bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Mobility Modes in Polymer Solutions Undergoing Thermal-Induced Phase Separation
Authors: Chan Philip K. 
Published: April 2011

ABSTRACTThe thermal-induced phase separation method is used to fabricate polymer membranes and polymer-dispersed liquid crystal films from polymer solutions. The resultant morphology consists of solvent droplets dispersed uniformly in a solid polymer matrix. Up till now, the modeling and computer simulation of the thermal-induced phase separation phenomenon in polymer solutions have considered the mobility to be a constant. The objective of this presentation is to compare the following three mobility modes: (1) mobility as a constant, (2) mobility following fast mode theory, and (3) mobility following slow mode theory. We present computer simulation results from models composed of the Cahn-Hilliard theory for phase separation, Flory-Huggins free energy density for polymer solutions, and the three aforementioned mobility modes. The numerical results indicate that there is no significant difference in the morphology formed; the only difference occurs in the phase separation time. Furthermore, the numerical results show that the only difference between the slow and fast mode theories is a factor of two; the mobility of the fast mode theory is twice that of the slow mode theory.
The Effect of Carbon Black and Colloidal Silica Fillers on the Fracture Toughness at Polymethylmethacrylate Interfaces
Authors: Bronner Mordechai J. , Shah Anshul A. , Kim Hyun-Joong , Peiffer Dennis G. , Rafailovich Miriam , Sokolov Jonathan 
Published: April 2011

ABSTRACTWe have measured the fracture toughness of PMMA slabs with carbon black and colloidal silica fillers placed at the interface. The results show that the fracture toughness decreases linearly with carbon black concentration. The fracture toughness scales as annealing time, t1/2indicating that it is diffusion limited. Addition of Colloidal Silica drastically reduces the fracture toughness regardless of concentration and annealing time. These results indicate that carbon black introduces physical cross links which decrease dynamics whereas colloidal silica produces permanent chemical cross links which prevent diffusion across the interface.
Surface Characterization of DNA Microarray on Silicon Dioxide and Compatible Silicon Materials in the Immobilization Process
Authors: Xu Wen , Li Jiong , Xue Mei , Carles Maria , Trau Dieter Wilhelm , Lenigk Ralf , Sucher Nikolaus J. , Ip Nancy Y. , Chan Mansun 
Published: April 2011

ABSTRACTIn this work, the surface properties of a DNA microarray formed on silicon based solid support are studied at different stages during the hybridization process. A modified immobilization process using the covalent immobilization of thiol-terminated DNA oligonucleotides on self-assembled layers of (3-mercaptopropyl) trimethoxysilane (MPTS) by disulfide bond formation is used to selectively attach DNA probes onto the surface of silicon dioxide. Contact angle measurement is used to monitor the bonding of MPTS on the surface. Atomic force microscopy (AFM) shows an increase in particle size before and after the growth of the MPTS layer. Fluorescence microscopy reveals the success of hybridization of complementary oligonucleotides labeled by FAM to the probe. The effects of modified immobilization process on other common material in silicon processing are also studied. As a result of the corrosive chemical used in the process, common metals used in micro-fabrication processes like aluminum are etched away. Silicon nitride is not affected by the immobilization and hybridization process, and thus can be used as a passivation and isolation material to conform the DNA to a specific area for DNA microarray to reduce cross-talk. The fluorescence image from the scanner indicates silicon nitride can effectively be used as an isolation material with linewidth down to 1 μm.
Calcium Phosphate Coating on Titanium Plates by Electrodeposition
Authors: Ishikawa Masahiko , Nishikawa Kouji , Kuroda Kensuke , Ryoichi Ichino , Okido Masazumi , Takai Osamu 
Published: April 2011

