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In the 1970s, a rare assemblage of trade beads was discovered inside a woven plant fibre bag in a rockshelter (the ‘Dillybag site’) near Laura, Cape York Peninsula, Queensland. Cached post-1895, the bag held more than 4000 glass beads strung on cotton, nylon and hand-spun (possibly human) hair twine. Seventy-eight percent of beads showed some degree of damage from bead-on-bead contact, suggesting that the assemblage accumulated gradually over time. All beads on hair twine were minute or small, and potentially reveal consumer choice in their selection, as does the large proportion of red, white and black beads, suggesting a preference for customary colours. This cache is not only the largest collection of glass beads recovered from an archaeological context in Australia, but also speaks to the dynamism, agency and persistence of the Indigenous people of southeast Cape York Peninsula following invasion. [ABSTRACT FROM AUTHOR]

It is well recognized that the liquefaction resistance is closely related to the consolidation stress in soils. However, previous studies investigated the effects of unidirectional consolidation loads rather than multi-directional consolidation loads on liquefaction resistance. In this study, two types of granular materials, spherical glass beads and irregularly-shaped sands, are tested under undrained conditions with the uni- and bi-directional loads to investigate the liquefaction resistance. The effects of consolidation loads on liquefaction resistance can be explained in terms of material anisotropy. In simple shear tests, the stress- and strain-controlled loading paths are adopted for the consolidation and the undrained shear process, respectively. The results indicate that the liquefaction resistances of both materials consolidated under the multi-directional consolidation loads are higher than those consolidated under the linear loads. More consolidation loading cycles induce a better liquefaction resistance of the specimens at a given relative density. In addition, the influence of consolidation stress on liquefaction resistance is demonstrated by the anisotropy of specimens. Cyclic vertical stress, unidirectional shear stress, and bidirectional shear stress applied during consolidation produce greater isotropy and improve the liquefaction resistance of the specimen compared with the monotonic vertical stress, and their effects align with an increasing order. [ABSTRACT FROM AUTHOR]

This is a material culture-based case study of two bandolier bags dated to the late nineteenth or early twentieth century in the Agnes Etherington Art Center collection in Kingston, Canada. The floral motifs that decorate these two bags are not made from porcupine quills, nor are all of them bilaterally symmetrical as in "traditional" Indigenous art. Instead, they are made from glass beads, and most of the floral designs are asymmetrical. The bags' surface patterns and materials were made possible through international trade, which facilitated the merging of European and other global designs, materials, and forms with Indigenous visual and material culture. Contemporary Western anthropological discourse framed these Indigenous objects as "hybrids" and alleged that they distorted the original meaning of such styles in a European context while simultaneously "corrupting" traditional Indigenous art and culture. Such art forms were denied a place in modernity due to their supposed inauthenticity. Ironically, "authentic" Indigenous art and material culture was likewise barred from being considered "modern" due to its hand-made, "preindustrial" nature. Connecting North American historical developments with discourse on Indigenous modernisms, I argue that on the contrary, these bags evince their makers' conscientious engagement with modernity and can be considered modern Indigenous art. [ABSTRACT FROM AUTHOR]

To operationalise the heterogeneous photocatalysis process, the present study investigated the efficiency of TiO2-P25 nanoparticles immobilised on glass beads using the heat attachment method to remove cefazolin (CEF) as an antibiotic contaminant. The characteristics of the glass beads coated with TiO2-P25 nanoparticles were probed by the Scanning Electron Microscopy (SEM) technique. The immobilised TiO2-P25 nanoparticles manifested considerable efficiency in CEF removal in different operational conditions. The impact of various parameters, such as the ultraviolet light radiation time, initial concentration of CEF, light source power, inlet liquid volumetric flow rate, and pH of the solution, on the efficiency of CEF removal were examined. The results reveal that the removal percentage goes up as the irradiation time, volumetric flow rate, pH of the solution, and light source power increase while declining with a rise in the initial concentration of CEF. According to the findings, an initial CEF concentration of 20 mg L−1 is entirely removed by 40 min UV irradiation with a 16 W light source, the volumetric flow rate of 300 mL min−1, and the pH of 9.5. The reaction rate constant and adsorption coefficient of CEF on immobilised TiO2 were estimated at 0.622 mg L−1 min−1 and 0.095 mg−1 L via Langmuir- Hinshelwood kinetics. The outcomes of the mineralisation studies also display a considerable reduction of TOC and evolution of significant mineralisation products, like $$NO_3^ - $$ N O 3 − , $$NO_2^ - $$ N O 2 − , $$NH_4^ + $$ N H 4 + , and $$SO_4^{2 - }$$ S O 4 2 − . The experimental results were modelled by artificial neural networks (ANN). Comparing the experimental results with the ANN-predicted data shows the acceptable efficiency of modelling with ANN. The minimum MSE, R2 value for all data (validation, training, and test), and R2 value for simulated data were obtained at 0.00027811, 0.9971, and 0.9809, respectively. The relative importance of the parameters affecting the process evaluated by the ANN weights indicates that the irradiation time is the most important factor in the photocatalytic removal of CEF. [ABSTRACT FROM AUTHOR]

