Explosive activity on Kīlauea’s Lower East Rift Zone fuelled by a volatile-rich, dacitic melt

Magmas with matrix glass compositions ranging from basalt to dacite erupted from a series of 24 fissures in the first two weeks of the 2018 Lower East Rift Zone (LERZ) eruption of Kīlauea Volcano. Eruption styles ranged from low spattering and fountaining to strombolian activity. Major element trajectories in matrix glasses and melt inclusions hosted by olivine, pyroxene and plagioclase are consistent with variable amounts of fractional crystallization, with incompatible elements (e.g., Cl, F, H2O) becoming enriched by 4-5 times as melt MgO contents evolve from 6 to 0.5 wt%. The high viscosity and high H2O contents (~2 wt%) of the dacitic melts erupting at Fissure 17 account for the explosive Strombolian behavior exhibited by this fissure, in contrast to the low fountaining and spattering observed at fissures erupting basaltic to basaltic-andesite melts. Saturation pressures calculated from melt inclusions CO2-H2O contents indicate that the magma reservoir(s) supplying these fissures was located at ~2-3 km depth, which is in agreement with the depth of a dacitic magma body intercepted during drilling in 2005 (~2.5 km) and a seismically-imaged low Vp/Vs anomaly (~2 km depth). Nb/Y ratios in erupted products are similar to lavas erupted between 1955-1960, indicating that melts were stored and underwent variable amounts of crystallization in the LERZ for >60 years before being remobilized by a dike intrusion in 2018. We demonstrate that extensive fractional crystallization generates viscous and volatile-rich magma with potential for hazardous explosive eruptions, which may be lurking undetected at many ocean island volcanoes.

THE ART OF STAINED GLASS IN THE ARCHITECTURE OF TEMPLE BUILDINGS OF THE RENAISSANCE PERIOD IN LVIV

The stained glass art of temples and chapels of the Renaissance period occupies a special place in the fine arts of Lviv. Special attention is drawn to the stained glass windows of Lviv's sacred buildings, which impress with their aesthetics, composition, colours, and artistic expressiveness. In the process of studying stained glass windows in the decoration of Renaissance churches and chapels in Lviv, the manufacturing technology, compositional solution, their colour scheme were analyzed and the main features of their artistic and figurative expression were revealed. Renaissance stained glass windows have not survived, all stained glass windows of Lviv temple buildings were made in the XIX-early XX centuries. The stained glass compositions of the Church of the Assumption are marked by a simple and at the same time refined composition and picturesque colours in light tones in contrast to the Gothic patterns. Ornamental stained glass compositions were used in the interiors of the chapels. Ukrainian artists of monumental art used the latest progressive technologies of making stained glass. Professional foreign artists - connoisseurs of stained glass art - were invited to make stained glass window compositions of Lviv Renaissance temple buildings. All stained glass windows of Lviv's sacred buildings are highly artistic decorative works and belong to Ukrainian artistic heritage.

Proportions, Timing, and Re-equilibration Progress During the 1959 Summit Eruption of Kīlauea: an Example of Magma Mixing Processes Operating During OIB Petrogenesis

Petrographic and chemical analysis of scoria samples collected during the 1959 Kīlauea summit eruption illustrate the progress of thermal and chemical homogenization of the melts, and the gradual growth and/or re-equilibration of olivine phenocrysts, over the course of the eruption. Glass compositions show that thermal equilibration was largely complete within the span of the eruption, while chemical homogenization was a work in progress. The olivine phenocryst population, known to contain conspicuous antecrystic components, is also hybrid within the euhedral population. The bulk of the olivine reached the level of the erupting magma on November 18-19, 1959. Zoning patterns in olivine phenocrysts show that initially unzoned grains developed normal zoning by the end of the eruption. Reverse zoning in relatively Fe-rich olivine phenocrysts (interpreted as cognate to the stored magma) was progressively eliminated from November 21 to December 19, 1959, by diffusive re-equilibration between crystals and melt. Toward the end of the eruption, the only olivine composition in direct contact with the melt was Fo84-86, with the original rim compositional heterogeneity gone in 4-5 weeks’ time. Activity in December 1959 differed from that in November, as high fountaining events were more closely spaced and almost all samples were picritic, with bulk MgO ≥16.5 wt %. Three different levels were in play during the 1959 eruption: a deep source for high-MgO melts and forsteritic (Fo87-89) olivines, an intermediate source for the bulk of the stored magma, and a shallower source for the most differentiated magma. This model is consistent with geophysical, petrologic and chemical observations. Comparison of the 1959 eruption with results from older explosive deposits suggest that stored and recharge melts and olivine from the deeper parts of Kīlauea’s plumbing are similar in composition to those observed or inferred in the 1959 eruption, so they behave similarly during extrusive and explosive periods alike.

