Materials Science

Lattice materials can be designed through their microstructure while concurrently considering fabrication feasibility. Here, we propose two types of composite lattice materials with enhanced resistance to buckling: (a) hollow lattice materials fabricated by a newly developed bottom-up assembly technique and the previously developed thermal expansion molding technique and (b) hierarchical lattice materials with foam core sandwich trusses fabricated by interlocking assembly process. The mechanical performance of sandwich structures featuring the two types of lattice cores was tested and analyzed theoretically. For hollow lattice core material, samples from two different fabrication processes were compared and both failed by nodal rupture or debonding. In contrast, hierarchical lattice structures failed by shear buckling without interfacial failure in the sandwich struts. Calculations using established analytical models indicated that the shear strength of hollow lattice cores could be...

A portable, electrical impedance spectroscopy device to monitor the bioimpedance’s resistive component of beef meat by injecting a sinusoidal current of 1mA at 65 kHz was developed. In 4 slaughtered beef both right and left longissimus dorsi muscles where trimmed and left muscle portion was frozen to -18° C up to 7 day while right one was meantime maintained at 5° C. Median value of specific resistivity of not-frozen sample was about twice Ω.cm with respect of that of frozen-thawed sample (P = 0.004). It was concluded that the device is reliable to monitoring the ripening of beef meat in situ with the possibility of reveal undeclared freezethaw cycles.

Waterborne-polyurethane dispersions, consisting of polyol and polyisocyanates building blocks are conventional finish materials for various applications in textile industry, particularly in denim industry. This study aims to prepare a multifunctional polyol block, which is compatible with commercially available polyisocyanates, for polyurethane formation. Therefore, well-defined polymers having both hydroxyl and tertiary amine functions prepared via controlled radical polymerization technique namely atom transfer radical polymerization (ATRP). Hydroxyl functions are considered as cross-linking domains with polyisocyanate to form polyurethane and tertiary amine moieties are considered as quaternarization domains with different length of alkyl-bromides. 1H-NMR and Dynamic light scattering (DLS) techniques are used for structural characterization and thermal stability evaluation of synthesized polymers respectively. Those synthesized materials are primarily used for surface modification of cellulosic fabrics to achieve wash-fast antimicrobial coatings. Dyeing studies with indigo dyestuff is conducted with both polymer treated and non-treated fabrics. Dyeing studies showed dye-uptake capabilities of polymer coated samples are found to be higher than non-treated fabrics. Datacolor spectrophotometer SF 600 Plus is used to evaluate color measurements.

Siegbhan and C.G. Granqvist. X-ray photoemission spectroscopy of electrochromic hydrated nickel vanadium oxide thin films upon proton intercalation and de-intercalation. In manuscript (To be suttmitted to Journal of Physical Chemistry B) 14. E. Avendaño, A. Azens, G.A. Niklasson and C.G. Granqvist. Phase transitions of electrochromic hydrated nickel based oxide studied by galvanostatic intermittent titration. Submitted to the Journal of the Electrochemical Society. 15. E. Avendaño, A. Kuzmin, J. Purans, A. Azens, G. A. Niklasson and C. G. Granqvist. X ray absorption fine structure analysis of electrochromic hydrated nickel vanadium oxide thin film upon ozone-induced coloration. In manuscript (To be suttmitted to Phycal Rewiew B) 16. E. Avendaño, H. Rensmo, A. Azens, A. Sandell, G.A. Niklasson, H. Siegbhan and C.G. Granqvist. X-ray photoemission spectroscopy of electrochromic hydrated nickel vanadium oxide thin films upon ozone coloration.

