Recordable Digital Versatile Disc Research Articles

Photochemical deposition of palladium nanoparticles on TiO2 nanoparticles and their application for electrocatalytic measurement of nitrate ions in potato, onion and cabbage using bipolar electrochemical method

A nanoparticle modified recordable digital versatile disc (DVD) blade was used as the bipolar electrode. The cathodic pole of the DVD blade was modified by TiO2 nanoparticles. Then, Pd nanoparticles were deposited at the TiO2NPs/DVD surface by photochemical method. In the proposed setup, when the required potential was applied by using a direct power supply, the nitrate ions are reduced electrocatalytic at the PdNPs/TiO2NPs cathodic pole and the oxidation reaction of the silver layer is performed at the anode pole of the bipolar electrode, simultaneously. The oxidation process led to the dissolution of the silver layer. The results show that the dissolution length of the silver layer on the surface of the anodic pole at constant interval time is proportional to the nitrate ion concentration in the analytical solution. Finally, this method was used to measure the concentration of nitrate ions in the various real samples and obtained satisfactory results.

Effect of insertion of bathocuproine buffer layer at grating-structured cathode–organic-layer interface in bulk-heterojunction solar cells

A grating-structured interface of a poly(3-hexylthiophene) (P3HT) and n-type [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)-based bulk-heterojunction (BHJ) photovoltaic (PV) cell was designed and fabricated to obtain a desirable thickness distribution of the deposited bathocuproine (BCP) buffer layer to efficiently utilize its potentials. As a master mold of the grating-structure, a commercially available recordable digital versatile disc (DVD-R) substrate was employed. The grating-structured surface of the P3HT:PCBM layer was successfully produced by duplication from a poly(dimethylsiloxane) secondary mold using the spin cast molding technique. From morphological observations of the grating-structured surface covered with vapor-deposited BCP, we roughly estimated the ratio of the BCP thickness at “walls” to that at “top” and “bottom” regions to be ∼0.5. The grating-type BHJ PV cell with a 5-nm-thick BCP layer exhibited the maximum power-conversion efficiency (ηp) of 3.51%. Compared with the conventional flat-type BHJ PV cell with a 20-nm-thick BCP layer, the performance of the grating-type BHJ PV cell with a 20-nm-thick BCP layer was remarkably improved, owing to the contribution of the wall side contact, which provides a lower-barrier path of the electrons toward the cathode through the thinner BCP layer.

A highly-sensitive electrocatalytic measurement of nitrate ions in soil and different fruit vegetables at the surface of palladium nanoparticles modified DVD using the open bipolar system

In the present research, a nanoparticle-modified recordable digital versatile disc (DVD) blade was used as a bipolar electrode to design a bipolar electrochemical method for nitrate ion measurement. The DVD blade was modified with copper and palladium nanoparticles. In the proposed setup, using a direct power supply and an appropriate potential, the electrocatalytic reduction of nitrate ions occurred at the cathode, and, simultaneously, the oxidation reaction of a silver layer was performed at the anode of the bipolar electrode. The oxidation process led to the dissolution of the silver layer. The results indicated that the length of the layer dissolution on the anode surface at a given time was directly related to the concentration of the nitrate ions in the analytical solution. Based on the proposed method, the electrochemical measurement of nitrate ions took place in two linear ranges between 0.5 and 3500.0 μM and a detection limit of 0.16 μM. Finally, this method was used to determine nitrate ion concentration in a mineral water, agricultural soil, cucumber, tomato, and bell pepper.

Surface Plasmon Polaritons Probed with Cold Atoms

We report on an optical mirror for cold rubidium atoms based on a repulsive dipole potential created by means of a modified recordable digital versatile disc. Using the mirror, we have determined the absolute value of the surface plasmon polariton (SPP) intensity, reaching 90 times the intensity of the excitation laser beam. Furthermore, we have also directly measured thermo-plasmonic effects accompanying SPPs excitation on gold submicron structures.

Digital versatile disc bipolar electrode: A fast and low-cost approach for visual sensing of analytes and electrocatalysts screening

This work represents a new, extremely low cost and easy method for fabrication of bipolar electrode (BPE) for rapid and simultaneous screening of potential candidates for electrocatalytic reactions and sensing applications. Our method takes advantage of the silver reflective layer deposited on already available recordable digital versatile disc (DVD-R) polycarbonate substrate which acts as BPE. Oxidation of the reflective layer of the DVD-R in anodic pole of the BPE results in a permanent and visually measurable dissolute length. Therefore, one could correlate the electrocatalytic activity of the catalyst at the cathodic pole of the BPE, as well as the concentration of analyte in the solution, to the dissolution length of the BPE. To illustrate the promising applications of this new substrate as BPE, p-benzoquinone (BQ) and hydrogen peroxide were tested as model targets for the sensing application. Moreover, in order to show the feasibility of using DVD BPEs for screening applications, the electrocatalytic activity of Pt, Pd, Au, and pristine DVD substrate toward hydrogen evolution reaction (HER) were compared using an array of BPEs prepared on DVD substrate.