"Radical Stitch: Art Gallery of Hamilton, February 11–August 27, 2023" is an exhibition at the Art Gallery of Hamilton, Canada, celebrating 37 artists across Turtle Island through beadwork. The show explores the relational network of artists and the sharing of cultural knowledge through beadwork as a form of storytelling. The exhibition, currently at the National Gallery of Canada, Ottawa, showcases diverse perspectives and histories, confronting difficult pasts while highlighting the generosity and reciprocity embedded in beadwork as a language of shared experiences." [Extracted from the article]

Next to pottery, items of adornment comprise the most abundant material excavated in Northeast Africa, often being the only evidence for long-distance interactions. Interdisciplinary research has been developed to demonstrate that beads, particularly those of Indian origin from port sites on the Red Sea coast of Egypt, may attest to intense relations between North Africa and Asia. Parallels and provenance examination of recent bead and jewellery finds (four silver and coral earrings, eight silver rings and about eleven ivory bangles) from two Late Antiquity tombs of the fourth/fifth centuries AD at Berenike also suggest links between the Red Sea coast and the Nubian Nile Valley. Additionally, these ornaments raise questions as to their function in multiple burials. It is not possible to determine whether they were used as part of the funerary ritual or as offerings to the individuals buried, but several observations can be offered. [ABSTRACT FROM AUTHOR]

The paper analyzed the economic transporting performance of k-epsilon turbulence models using the Eulerian two-fluid approach in transporting highly concentrated fine particulate slurry through horizontal pipelines using Kaushal et al. (2005) experimental data of glass beads slurry of 125 μm mean diameter for volumetric concentration ranging 30%–52% and flow velocity ranging 2–5 m/s. The primary components of economical slurry transport are Specific Energy consumption (SEC) and pressure drop; both have been examined in the performance of different κ-ϵ models and are yet to be unlighted on these parameters. The CFD model found the excellent performance of all k-epsilon models with slightly more effectiveness in the case of the Realizable κ-ϵ model. The analyzed and validated CFD model was subsequently used in examining the parameters of slurry flow, such as the secondary phase velocity, concentration distribution, and SEC analysis for the range of fine particles 125, 150, and 212 µm. The plotted contours from CFD are useful in visualizing slurry flow parameters at intermediates inlet values for slurry inlet flow velocity ranging 2–6 m/s and inlet volumetric concentration ranging 30%–55% for fine particles. Analysis revealed that the highly concentrated fine particles slurry transported at optimum volumetric concentration range of 40–45% are economical slurry transport. [ABSTRACT FROM AUTHOR]

This study evaluated the feasibility and optimization of the spouted bed drying to produce standardized dried Camellia sinensis extract. We explored processing variables such as inert particle type (Teflon® or glass beads), drying aid concentration (colloidal SiO2—Aerosil 200®), and drying inlet temperatures (80, 110, or 140 °C). Regression analysis of the results allowed for constructing response surface graphs, highlighting variable impacts on product properties and spouted bed performance. The optimal conditions involved Teflon® beads and a drying temperature of 110 °C, resulting in a product with excellent moisture content, water activity, and active constituent retention. The product demonstrated significant antioxidant activity in DPPH assays, with an IC50 between 4.4 to 6.7 µg/mL, surpassing the synthetic antioxidant butylated hydroxytoluene (BHT), which had an IC50 of 12.5 µg/mL. Rancimat assays showed that the dried extract effectively protected crude sunflower oil from oxidation, increasing its shelf life from 8.2 to 13.1 months. [ABSTRACT FROM AUTHOR]

Suffusion is one of the four mechanisms of internal erosion. The embankments and their foundations can exhibit different forms of heterogeneity which can be a major factor initiating suffusion. Although several experimental studies on the effect of heterogeneities have been performed, numerical studies remain less approached. In this paper, the effect of material heterogeneity is examined using the discrete element method and the computational fluid dynamics model (DEM-CFD). The suffusion process is studied by simulating a soils sample in a column, subjected to downward flow. Heterogeneity is addressed by adding coarse particles at two-layer positions (mid-length or downstream) at three coarse fractions (20%, 40%, 60%). Its effect is investigated in terms of erodible particles, retention efficiency, and contact forces at the particle scale. In particular, the numerical simulation results show that the erosion occurs in a heterogeneous way, and the downstream configuration provides more suffusion than the central one. In addition, the introduction of coarse particles can lead to increase the filtration efficiency. The effect of involved heterogeneities on erosion depends simultaneously on the coarse fraction and configuration heterogeneity. The comparison of the numerical results with those obtained by a suffusion test shows a concordance and validates the numerical approach. [ABSTRACT FROM AUTHOR]