It is dangerous when human are working in and around the high voltage environments. The safety of personnel in and around electric power the installations has been a prime concern. Specifically, this safety is generally in terms of the allowable touch and step voltages. These voltages are related to the ground resistance of human foot. In order to increase the safety of personnel, a high resistivity surface layer of gravel is normally existed in the substation switchyards or other high voltage areas. The thickness of this layer will affect the calculation of the ground resistance of human foot. Among them, the electromagnetic field factors are also considered in this paper. As a result, the surface layer of gravel can be used to reduce the ground resistance of human foot. The equivalent model of human foot was modeled by the circular plate conductor in the past. This paper investigates the present methods for estimating the ground resistance of human foot and proposes an equivalent model for calculating the ground resistance of human foot. A comparison of the proposed model and present methods is also shown in this paper.

The electromagnetic properties of materials are defined from the two following constitutive parameters: permittivity, ε, and permeability, µ; 'ε' indicates how the medium reacts when an electric field is applied (field E of the electromagnetic wave), whereas µ indicates how the material behaves further to a magnetic excitation (field H of the electromagnetic wave). To take into account the losses that occur in any material, permittivity and permeability need both to be expressed by complex values: ε= ε'-j ε", µ=µ'-jµ". But already, what represent these parameters? As, during this chapter we will mostly be interested by the measurement of the permittivity of materials, we'll going to explain the dielectric properties and similar explanation can be mounted for the magnetic properties. In general, a material is classified as "dielectric" if it has the ability to store energy when an external electric field is applied. Lets imagine a DC voltage source placed across a parallel plate capacitor, we'll have the ability to store an electric charge and called the capacitance 'C' defined to be the charge 'q' per applied voltage 'V' that is C 0 = q/V, where C is given in coulombs per volt or farad. The capacitance is higher, the larger the area A of the plates and the smaller the distance L between them. And so, C 0 = ε 0 (A/L), where ε 0 is a universal constant having the value of 8.85 × 10−12 F/m (farad per meter) and is known by the name permittivity of empty space (or of vacuum). Now lets insert a material between the plates, the new value of the capacitance 'C' is increased by a factor ε = C/C 0 , which lead to C = εε 0 (A/L), where 'ε' represents the magnitude of the added storage capability. It is called the (unit less) dielectric constant (or occasionally the relative permittivity εr). So, for the complex representation ε r = ε r '-j ε r ", the real part of permittivity (ε r ') is a measure of how much energy from an external electric field is stored in a material. The imaginary part of permittivity (ε r ") is called the loss factor and is a measure of how dissipative or lossy a material is to an external electric field. The imaginary part of permittivity (ε r ") is always greater than zero and is usually much smaller than (ε r '). the loss is usually denoted by: the loss tangent or 'tan δ' which is defined as the ratio of the imaginary part of the dielectric constant to the real part. The loss tangent 'tan δ' is called tan delta, tangent loss or dissipation factor.

Stability of multi-story one-bay space pallet racking system studied experimentally and theoretically to obtain the buckling length and the critical load for the upright of the racking system considering the beam-column connection, and frame bracing pattern. Five samples of space pallet racking system are studied to obtain the critical load and buckling lengths with different cases of loading, in addition two samples of short upright of the racking system are investigated under axial compression loads to carry out the upright capacity. The experimental results are re-evaluated using both the American Code of Racking (RMI 2012), and the European code of Racking (EN15512), moreover the investigated system are modeled and analyzed using SCIA Engineer software. The modes of failure of the experimented samples are recorded and evaluated. The experimental program has been conducted on the pallet racks using full-scale models.

We show that the shape of electroluminescence transients in organic semiconductors can be conveniently used to obtain the diffusion constant D of injected charge carriers, enabling the study of generalized Einstein relationship under nonequilibrium conditions as a function of the electric field. The appearance of peak at the onset of transient is shown to be the signature of diffusive regime of transport. We demonstrate it for two representative materials, Alq 3 and polymer poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene], with the focus on the role of hot carriers in transport and their diffusivity.

The accumulated science base in public research centres (PRCs), current learning processes in firms and emergent knowledge flows among actors are creating knowledge spaces at the regional level in Mexico. These conditions represent an advantage upon ...

