White Glass Research Articles

Dy3+-doped Ba-Na-B white light-emitting glass for w-LED applications

The Dy3+-doped barium sodium borate glasses with chemical composition 10BaO:25Na2O:(65-x)B2O3:xDy2O3 (where x = 0.50, 0.70, 1.00 and 1.50 mol%) were prepared by melt-quenching technique. The luminescence properties of the glass samples were studied to evaluate their potential for using as luminescence materials of w-LEDs applications. The density, molar volume and refractive index of the glass samples were carried out. The absorption spectra were investigated for UV-Vis and NIR regions in wavelength range 300 to 1900 nm. The excitation spectra measured under 575 nm emission wavelength showed peaks assigned by 6H15/2→4M17/2 (324 nm), 4I9/2 (336 nm), 6P7/2 (349 nm), 6P5/2 (363 nm), 4K17/2 (386 nm), 4G11/2 (424 nm), 4I15/2 (453 nm) and 4F9/2 (471 nm), the highest excitation peak centered at 349 nm. The emission spectra, excited with 349 nm excitation wavelength, showed the two major peaks assigned by 4F9/2→6H15/2 (482 nm, blue light emission) and 6H13/2 (575 nm, yellow light emission). The experimental lifetime were found to be 0.581, 0.441, 0.362 and 0.261 ms for 0.50, 0.70, 1.00 and 1.50 mol% of Dy2O3 doped in glasses, respectively. The color coordinates of all glass samples were found to be the same point at (0.38, 0.41) in the CIE 1931 chromaticity diagram and the CCT values of all glass samples were corresponding to the commercial cool white light (3100-4500K).

Tissue Engineering of Necrotic Dental Pulp of Immature Teeth with Apical Periodontitis in Dogs: Radiographic and Histological Evaluation.

To evaluate tissue engineering technology to regenerate pulp-dentin like tissues in pulp canals of immature necrotic permanent teeth with apical periodontitis in dogs. The study was performed on 36 teeth in 12 dogs. The experiment was carried out using split mouth design. In each dog 3 teeth were selected for implementing the study procedure. Apical periodontitis was induced in Group A and B teeth. Group (A): immature upper left 2nd permanent incisors that were transplanted with a construct of autologous dental pulp stem cells with growth factors seeded in a chitosn hydrogel scaffold. Group (B): immature upper right 2nd permanent incisor that received only growth factors with scaffold. A third tooth in each dog was selected randomly for isolation of dental pulp stem cells (DPSCs). Both groups were closed with a double coronal seal of white MTA (Mineral trioxide aggregate) and glass ionomer cement. Both groups were monitored radiographically for 4 months and histologically after sacrificing the animals. There was no statistically significant difference in radiographic findings between group (A) and group (B) for healing of radiolucencies, while there was statistically significant difference between group (A) and group (B) regarding radicular thickening, root lengthening and apical closure. Histologically, group (A) teeth showed regeneration of pulp- dentin like tissue while group (B) teeth did not show any tissue regeneration. Dental pulp stem cells and growth factors incorporated in chitosan hydrogel are able to regenerate pulp- dentine like tissue and help in complete root maturation of non-vital immature permanent teeth with apical periodontitis in dogs.

Fluidized Bed Opposed Jet Mill System for Processing Inorganic Materials

A jet mill system was built aiming to give values for processing inorganic materials, to be used for different industry. The milling housing of the system is composed of; milling chamber, compressed air nozzles which deliver compressed air in the milling chamber to accelerate sample particles. The classifier wheel is composed of two concentric pieces welded together under argon and coupled to a AC Motor, 0 - 9000 rpm, 2 kW, with AC frequencies convertor. The performances of this jet mill system were tried on five cheap locally available materials, viz. white sand, glass, iron oxide, black carbon and alum. It is possible to get particle sizes of less than 1 μm with narrow distribution of particle sizes.