This paper estimates the effective stagnant thermal conductivity of a spherical packed bed using an experimentally validated modified collocated unit cell model. The study focused on the effect of primary and secondary parameters on effective thermal conductivity. The effects of concentration of the spherical packed bed, thermal conductivity ratio, contact conductance resulting from particle-to-particle contact, and moderate temperature are studied in detail. Analytical expressions are derived for the in-line contacting three-dimensional solid cubic arrays by adopting the unit-cell-based thermal resistance method for determining the effective stagnant thermal conductivity. The effective thermal conductivity of different heterogeneous packed beds with solid-fluid materials possessing conductivity ratio in the range of 1-1000 and concentrations in the range of 0-1 are predicted for various temperatures at constant pressure regimes using the developed model. Furthermore, the developed model is used to estimate the effective stagnant thermal conductivities of packed beds filled with glass and ceramic bead materials, which are compared with values measured using the steady-state square guarded hot plate apparatus over the moderate temperature range of 323-673 K. The values for both uniform-sized glass and ceramic beads are found to be within ±11.26% and ±13.35% of each other. [ABSTRACT FROM AUTHOR]

Colloid-facilitated contaminant transport in porous media has been widely observed in laboratory and field studies. In this study, the influence of two dissolved organic matters (DOMs), humic acid (HA) and bovine serum albumin (BSA), on the colloid-associated heavy metal transport, was investigated. Soil colloids with particle sizes <2 μm were prepared from bentonite. Glass bead was used as porous media for the column tests. The influence of DOM on the adsorption of Pb2+ and Cu2+ onto colloids was tested. Colloid mobility and colloid-metal co-transport in the presence/absence of DOMs were investigated by breakthrough tests. The test results showed that DOMs facilitated colloid mobility. The measured ζ-potentials showed that DOMs enhanced the electrostatic repulsion between colloids and glass beads and reduced colloid deposition. These findings were further confirmed by calculating the interaction energy using the DLVO theory. Batch tests showed the strong adsorption of Pb2+ and Cu2+ on the colloid, and the adsorption was enhanced by DOMs. The colloid-metal co-transport tests showed that colloids can significantly facilitate the transport of Pb2+ and Cu2+ and that the facilitation was further enhanced by DOMs. By heavy metals, the colloid mobility was retarded, mainly due to the increased deposition. The transport of Cu2+ facilitated by DOM was more obvious than that of Pb2+. Compared to BSA, the effect of HA on enhancing colloid mobility, increasing colloid adsorption to heavy metals, and hence on the facilitation of colloid-associated heavy metals transport was more prominent. [ABSTRACT FROM AUTHOR]

In this work, porous glass beads grafted with polyethylene glycol (PEG) were used as an adsorbent to purify lipase from Burkholderia metallica in column chromatography. The purification parameters viz. salt stability, types and concentrations of PEG and salt, pH of the binding solution, and flow rate were studied to determine the performance of the purification system in an XK16/20 column. The crude lipase was mixed with different types and concentrations of salts 1–5% (w/w) (sodium citrate, potassium citrate, and sodium acetate) and subjected to the column containing the polymeric glass bead. One-variable-at-a-time experimentation revealed that 20% (w/w) PEG 6000 g/mol impregnated glass beads with a binding solution of 5% sodium citrate at pH 7.7, a flow rate of 1.0 mL/min and extraction time of 10 min resulted in the highest purification factor and recovery yield at 3.67 and 88%, respectively. The purified lipase has 55 ∼ 60 kDa molecular mass. The outcome of the study showed PEG could be applied to modify the inert glass beads into polymeric form, providing a biocompatible and mild separation condition for lipase. Thus, PEG could be successfully applied for the purification of lipase from B. metallica fermentation broth using column chromatography. [ABSTRACT FROM AUTHOR]

In this paper, the performance of particle swarm optimization–radial basis function (PSO–RBF) neural network was examined to predict the shear strength of granular material. Direct shear tests were conducted on glass beads (400–600 mm in size) with 2% of liquid content at different powder contents (1, 2, 3, 4, and 5%) as the binder. Hydrated lime (HL), quick lime (QL), calcite, and sodium lignosulfonate (SL) powders were used to compare their shear strength characteristics. The actual loading stress was controlled at five levels (6.9, 10.3, 13.8, 17.3, and 20.7 kPa), and five further levels (24.2, 27.7, 31.2, 34.6, and 38.1 kPa) were used for prediction. Results showed that at 2% of water, the shear strength regularly increased at all amounts of HL, QL, and calcite powder. With the increased SL powder, the shear strength decreased. The actual and predicted maximum shear stress values for different levels of normal stress were fitted using the widely accepted Mohr–Coulomb criterion to determine the internal friction angle and cohesion, and R2 was improved from 0.98 to 0.99. The PSO–RBF neural network model was a flexible and accurate method for the prediction of the shear strength of granular material. [ABSTRACT FROM AUTHOR]