Double Feedforward Control System Based on Precise Disturbance Modeling for Optical Disk

Optical disk drive systems must realize high-precision tracking control for their proper operation. For this purpose, we previously proposed a tracking control system that is composed of a high-gain servo controller (HGSC) and a feedforward controller with an equivalent-perfect tracking control (E-PTC) system. However, it is difficult to design the control parameter for actual multi-harmonic disturbances. In this paper, we propose a precise disturbance model of an actual optical disk using the experimental spectrum data of a feedback controller and describe the design of a fine tracking control system. In addition, we propose a double feedforward control (DFFC) system for further high-precision control. The proposed DFFC system is constructed using two zero phase error tracking (ZPET) control systems based on error prediction and trajectory command prediction. Our experimental results confirm that the proposed system effectively suppresses the tracking error at 6000 rpm, which is the disk rotation speed of Digital Versatile Disk Recordable (DVD+R).

Evaluation of Data Stability and Analysis of Degradation Factors of Digital Versatile Disk Recordable (DVD+R) for Archival Application

Optical disks are widely used in libraries and archives as digital data media due to their archival storage stability. Nevertheless, there is relatively less focus on the understanding of physical and chemical degradation mechanism. To observe the degradation mechanism of an optical disk, the accelerated aging test was designed with high temperature and relative humidity of 85 °C and 85% in this study. After 1500 h of aging, digital versatile disk recordable (DVD+R) media resulted in a high value of over 280 in the PI sum 8 value, which means a severe data degradation in the media. From the microstructural observation of recorded marks and the chemical analysis of the reflective layer after this accelerated aging test, gradual physical deformation of recorded mark edges and chemical change of the reflective layer were observed, and they might be related to the severe increase of PI sum 8.

Evaluation of Data Stability and Analysis of Degradation Factors of Digital Versatile Disk Recordable (DVD+R) for Archival Application

Evaluation of Data Stability and Analysis of Degradation Factors of Digital Versatile Disk Recordable (DVD+R) for Archival Application

ディジタル・ヴァーサタイル・ディスク・レコーダブル用オキソノール色素の熱化学的性質の制御--高速記録時の熱的干渉の抑制

ディジタル・ヴァーサタイル・ディスク・レコーダブル用オキソノール色素の熱化学的性質の制御--高速記録時の熱的干渉の抑制

In-Line-Type Differential Push-Pull Methods for Tracking Error Detection

The validity of in-line-type differential push-pull (DPP) methods for digital versatile disc-recordable (DVD-R) and digital versatile disc-random access memory (DVD-RAM) is presented by numerical calculation. In these methods, segmented gratings which are divided into two or three regions each with a specific phase value and a width are used to generate subspots on the optical disk. Tracking error signals are calculated with respect to the objective lens shift under parameter conditions of the widths of the segmented regions. The obtained results show that the relationship between the signal characteristics and grating types becomes clear in both cases of DVD-R and DVD-RAM.

Investigation on Life Expectancy of High-Speed Recordable Optical Disks

This study is intended to establish a standard technique for measuring high-density optical disk life expectancy. The life expectancy of archival performance for high-speed recordable optical disks [digital versatile disc-recordable (DVD-R) disk] was examined using two acceleration test models, namely, the Arrhenius and Eyring models, and an analysis of statistical techniques based on the ISO method. Results demonstrate that the statistical distribution of failure time using both acceleration test models follows a lognormal distribution. Thus, we can estimate a standard life expectancy of 95% survival probability with a 95% confidence level for each acceleration test model.

Dual-Layer Recordable Digital Versatile Disc Having Protruded Land Pre Pit in L1 Layer Fabricated by Inverse Stack Method

The dual-layer recordable digital versatile disc (DVD-R DL) fabricated by an inverse stack method has not been released in the market because of unstable land pre pit (LPP) addressing in an L1 layer due to its peculiar disc structure. We have developed a DVD-R DL disc that has the novel shape of the protruded LPP in the L1 layer fabricated by an inverse stack method. The height of the protruded LPP is larger than the land height of the L1 substrate to restrain extensions in the radial direction of recording marks. We have confirmed that the protruded LPP disc satisfies the specifications of DVD-R DL and enables stable LPP addressing.