Acinetobacter pittii biofilm formation on inanimate surfaces after long-term desiccation

The survival of pathogenic micro-organisms in the healthcare environment has a major role in nosocomial infections. Among the responsible mechanisms enabling nosocomial pathogens to persist with these stress conditions is their ability to resist desiccation and to form biofilms. To investigate the survival behaviour of Acinetobacter pittii isolates on inert surfaces and saline microcosms. Five A.pittii clinical strains were spotted over white laboratory coat fragments, glass, and plastic surfaces, or inoculated into sterile saline and monitored at room temperature for a period of 43 days. Although the permanence on solid surfaces negatively affected the culturability of the strains used, a fraction of stressed cells survived for at least the period of study. On average, A.pittii culturability was reduced by 77.3%, 80.9%, and 68.1% in white coat, plastic, and glass surfaces, respectively. However, ∼85.6% of the populations retain their culturability in saline solution. Culturability correlated with the presence of cells with an intact membrane, as demonstrated after live/dead staining. Supplementation of the culture medium with sodium pyruvate favoured the culturability of strains from all conditions; but, in general, A.pittii populations did not enter a viable but non-culturable state. After long-term desiccation, all A.pittii strains retained, or even increased, their ability to form biofilms after they had been fed with nutrient media. This suggests that A.pittii may recover easily from desiccation and may express adherence factors to infect new hosts after rehydration.

Using handheld pXRF to study medieval stained glass: A methodology using trace elements

ABSTRACTThe surfaces of 30 pieces of glass from panel 3b of the Great East Window of York Minster (1405-1408 CE) were analyzed by handheld portable X-ray fluorescence (pXRF) and small samples from the same pieces were analyzed by electron microprobe (EPMA). Comparison of the two methods reveals significant divergences which are not systematic, particularly for elements lighter than Ti. Rather than a problem with pXRF calibration or correction software, the non-systematic error is attributable to the presence of a thin surface layer of weathered glass. Analysis of the depths of X-ray generation indicate that virtually all X-rays characteristic of Ca and K are generated within the top 50 µm of the glass. However, for heavier elements such as Rb, Sr and Zr, most emitted X-rays are generated below 100 µm. Using pXRF data for the heavier elements, it is possible to replicate the compositional groupings identified by quantitative EPMA. White glass in the window is likely to have originated in England, while colored glasses were probably obtained from the Continent. The alkali contents of the green and yellow glasses appear to have been manipulated to generate their colors. Glass which is medieval in technology but not original to the panel was identified. In particular, zirconium proved a useful indicator of glassmaking regions, and rubidium and strontium were more sensitive to differences between batches, which has interesting implications for future work.

Characterization and Structural Property of Indium Tin Oxide Thin Films

In this study, Indium Tin Oxide (ITO) thin films were deposited by electron beam evaporation on white glass substrates with thicknesses of about 50, 100 and 170 nm. We investigated structural properties by X-ray Diffraction (XRD) and X-ray reflectivity (XRR). The results showed that ITO thin films have a crystalline structure with a domain that increases in size with increasing thickness. For uniform electron density, as the thin film roughness increases, reflectivity curve slope also increases. Also thinner film has more fringes than thicker film. The roughness determines how quickly the reflected signal decays. XRR technique is more suitable for very thin films, approximately 20 nm and less.

Assessing the effects of different prebiotic dietary oligosaccharides in sheep milk ice cream

The objective of this study was to assess the effects of different prebiotic dietary oligosaccharides (inulin, fructo-oligosaccharide, galacto-oligossacaride, short–chain fructo-oligosaccharide, resistant starch, corn dietary oligosaccharide and polydextrose) in non-fat sheep milk ice cream processing through physical parameters, water mobility and thermal analysis. Overall, the fat replacement by dietary prebiotic oligosaccharides significantly decreased the melting time, melting temperature and the fraction and relaxation time for fat and bound water (T22) while increased the white intensity and glass transition temperature. The replacement of sheep milk fat by prebiotics in sheep milk ice cream constitutes an interesting option to enhance nutritional aspects and develop a functional food.

