Tape Format Research Articles

An Analytical Friction Model for Handling and Spreading of Carbon Fiber Tows for Composite Prepregging Applications

Abstract A novel co-extrusion system for continuous fiber-reinforced thermoplastic composites in filament and narrow-tape format was designed, fabricated, and tested. The new modified pultrusion process, called In Situ Impregnation, impregnates continuous dry fiber reinforcement tows in situ with thermoplastic matrix for applications ranging from 3D printing using robotic manipulation to automated fiber placement. The technical goal of the system is to directly co-extrude and impregnate a reinforcement fiber tow (carbon) with thermoplastic matrix injected by an extruder fed with thermoplastic pellets. This approach uses inexpensive materials instead of “prepreg” tow in order to streamline the additive manufacturing process, cut costs for advanced composites manufacturing, and deliver fully customizable fiber orientation. The purpose of this paper is to discuss analytical modeling of friction and fiber tensioning in the system which allows for the full impregnation of the fibers. Experiments were conducted on a working pultrusion system where load was adjusted through the tensioning system to better understand the amount of friction throughout the system, the magnitude of tension in the fiber tow, and to validate the models. The resulting friction model can be used by machine designers to estimate the tension in tows, ropes, fibers, etc. in similar tensioning devices, and estimate automated system specifications such as motor requirements. A brief description of the new manufacturing process is also provided. Future work includes commercialization of the technology, automation of the manufacturing system, and further modeling work to predict fiber spreading behavior based on geometric factors.

The Structural Characterisation and DFT-Aided Interpretation of Vibrational Spectra for Cyclo(l-Cys-d-Cys) Cyclic Dipeptide in a Solid State.

Cyclic dipeptides with two intramolecular peptide bonds forming a six-membered 2,5-diketopiperazine ring are gaining significant attention due to their biological and chemical properties. Small changes in the local geometry of such molecules (from cis to trans) can lead to significant structural differences. This work presents the results of a study of cyclo(l-Cys-d-Cys), a dipeptide comprising two cysteine molecules in opposite chiral configurations, with the functional groups situated at both sides of the diketopiperazine ring. X-ray diffraction (XRD) experiment revealed that the molecule crystallises in the P-1 space group, which includes the centre of inversion. The IR and Raman vibrational spectra of the molecule were acquired and interpreted in terms of the potential energy distribution (PED) according to the results of density functional theory (DFT) calculations. The DFT-assisted analysis of energy frameworks for the hydrogen bond network within molecular crystals was performed to support the interpretation of X-ray structural data. The optimisation of the computational model based on three-molecule geometry sections from the crystallographic structure, selected to appropriately reflect the intermolecular interactions responsible for the formation of 1D molecular tapes in cyclo(l-Cys-d-Cys) crystal, allowed for better correspondence between theoretical and experimental vibrational spectra. This work can be considered the first complete structural characterisation of cyclo(l-Cys-d-Cys), complemented via vibrational spectroscopy results with full band assignment aided with the use of the DFT method.

Diminishing Dreams

Diminishing Dreams

Реализация функции долговременного хранения научных данных большого объема в вычислительном центре

Long-term data storing is an important task for many modern scientific laboratories and datacenters. In order to reduce cost of digital information ownership, some solutions use magnetic tape technology and special software to control medium and data. Considering the on-site infrastructure specifics and well-established workflows of data processing, these organizations build and support such systems mainly by their own efforts, what becomes an important task in seeking to acquire the technological sovereignty. This paper describes long-term data storage issues in the computing center of the Zababakhin All-Russia Research Institute of Technical Physics where mathematical modeling computations generate vast amount of scientific data. The architecture and functional composition of the developed Archive Data Storage System are given as well as its internal data model, the chunk grouping rules, and the low-level tape format used. The measures taken to ensure an archived data consistency, methods of storage media management and issues of archival fund maintenance, are also considered. The calculation scheme of a typical archive system site’s hardware configuration, sufficient to process archiving data flows existing in datacenter, is given.

