Increasing diskette capacity with Floptical technology

Floppy and compact discs gradually loose their quality. On closer examination deteriorated discs showed diverse microbial growth on their surfaces. Among the associated organisms 15 actinomycetes and 12 bacterial isolates were selected for detailed studies. The selected actinomycetes were Streptomyces diastaticus, S. rimosus, S. cyaneus, S. olivaceoviridis, S. halstedii, S. fulvissimus, S. albidoflavus, S. exfoliates and S. griseoflavus and the bacterial strains were Bacillus lentus, B. circulans, B. badius, B. laterosporus, B. larvae and B. thuringiensis. In addition, Micrococcus sedentarius was also isolated. Utilization of crushed disc materials was observed during this study, which was indicative of deterioration of floppy and compact discs. Â Key words: Compact disc, Floppy disc, Microorganisms, Recalcitrant doi:10.3329/bjb.v37i1.1557 Bangladesh J. Bot. 37(1): 7-14, 2008 (June)

The term binary optics was first employed to the best of my knowledge by Wilfred Veldkamp of MIT Lincoln Laboratory; although, these devices have been in existence prior to this of this term. Generally the term refers to optical components whose transmittance or reflectance occurs in binary steps. Usually fabricated by use of one or more binary masks. Other than simple diffraction gratings the earliest examples of binary optics would be computer generated holograms. Computer generated holograms, or more generally digital holograms, have been used since the middle 1960's, and like holography in general, digital holograms have found a few, but very few, useful applications. It has not been until thinking began to focus on more general diffractive optical concepts, and less on the principles of holography, that new applications began to materialize in the area of binary optics. Two exampies would be compact disc technology and the correction for chromatic aberation in refractive lenses.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We demonstrate that standard polycarbonate compact disk surfaces can provide unique adhesion to Al films that is both strong enough to permit Al film nanopatterning and weak enough to allow easy nanopatterned Al film detachment using Scotch tape. Transferred Al nanohole arrays on Scotch tape exhibit excellent optical and plasmonic performance.

Digital magnetic recording on flexible media has grown from ½ in tape in 1959 to include mass storage systems, digital cassettes, data cartridges and flexible disks in 1980. The properties of greatest interest are the capacity of the removable unit, the access time to the data and the rate at which data can be communicated to another device. To the customer the price he must pay per bit of data stored is very important but he must also consider the price of the drive unit and not just the price of the removable unit. The characteristic by which different storage devices are most commonly compared is their storage capacity. To increase this continuously in response to the ever-increasing amount of information that must be stored in machine-accessible form requires a steady improvement in the amount of data that can be packed into each unit of area. The problems encountered in increasing this areal storage density are discussed in detail. Three kinds of limit to bit and track density are considered: the fundamental limit, the technological limit and the economic limit. No estimate is attempted for the economic limit which is strongly machine-dependent but the fundamental limit to bit and track density is given as 20 000 bits or tracks per mm (500 000/in). The technological limit for bit density is given as 4000–8000 b/mm (100 000–200 000 bpi) and for track density 600 t/mm (15 000 tpi).

Compact discs (CDs), offering a total of 640 MB of storage, revolutionised the information storage industry when first introduced in 1982. The CD has since proliferated worldwide and become a cornerstone of optical data storage (ODS). Although still widely used, the storage capacity of CDs proved insufficient for a number of consumer needs.

This study was carried out to evaluate the effect of supplementing diet with different garlic powder concentrations (300 and 600gm/Ton) on performance, carcass characteristics and meat quality (fat %) of Muscovy ducks exposed to different stocking densities; standard stocking density (4 birds/m2) and high stocking density (8 birds/m2). A total number of 180 one -day -old Muscovy ducklings were used in this experiment. Birds were randomly allocated into 18 symmetrical pens classified into 6 treatment groups (3 replicate / treatment). Groups (C, SS+G300, SS+G600) raised on standard stocking density and fed on basal diet supplemented with (0 , 300 and 600 g. garlic powder,/ton feed ) respectively while groups (HS, HS+G300, HS+G600) raised on high stocking density and fed on basal diet supplemented with (0 , 300 and 600 g. garlic powder/ton feed) respectively. The data of growth performance indicated that supplementation of garlic (600 gm / ton) significantly (p > 0.05) improved performance (body weight gain and FCR ) of ducks in standard stocking density (SS+G600) group and high stocking density in (HS+G600) group. Concerning carcass characteristic and meat quality, results indicated that, garlic supplementation reduced fat % in thigh and breast muscles. It can be concluded that, adding garlic powder to duck ration can effectively compensate the negative effects of the high stocking density in Muscovy ducks.