Ion beam analysis of glass inlays from the Staffordshire Anglo-Saxon Hoard

The glass inlays in six objects from the Staffordshire Hoard were subjected to compositional analysis by proton induced X-ray and gamma ray emission (PIXE and PIGE) at AGLAE, Paris. The opaque blue and white glasses are of a natron-based composition and are very likely to be reused and reworked Roman glass, possibly mosaic tesserae. The opacifiers used in their production are also those expected for Roman glasses. These glasses share some compositional parallels with the opaque glasses analysed from the Anglo-Saxon Sutton Hoo ship burial. The transparent red glasses in the Staffordshire Hoard have a similar base composition to the opaque blue and white glasses, but with elevated potash and magnesia levels. Glass in this group also appears to have been made of natron glass, but with the addition of what was probably a plant ash. It is possible that this addition was made to extend the amount of glass available to northern European craftsmen. The discovery of transparent red glass in millefiori with a composition related to Anglo-Saxon vessel glass suggests that these millefiori were being produced by contemporary north-western European, and possibly Anglo-Saxon, glass workers.

Target–projectile interaction during impact melting at Kamil Crater, Egypt

In small meteorite impacts, the projectile may survive through fragmentation; in addition, it may melt, and chemically and physically interact with both shocked and melted target rocks. However, the mixing/mingling between projectile and target melts is a process still not completely understood. Kamil Crater (45m in diameter; Egypt), generated by the hypervelocity impact of the Gebel Kamil Ni-rich ataxite on sandstone target, allows to study the target–projectile interaction in a simple and fresh geological setting. We conducted a petrographic and geochemical study of macroscopic impact melt lapilli and bombs ejected from the crater, which were collected during our geophysical campaign in February 2010. Two types of glasses constitute the impact melt lapilli and bombs: a white glass and a dark glass. The white glass is mostly made of SiO2 and it is devoid of inclusions. Its negligible Ni and Co contents suggest derivation from the target rocks without interaction with the projectile (<0.1wt% of projectile contamination). The dark glass is a silicate melt with variable contents of Al2O3 (0.84–18.7wt%), FeOT (1.83–61.5wt%), and NiO (<0.01–10.2wt%). The dark glass typically includes fragments (from few μm to several mm in size) of shocked sandstone, diaplectic glass, lechatelierite, and Ni–Fe metal blebs. The metal blebs are enriched in Ni compared to the Gebel Kamil meteorite. The dark glass is thus a mixture of target and projectile melts (11–12wt% of projectile contamination). Based on recently proposed models for target–projectile interaction and for impact glass formation, we suggest a scenario for the glass formation at Kamil. During the transition from the contact and compression stage and the excavation stage, projectile and target liquids formed at their interface and chemically interact in a restricted zone. Projectile contamination affected only a shallow portion of the target rocks. The SiO2 melt that eventually solidified as white glass behaved as an immiscible liquid and did not interact with the projectile. During the excavation stage dark glass melt engulfed and coated the white glass melt, target fragments, and got stuck to iron meteorite shrapnel fragments. This model could also explain the common formation of white and dark glasses in small impact craters generated by iron bodies (e.g., Wabar).

Late Precontact and Protohistoric Glass Beads of Alaska

Glass trade beads are tiny packets of information that are commonly misunderstood by archaeologists. Evidence is accumulating to indicate that they were introduced to Alaska before contact through existing indigenous trade networks. This study identifies a pattern of bead types from the precontact or protohistoric in western and northern Alaska. Green-, clear-, and gray-centered red varieties (Type IVa) were introduced into the Bering Strait region during the historic period, probably during the 19th century. However, large wound pale blue, turquoise, or white glass beads (Type WIb) were reported in the late precontact to protohistoric range. Another characteristic of glass beads during this period was split, or half beads. These early bead types were quickly integrated into existing socioeconomic systems and material culture, so much so that by 1791, glass beads were valued commodities.