ABSTRACTCalcium phosphate films were deposited on titanium electrodes cathodically from CaCl2·2H2O and Ca(H2PO4)2 · H2O aqueous solutions. In this study, H2O2 addition into electrolytes was applied to enhance the electrochemical process at the solution/electrode at a smaller cathodic potential than no H2O2 addition. Deposited films were analyzed by scanning electron microscopy (SEM) observation and X-ray diffraction (XRD). Cathodic current of the Ti electrode decreased once and increased in the solution with H2O2. It shows a cathodic current peak at c.a. 25 min in the case of potentiostatic condition at - 0.756 V (vs. Ag - AgCl, sat. KCl). The calcium phosphate film grows mainly with the decrease in current after the cathodic peak. The characteristics for the electrodeposited film such as crystal morphology depends on cathodic potential, solution pH, deposition temperature and amount of H2O2 addition. Dense calcium phosphate film composed of relatively good crystalline was obtained at pH 5.5 and – 0.756 V. Film adhesion on Ti appeared to be strong by peeling test. At larger cathodic potential of – 1.156 V, the film coverage on titanium plates was smaller and film adhesion worsened. Larger cathodic polarization of more than – 1.556 V was necessary to reduce water in case without H2O2 addition.
Processing, Magnetization and Structural Studies of Bioactive Ferromagnetic Glass-Ceramics
Authors: Leventouri Theodora , Kis Antonella C. , Sorge Korey , Bunaciu Camelia E. , Thompson James R. 
Published: April 2011

ABSTRACTA series of ferromagnetic bioceramic samples in the system 45(CaO, P2O5), ySiO2xFe2O3 were synthesized with various processing parameters in order to study correlations between structure, magnetic properties and preparation variables. X-ray powder diffraction shows that the qualitative as well as the quantitative structure of the samples is strongly affected by processing parameters, including composition, annealing temperature and the chemical reactions. Magnetic measurements illustrate a strong correlation between the saturation magnetization, and hysteresis loss, with the processing parameters of the material.
Development of No-Rejection Aqueous Humor Pressure Control Membrane in The Eyeball for Glaucoma Implant Devices
Authors: Sato Y. , Parel J.M. , Murahara M. 
Published: April 2011

ABSTRACTThe inner porous part of the PTFE [poly-tetrafluoroethylene] membrane was substituted with a hydrophilic group using irradiation by an ArF laser. Water was employed for a defluorination agent in order to inhibit rejection. The membrane was developed that automatically pumps out water when the pressure is raised above a fixed value. The increased intraocular pressure with aqueous outflow failure causes glaucoma. In healthy humans intraocular pressure is maintained at a normal physiological level of between 8 to 18 mmHg. When the pressure exceeds 21 mmHg, a diagnostic of glaucoma may be predicted.We designed a new type of membrane to pump the aqueous humor and regulate its outflow. The membrane has gained characteristics of aqueous humor penetration by substituting a part of a hydrophobic group that exists inside the porous PTFE with the hydrophilic group. Furthermore our previous studies have found that B, Al and H atoms are effective for defluorination of atoms from fluorocarbon. In this study three kinds of reaction liquid containing B, Al and H respectively were used. By this defluorination reaction B and Al atoms were better than H atoms. We prepared a boric acid water solution (B(OH)3), nitro aluminate water solution (Al(NO3)3) and water (H2O) as chemical compounds for defluorination and OH substitution. When ethyl alcohol is dropped on the porous PTFE, it penetrates into inner porous PTFE easily. When the three kinds of chemical compound water solutions are dropped onto the porous PTFE membrane, the solution is trapped up to the inner side of porous PTFE. When each sample with hydrophilic property treatment was implanted into rabbits' eyes and its biocompatibility was tested, some samples using Al and B atoms for defluorination have shown the rejection reaction called neoplasm blood vessel. However, the other samples using water as the reaction liquid have shown no rejection.
Non-destructive analysis of Nineteenth century Scottish calotype negatives and salt prints
Authors: Eremin Katherine , Tate James , Morrison-Low Alison , Berry James , Stevenson Sara 
Published: April 2011