Towards the Feasibility of Instituting a Philippine Digital Audio Library: A Case Study

As a spearhead force in music research, especially in the area of South East Asia region, the University of the Philippines (UP) Center for Ethnomusicology (UPCE) caters to a gigantic collection of audio materials which covers different musics and musical traditions in the Philippines, South East Asia and representative areas from other continents. As an outcome of its former appellation, the “UP Ethnomusicology Archives”, UPCE hosts an ethnomusicological collection of about 2500 hours of recorded music in open reel and cassette tape formats, under the authorship of Jose Maceda whose visionary work of putting together these valuable recorded materials left a treasure for ethnomusicology scholarship and research. In recognition of his influential contribution that made the UCPE an archive and repository of materials on music, philosophy, anthropology and other cognate disciplines, these audio materials, together with field notes, music transcriptions, song texts, photographs, music instruments, music compositions, personal files, about 200 books and journals, all of which he personally initiated and developed as a unified institution resource for music research are called “Jose Maceda Collection”.

4-[(2,4-Dichlorophenyl)carbamoyl]butanoic Acid

The synthesis and spectroscopic characterization of the glutaric acid-amide derivative, 2,4-Cl2C6H3N(H)C(=O)(CH2)3C(=O)OH (1), are described. The X-ray crystal structure determination of (1) shows the backbone of the molecule to be kinked about the methylene-C–N(amide) bond as seen in the C(p)–N–C(m)–C(m) torsion angle of −157.0(2)°; m = methylene and p = phenyl. An additional twist in the molecule is noted between the amide and phenyl groups as reflected in the C(m)–N–C(p)–C(p) torsion angle of 138.2(2)°. The most prominent feature of the molecular packing is the formation of supramolecular tapes assembled through carboxylic acid-O–H…O(carbonyl) and amide-N–H…O(amide) hydrogen bonding.

4-[(4-Chlorophenyl)carbamoyl]butanoic Acid

The X-ray crystal structure determination of the glutaric acid-amide derivative, 4-ClC6H4N(H)C(=O)(CH2)3C(=O)OH (1), is described. The backbone of the molecule adopts an extended, all-trans configuration but the terminal carboxylic acid and phenyl resides are twisted out of the plane through the bridging atoms, as seen in the torsion angles of O(carboxylic acid)–C(m)–C(m)–C(m) [13.9(5)°] and C(m)–N–C(p)–C(p) [47.1(4)°]; m = methylene and p = phenyl. The most striking feature of the molecular packing is the formation of supramolecular tapes mediated by carboxylic acid-O–H⋯O(carbonyl) and amide-N–H⋯O(amide) hydrogen bonding.

Some Assembly Required: Low-Cost Digitization of Materials from Magnetic Tape Formats for Preservation and Access

Recent work discussing the digitization and preservation of magnetic tape materials has maintained that it should be left to expert practitioners and that the resulting digital materials should be stored in digital repositories. This article suggests that librarians and archivists lacking extensive technical skills or access to expertise can digitize these materials themselves. It provides a detailed account, including challenges faced, of how a team of practitioners without prior training or experience digitized historical audio recordings on cassette and open reel tape at Northern Illinois University Libraries. The discussion reviews the assembly of equipment and software that the team used for digitization work, discussing each element’s significance and how they came together as a functioning workflow. The authors also emphasize the fact that while the digitization of fragile and/or degraded magnetic tape materials may contribute to the preservation of their contents, this action also creates a new set of materials with their own preservation needs. Realizing that many practitioners serving medium-sized and smaller institutions lacking large financial resources may not have access to a full-fledged digital repository, they suggest the use of the National Digital Stewardship Alliance’s Levels of Digital Preservation rubric as a means by which practitioners may incrementally increase the probability that digital materials made from magnetic tapes will remain accessible.

Simplified formats of modern biosensors: 60 years of using immunochromatographic test systems in laboratory diagnostics.