The traditional way of creating and typesetting a manuscript hampers the necessary modernization of the production process and particularly the dissemination and accessibility of information. This is caused by the use of wordprocessing packages and the nature of typesetting instructions. Both wordprocessing codes and typesetting codes contain insufficient information, because they only aim at a single presentation of the text. Scientific publications, however, can be distributed in many different forms: on paper, in all possible layouts; in whole or in part via electronic means such as floppy disks, compact disks, datacommunication, etc. In addition information should be accessible from many points of view. New electronic tools (i.e. micro-computers) and databases with advanced search software have the technical possibilities for this. The Standard Generalized Markup Language, the new ISO-standard, is a method of recording texts in such a way that the afore-mentioned can be achieved. This method has two basic principles: 1. the descriptors of texts (called SGML-tags) must be based on content and not on form. 2. the SGML-tags used for description of texts must be defined in a document description. This is based on the principle that texts are structured, i.e. independent of its purpose. It enables one to describe the elements of which a text consists, the order they have to be in the text, and whether they are optional or obligatory, and/or repetitive. The description of the content of texts makes it possible to create conversions (via software) to a diversity of printed and electronic forms (distribution). It is also possible to search databases for e.g. an article about a certain subject or written by an author of a special institute or a university (information retrieval).

High capacity storage systems with fast data access are essential prerequisites for future multimedia services. For many applications, optical memories such as Compact Discs (CD) or Digital Veratile Discs (DVD) are prefered to magnetic high density systems due to the low production costs and high portability. However, optical disc systems store the data two dimensionally and a further increase in the storage capacities is only expected when blue laser diodes become commercially available and dual layer systems are developed. On the other hand, three dimensional storage systems have been proposed on the basis of holographic recording techniques. These systems use either photorefractive crystal cubes1 or layers of photopolymers2 to record complete digital data pages. Experiments demonstrate that holographic methods allow ultra high storage capacities but they need complex write and read-out devices, a fact which has up to now impeded the design of commercial products.

Simulations of Polymer Interpenetration in 2D Melts

LA CATALASE EST UNE ENZYME DONT LE ROLE EST D'ELIMINER L'EAU OXYGENEE. CERTAINES CATALASES A HEME UTILISENT LE NADPH ET SON MODE D'ACTION RESTE OBSCUR. LA CATALASE DE PROTEUS MIRABILIS (PMC) PEUT ETRE PURIFIEE AVEC ET SANS NADPH FIXE. LES OBJECTIFS DE CE TRAVAIL ETAIENT D'UNE PART DE MIEUX COMPRENDRE LE MECANISME FONCTIONNEL DE LA CATALASE ET LE ROLE DU NADPH, EN UTILISANT PMC COMME ENZYME MODELE, D'AUTRE PART D'IDENTIFIER L'ORIGINE DE LA RESISTANCE A L'EAU OXYGENEE DU MUTANT PR DE PROTEUS MIRABILIS, QUI A SERVI DE SOURCE DE PMC TYPE SAUVAGE. L'ENZYME PMC RECOMBINANTE SUREXPRIMEE CHEZ E. COLI PRESENTE LA CARACTERISTIQUE D'INCORPORER DE LA PROTOPORPHYRINE IX A LA PLACE DE L'HEME. SA STRUCTURE CRISTALLOGRAPHIQUE (2 A DE RESOLUTION) MONTRE QUE LA LIAISON A L'ATOME DE FER N'EST PAS INDISPENSABLE AU REPLIEMENT DE L'ENZYME. NEUF MUTANTS PONCTUELS ONT ETES CONSTRUITS ET EXPRIMES CHEZ E. COLI ET LEURS PROPRIETES BIOCHIMIQUES ONT ETE COMPAREES A CELLES DE PMC, TYPE SAUVAGE. LE ROLE DES RADICAUX PROTEIQUES DANS LA REACTION DE LA CATALASE AVEC LES NUCLEOTIDES A ETE ETUDIE GRACE AUX MUTANTS F194Y ET F215Y DONT LES STRUCTURES CRISTALLOGRAPHIQUES ONT ETE DETERMINEES A 2,11 A ET 2,4 A DE RESOLUTION. DANS LE MUTANT F194Y, ON OBSERVE DEUX MECANISMES, UN MECANISME D'OXYDATION DIRECTE A DEUX ELECTRONS AVEC NADPH ET UN MECANISME A UN ELECTRON (TYPE PEROXYDASIQUE) DECLENCHE PAR LA FORMATION D'UN RADICAL TYROSYL AVEC NMNH. ON PEUT EN CONCLURE QUE LA REACTION AVEC LE NADPH NE DEPEND PAS DE LA FORMATION D'UN RADICAL TYROSYL SUR L'ENZYME. LA DIFFUSION DE SUBSTRAT ET DE PRODUITS DANS LA CATALASE A ETE SIMULEE PAR DYNAMIQUE MOLECULAIRE. LES RESULTATS MONTRENT QUE SEUL LE CANAL D'ACCES PRINCIPAL SERT POUR LA CIRCULATION DE CES MOLECULES. UN MECANISME CONCERNANT LA CIRCULATION DE L'EAU OXYGENEE, DE L'EAU ET DE L'OXYGENE AU NIVEAU DU SITE ACTIF EST PROPOSE. L'ANALYSE DU MUTANT PR DE P. MIRABILIS MONTRE QUE LA RESISTANCE AUX PEROXYDES EST LIEE A LA SUREXPRESSION DE LA CATALASE ET DE DEUX AHPC.