Optical glass and glass ceramic components with angstrom-level surface roughness and nanometer-level dimensional accuracy are in potential demand for sophisticated optical fabrication. In recent years, aspherical and free-form surfaces are gaining prominence for high performance applications. Moreover, the new optical materials and fabrication process which exhibit superior mechanical properties are being developed to meet the stringent requirements and harsh environment. Fabrication of complex-shaped high optical finish components becomes a significant challenge as conventional finishing techniques are unable to machine aspherical or free-form surfaces precisely. This situation demands few highly advanced and precise finishing processes which ensure stress-free surfaces. Mostly, the optical components are fabricated by shaping or pre-finishing methods followed by final finishing processes. Final finishing processes include more deterministic and flexible polishing techniques that can achieve desired surface finish, figure accuracy and surface integrity to make it suitable for shorter wavelength applications. In this chapter, basic principle, mechanism of various material removal processes, and precision polishing techniques such as magnetorheological fluid-based finishing were discussed and are compared with the convention polishing techniques.

Perforated walls and transpiration flow play an important role in aerodynamics due to an increasing interest in application of flow control by means of blowing and/or suction. An experimental study was carried out which has led to the determination of a transpiration flow characteristics in the form of a simple formula that is very useful in modelling such flows. In connection to this relation a method of "aerodynamic porosity" determination has been proposed which is much more reliable than geometric description of the porosity. A theoretical analysis of the flow through a perforation hole was also carded out. The flow was considered as compressible and viscous. The gasdynamic analysis led us to a very similar result to the relation obtained from the experiment. The adequacy of the theoretical result is discussed in respect to the experiment.

Novel high hydroxyl number and high functionality polyols were developed using thiol-ene reaction of castor oil with mercaptoethanol or mercaptanized castor oil with allyl alcohol (by photochemical reaction) and 2-hydroxyethyl acrylate (by Michael thiol-ene reaction). The polyols had OH numbers of 220-295 mg KOH/g and functionalities close to 6. Cast polyurethane resins were prepared with methylene diphenyl diisocyanate (MDI), dicyclohexylmethane-4,4'diisocyanate (HMDI) and m-xylylene diisocyanate (XDI). XDI gave rubbery to leathery polyurethanes with all three polyols, while MDI and HMDI gave amorphous glasses with good mechanical properties. Rigid polyurethane foams of good properties were made with MDI and three castor oil-based polyols.

Solid-phase techniques have facilitated the handling of biochemical analytes. This has stimulated the development of systems by which large sample panels can be analyzed with high levels of security and quality. We describe a sample transfer device based on the principle of vacuum filtration, which enables parallel handling of 96 samples of analytes bound to Sepharose beads. The tool was employed for strand separation of DNA samples, by attracting the beads to filter probes while passing them between the reagent solutions. The samples were analyzed using Pyrosequencing technology and proved to yield genotyping results of high quality. The presented sample preparation procedure provides an important link in the development of integrated systems for rapid genetic analysis at a low cost. In addition, the same filter could be reused extensively with very low risk for detectable cross-contamination between assays and without any reduction in processing capacity, thus further reducing the cost per analyzed sample.

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Low-temperature plasma physics and technology are diverse and interdisciplinary fields. The plasma parameters can span many orders of magnitude and applications are found in quite different areas of daily life and industrial production. As a consequence, the trends in research, science and technology are difficult to follow and it is not easy to identify the major challenges of the field and their many sub-fields. Even for experts the road to the future is sometimes lost in the mist. Journal of Physics D: Applied Physics is addressing this need for clarity and thus providing guidance to the field by this special Review article, The 2012 Plasma Roadmap.