Immunochromatographic test systems known to foreign laboratory diagnostic experts as lateral flow immunoassay (LFIA) are simplified tape formats of modern biosensors. For 60 years, they have been widely used for the rapid detection of target molecules (ligands) in biosubstrates and the diagnosis of many diseases and conditions. The growing popularity of these test systems for providing medical care or diagnostics in developing countries, medical facilities, in emergency situations, as well as for individual home use by patients while monitoring their health are the main factors contributing to the continuous development and improvement of these methods, the emergence of a new generation of formats. The attractiveness and popularity of these fast, easy-to-use, inexpensive and portable diagnostic tools is associated primarily with their high analytical sensitivity and specificity, as well as the ease of interpretation of the results. These qualities have passed the test of time, and today LFIA test systems are fully consistent with the modern world concept of «point-of-care testing», finding wide application not only in medicine, but also in ecology, veterinary medicine, and agriculture. This review will highlight the modern principles of designing the most widely used formats of immunochromatographic test systems for clinical laboratory diagnostics, summarize the main advantages and disadvantages of the method, as well as current achievements and prospects of LFIA technology. Modern innovations aimed at improving the analytical characteristics of LFIA technology are interesting, promising and can bring additional benefits to immunochromatographic platforms that have gained popularity and attractiveness for six decades.

Structure formation and functional properties of thin-gauge tapes made of copper-based alloys obtained by melt spinning

The article presents evidence proving that the alloys of the CuZnAl system, unlike the CuAl (Ni, Mn) system, have a smaller contact area with the quenching disk. It is caused by the condensation of Zinc vapors from the melt on its quenching surface. In addition, it is shown that Bronze alloys, in comparison with Brasses, are preferable for obtaining tapes by spinning. The main patterns of changes in critical points and the value of the Shape Memory Effect (εSME), depending on the types of heat treatment are also analyzed in this paper. Exposure of the alloy to the mold setting temperature of T = 800÷850 °C is accompanied by grain growth, increase in critical points, and decrease in the value of Shape Memory Effect. In this regard, the holding time at the mold setting temperature should not exceed t = 3÷5 min.

Nb sheathed MgB2 superconducting tape with addition of VB2

MgB2 superconductor is a strategic material for practical applications, due to its superconducting properties as well as the low cost of the raw materials. For many technological applications cable, wire or tape format are required. The addition of VB2 in the MgB2 superconducting bulk had already been used in previous works as an efficient method to enhance the critical current density of the MgB2. In the present work, MgB2 superconducting tapes were developed and characterized using different amount of VB2 addition. Niobium was used as sheath material. The goal of this work is to create an efficient method to improve the transport properties of MgB2 superconducting tapes to be useful for practical application. The results include microstructural, crystallographic, magnetic and transport characterizations. All analyzes were performed together to study the influence of the VB2 addition on the superconducting behavior of MgB2 tapes.

Helical-Ribbon and Tape Formation of Lipid Packaged [Ru(bpy)3]2+ Complexes in Organic Media.

Anionic lipid amphiphiles with [RuII(bpy)3]2+ complex have been prepared. The metal complexes have been found to form ribbon and tape structures depending on chemical structures of lipid amphiphiles. Especially, the composites showed hypochromic effect and induced circular dichroism in organic media, and flexibly and weakly supramolecular control of morphological and optical properties have been demonstrated.

Safeguarding National Heritage through Conservation of Oral History Collections at Bulawayo National Archives, Zimbabwe

 Oral history collections are vital assets that represent national heritage. While transcribed collections are kept in a proper archival repository at the Bulawayo National Archives, the audio-visual collections are kept unprocessed and unprotected in unsuitable housing such as cardboard boxes within the Principal Archivist’s office. Storage conditions are not conducive and therefore, unbearable. The study, therefore, explored issues relating to how national heritage contained in oral history collections can be protected through conservation at the institution. In this regard, the study opted to employ the qualitative research methodology, using the case study research design. The informants were purposively sampled, while data were collected through questionnaires, in-depth interviews, and document analysis. Questionnaires were administered to the chosen respondents through hand delivery. Researchers conducted in-depth interviews that lasted between 20–30 minutes. The Director’s Annual Reports from 1990 to 2016 were analysed for the study. The findings of the study indicated that the Bulawayo National Archives captures and stores oral history in paper, cassettes, magnetic tape, and digital formats, and according to various subject areas; which include chieftaincy, minority groups, land question, religion and liberation wars. However, the institution does not have a conservation unit nor an Oral Historian in charge of the collections. In this regard, we recommend that the institution sets up a conservation unit to protect oral history collections, and facilitate the restoration of the already damaged and deteriorated oral history collections.Â