Glass beads from two maritime sites were analyzed: the Dutch East India Company vessel Rooswijk, wrecked in 1740 on Goodwin Sands off the Kent coast, UK, and an unidentified vessel known as the Bead Wreck, located off Saint Peter Port, Guernsey, in the Channel Islands. Both vessels were carrying drawn, lead glass beads, which are found mainly in 17th- and 18th-century contexts. The study demonstrates the value of analysing glass beads from wreck sites because the information has the potential to help characterize unidentified vessels and further refine bead chronologies at post-medieval archaeological sites. [ABSTRACT FROM AUTHOR]

Cree visual artist Ruth Cuthand utilizes traditional and contemporary Indigenous beading techniques to craft multicolored, enlarged images of deadly diseases spread during contact with European settlers. The beaded virus makes visible the 500-year history of biological warfare waged against Indigenous communities, while the act of beading, a form of medicine in itself, is a centuries-old practice of continuity and memory. The paper builds upon Avery Gordon's (2008) theory of hauntings to investigate traces of memory contained in viruses, beads and beadwork. I argue that the continuous outbreak of viruses that Indigenous communities experience operate as ghostly matter that make present the ghost of colonial violence. Building on decolonial feminist theories of inoculation, theories of temporality and semiology, bio-medical innovation and material history, I consider the viral impact of glass beads to argue that Cuthand's beadwork acts as decolonial inoculation: a technology that indigenizes the elements of colonial invasion to enable Indigenous resurgence and continuity. I examine Cuthand's beadwork as well as the role of the needle in both Western scientific and Indigenous practices of medicine. The paper closes with an examination of works made by Cuthand during the COVID-19 pandemic including A Remembrance of COVID-19 (2022) and a photo of Cuthand wearing an N-95 respirator mask beaded with COVID-19 microbes. I propose the mask is an act of temporal recurrence and discontinuity: it aligns the present with past moments of bioterrorism but reflects a divergence, a move toward Indigenous communicability as an act of survival. [ABSTRACT FROM AUTHOR]

As solid matrices can bond with other materials and enhance the mechanical properties of engineering structures, investigating the mechanical properties and cementation mechanism of cemented granular materials has become increasingly significant. However, most experiments were conducted only at macroscopic or microscopic levels. Further, it is difficult to compare and analyze the results at macroscopic and microscopic levels because of the complex spatial and mechanical effects between cemented particles at the mesoscale. In this study, we created a well-defined cohesive granular material with controllable cementation held together by mixing glass beads and a solid matrix. First, we explored the influence of the confining pressure and solid matrix content on the mechanical strength of the cemented granular materials through a consolidated undrained triaxial compression test to address the cementation effect quantitatively. Second, through tensile and shear tests on cemented units with different matrix volumes, the cementation mechanism of the cemented units was explored for the first time from the perspective of the stress–strain relationship. Finally, we qualitatively explained the mechanical phenomena of macroscopic cemented granular materials through the microscopic interaction between particles and realized a multi-scale analysis of the mechanical response of cemented granular materials, which may provide new ideas for the study of cemented granular materials.ism [ABSTRACT FROM AUTHOR]

In this research, complementary numerical and experimental physical models were conducted to investigate flow parameters around an isolated permeable spur dike using ANSYS FLUENT ver. 16.1 software. The volume of fluid method VOF with the help of CFD technique and the κ − ε turbulence model was used to simulate the complex free-surface flow by applying a geometric reconstruction scheme. Two different mediums with different porosities were used, namely, gravel and glass beads. It was found that, for low flow rate values, there are no significant changes in the water profiles in both longitudinal and lateral directions for both media. Although for high flow rate values, the differences tend to be clearer. Results showed that there is a slight effect of the medium's properties if the dike width is less than 1/3 of width of the channel, in particular with low flow rate values. Good agreement was observed between the computational and the measured results for the water surface profiles. Also, there is an exact match between the lateral velocity distribution of gravels and glass beads. Downstream the dike, the lateral velocity profiles exhibit an S shape curve due to high velocity in the free flow and small flow velocity behind the porous dike. The results show good agreement between the CFD results and the experimental observations of the water surface profiles and velocity distribution according to the statistical analysis using some standard indexes error. [ABSTRACT FROM AUTHOR]