Electronic learning systems have been an area of interest for researchers in the past few decades as it offers flexible, reusable, scalable, available, affordable services to a wide variety of users including content generators, content users, and content managers. E-learning system involves digital content development, administration, and delivery of learning contents that can be made available even to remote locations. In the advent of huge digital content available on the internet, an effective e-learning system requires collaboration among the content creators, users, and administrators, further, it requires huge computational power and storage capacity. Presently, the system focuses mostly on the delivery of content to learners rather than concentrating on the effective storage and efficient retrieval of the content based on the skill of the individual learners. Several approaches have been attempted towards the personalised content delivery based on the basic skill of learners. However, the system maintained a repository of verified contents relatively than a validated content. In order to maintain a validated content for efficient retrieval, distributed models with respect to a different perspective of validation may be fruitful. This paper studied various distributed models that are developed in the domain of e-learning with respect to the learning environment, learning objects and learning style.

The self-consistent iterative simulation of the digital magnetic recording channel has been established as the most powerful and the only adequate treatment of high bit density systems with a limiting write-demagnetization process. By a comprehensive treatment of the wavelength and frequency-dependent losses in the transducer, the media, and the circuits of the recording channel, the one dimensional model, applicable for relatively thin media which are a requirement for very high bit density systems, has been developed into a versatile and powerful tool for the automated design of advanced recording systems. The skeleton of the computational formalism is presented, along with some pertinent results regarding the nature of limitations in high bit density systems.

Conventional helical-scan magnetic recording requires precise head tracking, precise tape path and accurate servo control for them. We have developed a magnetic tape recording system based on a new concept, "Non-tracking Method" which requires less accuracy of them. By combining double track scanning and data rearrangement through a memory divice, all data can be reproduced in correct order without precise head tracking. When track pitch is 9.8μm, the non-tracking method expands the tolerance on head tracking to plus and minus 100μm, while the head tracking tolerance of plus and minus 5μm is needed in conventional recording. Using the non-tracking method, a newly developed rotary head drum loading system which is called "non-tape-loading" and also a newly developed metal-evaporated tape, we have developed a extremely high density digital audio tape recording system, including a stamp-sized tape cassette and a tiny digital audio recorder. Two hours stereo digital recording is realized with the tiny cassette.

Triplex is a newly conceived high information density code compatible with present day digital recording systems. It conveys data on position (phase), polarity (transition direction) and amplitude (breakwidth) and offers efficient overwrite, self-clocking and a generous window margin. For a two amplitude level encoding scheme, n cells can be mapped into 5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sup> -1 symbols in triplex as opposed to 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sup> in MFM code. This corresponds to 130% increase in information density over MFM. Triplex offers one of the highest density ratios practically realizable in the domain of saturated digital magnetic recording.

Three species of arboreal nesting termites common in New Guinean coconut plantations: Microcerotermes biroi (Desneux), Nasutitermes princeps (Desneux), and Nasutitermes novarumhebridarum (N. and K. Holmgren), are in competition with each other. This work evaluated the influence of environmental factors on this community. We compared the arboreal nesting termite distribution, abundance, and colony size in the following 3 types of coconut plantation: (1) open plantations with tall trees (=25 m) at low density (≤100 trees per hectare); (2) standard plantations with medium size trees (=13 m) at standard density (100–180 trees per hectare); (3) dense plantations (180–300 trees per hectare) with medium size or mixed size trees (13–25 m). The overall proportion of coconut trees occupied byarboreal termites increased from 25% in open plantations to 56% in standard or dense plantations. M. biroi was less abundant in open plantations than in standard or dense ones, whereas N. princeps was scarcest in standard plantations. N. novarumhebridarum occupied =2% of the trees in all plantation types, but showed a clear preference for dead trees. Nest volumes of all species and colony territories were larger in dense plantations, especially for N. princeps . Data on nest thermoregulation suggest that M. biroi is the most affected by sun exposure, which could constitute a limiting factor in open plantations. N. princeps incipient colonies would be particularly hindered by competition with first established colonies of M. biroi in standard plantations. Large territories of N. princeps in dense plantations suggest that this species is especially favored by high tree densities, allowing easy colony expansion by galleries or satellite nests and reproduction by budding. We propose that arboreal termite community structure is mainly shaped by microclimatic conditions and food availability in open plantations, and by interspecific competition in denser habitats, although the incidence of other factors, such as predation or intraspecific competition, remains to be studied.