ABSTRACTNineteenth century negatives and positives in the collections of the National Museums of Scotland (NMS) and the National Galleries of Scotland (NGS) were analysed non-destructively to identify the techniques used in their manufacture. Modern positive and negative images prepared using known nineteenth century processes were also analysed for comparison. Air-path energy dispersive x-ray fluorescence analysis and controlled pressure scanning electron microscopy with energy dispersive microanalysis enabled the images to be divided into groups based on the levels of bromine, iodine and silver, and the likely processes used inferred. An early group of positives were probably sensitised with either silver chloride or silver bromide and fixed with potassium bromide. However, most positives were probably sensitised with silver chloride and fixed with sodium thiosulphate. Most negatives were probably sensitized with silver iodide and fixed with potassium bromide (predominant), sodium thiosulphate or potassium iodide. Cobalt and arsenic are present due to the use of smalt in the production of white paper. Copper and zinc are attributed to incorporation of fragments of brass buttons left on the rags used in paper production, observed as small blue spots. The presence of iron, sometimes visible as orange spots, may be from rust off the paper making machines.
Recovering and Re-Discovering Craft
Authors: Vandiver Pamela B. 
Published: April 2011

ABSTRACTMany studies have shown that craft involves know-how, practice and problem solving that represents activities that can be recovered by study of various artifact assemblages and contexts within archaeological sites. The types of conclusions differ with nature of the research question, sample size and its variability, methods of study and organization of collecting in the field, as well as the results of areal study: ethnographic information, resource survey and landscape reconstruction. Questions generated through analysis of materials, processes and properties often generate questions that can only be answered by replicative experiments of all aspects of a chaine operatoire, only part of it or only those critical aspects about which questions remain. The integration of the laboratory/workshop results with the archaeological evidence, both objects and context, can lead to a re-discovery of craft. The conjectured details of materials composition and structure, sequence of processing, properties, performance or use essentially reverse engineer the typical way that modern materials research is conducted. This paper aims at developing a widening dialogue about craft know-how among materials scientists working in museums and artist-craftsmen. To learn about our history and the human condition is not just to analyze and preserve the objects and artifacts, but also to investigate and understand the knowledge and skills used to produce and use them-- essentially this is the preservation of intangible cultural heritage and culture history.
The Characterization and Conservation of Aged Aluminum Alloys: Buckminster Fuller's Dymaxion House
Authors: Trentelman Karen A. , Ashby James , Donlon William T. 
Published: April 2011

ABSTRACTThe Dymaxion House is a unique historic dwelling structure designed by Buckminster Fuller. Built in the 1940s, the house was constructed of modern materials, most notably aluminum, which formed the walls, roof and many of the structural elements. The challenge faced in reconstructing the Dymaxion House at Henry Ford Museum & Greenfield Village was to preserve the original structure as much as possible while simultaneously accommodating the needs of exhibition (i.e. to restore the visual appearance and ensure sufficient structural integrity to allow the entrance of visitors). The primary aluminum alloys used in the house are equivalent to the modern alloy designations 2014 and 2024; both extruded forms and Alclad sheets were used. The alloy composition, age-hardening characteristics, cladding layers, grain structure and corrosion products of the aged aluminum components of the Dymaxion House have been studied. The results of these studies were used in consultation with conservators, engineers and corrosion scientists to determine the most appropriate course of treatment.
Assessment of Cleaning Conservation Interventions on Architectural Surfaces Using an Integrated Methodology
Authors: Moropoulou Antonia , Delegou Ekaterini T. , Avdelidis Nicolas P. , Koui Maria 
Published: April 2011

ABSTRACTIn this work, pilot cleaning interventions applied by a wet micro-blasting method on architectural surfaces of three historic buildings in marble and porous stone were evaluated in situ and in the laboratory. The investigation was performed on characteristic stone surfaces (marbles and porous stone) of the following historic buildings: Athens Academy and National Library of Greece in Athens center polluted urban environment and Bank of Greece in Piraeus marine environment. The materials of the facades were characterized, and the mechanism of decay was diagnosed. In addition, the cleaning method's efficiency was evaluated based on the acceptability of the alteration of the cleaned architectural surfaces. Criteria were both aesthetic and physico-chemical. In particular, the architectural surfaces were examined in situ by the means of fiber optic microscopy, infrared thermography and colorimetry. In the laboratory, methods of investigation were optical microscopy, X-ray diffraction, scanning electron microscopy with energy dispersion by X-ray analysis, mercury intrusion porosimetry, Fourier transform infrared spectroscopy, conductivity and pH measurements. The majority of measurements and analyses were applied before and after the pilot cleaning interventions. Finally, the results of this study contribute to the development of an integrated methodology for the assessment of cleaning interventions applied on architectural surfaces.
Rheology Optimization of Particle Modified Consolidants
Authors: Aggelakopoulou Eleni , Charles Pamela , Acerra Matilde E. , Garcia Ana I. , Flatt Robert J. , Scherer George W. 
Published: April 2011

