli random process. The proposed fuzzy H_∞ FIR filter is in the form of fuzzy-basis-independent linear matrix inequalities (LMIs) that guarantee H_∞ performance. Two simulation examples are given to illustrate the effectiveness and robustness of the proposed fuzzy H_∞ FIR filter.     

Antifungal Activity of Bacillus velezensis CE 100 against Anthracnose Disease (Colletotrichum gloeosporioides) and Growth Promotion of Walnut (Juglans regia L.) Trees

Walnut anthracnose caused by Colletotrichum gloeosporioides is a deleterious disease that severely affects the production of walnut (Juglans regia L.). The aim of this study was to assess the antifungal and growth promotion activities of Bacillus velezensis CE 100 as an alternative to chemical use in walnut production. The crude enzyme from B. velezensis CE 100 exhibited chitinase, protease, and β-l,3-glucanase activity and degraded the cell wall of C. gloeosporioides, causing the inhibition of spore germination and mycelial growth by 99.3% and 33.6% at 100 µL/mL, respectively. The field application of B. velezensis CE 100 culture broth resulted in a 1.3-fold and 6.9-fold decrease in anthracnose disease severity compared to the conventional and control groups, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (up to 1.4 µg/mL) and exhibited the potential for ammonium production and phosphate solubilization to enhance the availability of essential nutrients. Thus, field inoculation of B. velezensis CE 100 improved walnut root development, increased nutrient uptake, enhanced chlorophyll content, and consequently improved total biomass by 1.5-fold and 2.0-fold compared to the conventional and control groups, respectively. These results demonstrate that B. velezensis CE 100 is an effective biocontrol agent against anthracnose disease and a potential plant growth-promoting bacteria in walnut tree production.     

Anti‐inflammatory Potential of Quercetin‐3‐O‐β‐D‐(“2”‐galloyl)‐glucopyranoside and Quercetin Isolated from Diospyros kaki calyx via Suppression of MAP Signaling Molecules in LPS‐induced RAW 264.7 Macrophages

Diospyros kaki (DK) contains an abundance of flavonoids and has been used in folk medicine in Korea for centuries. Here, we report for the first time the anti‐inflammatory activities of Quercetin (QCT) and Quercetin 3‐O‐β‐(“2”‐galloyl)‐glucopyranoside (Q32G) isolated from DK. We have determine the no cytotoxicity of Q32G and QCT against RAW 264.7 cells up to concentration of 50 μM. QCT and Q32G demonstrated potent anti‐inflammatory activities by reducing expression of nitric oxide (NO), tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, IL‐6 inducible NO synthase (iNOS), cyclooxygenase (COX)‐2, and mitogen‐activated protein kinase (MAPKs) in mouse RAW 264.7 macrophages activated with lipopolysaccharide (LPS). Both QCT or Q32G could decrease cellular protein levels of COX‐2 and iNOS as well as secreted protein levels of NO, PGE₂, and cytokines (TNF‐α, IL‐1β, and IL‐6) in culture medium of LPS‐stimulated RAW 264.7 macrophages. Immunoblot analysis showed that QCT and Q32G suppressed LPS‐induced MAP kinase pathway proteins p‐p38, ERK, and JNK. This study revealed that QCT and Q32G have anti‐inflammatory potential, however Q32G possess comparable activity as that of QCT and could be use as adjuvant to treat inflammatory diseases.