Recovery of heritage software stored on magnetic tape for Commodore microcomputers

Digital games make up a significant but little known chapter in the history of the moving image in Australia and New Zealand. Beginning in the early 1980s, the Australasian software industry developed a remarkable record of content creation. The ``Play It Again'' project is conducting research into the largely unknown histories of 1980s game development in Australia and New Zealand, ensuring that local titles make it into national collections and are documented and preserved, enabling the public to once again play these games. Microcomputers from the 1980s made extensive use of compact audio cassettes to distribute software as an inexpensive alternative to the floppy disk technology available at the time. Media from this era are at risk of degradation and are rapidly approaching the end of their lifespan. As hardware platforms and peripheral devices become obsolete, access to the data for future scholars and other interested parties becomes more difficult. In this article, we present a case study, wherein we investigate the issues involved in making digital copies with a view to the long term preservation of these software artefacts. A video game title stored on standard compact cassette for Commodore's popular VIC-20 machine, ``Dinky Kong'' by Mark Sibley was recorded using both inexpensive amateur and professional playback equipment. The audio files obtained were processed using freely available software, alongside a customised decoder written in MATLAB and Perl. The resulting image files were found to be playable using an emulator. More importantly, the integrity of the data itself was verified, by making use of error detection features inbuilt to the Commodore tape format, which is described in detail. Issues influencing the quality of the recovered image files such as the bit rate of the digital recording are discussed. The phenomenon of audio dropout on magnetic tape is shown be of some concern, however there exist signal processing techniques to compensate for such errors. The end result of the imaging process was a file compatible with a popular Commodore VIC-20 emulator, the integrity of which was verified by using inbuilt checksums.

Tellurium addition as a solution to improve compactness of ex-situ processed MgB2-SiC superconducting tapes

Ex-situ spark plasma sintering (SPS) was used to obtain dense MgB2-based tapes in a Fe sheath with the starting composition (MgB2)0.975 + (SiC)0.025 + Te0.01. Prior to the SPS procedure of tape formation, the samples were submitted to a series of cold working processes typical for the powder-in-tube technique. The tapes were compared with optimal doped bulk samples (having the same starting composition) and a pristine MgB2 tape. The morphology of the composite samples, the phase structure of both the core and the inner face of the metallic sheath shows the formation of a plethora of traces as a result of interaction between MgB2, additives, and the Fe sheath. Important critical parameters, like critical current density and the irreversibility field, show that there is a field and temperature range where the SiC and Te-added tapes display better critical parameters comparative to either pristine MgB2 tapes in the Fe sheath or SiC and Te doped MgB2 bulk samples.

Information Loss from Technological Progress

Progress in electronics and optics offers faster computers, and rapid communication via the internet that is matched by ever larger and evolving storage systems. Instinctively one assumes that this must be totally beneficial. However advances in software and storage media are progressing in ways which are frequently incompatible with earlier systems and the economics and commercial pressures rarely guarantee total compatibility with earlier systems. Instead, the industries actively choose to force the users to purchase new systems and software. Thus we are moving forward with new technological variants that may have access to only the most recent systems and we will have lost earlier alternatives. The reality is that increased processing speed and storage capacity are matched by an equally rapid decline in the access and survival lifetime of older information.This pattern is not limited to modern electronic systems but is evident throughout history from writing on stone and clay tablets to papyrus and paper. It is equally evident in image systems from painting, through film, to magnetic tapes and digital cameras. In sound recording we have variously progressed from wax discs to vinyl, magnetic tape and CD formats. In each case the need for better definition and greater capacity has forced the earlier systems into oblivion. Indeed proposed interactive music systems could similarly relegate music CDs to specialist collections.The article will track some of the examples and discuss the consequences as well as noting that this information loss is further compounded by developments in language and changes in cultural views of different societies.