ABSTRACTEthyl silicate-based consolidants are used to restore strength to degraded stones. One of the limitations of strength development using these products is their reported cracking behavior during drying. Particle Modified Consolidants (PMC) consist of a silicate matrix plus colloidal oxide particles. The presence of particles physically limits the silicate network from shrinking under capillary pressures, and thereby reduces strength loss during drying. In addition, the network maintains a higher permeability, because the dried consolidants remains porous. When the particles used are pigments, it is also conceivable to adjust the consolidant color. Moreover, a careful choice of particles should allow matching the thermal dilatation of the consolidant to that of the stone. An important limitation to further development of PMC has been the ability to avoid particle agglomeration in the dispersion. When agglomerates are present, not only do they increase the viscosity but they also can block pore entrances, preventing consolidant fromentering the stone. In this work we demonstrate the feasibility of adsorbing nano-silica particlesonto pigment particles to create a steric barrier to agglomeration. Rheology and density measurements confirm that the resulting dispersion is fluid and stable against settling. The consolidant readily penetrates Ohio Massilian sandstone, providing improved strength, stiffness, and salt resistance, compared to a commercial silicate consolidant.
Reconstructing the Materials and Technology of Egyptian Faience and Frit
Authors: Griffin Patricia S. 
Published: April 2011

ABSTRACTThis paper presents a research project undertaken at the Cleveland Museum of Art to study and characterize its collection of more than one hundred and fifty Egyptian artifacts made from faience or frit. An overview of the project is presented here, followed by a summary of faience technology that draws upon other published studies as well as the insights gained during this project. Where appropriate, this technological discussion will be illustrated using examples of Egyptian artifacts studied during this project. For some objects discussion will be limited to one or two aspects of manufacture. However, the proposed manufacturing sequence of several key artifacts will be described more fully.A multi-faceted approach to the study of these materials was designed. Examination procedures used to study the collection included microscopy (surface examination using a lowpowered microscope, and microstructural characterization of exposed fracture surfaces or small samples using a scanning electron microscope), structural analysis using Xero-radiography, and nondestructive qualitative compositional analysis of glazes and pastes using x-ray fluorescence spectroscopy. Hardness testing using fine metal points graded to the Moh's scale, Munsell color evaluations and qualitative gloss determinations were also employed. Replication experiments were used extensively to understand visual features remaining on the surfaces of objects, to provide comparison standards for examination of fracture surfaces with magnification, and to test the validity of theories on paste recipes and forming practices.The primary goal of the project was to provide accurate descriptions of the materials and technology of each object as possible. This included characterization of technological features such as glaze (probable application method, composition, color, and gloss), paste (grain size, color, hardness, composition, and extent of vitrification) and forming methods (modeling, molding, template, cores, wet working and/or dry working). Careful documentation of these features enabled detailed technological descriptions to be prepared for each artifact. This work also elucidated many aspects of faience production as it may have been practiced in ancient Egypt, and suggested directions for further study. It is hoped that in the future, technological criteria for dating artifacts that cannot be securely dated using traditional typological art historical criteria can be developed by the careful documentation of characteristics of the paste, glaze and forming processes.
Analyzing Style and Technology in the Eastern Woodlands
Authors: Rieth Christina B. 
Published: April 2011