New Laser Labeling Technology for Recordable Digital Versatile Disc

A new labeling technology, i.e., “LabelflashTM”, is reported. This technology uses the digital versatile disc (DVD) drive data recording head to burn high-quality images directly into a specialized dye layer on the label side of DVD discs. The basic structure of the disc is similar to a conventional double-sided recordable digital versatile disc (DVD-R). Consequently, a Labelflash disc shows various features as follows: non consumable, no special optical path or drive control system, the same working distance as that for data recording, manufactured using conventional equipment for double-sided DVD-R, fast drawing speed, high durability, and professional appearance. Moreover, four color variation types and mat-type discs were developped. The graphic quality performance index for Labelflash was newly proposed. The values were closely matched by the subjective evaluations of contrast.

New Recording Layer of Recordable Digital Versatile Disc with CrOx Film Using Red Laser

In this study, CrOx film deposited by rf magnetron reactive sputtering was used as a new recording layer for a recordable digital versatile disc (DVD-R) with a red laser. X-ray photoelectron spectroscopy (XPS) indicated the films have three major components: CrO2, CrO3, and Cr2O3. From disc dynamic tests and atomic force microscope (AFM) images of a polycarbonate (PC) substrate, a DVD-R structure of PC/ZnS–SiO2 (30 nm)/CrOx (120 nm)/ZnS–SiO2 (40 nm)/Ag (50 nm), deposited by sputtering at an O2/Ar flow rate ratio of 0.4, had an improved carrier-to-noise ratio (CNR). The principle of recording depends primarily on the explosive pressure of the O2 released due to laser heating of the annealed CrOx film.

Adaptive write strategy selection mechanism for optical recording systems

This paper discusses a smart algorithm for setting the write strategy in an optical recording device like consumer DVD (digital versatile disc) recorders. The proposed algorithm improves the quality of recorded optical media, being particularly efficient for recordable and rewritable DVDs. One of the biggest challenges faced by optical recorder manufacturers is the increasing availability of low-cost optical media that obey marginally the standardized specifications causing poor recordability and corrupt discs. As the mass market embraces optical recorders in their homes, this problem aggravates resulting in consumer dissatisfaction. This paper presents a novel, yet not very complex method to improve the compatibility of conventional DVD recorders with widely available media.

Residual stresses in a digital versatile disc recordable

The residual stresses in a multi-layer digital versatile disc recordable (DVD-R) were studied. The DVD-R consisted of a recording layer, a reflective layer and a protective layer deposited on a polycarbonate substrate. After deposition of each layers, the bending curvatures of the substrate were measured successively and the corresponding residual stresses in each layer were calculated using a closed-form solution of bending of a multi-layer composite plate. The residual stresses were found to be compressive in the recording and reflective layers. In the protective layer, the stress was compressive near the bottom interface and tensile near the top free surface. The stress distribution in the thick substrate was close to a pure bending under compression near the bottom free surface and tension near the top interface. The bending and neutral axes were also determined and discussed.

A 11–177 Mbps Recordable Digital Versatile Disc (1–16× DVD-R) Using a New Dye

The possibility of 11 to 177 Mbps (1× to 16×) speed recording was confirmed by the investigation of the recordable digital versatile disc (DVD-R) using a new oxonol dye. Low jitter and a high aperture ratio (AR) even after high-speed recording are attributed to the unique thermal decomposition behavior of the dye, i.e., its low decomposition temperature, small heat generation and well defined void generation. The dye neither contains toxic heavy metals nor corrodes a pure silver reflective layer.

Spectral and optical recording properties of azo nickel thin film

A new azo nickel chelate (Ni(azo) 2) thin film has been developed for digital versatile disc recordable (DVD-R) by means of a spin-coating method. The absorption and reflectivity of the film matches very well with the wavelength of the GaAlInP semiconductor diode laser (650 nm). Optical parameters of the thin film were measured by a spectroscopic ellipsometer system. Thermal property of azo nickel chelate indicated that the rapid decomposition of the dye happens in the narrow temperature zone. The performance of DVD-R disc of the Ni(azo) 2 thin film exhibited that low jitter and high modulated amplitude could be achieved under optimistic write power.

Recordable Digital Versatile Disc for High Data Transfer Rate Recording

We studied the characteristics of the 4.7 GB recordable digital versatile disc (DVD-R) for a high data transfer rate higher than 44 Mbps. Using simulation, analytical pulse sequence and atomic force microscopy (AFM) measurement, we analyzed the thermal interference. We also used originally synthesized dye with low thermal interference and realized good recording characteristics with jitter values of around 8% at 66 Mbps recording and 11% at 89 Mbps recording.

Hemicyanine Dye for Optical Recording

A hemicyanine dye was synthesized and investigated to apply for digital versatile disc recordable (DVD-R). The optimized dye showed excellent recording performance, which satisfies the specification of DVD-R. It was clearly shown that the hemicyanine dye is a promising candidate for optical recording material for DVD-R.