Tape Format Research Articles

Prevalence of the thioamide {⋯H–N–CS}2 synthon—solid-state (X-ray crystallography), solution (NMR) and gas-phase (theoretical) structures of O-methyl-N-aryl-thiocarbamides

Structural investigations, i.e. solid-state (X-ray), solution (1H NMR) and gas-phase (theoretical), on molecules with the general formula MeOC(S)N(H)C6H4-4-Y: Y = H (1), NO2 (2), C(O)Me (3), Cl (4) have shown a general preference for the adoption of an E-conformation about the central C–N bond. Such a conformation allows for the formation of a dimeric hydrogen-bonded {⋯H–N–CS}2 synthon as the building block. In the cases of 1–3, additional C–H⋯O interactions give rise to the formation of tapes of varying topology. A theoretical analysis shows that the preference for the E-conformation is about the same as the crystal packing stabilisation energy and consistent with this, the compound with Y = C(O)OMe, (5), adopts a Z-conformation in the solid-state that facilitates the formation of N–H⋯O, C–H⋯O and C–H⋯S interactions, leading to a layer structure. Global crystal packing considerations are shown to be imperative in dictating the conformational form of molecules 1–5.

Characteristics of a low-temperature emitting cathode: T. Sugimura, Y. Tanaka. (NEC Ltd., Otsu, Japan.) J. Japan Soc. Powder/Powder Metall., Vol 49, No 1, 2002, 25–31. In Japanese

The use of alloy sheath is effective to increase the strength of Ag-sheathed Bi2223 tapes. However, the Jc value of alloy sheathed tapes was not high enough since the undesired reaction to form impurity phases and the change in formation rate of Bi2223 were disturbed by the microstructure of the filaments . In this study, the effect of 2223 contents in precursor on the formation and property of Bi2223 tapes sheathed with Ag–Mg alloy was investigated. The conversion rate of Bi2223 from Bi2212 was increased by the addition of Bi2223 phase in precursor but the conversion rate in Ag–Mg alloy sheathed tapes was slower than that in the Ag–Cu alloy sheathed tapes. This reduction of conversion speed of Bi2223 may be attributed to the decrease in the growth rate of Bi2223 crystals in Ag–Mg alloy sheath. Since the tapes with small Bi2223 crystals after first sintering showed many outgrowths after final sintering, the formation of outgrowth would be caused in the case of small crystal size. The Jc value of 2.2 × 104 A/cm2 was achieved in the samples using the precursor with 10 wt.% 2223. The high Jc value can be achieved by the proper control of precursor condition including the contents of Bi2223 and corresponding heat treatment pattern in Ag–Mg alloy sheathed tapes.

Effect of type of solvent and dispersant on NANO PZT powder dispersion for tape casting slurry

Dispersion of PZT powder of average particle size ∼75 nm in commonly used solvent systems for tape casting namely, toluene-ethanol and MEK-ethanol (azeotropic), xylene-ethanol (zeotropic) along with triton x-100, menhaden fish oil and phosphate ester as dispersants has been studied using simple sedimentation experiments. The relative merits of these three solvent systems and dispersants in dispersing PZT powder was analyzed. In all the three solvent systems, phosphate ester was found to be the best dispersant. Xylene-ethanol with phosphate ester gave the excellent dispersion characteristics for nano-PZT powder. The results of initial dispersion studies were confirmed by the formation of defect free, denser and smooth green tapes using xylene-ethanol and phosphate ester, while the other two solvent systems gave defective green tapes. The influence of phosphate ester on dispersion is explained by the dissociation and ionization, and the dominance of electrostatic repulsion even though organic solvent systems were used.

Healthcare data warehousing and quality assurance

Healthcare data warehousing presents unique challenges. The industry is rife with often incompatible medical standards and coding schemes that require careful translation. Healthcare data comes from many sources and is delivered in many forms, including published books, individual spreadsheets, and several tape or data formats. Results derived from a healthcare data warehouse must be delivered in accessible form to diverse stakeholders, including healthcare regulators, physicians, hospital administrators, consumers, community activists, and members of the popular press. The industry's widely decentralized and largely autonomous data collection efforts make data quality a significant challenge. Finally, the sensitivity of healthcare data makes privacy and security issues paramount. Healthcare data warehousing will make rigorous, quantitative information available to healthcare decision makers. The authors describe a fully functional healthcare data warehouse used to produce several reports for communities throughout Florida. Building on this work, they're actively pursuing a research agenda to enhance technical data warehousing capabilities while investigating innovative community and clinical healthcare applications.