ABSTRACTTrace element analysis was used to assess the provenance of manufacture of ceramic vessels recovered from six Early Late Prehistoric sites (A.D. 700-1300) in the Susquehanna Valley of New York and Pennsylvania. The compositional profiles of 93 sherds were recorded and compared with the profiles of known clays in the valley. The results of this project suggest that the vessels from these sites form five different clay groups with most vessels manufactured from local clays. Some non-locally manufactured pots were also identified and may represent interaction between neighboring groups.
An Unusual Dark Patina on Egyptian Copper Alloy Objects in the Royal Ontario Museum Collection
Authors: Whyte Alison , Stock Susan , Murray Alison 
Published: April 2011

ABSTRACTThe unusual appearance of a dark patina on a select group of Egyptian copper alloy objects in the Royal Ontario Museum (ROM) collection has raised the question of both its composition and formation and therefore, its authenticity. The purpose of this project was to determine both the constitution of the patina and the process by which it was formed. A cross section sample from one artifact was analysed using optical, metallurgical and scanning electron microscopy in order to clarify the relationship between the patina layer and the body metal. In addition, energy dispersive spectroscopy was employed to establish the chemical composition of the body metal. Surface samples were removed from all the objects and subjected to x-ray diffraction in order to identify the crystalline compounds present. Fourier transform infra-red spectroscopy was used to establish the presence of any organic compounds in the surface samples. Although further analysis is required, the results of the research suggest that the patina may have been formed as a result of a modern cleaning treatment possibly followed by an artificial re-patination treatment.
An Examination of Deterioration Products Found on Tin Ingots Excavated from the 14thCentury B.C., Late Bronze Age Shipwreck, The Ulu Burun, Near Kas, Turkey
Authors: Lipcsei Laura , Murray Alison , Smith Reginald , Savas Mahmut 
Published: April 2011

ABSTRACTThe purpose of this study was to investigate the deterioration of tin ingots recovered from a late 14th century B.C. (Late Bronze Age) shipwreck off Ulu Burun (Kas) Turkey. As so little elemental tin has been excavated from underwater sites and preserved to date, the Ulu Burun ingots offer a unique opportunity to study the degradation products of ancient tin artifacts from a natural marine environment. The current investigation had three major objectives: to identify corrosion products; to confirm or refute the presence of ‘tin pest’, which has been asserted as one of the major reasons for the disintegration of the ingots and a topic of much controversy in the conservation and museum communities; and, finally, to contribute to the overall understanding of marine tin. The following instrumental techniques were used to analyze ingot samples: x-ray diffraction, atomic absorption, inductively coupled plasma emission spectroscopy. The results of the analysis have identified corrosion products that are characteristic of the type of products anticipated on tin objects from a marine environment. The presence of the controversial tin pest disease was confirmed in two of the six samples tested. Sample preparation appears to be a potential factor in the determination of tin pest using XRD.
Reproduction of Japanese Traditional Pigment Based on Iron Oxide Powders With Yellowish Red Color
Authors: Asaoka Hiroshi , Nakanishi Makoto , Fujii Tatsuo , Takada Jun , Kusano Yoshihiro , Murakami Ryu 
Published: April 2011

ABSTRACTSince the beginning of the 18th century A.D., an artificial iron oxide pigment (hematite, called “bengara” in Japanese) and having a beautiful yellowish red color, has been produced in Japan and applied to pottery, textiles and paintings. However, in 1965 the traditional “bengara” could not be produced anymore, mainly because of environmental pollution. The purpose of this study is to make clear the features of traditional “bengara” and to reproduce high quality “bengara” using modern high-purity reagents. Traditional “bengara” has been characterized as hematite containing a small amount of Al. The average size of the “bengara” particles is approximately 100 nm. The color becomes more yellowish-red with increasing Al content. A monophase of hematite prepared by heating a mixture FeSO4-7H2O and α-Al2O3 to about 680 °C included a small amount of Al substituted in a solid solution. The particle size greatly decreased as the heat treatment temperature was decreased: 100 nm at 770 °C but 50 nm at 650 °C. The color of the particles becomes more vivid as the temperature is decreased, but within bounds this color is independent of the amount of Al in solid solution.