Gas-solid fluidized bed is an effective dry method for beneficiation of −6mm fine coal, belonging to Geldart D particle. Due to the density difference of concentrates and gangue in the raw coal, the bed can remove gangue through segregation of binary particles. The core problem is how to reduce the bubble coalescence and improve segregation degree in the bed. In this study, glass beads and plastic beads were selected to simulate high-density and low-density particles in pulsed gas-solid bed (PGFB). And different pulsation frequencies (f = 0–7 Hz) and gas velocities (N = 1.1–1.7) were selected in this work. The results showed that gas velocity and pulsation frequency played important role on particle segregation and mixing behavior. The segregation index reached the maximum value at pulsation frequency f = 3.49 Hz and gas velocity N = 1.3 when h = 80 mm, indicating pulsed gas-solid fluidized bed can effectively separate particles of different densities. With the increase of bed height, the standard deviation of separation index decreases, and the optimal frequency moves to the low frequency region. This work provides guidance for the study of segregation and mixing behavior of Geldart D binary particles in pulsed fluidized bed. [ABSTRACT FROM AUTHOR]

Several thousand glass beads excavated in the Maryam Anza (Tigray, Ethiopia) cemetery over three seasons between 2014 and 2016 tell the story of the direct or indirect long-distance contacts of the people buried there. By combining typological and quantitative studies of drawn glass beads, this paper provides new bead evidence on the subject of the Red Sea and Indian Ocean trade in Late Antiquity. The assemblage is dominated by tiny monochrome glass beads of mid-fourth/fifth-century AD date that were brought as ships' cargo from South Asia through Arabian ports, reaching Northeast Africa at a time of intensive Indian Ocean trade. Close proximity to the Red Sea port at Adulis (in modern Eritrea) also allowed the transport of other overseas bead imports produced in Egypt or the East Mediterranean region. Comparative percentage analysis makes Aksum and the Maryam Anza community one of the major accumulators of India/Sri Lankan beads in Northeast Africa. [ABSTRACT FROM AUTHOR]

This paper deals with research into the influence of surface preparation before adhesive bonding of galvanised and non-galvanised steel substrates. The steel substrates were experimentally treated with chromate-free zirconate passivation, iron phosphate, zinc phosphate and an experimental organosilane-based preparation. The roughness of the treated substrates was evaluated by a set of selected vertical and horizontal parameters. The corrosion rate of the treated substrates was tested by electrochemical impedance spectroscopy and linear polarisation. Single-lap joints were created using one-component epoxy/PVC-polymerblend adhesive with glass beads, to ensure an evenly glued gap. The joints were tested for shear strength by tension, in accordance with STN EN 1465 in the as-bonded state, as well as after the climatic cyclic test PV1200. The results show that the adhesive used had a higher adhesion to galvanised substrates with a specific morphology. Adhesion to non-galvanised substrates has been significantly improved by using organosilane for surface preparation. The organosilane layer, containing epoxy organic functional groups, was incorporated into the organic binder of the adhesive and showed increased bond strength. [ABSTRACT FROM AUTHOR]

In contemporary academia, education is often perceived as a supplement to an academic career or a tool to satisfy management through course evaluations and this can alienate academics from teaching. To create inspiration and deepen the understanding of teachers' alienation as well as disalienation in the management classroom, we draw on Hermann Hesse's last novel 'The Glass Bead Game'. The story of Joseph Knecht who escapes an elitist pedagogical province to engage in personal teaching serves as an inspiration through which we discuss the act of resisting alienation in contemporary management education. Alienation, as we learn from Hesse, is not an unchangeable condition and it can be resisted through reinventing personal teaching, re-focusing attention from the demands of academic excellence to the imperfection of human beings, and acknowledging education as a history maker and teaching as a preparation for life and death. [ABSTRACT FROM AUTHOR]

The single-layer coated fabric was prepared using the polyurethane and the coating technology on the nylon. The influence of the wave-absorbing functional particles (graphene, graphite, hydroxy nickel powders, micron iron powders, silver-coated copper powders, silver-coated hollow glass beads) on the electromagnetic properties and the mechanical properties of coated fabrics was explored. Results showed that within the frequency range of 0 MHz∼1000 MHz, when the ratio of contents of the graphite as the wave-absorbing functional particle and the graphene was 1:1, the real and imaginary parts and the loss tangent of the dielectric constant of the graphene single-layer coated fabric were all the largest, namely the material's polarizing ability, the loss ability and the attenuation ability to electromagnetic waves were all the strongest; within the frequency range of 0 MHz∼40 MHz, when the ratio of contents of the micron iron powder as the wave-absorbing functional particle and the graphene was 1:1, the shielding effectiveness of graphene single-layer coated fabric was the largest, the shielding ability to electromagnetic waves was the the strongest. [ABSTRACT FROM AUTHOR]