Reuse of Industrial Waste Soda White Lime Glass Powder and SiC as Reinforcements to Improve Properties of Composite Material

Soda white lime glass powder is an industrial waste which is available in abundant quantity all over India, it has to be disposed which is a problem related to pollution. The best way of treating industrial waste is to recycle or reuse so that the disposal and pollution can be controlled. Although glass powder is a waste it has some useful properties of materials which can be utilised Aluminium alloy has a major role in engineering applications because of its light weight and low cost. Many researchers have done works to improve the properties of Aluminium alloy by reinforcing with various harder materials like Al2O3, SiC, B4C etc. In this work we focused on Aluminium 6082 alloy which has similar but not equivalent physical properties like Al 6061, we indented to improve the strength, hardness and corrosion resistance by reinforcing Al 6082 with silicon carbide to improve hardness and soda lime glass powder to improve high temperature and chemical resistance. No researchers have so far used soda lime glass powder as reinforcement in fabrication of metal matrix composite material. We found tested samples have significant improvement in tensile strength, hardness and corrosion resistance. Aluminium being light weight material it tends to corrode more in real time applications. In this work the fabricated specimen are tested in pin on disk apparatus to find the wear strength and the optimum wear testing conditions are predicted.

High performance hierarchical nanoporous antireflective films by a facile sol–gel process

Single layer antireflection (SLAR) sol–gel films on super white glass substrates were prepared by hierarchically introducing hollow silica nano-spheres (HSNs) and F127 templated nano-pores.

Performance analyses of building energy on phase transition processes of VO2 windows with an improved model

A new model is established to obtain the building energy with a gradual change process of VO2 optical properties. Based on this method, three types of existing VO2 films are employed to simulate the heating and cooling energy consumptions in five typical Chinese cities. The results show that the smart characteristic is not evident in VO2 glasses because these films are almost in the cold state or cold transition state in the entire year. To improve this situation, the concept of an ideal thermochromic intelligent glass is put forward. Unexpectedly, the level of energy consumption increases with the film phase transition temperature decreasing in the heating period. However, the energy-saving effects will be effectivelyimproved both in the cooling and heating periods when the phase transition process interval is shortened. The cooling energy consumptions for the ideal glass decrease by at most 81.7% and 70.5% compared with white glass and Low-E glass, respectively. In the heating period, the level of energy consumption for the ideal glass is better than Low-E glass.

Preparation of silver thin films, and the study of the annealing effects on their structures and optical properties

In this study, using an electron beam, silver thin films with a thickness of about 120 Å were coated on white glass with thickness of (1 mm) by electron beam irradiation method, and the effects of annealing temperature on the morphology and optical properties of the thin films were investigated. The silver films were annealed at the temperature of 550, 625, 700, 775 and 850 K in the presence of air; in addition, a single sample that had undergone no annealing has also been provided for further comparisons. Their physical and morphological properties were analyzed using the spectroscopy of Ultra-Violet and Visible (UV–vis), x-ray radiation (XRD) and the SEM and AFM methods. The results obtained from this study show that by increasing the annealing temperature of the nanoparticles, the size of the mentioned particles has also increased.

Archaeometric analysis of vitreous material ornaments from the Villa di Villa site (Treviso, Italy)

The research focused on chemical and mineralogical analyses of eight vitreous material ornaments with a not well-defined chronology, coming from the protohistoric and Roman site of Villa di Villa in Cordignano–Colle Castelir (Treviso, north-eastern Italy). Eleven microsamples from the bodies and decorations of the ornaments underwent wavelength-dispersive electron probe microanalysis, scanning electron microscopy combined with energy dispersive spectrometry (EDS) and micro-Raman Spectroscopy. Non-invasive X-ray powder diffraction was performed on the surface of the ornaments. All vitreous materials were obtained using natron as flux except for one annular blue bead produced with mixed alkali plant ashes. The analyzed dark blue glasses are Co colored, only the pale blue melon bead faience is Cu colored. Opaque white and yellow glasses of two objects are opacified by Ca and Pb antimonates, respectively. The heterogeneous texture of some glasses is due to unreacted raw materials and/or newly formed crystals. The relationship between the Villa di Villa ornaments and coeval European/Mediterranean vitreous materials is also discussed. Composition, texture and morphological characteristics of the ornaments shed light on the different types of raw materials used and allow us to verify the main types of glass that occur during the great time span of life of the site and above all to answer to specific archaeological questions about possible chemical correlations between similar objects from the same or different SU. In two cases, the analytical data provide more detailed information about the ages of the ornaments.