This article reports the results of an investigation into the efficiency of mechanical activation to increase the reactivity in alkali activated mortar synthesized from low-grade clay. Mechanical activation significantly changed the structure of clay, increasing the specific surface area, and decreasing the particle size. The 7-day compressive strength of mortar synthesized from untreated clay was 31.7 MPa, which increased to 35.3 after 4 h milling. A further increase of grinding time to 8 h did not result in any increase in compressive strength which is attributed to a decrease in the workability. However, the extent of reactivity did significantly increase as determined from solid-state MAS NMR, FTIR, and EDS analyses. Solid-state MAS NMR results revealed the increased formation of Q 4 (2Al) silicon sites, which is correlated with improved reaction. Furthermore, the EDS and FTIR analysis results indicated greater incorporation of aluminium into the matrix structure with increased grinding time.

Nowadays, tail lights using Two-Colour (2K) Molding Process with the material of PMMA is facing crack defects in automotive production plant. Furthermore, the cost of replacement of this component is expensive. Therefore, for this analysis it would be focusing on finding the root-cause of the pre-initial stress of the tail lights after being assembled on the car which needs to be concluded whether there’s a fault in assembly itself or material.

Volume 1 Physical Aspects of Cleaning Processes (W. von Rybinski). Laundry cleaning of textiles (J. Burckett St. Laurent et al.) Formulation of Carpet Cleaners (J. Williams). Dish and Household Cleaning (G. Szewczyk). A review of key ingredients used in Auto-dishwashing formulations past and present and the physico-chemical processes they facilitate. (A. Tomlinson, J. Carnali). Personal Cleansing (Kumar Subramanyan, K.P. Ananthapadmanabhan). Shampoo Formulation (K. Klein, I. Palefsky). Surfactant Action on Skin and Hair: Cleansing and Skin Reactivity Mechanisms (L. Rhein/Sheads). The Cleaning of Teeth (A. Joiner). Dry Cleaning of Textiles (K.D. Hasenclever). Wet Cleaning of Textiles (K.D. Hasenclever). Vehicle Cleaning (Mahnaz Company, D.R Karsa). Back End of Lines (BEOL) cleaning (S. Raghavan et al.). Cleaning of Trace Metallic Impurities From Solid Substrates Using Liquid Media (Dr. S. Verhaverbeke). Elevated Pressure CO2-based Fluids Containing Polar Co-solvents for Cleaning in M...

This article presents a new method to pre-cure natural rubber-compounding (NRc) by using microwave energy at a frequency of 2.45 GHz with a rectangular wave guide. The influences of microwave power input, specimen thicknesses, and vulcanized sulfur contents on the dielectric and thermal characteristics and crosslinked contents of microwave-cured NRc are studied. Furthermore, a generalized mathematical model for predicting temperature distribution inside the specimen during pre-heating is proposed. Significant results show that microwave energy can produce partial cross-linking at temperatures below the actual vulcanizing process. The numerical results from the model agree well with the results from the experiments.

Synthesis of nanomaterials by a simple, low cost and in high yield has been a great challenge since the very early development of nanoscience. Various bottom and top down approaches have been developed so far, for the commercial production of nanomaterials. Among all top down approaches, high energy ball milling, has been widely exploited for the synthesis of various nanomaterials, nanograins, nanoalloy, nanocomposites and nano -quasicrystalline materials. Mechanical alloying techniques have been utilized to produce amorphous and nanocrystalline alloys as well as metal/non-metal nanocomposite materials by milling and post annealing, of elemental or compound powders in an inert atmosphere. Mechanical alloying is a non-equilibrium processing technique in which different elemental powders are milled in an inert atmosphere to create one mixed powder with the same composition as the constituents. In high-energy ball milling, plastic deformation, cold-welding and fracture are predominant factors, in which the deformation leads to a change in particle shape, cold-welding leads to an increase in particle size and fracture leads to decrease in particle size resulting in the formation of fine dispersed alloying particles in the grain-refined soft matrix. By utilizing mechanical milling various kind of aluminium/ nickel/ magnesium/ copper based nanoalloys, wear resistant spray coatings, oxide and carbide strengthened aluminium alloys, and many other nanocomposites have been synthesized in very high yield. The mechanical milling has been utilized for the synthesis of nanomaterials either by milling and post annealing or by mechanical activation and then applying some other process on these activated materials. This review is a systematic view of the basic concept of mechanical milling, historical view and applications of mechanical milling in the synthesis of various nanomaterials, nanosomposites, nnaocarbons and nano quasicrystalline materials.