ChemInform Abstract: Chirality-Directed Self-Assembling of Long-Chain Dialkyl 3,7-Diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylates.

Dihexyl and didodecyl 3,7-diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylates 4a,b were synthesised, and the self-assembling of the molecules of strictly alternating configurations was observed in a crystal of bis-lactam 4b, which resulted in formation of H-bonded heterochiral polymer tapes of a diagonal zigzag type combined into monomolecular layers separated by hydrophobic groups.

Mesoscopic Tapes Formed by Amphiphilic Two-Dimensional Colloids on Water Surface

A two-dimensional (2D) analogue of 3D fibrous supramolecular assemblies was formed spontaneously on the water surface by a short chain carboxyazobenzene derivative. It is a mesoscopic tape 1 nm thick, 80 nm wide, and can be as long as 0.1 mm. The tapes are obtained as Langmuir−Blodgett (LB) films on mica and examined by atomic force microscopy (AFM). AFM images exhibit complex internal structures, indicating that the tapes are not single crystals. They are not produced by LB processes, such as compression and lifting, and are not induced by the mica surface. The mesoscopic tape is self-contained and exists independent of surface pressure whose equilibrium value is nearly zero. UV−vis reflection spectroscopy on the water surface shows a peak at 305 nm. Increasing the water temperature to above 30 °C or leaving the film on the water surface for 14 h caused the tapes to disintegrate into small clusters and the UV−vis peak to shift to 365 nm. The concentration at which the solvent evaporates controls the tape formation. At low concentrations, the tapes coexist with the domains of an ordinary phase. Then, there is a critical aggregation concentration at 8 nm2/molecule that the tape fraction increases abruptly. These results suggest that the tape is closely related to associations of 2D clusters.

Aminotriazines as Locking Fragments in Macrocyclic Synthesis.

The macrocyclic compounds (6-(4',6'-diamino-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) triperchlorate dihydrate, [Cu(HL(2))](ClO(4))(3).2H(2)O, (6-(6'-amino-4'-oxo-1'H-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) diperchlorate hydrate, [CuL(3)](ClO(4))(2).H(2)O, and [(6-(4',6'-dioxo-1'H-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II)] diperchlorate, [CuL(4)](ClO(4))(2), have been synthesized. The macrocycles synthesized contain respectively pendant melamine, ammeline, and ammelide rings. The X-ray cyrstallographic analyses of [Cu(HL(2))](ClO(4))(3).2H(2)O, triclinic, space group P&onemacr;, a = 9.489(10) Å, b = 12.340(2) Å, c = 24.496(4) Å, alpha = 87.74(10) degrees, beta = 85.51(10) degrees, gamma = 70.95(10) degrees, and Z = 4, and {[CuL(3)](ClO(4))(2).H(2)O}(2), monoclinic, space group C2/c, a = 18.624(8) Å, b = 17.160(2) Å, c = 15.998(6) Å, beta = 117.82(2) degrees, and Z = 4, are reported. The structure of [Cu(HL(2))](ClO(4))(3).2H(2)O shows the formation of linear tapes, formed by a combination of hydrogen bonds and pi-pi stacking interactions. The structure of [CuL(3)](ClO(4))(2).H(2)O displays formation of dimers, formed by a coordinate bond from the oxygen in one molecule to the copper atom of another. The tautomeric forms of the ammeline and ammelide moieties have been determined. The potential of these compounds as subunits for cocrystallization has been investigated.

Studies of the formation mechanism of the phase

The formation mechanism of the phase has been studied starting from calcined precursor powders in the Pb-containing as well as in the Pb-free system. In both cases, a nucleation and growth model was found to be suitable to describe the transformations. The formation of the phase inside Ag-sheathed tapes was also investigated. Indications for a nucleation and growth mechanism were found in this case as well.