Development of white titanic enamel coatings with reduced burning temperature

The work contains research of the influence of modifying additives Li 2 O and ВаО on the properties of frits and optical characteristics of white titanium low-fluoric enamel coatings. Optimal concentration of research oxides (0,5 mas. % Li 2 O and 0,75 mas. % ВаО ) is determined in composition of enamel coatings. White low-fluoric titanic glass coatings are obtained with specified optical characteristics: diffuse reflectance (DR) – 78 %, yellowness (G) – 4,57 %, regular reflectance (RR) – 75 %. Softening temperature of glass enamel being lower than domestic industrial analog is established by the method of differential and thermal analysis. Prevailing crystalline phase represented foremost in anatase form of titanium dioxide is using roentgen and phase analysis. The developed enamel glass coatings with specified optical parameters are more fusible compared with industrial analogs and meet the requirements of standards for internal and external enamel coatings and can be recommended for industrial testing with low-temperature short-term mode of burning.

Research on Waste Glass Concrete Elasticity Modulus

Waste glass is an industrial waste and household garbage, having a "flash color pollution" notoriety. Although some white glass can be processed into glass again, however, low utilization. But much of the waste glass still cannot be recycled. The key to improve the utilization of waste glass is how to effectively use colored and mixed waste glass. Waste glass aggregate concrete as a new material, the study of its basic performance is not mature. Taking into account the impact of different glass replacement rate on their basic mechanical properties, this paper tests carried out static compressive elasticity modulus test with glass concrete. Study the mechanical properties and deformation performance of glass concrete columns the basis of its basic mechanical properties, in order to obtain the glass concrete column of structure performance parameters.

Influence of thermal annealing on the structural and optical properties of maghemite (γ‐Fe2O3) nanoparticle thin films

In this study, maghemite (γ‐Fe2O3) nanoparticles were initially synthesized via chemical co‐precipitation and then deposited by spray pyrolysis as thin films on white glass substrates. The thin films were annealed for 8 h at 400, 450, 500, 550, and 600 °C in an oven. The structural studies of maghemite nanoparticles were carried out using X‐ray diffractometer. Structural properties that we investigated by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, SEM, and Energy dispersive X‐ray analysis (EDS). Optical properties of the samples were also investigated by ultraviolet‐visible (UV–vis) spectroscopy. The results showed that maghemite nanoparticles have crystalline structure with domain that increases in size with increasing annealing temperature. The optical band gap values were found to reduce from 2.9 to 2.4 eV with increase in annealing temperature. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Revisiting the beginnings of tin-opacified Islamic glazes

The generally accepted theory is that the demand for Islamic glazed pottery started in Abbasid Iraq in the 9th century AD with the production of a range of glazed wares in response to the import of Chinese stonewares and porcelains. However, Oliver Watson has recently proposed that the demand for Islamic glazed pottery first occurred in Egypt and Syria in the 8th century AD resulting in the production of opaque yellow decorated wares. Using a combination of SEM analysis of polished cross-sections, and surface analysis using hand-held XRF or PIXE, Coptic Glazed Ware from Egypt, Yellow Glazed Ware from Syria, and comparable wares from Samarra, Kish and Susa have been analysed. The analyses show that the opaque yellow decoration was the result of lead stannate particles in a high lead glaze, which it is suggested was produced using a lead-silica-tin mixture. The use of lead stannate in the production of yellow opaque glazes is explained in terms of technological transfer from contemporary Islamic glassmakers who continued the Byzantine tradition of glassmaking. It is further argued that the introduction of opaque yellow glazed pottery into Mesopotamia could have provided the social context for the sudden emergence of tin-opacified white glazed pottery in Abbasid Iraq in the 9th century AD. However, in view of the very different glaze compositions employed for the yellow and white opaque glazes, it seems probable that the white tin-opacified glazes used for Abbasid cobalt blue and lustre decorated wares represent a separate but parallel technological tradition with its origins in the production of Islamic opaque white glass.