This article explores a new open-source method for developing and manufacturing high-quality scientific equipment suitable for use in virtually any laboratory. A syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them. Details are provided covering the use of the CAD software and the RepRap 3-D printer. The use of an open-source Rasberry Pi computer as a wireless control device is also illustrated. Performance of the syringe pump was assessed and the methods used for assessment are detailed. The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications.

Currently, no consensus exists regarding the best adhesion protocol for zirconia used in dentistry; this is important particularly for restorations where mechanical retention is deficient. This systematic review analyzed the adhesion potential of resin-based and glass-ionomer luting cements to zirconia and aimed to highlight the possible dominant factors affecting the bond strength results to this substrate. Original scientific papers on adhesion to zirconia published in the MEDLINE (PubMed) database between 01/01/1995 and 01/06/2011 were included in this systematic review. The following MeSH terms, search terms, and their combinations were used: "Dental bonding", "Zirconium", "Zirconia", "Y-TZP", "Y-TZP ceramic", "Materials Testing/methods", "Test", "Cement", and "Resin bonding". Two reviewers performed screening and data abstraction. Descriptive statistics were performed and the frequencies o...

In this work, we report on the electrodeposition of ZnO thin films on n-Si (1 0 0) and glass substrates. The influence of the deposition time on the morphology of ZnO thin films was investigated. The ZnO thin films were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDS) and scanning electron microscopy (SEM). The results show a variation of ZnO texture from main (0 0 2) at 10 min to totally (1 0 1) at 15 min deposition time. The photoluminescence (PL) studies show that both UV (∼382 nm) and blue (∼432 nm) luminescences are the main emissions for the electrodeposited ZnO films. In addition, the film grown at 15 min indicates an evident decrease of the yellow-green (∼520 nm) emission band comparing with that of 10 min. Finally, transmittance spectra show a high transmission value up to 85% in the visible wavelength range. Such results would be very interesting for solar cells applications.

To prepare miscible polyethylene glycol diacrylate/polyvinylidene fluoride ͑PEGDA/PVdF͒ blend gel polymer electrolytes, low molecular weight (M ϭ 742) liquid PEGDA oligomer was mixed with PVdF-HFP dissolved in ethylene carbonate/dimethyl carbonate/LiPF 6 liquid electrolytes, and then cured under ultraviolet irradiation. Room temperature conductivity of PEGDA/PVdF blend films was found to be comparable to that of PVdF-HFP gel polymer electrolytes, and they were electrochemically stable up to 4.6 V vs. Li/Li ϩ. Scanning electron micrographs revealed that PEGDA/PVdF blend electrolytes have pore size intermediate between dense PEGDA and highly porous PVdF-HFP. It was confirmed by weight change measurement that liquid electrolyte was likely to evaporate through large pores in PVdF-HFP at 80°C, while PEGDA/PVdF blend showed better liquid electrolyte retention ability. This result was in good agreement with more stable interfacial properties of PEGDA/PVdF blend at 80°C in ac impedance analysis. Consequently, both PVdF-HFP and PEGDA/PVdF gel polymer electrolytes delivered similar discharge capacity at room temperature, but PEGDA/PVdF blend gel polymer electrolyte showed much better cycle performance than pure PVdF-HFP at 80°C.