Tosylate salts of the anticancer drug lapatinib

Two tosylate salts of an anticancer drug lapatinib, viz. a monotosylate [systematic name: ({5-[4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)quinazolin-6-yl]furan-2-yl}methyl)[2-(methylsulfonyl)ethyl]azanium 4-methylbenzenesulfonate], C29H27ClFN4O4S(+)·C7H7O3S(-), (I), and a ditosylate [systematic name: 4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)-6-]5-({[2-(methylsulfonyl)ethyl]azaniumyl}methyl)furan-2-yl[quinazolin-1-ium bis(4-methylbenzenesulfonate)], C29H28ClFN4O4S(2+)·2C7H7O3S(-), (II), were obtained during crystallization attempts for polymorphism. In both structures, the lapatinib cation is in a distorted U-like conformation and the tosylate anion is clamped between the aniline N atom and methylamine N atom through N-H···O hydrogen bonds, forming an R2(2)(15) ring motif. The 4-anilinoquinazoline ring system is essentially planar in (I), while it is twisted in (II), controlled by an intramolecular C-H···N interaction. In (I), alternating cations and anions are linked by N-H···O hydrogen bonds into C2(2)(6) chains. These chains are linked by cations in a helical manner. The presence of the additional tosylate anion in (II) results in the formation of one-dimensional tapes of fused hydrogen-bonded rings through N-H···O and C-H···O interactions. These studies augment our understanding of the role of nonbonded interactions in the solid state, which is useful for correlation to the physicochemical properties of drug products.

N,N′-Bis(pyridin-2-yl)benzene-1,4-diamine–naphthalene (2/1)

The asymmetric unit of the title compound, C10H8·2C16H14N4, consists of one mol­ecule of N,N′-bis­(pyridin-2-yl)benzene-1,4-diamine (PDAB) and one half of the centrosymmetric naphthalene mol­ecule. The PDAB mol­ecule adopts a non-planar conformation with an E configuration at the two partially double exo C N bonds of the 2-pyridyl­amine units. In the crystal, N—H⋯N hydrogen bonds between the PDAB mol­ecules generate a cyclic R 2 2(8) motif, leading to the formation of PDAB tapes extending along [100]. The tapes are arranged into (010) layers and the naphthalene mol­ecules are enclosed in cavities formed between the PDAB layers.

2-[N-(3-Amino-4-nitrophenyl)carboximidoyl]phenol

The title compound, C13H11N3O3, is essentially planar (r.m.s. for the 19 non-H atoms = 0.031 Å), a conformation stabilized in part by intra­molecular O—H⋯N and N—H⋯O hydrogen bonds. The configuration about the imine bond [1.2919 (12) Å] is E. The presence of N—H⋯O(nitro) hydrogen bonds leads to the formation of supra­molecular tapes in the crystal structure. These are connected into layers by π–π inter­actions [centroid–centroid distance = 3.6046 (6) Å] occurring between the hy­droxy- and amino-substituted benzene rings.

Water-induced pseudo-quadruple hydrogen-bonding motifs in xanthine–inorganic acid complexes

In xanthinium nitrate hydrate [systematic name: 2,6-dioxo-1,2,3,6-tetrahydro-9H-purin-7-ium nitrate monohydrate], C(5)H(5)N(4)O(2)(+)·NO(3)(-)·H(2)O, (I), and xanthinium hydrogen sulfate hydrate [systematic name: 2,6-dioxo-1,2,3,6-tetrahydro-9H-purin-7-ium hydrogen sulfate monohydrate], C(5)H(5)N(4)O(2)(+)·HSO(4)(-)·H(2)O, (II), the xanthine molecules are protonated at the imine N atom with the transfer of an H atom from the inorganic acid. The asymmetric unit of (I) contains a xanthinium cation, a nitrate anion and one water molecule, while that of (II) contains two crystallographically independent xanthinium cations, two hydrogen sulfate anions and two water molecules. A pseudo-quadruple hydrogen-bonding motif is formed between the xanthinium cations and the water molecules via N-H···O and O-H···O hydrogen bonds in both structures, and leads to the formation of one-dimensional polymeric tapes. These cation-water tapes are further connected by the respective anions and aggregate into two-dimensional hydrogen-bonded sheets in (I) and three-dimensional arrangements in (II).