Quantifying disturbed hill dipterocarp forest lands in Ulu Tembeling, Malaysia with HRV/SPOT images

A satellite remote sensing survey was conducted in a disturbed logged-over hill dipterocarp forest of Ulu Tembeling in northern Pahang, Malaysia to identify and quantify the site disturbance classes due to road construction and logging activities. The merged SPOT data path/row K271-J341 was taken in October 3, 1988. The SPOT scene was obtained in a computer-compatible tape format and manual analysis was initiated by selecting a representative subsection of the scene that covered the study area. Ground truthing/field work was carried out and parameters such as causal factors, forms, sizes, shapes and patterns of soil disturbance were recorded, measured and correlated with image classification. Image interpretation, registration and classification were conducted for visual image analysis. The results showed that forest soil disturbance could be easily detected and monitored with 93% accuracy. Six classes of soil disturbance were quantified and recognized, namely (i) primary forest road, (ii) secondary forest road, (iii) skid road, (iv) skid trail, (v) secondary landing, and (vi) primary landing. By reference to maps of licensing applications and logging permits, legal and unpermitted logging activity can be well identified. However it is emphasized that interpreters should have a prior knowledge of the topography and the soil disturbance pattern of a logged-over forest area to be quantified and identified before actually beginning with image interpretation.

A Proposal for a Digital Tape Format to Complement Disc-Based Editing

Editing techniques in film and television are changing rapidly. Nonlinear, disc-based systems already enjoy a substantial installed base addressing off-line, news quality, and full post-production requirements. Undoubtedly the role of the VTR in editing and post-production is diminishing, being superseded by more flexible and cost-effective nonlinear systems. This trend suggests a tapeless future, and proposals already exist for disc-based camcorders and magneto-optical (M/O) technology archiving. Technologically exciting, many such schemes capitalize on the inflexibilities and occasional unreliability built into videotape formats by the need to edit on tape. Starting from the viewpoint that all editing will be performed in a nontape environment, this paper analyzes the true expectations and requirements of a tape format. Concentrating only on tape for acquisition frees the format in many ways. Constant speed and data rate may be parameters of the past. Flying erase heads, full-width erase heads, and frame-accurate servos could be technology of the past. A cruder variable-speed recorder may suffice. A new format capable of handling compressed and full CCIR 601 quality could enjoy wide acceptance.

PBS: Through the A-to-D Converter

The Public Broadcasting Service (PBS) is in the final stages of a project converting to an all-digital origination facility. The goals were to increase capacity without increasing staff, improve technical quality and the physical environment, and provide for HDTV tape origination, PBS faced signal and tape format decisions in the conversion. The new facility had to be built within the existing facility with analog and digital systems coexisting for the transition. An Interformat Room was built to transfer incoming tapes to the main format. An audio/video server, master control rooms, and a transmission center were also provided. PBS adopted a satellite compression system to deliver its signals to the member stations.

That Smell in the Vaults

THAT SMELL IN THE VAULTS: THE DEGRADATION OF POLYMERS IN AV MATERIALS VINEGAR Syndrome(1), Rancid Butter Syndrome(2), Rotten Fish Syndrome -- evocative but accurate descriptions of the pervasive killers of our sound and moving image heritage. Leaving aside the well-known problems of nitrate film we are faced with the stability problems of our polymer-based supports. All polymers are subject to decay; and the cellulose nitrate, cellulose diacetate, cellulose butyrate, cellulose propionate and cellulose triacetate bases are no exception. The problem is not limited to film -- audiotape, videotape, computer tape, computer disk and other formats are subject to the same inevitable decay and destruction. Over the last few years it has come to the attention of archivists around the world that the life expectancy of our audio-visual heritage is not what we once thought it should be. Storage conditions naturally have dramatic impacts on life expectancy. We...

Trick play schemes for advanced television recording on digital VCR

Three technical elements that together implement trick-play modes of digital VCR for ATV recording are proposed: a data arrangement format, a trickplay tracking algorithm, and a coefficient extraction algorithm. First, an efficient tape format is carefully designed for fast forward and reverse playbacks at various speeds. It can accommodate two pickup head configurations. The success of this formal relies on a reliable trick-play tracking scheme. This tracking scheme is capable of automatically driving the pickup heads to trace the correct trajectory in typically less than 350 ms. Lastly, an adaptive coefficient extraction algorithm is presented, which produces fairly good quality trick-play images under severe bit limitation. A related issue is to choose a balanced bit budget that provides a good compromise between picture spatial quality and temporal quality. Simulations at a video recording bit rate of 25 Mb/s have been conducted to demonstrate the effectiveness of our proposed system.

Digital field tape format standards — SEG-D, REVISION 1

A number of additions are being made to the SEG-D field tape format to make the format more useful in the current seismic data acquisition environment. These changes are intended to address the majority of short term needs in the industry today. A more extensive revision to the field tape format will be required within the next few years in order to address long term needs.