Influence of Packaging Materials and Storage Conditions on the Vitamins A and E Storage Stability of Palm Oil in Nigeria

Aims: Despite the presence of natural antioxidants contained in palm oil, it is still susceptible to quality deteriorations if not properly stored. This study therefore evaluates the storage stability of vitamins A and E in palm oil in four prominent packaging materials (metal cans, white plastic bottles, glass bottles and pet bottles) used in Nigeria and under three storage conditions [(refrigeration (5oC), closed cupboard (27oC) and direct sunlight (35oC)]. Study Design: Freshly produced palm oil was filled in metal cans, white plastic bottles, glass bottles and pet bottles and stored in open, direct sunlight (35±1oC), closed wooden cupboard (27±1oC) and a refrigerator (5±1oC) for a period of 120 days The samples were stored in a 4 Original Research Article Oluwalana et al.; AIR, 4(3): 191-202, 2015; Article no.AIR.2015.074 192 (packaging materials) x 3 (Temperature) factorial arrangement making 12 treatments for each analysis sampled every 30 days for a period of 120 days. Vitamins A and E contents of palm oil samples were determined at 30 days intervals using ultraviolet spectrometer and high Performance Liquid Chromatography, respectively. Data values of triplicate determinations of vitamins A and E contents obtained from analysis were subjected to analysis of variance (ANOVA) and mean values were separated using Duncan New Multiple Range (DNMR) test using the Statistical Package for Social Sciences (SPSS) version 17.0. The rates of changes in the Vitamins A and E contents over the storage period of 120 days were also determined using Linear Regression analysis. Place and Duration of Study: Department of Food Science and Technology, Federal University of Technology, Akure, Nigeria between January, 2012 and December 2013. Methodology: Palm oil filled into the four different packaging materials was stored in the three storage conditions for a period of 120 days. Vitamins A and E contents of palm oil samples were determined at 30 days intervals using ultraviolet spectrometer and high Performance Liquid Chromatography, respectively. Data obtained were subjected to Analysis of Variance (ANOVA) to determine the statistical significant differences in the packaging materials and the storage conditions and the interactions between them. Mean values of vitamin A and vitamin E of different packaging methods and storage conditions were separated by Duncan New Multiple Range (DNMR) test to indicate their levels of significant differences. Linear Regression Analysis was also performed to determine the rates of changes in the vitamin A and E with time during storage. Results: The vitamins A and E content of the samples stored in open, direct sunlight were virtually lost at the end of the storage period. For samples stored in sunlight, the vitamin A values in metal cans decreased by 97.45%, in white plastic bottle by 92.19%, in glass bottle by 92.46% and in pet bottle by 93.13% while vitamins E also decreased by 92.31%, 61.54%, 75.48% and 82.05%, respectively. Samples stored at room temperature suffered a higher amount of losses compared to the refrigerated samples. The refrigerated samples recorded only a minimal amount of loss. For the storage in both the sunlight and the dark cupboard and storage under refrigerating temperature of 5oC, the order of preference for the packaging materials was white plastic bottle > glass bottle > pet bottle > metal can. Conclusion: The results obtained from this study have demonstrated that packaging palm oil in white plastic bottle is the best method of preserving palm oil under refrigerating condition and lacquered metal under sunlight and dark cupboard. It has also shown that vitamins A and E degrade faster when palm oil is stored under sunlight and totally unfit for human consumption at the end of the storage period hence, palm oil should be stored in cold, dry places to limit their losses of antioxidant components.