In this study, the effects of quick lime (QL), calcite, and sodium lignosulfonate (SL) powders combined with liquid on granular system were compared. Different loading stresses were used to compare their shear and tensile characteristics. Glass beads (400–600 µm in size) and varying powder-to-liquid contents (from 0% to 5% in mass) as the binder in mixture were used to investigate their shear behavior and bulk density. Results showed that the shear strength was improved for all tested powder binders with their increased content in mixture. QL and calcite powders were weak when the liquid content was large (4–5%). Meanwhile, SL powder sufficiently controlled liquid and improved cohesion-related forces required to form and maintain granular bed stability. It also exhibited higher tensile strength than the other powders. Similar to SL powder, QL powder maintained significant tensile strength. The cohesion was enhanced and varied in the range of 0.17–1.46 kPa for QL powder and 0.10–1.08 kPa for calcite powder. By contrast, SL powder resulted in a high cohesion of 0.39–1.59 kPa for overall contents. The measured bulk density decreased to a certain extent and then increased for all powder binders with liquid content. [ABSTRACT FROM AUTHOR]

This paper presents results of experimental tests on soil specimens reinforced by stone columns. The experimental investigations have been conducted by setting up a laboratory scaled model. The main objective is to evaluate the effects of various reinforcing materials and stone columns configurations on the axial deformation during a vertical loading test of cylindrical samples of unreinforced and reinforced soil. The findings have been compared to existing experimental results proposed in literature. The specimens of soil consisted in an analogic material of poly-dispersed glass beads (GB) with a grain size smaller than 50 µm. Two reinforcing materials have been considered as ballasts: crushed sand (CS) and coarser granularity GB (0.7–1.0 mm). The results show that the material type and spacing between columns in a triangular or square configuration can greatly affect the reinforcement efficiency. The proposed results are applicable to predict the improvement of granular soils of medium density when subjected to the vibrocompaction technique. [ABSTRACT FROM AUTHOR]

Groundwater is the only source of high quality water for human consumption in most parts of the world; however, it can be easily contaminated by domestic, industrial, and agricultural wastes such as fertilisers and pesticides. The main objective of the present research was to study the photocatalytic removal of 2,4-Dichlorophenoxyacetic acid pesticide (2,4-D) from aqueous media. This was a laboratory scale study in which the zinc oxide nanoparticles were doped with 0.5, 1, and 2 molar percent of tungsten oxide. The nanoparticles synthesised were characterised using powder XRD, SEM, FTIR, and UV-Vis Spectroscopy analyses. During the photodegradation of 2,4-D, the operational parameters studied were pH, nanoparticles dosage, initial pesticide concentration, light intensity, contact time, and the mineralisation trend of organic matter. It was found that the doped nanoparticles had a smaller band gap energy, which confirms the effect of doping. The percentage of the dopant can affect the pesticide removal efficiency. The optimal pH value obtained was 7. In addition, the process efficiency, increased from 27% to 78% with increasing UV light intensity from 172 to 505 W/m2 respectively. Moreover, it was found that, with increasing light intensity, contact time and nanoparticle concentration all caused the pesticide removal efficiency to be increased too. In addition, the increase of the pesticide concentration would cause a reduction in the process removal efficiency. This study indicated that the photocatalytic process using tungsten doped zinc oxide nanoparticles can remove the 2,4-D pesticide by around 80% from the aquatic environment. [ABSTRACT FROM AUTHOR]

Soil liquefaction can be induced by natural events that entail complicated loading directions and magnitudes. To investigate the liquefaction behaviour of granular material under complex loading conditions, a series of strain-controlled cyclic simple shear tests are conducted on the uniform-sized glass beads. These tests include uni-directional and multi-directional loading paths. An energy-based method is used to assist the understanding of the cyclic behaviour of the specimens. After the first liquefaction happens, the specimens are re-consolidated and subjected to monotonic undrained shearing to investigate their post-liquefaction behaviour. The test results indicate that the specimens subjected to multi-directional cyclic shearing are more prone to liquefy than those under uni-directional loading. Furthermore, the cyclic shear strain amplitude and cyclic loading path have significant influences on the soil liquefaction resistance, re-consolidation volumetric strain and post-liquefaction shear strength. Nevertheless, the total energy that is dissipated for liquefying a specimen is only dependent on its relative density. [ABSTRACT FROM AUTHOR]