Implementation of a Large Digital Routing System at the CBC Broadcast Centre

In the design of a digital television broadcast plant there are many issues to consider, such as digital format, tape format, embedded audio, and future advanced image formats. The heart of any broadcast plant is the central routing and distribution system. For CBC's new Broadcast Centre in Toronto, a large, multimatrix digital routing system was designed by a multidisciplinary team formed from several different companies. The design incorporated a complex, custom-designed control and supervisory system, and CRT-type custom control panels. In the absence of final standards and established test procedures for digital systems, new approaches were investigated to establish testing criteria and methodologies.

Fabrication and properties of silver-sheathed (Bi,Pb) 2Sr 2Ca 2Cu 3O 10 high temperature superconducting tapes

Silver-sheathed (Bi,Pb) 2Sr 2Ca 2Cu 3O 10 superconducting tapes with critical current density up to 40,000 A/cm 2 at 77K and 0T have been successfully fabricated through the combination of powder-in-tube technique and a repeated pressing and annealing process. The obtained tapes were characterised in terms of phase analyses, microstructural observations and electrical measurements. The results indicate that pure high-T c phase, high degree of grain alignment and intimate connection between grains are essential for achieving a high current carrying capacity in the Bi-Pb-Sr-Ca-Cu-O superconducting tapes. J c development during the process of heat treatment was related to the high-T c phase formation and microstructural evolution of tapes.

Data-placement procedure for multi-speed digital VCR

We have studied the ATV-VCR tape format, which realizes the multi-speed mode, based on the 6 mm VCR. A larger data amount are assigned for the slower trick play to realize a high picture quality in accordance with the human visual characteristic. The tape format and data placement require easy tracking and flexibility of various head structures. The tape format is based on 4-track sequence for easy tracking. Each trick play data has its own data recording area.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An Experiment on Half Inch Hi-Vision Digital VCR: Tape Format and Mechanism

An experimental half-inch-tape Hi-Vision digital VCR has been developed, with the ability to record for two hours using 11 ?m thick tape, at a recording wavelength of 0.47 ?m and 12.7 ?m track width, with tape housed in a small-size cassette. This article explains the basic design concepts underlying the main specifications and tape format, then describes the construction and characteristics of the tape transport mechanism, designed to accommodate 11 ?m thick tape, the construction of the 40 mm dia. small drum, the construction and characteristics of the high-performance FeTaN magnetic heads, and the software servo control mechanism.

Technical summary of the Naval Air Warfare Center (NAWC)−Open Water Facility (OWF)

The NAWC-OWF is a Navy-owned facility dedicated to the development and measurement of sonobuoy transducers. It is located at a flooded quarry in Pennsylvania about 30 mi north of Philadelphia. Measurements are performed from a laboratory barge where the water depth is 60 ft and the nearest wall is 180 ft away. Acoustic and mechanical measurements consist of: (a) transmitting and receiving responses, (b) directivity patterns, (c) impedance and admittance, (d) hydrostatic simulation up to 8000 psig, (e) flow simulation from 0.1 to 1.0 kn using a 100-ft I beam rail, (f) first-order sea-state simulations up to sea state five, and (g) lift and drag with 18 data channels. Data are obtained via hard wire or rf link. The low-frequency cutoff is 200 Hz for pulse measurements and 3 Hz for continuous wave (CW) measurements. Instrumentation is controlled with menu-driven software and data outputs are real time in paper, disk, or tape format. The facility weight limits, in water, are 500 lbs for acoustic data and 100 lbs for mechanical data. The facility has phone and FAX service and a photo copy machine.

Digital consumer HDTV recording based on motion-compensated DCT coding of video signals

In this paper we consider consumer digital HDTV recording, using small magnetic recording mechanics and advanced bit-rate reduction techniques. A system concept based on the existing 8 mm tape format is described, which opens the possibility for designing a small portable recorder suited for digital HDTV and SDTV recordings for home use. It appears that, when a system is worked out which can cope with 25 Hz and 30 Hz environments, only a very few recording bit-rates are applicable. At the same time, an elegant possibility for recording SDTV and HDTV on the same machine should be maintained. Since small recording mechanics are proposed, HDTV signals must be substantially compressed to obtain sufficient playing time. For this reason, motion-compensated DCT coding of HDTV signals has been studied for digital home-use HDTV recording, because high-quality images can be obtained with a compression factor of 7–10. The total recording system concept would result in 2 hours playing time for HDTV and 4 hours for SDTV, using an 8 mm-type cassette.