Standard fused filament fabrication (FFF)-based 3-D printers fabricate parts from thermopolymers, such as polylactic acid (PLA). A new range of metal based PLA composites are available providing a novel range of potential engineering materials for such 3-D printers. Currently, limited material data, specifically thermal property characterization is available on these composites. As a result, the application of these materials into functional engineered systems is not possible. This study aims to fill the knowledge gap by quantifying the thermal properties of copperFill, bronzeFill, magnetic iron PLA, and stainless steel PLA composites and provide insight into the technical considerations of FFF composite 3-D printing. Specifically, in this study the correlation of the composite microstructure and printing parameters are explored and the results of thermal conductivity analysis as a function of printed matrix properties are provided. Considering the relative deviation from the filament raw bulk analysis, the results show the printing operation significantly impacts the resultant component density. Experimentally collected thermal conductivity values, however, do not correlate to the theoretical models in the literature and more rigorous quantitative exercises are required to determine true percent porosity to accurately model the effect of air pore volume fraction on thermal conductivity. Despite this limitation, the thermal conductivity values provided can be used to engineer thermal conductivity into 3-D printed parts with these PLA-based composites. Finally, several high-value applications of such 3-D printed materials that look metallic, but have low thermal conductivity are reviewed.

Chemical Vapour Deposition (CVD) of films and coatings involve the chemical reactions of gaseous reactants on or near the vicinity of a heated substrate surface. This atomistic deposition method can provide highly pure materials with structural control at atomic or nanometer scale level. Moreover, it can produce single layer, multilayer, composite, nanostructured, and functionally graded coating materials with well controlled dimension and unique structure at low processing temperatures. Furthermore, the unique feature of CVD over other deposition techniques such as the non-line-of-sight-deposition capability has allowed the coating of complex shape engineering components and the fabrication of nano-devices, carbon-carbon (C-C) composites, ceramic matrix composite (CMCs), free standing shape components. The versatility of CVD had led to rapid growth and it has become one of the main processing methods for the deposition of thin films and coatings for a wide range of applications, including semiconductors (e.) used for hard coatings, protection against corrosion, oxidation or as diffusion barriers; metallic films (e.g. W, Mo, Al, Au, Cu, Pt) for microelectronics and for protective coatings; fibre production (e.g. B and SiC monofilament fibres) and fibre coating. This contribution aims to provide a brief overview of CVD of films and coatings. The fundamental aspects of CVD including process principle, deposition mechanism, reaction chemistry, thermodynamics, kinetics and transport phenomena will be presented. In addition, the practical aspects of CVD such as the CVD system and apparatus used, CVD process parameters, process control techniques, range of films synthesized, characterisation and co-relationships of structures and properties will be presented. The advantages and limitations of CVD will be discussed, and its applications will be briefly reviewed. The article will also review the development of CVD technologies based on different heating methods, and the type of precursor used which has led to different variants

We studied the morphology, structure, and magnetic properties of Fe nanowires that were electrodeposited as a function of the electrolyte temperature. The nucleation mechanism followed instantaneous growth. At low temperatures, we observed an increase of the total charge reduced into the templates, thus suggesting a significant increase in the degree of pore filling. Scanning electron microscopy images revealed smooth nanowires without any characteristic features that would differentiate their morphology as a function of the electrolyte temperature. X-ray photoelectron spectroscopy studies indicated the presence of a polycarbonate coating that covered the nanowires and protected them against oxidation. The X-ray diffraction measurements showed peaks coming from the polycrystalline Fe bcc structure without any traces of the oxide phases. The crystallite size decreased with an increasing electrolyte temperature. The transmission electron microscopy measurements proved the fine-crystal...

Abstracts.
Cameroon like most developing countries does not have a reliable network  for collecting statistics on energy systems country. This has been a major drawback for an accurate assessment of the energy generation potential of the major energy technological systems in the country. A viable alternative is to obtain the data from international energy Agencies like Reep policy data base,  Energy Information Administration (EIA), World bank or from  local energy managing companies like ARSEL, the Electricity Regulatory Agency; AER, the Rural Electrification Agency;AES-SONEL ; and, SNH, the National Oil Company, in charge of the oil and gas sector. In this paper, the energy output, Energy resources and the state of all energy technological systems in Cameroon has been analysed using data from various energy Agencies highlighted above.
An economic assessment revealed that a simple demand for electricity in Cameroon in an estimate  reached 1455MW in 2014 and almost estimated to reach  5000MW in 2020 taking into consideration the unmet demand due to the low rate of electrification and access to the electricity grid as well as the needs of major industrial projects required to transform the country’s economy