This paper presents the shear strength behavior of glass beads with two particular sizes under the influence of 0–5% liquid and hydrated lime (HL) contents. Experimental work was performed to analyze the influence of liquid–powder mixture ratios on a wet granular system under various loading stresses. Results showed that shear resistance (i.e., cohesion and friction) initially increased then decreased with the increase in liquid amount. HL increased the shear resistance of the mixture with a low liquid content (up to 3%), whereas it showed ineffective behavior in the mixture with a high liquid content (from 4% to 5%) because of the dominant liquid-related forces in the intermediated adhering layer. HL addition to the mixture increased the cohesion constants of small (from 0.04 kPa to 1.41 kPa) and large (from 0.2 kPa to 1.78 kPa) glass beads. Bulk density initially decreased with an increase in liquid content to a certain extent and increased afterward. HL was effectual (from 1% to 4%) and decreased the bulk density, but further addition of HL exerted an indeterminate effect. Hence, the bulk density and shear resistance evaluation help to assess the growth and strength of agglomerated products. [ABSTRACT FROM AUTHOR]

Links between flow properties and formulation of powders of 100 and 500 µm mean particle sizes were investigated. To determine the influence of surface treatment, the flow properties of glass beads were analyzed after various surface treatments leading to hydrophilic, hydrophobic, and lactose-coated surfaces. Furthermore, to investigate the influence of powder core composition, agglomerated lactose powders of circa 100 and 500 µm mean particle size were also produced by high-shear wet granulation and characterized. Hydrophilic and hydrophobic surface treatments did not alter surface topography and particle size distribution, whereas lactose-coated glass beads and agglomerated lactose powders presented noticeable changes of surface structure and particle size increase. Furthermore, all 100 µm powders were classified as easy flowing; hydrophobic glass beads and agglomerated lactose presented the highest and lowest powder flowability, respectively. For 500 µm powders, hydrophilic glass beads and agglomerated lactose powders had the highest and lowest flowability, respectively. The poorer flowability of agglomerated lactose may arise from their angular shape, their higher width of particle size distribution, the lower core density and the higher cohesion of lactose-coated particles. Last, no significant difference of powder compressibility was observed and all studied powders were hardly fluidizable, due to their high particle weight. [ABSTRACT FROM AUTHOR]

Free gossypol is a toxic compound which naturally occurs in cottonseed and its derivates, affecting animal and possibly human health. Consequently, alternatives for gossypol destruction must be evaluated. This work evaluated the emerging technology of ozone processing for free gossypol destruction in cottonseed meal. Ozonation was carried out in the actual cottonseed meal and also a model system, designed to describe the involved mode of action. The model system consisted of glass pearls beads covered with free gossypol. Ozonation was performed in two ways: as a static process, i.e., without homogenising the sample after placing them in the reactor, and also homogenising it. Ozone degraded free gossypol in all the systems, but reaching different levels. Free gossypol reduction was higher in the model system than the cottonseed meal, and higher in the homogenised processing than the static one: cottonseed meal in homogenised (56%) and static (25%); model system homogenised (98%) and static (80%). The obtained differences suggest a problem of gas penetration in the solid particles, the effect of unexposed surfaces due to contact areas, and the reaction with other organic molecules further than the target. Ozonation is a promising technique for gossypol degradation in cottonseed meal, but additional strategies are needed to optimise the ozonation process and evaluate toxicological aspects. [ABSTRACT FROM AUTHOR]

Excavated glass artifacts are usually environmentally impacted, causing spatial inhomogeneity which poses great challenges for accurate and non-destructive chemical characterization. Here, we present our study on accurate characterization of archaeological glass with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), a high-precision and minimally destructive analytic method. Using three corroded glass beads excavated from Guangnan, Yunnan, Southern China as examples, we discuss the issues that may be involved when observing signal curves of highly inhomogeneous archaeological glass, as well as provide chemical characterization for the intact pristine body. Results indicate that these Indo-Pacific monochrome beads are of the potassium silicate glass type and used mineral potash source, and that they contain copper as the colorant. By discussing the breadth and depth types of inhomogeneity and focusing on perturbation endured by major elements, we identify the extent of environmental alteration and describe how different elements and matrices can respond differently to the archaeological environment, leading to various corrosion behaviors. For such samples LA-ICP-MS is shown to be an advantageous tool to provide archaeologically relevant information, or to probe artifact conditions for conservation purposes. A good understanding of sample conditions, and close attention to the experimental and calibration process are required to overcome inhomogeneity when tackling archaeological glass. [ABSTRACT FROM AUTHOR]

This study reports the effectiveness of silver nanoparticles coated onto polyurethane foam (CPU), fused into polyurethane foam (FPU), and glass beads in a fixed bed column for removal of pesticide "Chlorpyrifos." Silver nanoparticles coated on substrates were synthesized in laboratory using hibiscus leaf extract (SNP) and was compared with commercial silver nanoparticles (CNP). Characterization of silver nanoparticles and its interaction with the substrate were probed using XRD, TEM, and FTIR, respectively. Experiments were conducted by varying flow rate (20–40 mL/h) with a fixed bed height and pesticide concentration. The maximum removal of pesticide was obtained as 92% and 94% for CPU; 90% and 96% for FPU; 81% and 72% for glass beads with SNP and CNP, respectively, at 20 mL/h flow rate. A decrease in removal efficiency and breakpoint time was observed with an increase in flow rate of pesticide-laden water. The outcome of the study reveals that the polyurethane foam as substrate for silver nanoparticles is more effective for the removal of pesticide from the aqueous solution, which can be further developed into continuous portable modules at commercial scale. [ABSTRACT FROM AUTHOR]