Influence of small additives of germanium on the physical properties of chalcogenide glasses based on composition As30.5S44.5I25

Advanced for the infrared region of the spectrum chalcogenide glass composition As30.5S44.5I25 with small germanium additives were investigated. The concentration dependences of some physical and chemical properties indicate an increase in the performance of glasses due to the modification of the glass network. The character of the change in the short-wavelength absorption edge with an increase in the content of germanium atoms had an exponential character, shifting from 597 to 582 nm. A non-monotonic dependences were also found for the values of density, refractive index, and glass transition temperature. A joint analysis of the results obtained and structural studies described in the literature for similar glass systems made it possible to propose possible structural groups of glass compositions under investigation.

Dissolution behaviour and imageability of ternary borate glasses for use in geniculate artery embolization

Sixteen borate glass compositions comprising K2O and SrO were screened, using a design of mixtures approach, to model compositional effects on dissolution, CT imageability, and MRI relaxivity (R2). Based on the characteristics of each network, together with dose determination and toxicological risk, the composition identified as BKSA16 was selected as a preferred composition for pre-clinical evaluations related to geniculate artery embolization (GAE). Accordingly, BKSA16 particles were subjected to a flame spheroidization process and recharacterized, including the evaluation of residual mass at 72 h in physiologically representative media along with clinical determinations of suspension time (ease of use). For both the irregular particles and microspheres residual mass was present at 72 h in physiologically representative media. Additionally, both the microspheres and irregular particles achieved suspension times deemed to be acceptable for clinical use. The collective data confirms that BKSA16 microspheres have a range of beneficial features (specifically both degradable and imageable) suited to GAE.

The Use of Controlled Dissolution Glasses to Consolidate and Create Permeable or Impermeable Minerals in Formation

Scope Controlled dissolution glasses form a permanent consolidating mineral matrix inside formations with either permeable or impermeable properties. The unique solution has a low injection viscosity and can be easily injected into a wide range of formations. The application method is simple and does not require multiple fluids or pre- and post-flushing. This paper focuses on the benefits of controlled dissolution glasses and potential applications in the oil and gas industry. Methods, Procedures, Process Controlled dissolution glasses have been researched extensively by Glass Technology Services (GTS) since 1999 for the biomedical industry, nuclear waste storage industry, and defense and aerospace industries. GTS together with operators have been performing research and development for the oil industry over the last 10 years. The research investigated different glass compositions to determine their injectability and change in formation properties post-treatment. Sandstone, chalk, and shale formations were used in the testing. Flow testing using a Hoek cell and a core flood apparatus was used to determine the post-treatment permeability. For post-treatment strength measurement, Brazilian tensile strength tests and modified cone penetration tests were used to determine tensile strength and shear strength respectively. The testing evaluated different mixing fluids, such as water and different brines, compatibility, corrosion testing, and concentrations. Results, Observations, Conclusions The testing identified different glass compositions and concentrations that are suitable for different applications and formations. Certain glass compositions increase tensile strength significantly while also maintaining the permeability in the formation. Other glass compositions have similar tensile strength increase, but result in an impermeable seal. The liquid glass solutions react with the formation to form a mineral precipitation inside the formation. The reaction with the formation occurs quickly at downhole conditions, within hours of placement. The glass can be mixed with water and variety of brines to form a stable solution across a range of densities. The testing and results to date have laid the foundation for use in a variety of consolidation and P&A applications in oil and gas wells. Testing is ongoing for a chalk and sandstone consolidation solution and for a sealing solution. Novel/Additive Information These novel glass solutions can solve many of the production and instability challenges that plague weak formations. The glasses can be injected into very low permeability formation to either seal or consolidate.

Incorporation of Novel Elements in Bioactive Glass Compositions to Enhance Implant Performance

Increasing popularities of bioactive-glasses and their potential medical applications have led to countless studies into improving their material characteristics and overall performance. Some scientists hope to create new bioactive-glass compositions, while others seek to merely modify existing ones such as the novel 45S5 bioactive-glass composition; created by Dr. Larry Hench. These modifications aim to address potential complications that may arise at a site following implantation such as bacterial infections. In other cases, the incorporation of a selected element or compound may aim to improve the implant functioning by increasing cell proliferation. Although possibilities are plentiful, researchers avoid compromising the typical bioactive glass characteristics when doping with elements such as silver, or gold to achieve additional properties. This chapter elaborates on the incorporation of popular elements by doping bioactive-glass compositions to introduce desired properties based on the implant application.

W skali szarości – krótka historia srebrzystego ołowiu łączącego kolorowe szkła witrażowe

Katarzyna Pyka discusses lead as a substance which for centuries has made possible stained glass glazing both in sacral and secular buildings. This article focuses on the uses of lead and compares the work of stained glass artists in the past and today. Contrary the associations of this craft with vivid multicolored compositions, Pyka has decided to keep her discussion in grayscale; her purpose has been to emphasize the importance of this silvery metal, which has enriched the history of art from the Middle Ages by making possible the beauty of stained glass compositions.