TiO 2 polycrystalline sub-micron fibers can be used as photocatalysts for the degradation of a variety of organic molecules. Here we report on the optimization of these fibers for decontaminating pharmaceutical agents in aqueous medical waste streams. Mixed-phase TiO 2 fibers have been prepared via a sol-gel technique followed by electrospinning and calcination. By adjusting the calcination temperature, the rutile phase fraction in TiO 2 fibers can be tuned relative to the anatase phase from 0% to 100%. The effect of rutile phase fraction on grain size and specific surface area as well as their subsequent influences on the photocatalytic activity was investigated. An optimal grain size in post-calcined TiO 2 fibers was found to be critical to balance the e-/h + volume recombination, surface recombination rate, and charge diffusion rate. The photocatalytic activities of the post-calcined TiO 2 fibers with different rutile fractions were measured by monitoring the decreasing concentration of phenazopyridine in aqueous solution under UV illumination using UV-Vis absorption spectroscopy. Post-calcined TiO 2 fibers composing of 38 wt% rutile and 62 wt% anatase exhibited the highest initial degradation rate constant of 0.044 min-1. This optimal photocatalytic activity can be attributed to the combined influences of the fibers' phase composition, surface area and grain size.

This project, consisting of a guide, an information database, and preservation recommendations, is directed primarily towards conservators and restorers, and secondly archivists, collectors, and curators. This investigation can serve as a foundation for conservators in their own research and as an identification aid for digital prints in a collection. The fact that no hardcopies are present in a collection today should not exclude the possibility of their future presence in that collection, which is, in fact, very probable. The identification guide as well as the recommendations for preservation must be tested and evaluated by the end users for their correctness and feasibility. In addition, the information must be presented to the user in such a way that it is easily understandable. Four different types of potential users should test the product: a conservator, an archivist, a scientist, and a person from another field altogether. The mentors who monitored my progress and results, Dr. Franziska Frey and Dr. James Reilly, both of the Image Permanence Institute, Rochester, NY, are each specialists in their fields. I would like to thank James for guiding me in the scope and direction of this investigation, and Franziska for being a guide and a friend during the complete investigation and for overloading me with information sources, contacts, and articles.

Product development is usually a response to an existing problem in a product, or it is identifying users' needs in order to ameliorate the living conditions of people or to enhance life in general. Some patients with certain ailments and geriatrics in general usually have an incontinence problem. Disposable products are available at relatively expensive price and not easily available for certain people or for financially marginalized people, and yet there is need for these products. This research was done to develop an affordable, re-usable product for adults who have an incontinence challenge. Terry cloth was used as an absorbent fabric for the future product and three water repellent fabrics were tested for water repellency and bleaching, prior to designing and evaluating the product. All three fabrics were water repellent and only one was resistant to chlorine bleach used in the development of this product. The chlorine resistant fabric was used in constructing the adult was...

Waterborne epoxy coatings were commercially introduced about 40 years ago, mainly as an environmentally friendly replacement to solvent-borne epoxies in countries with strong environmental and worker safety regulations. Their growth was mainly driven by the desire to reduce the emission of organic solvents. This technology grew most rapidly in the concrete protection market, though there is also use over metal substrates and for some OEM applications. This paper will review the classification of waterborne epoxy coatings according to the type of epoxy resin being used. Type I systems are based on low molecular weight, liquid epoxy resin, and the curing agent typically doubles as the emulsifier for the resin. Type II systems are based on high molecular weight, solid epoxy resin dispersions. Properties like pot-life behavior, dry time and drying mechanisms (film formation) will be reviewed for both systems.

This standard is issued under the fixed designation A380/A380M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.