Although the scientific literature is replete with reports that host and plant volatiles elicit behavioural responses in Trichogramma, most do not compare the relative importance of olfaction, vision, or their interaction; this may be an oversight. We conducted experiments to evaluate whether vision, odour, or their interaction mediated host location by T. ostriniae over small spatial scales. T. ostriniae were given choices between odour cues and visual cues from Ephestia kuehniella, Ostrinia nubilalis, Manduca sexta, and polymer and glass beads, or between visual cues with and without an odour component. There generally was no preference for an odour component, suggesting that random encounter or visual guidance was the likely mechanism of location. For females who successfully located a cue, we found little evidence that odour was the primary mode of detection. However, when M. sexta eggs were the odour source, and compared to eggs washed with solvent to remove volatiles, females showed a predilection toward visual cues with an odour component. However, when Manduca spp. moth scales were applied to glass beads under conditions of high visual contrast, there was no significant preference for odourised visual cues. There is little doubt that Trichogramma rely on olfaction, but many studies include no visual components, no evaluation of the magnitude of olfaction relative to vision nor their interaction. We offer that random movement and vision may determine much of host-finding, especially with Trichogramma augmentatively released into monocultures, but there is likely some interaction with odours at some small spatial scale. [ABSTRACT FROM AUTHOR]

A novel method of the accelerated equilibration of 18O between CO2 and H2O for the measurement of the 18O/16O isotope ratios in aqueous samples with natural isotope abundances is presented. This rapid equilibrium method is based on the in vitro application of the enzyme carbonic anhydrase (CA). The CA from bovine erythrocytes was adsorptively fixed to 3-mm glass beads with an etched surface. After the addition of this carrier-fixed CA catalyst to the water sample, the isotope equilibrium was already reached after 1 h. The previously used non-catalysed 18O isotope exchange in water samples needs about 24 h. Whole blood samples also showed fast 18O isotope equilibration, which definitely results from the native presence of CA in erythrocytes. By shortening the time for sample preparation, the CA catalysed technique can significantly increase the throughput of the samples to be measured, and also 18O and 2H measurement by means of isotope ratio mass spectrometry (IRMS) may be synchronized. The 2H and 18O sample preparation can be performed in the same reaction vessel because cross-effects at the simultaneous use of Pt and CA catalysts do not occur. [ABSTRACT FROM AUTHOR]

Jet fuel may be released in the environment either by in-flight fuel jettisoning (fuel dumping) or accidentally from spills and leaks, and eventually can reach subsurface formations where it can remain as long-term source of pollution. Remediation of aquifers contaminated by jet fuels is not a trivial task. This experimental study examined the effectiveness of a water-soluble, DNA–protein-based biodegradable non-living catalyst, with commercial name GreenZyme® for the remediation of water saturated porous media polluted with jet fuel (JP-5). Also for comparison purposes, the commercial surfactant sodium dodecyl sulfate (SDS) was used. Bench scale experiments were conducted in a glass column packed with glass beads. The migration of JP-5 in the glass column under various conditions, with and without the presence of GreenZyme® was monitored by a well-established photographic method. Digital photographs of the packed column were captured under fluorescent lighting. The fluorescent intensity of JP-5 dyed with Red Oil O within the column was analyzed using the Matlab Image Processing Toolbox. The colour intensities were converted to concentrations via appropriate calibration curves. The experimental results suggested that GreenZyme® was an efficient biosurfactant capable of enhancing significantly the migration of JP-5 in the glass column, which performed considerably better that SDS under the experimental conditions of this study. [ABSTRACT FROM AUTHOR]

Excavated glass artifacts are usually environmentally impacted, causing spatial inhomogeneity which poses great challenges for accurate and non-destructive chemical characterization. Here, we present our study on accurate characterization of archaeological glass with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), a high-precision and minimally destructive analytic method. Using three corroded glass beads excavated from Guangnan, Yunnan, Southern China as examples, we discuss the issues that may be involved when observing signal curves of highly inhomogeneous archaeological glass, as well as provide chemical characterization for the intact pristine body. Results indicate that these Indo-Pacific monochrome beads are of the potassium silicate glass type and used mineral potash source, and that they contain copper as the colorant. By discussing the breadth and depth types of inhomogeneity and focusing on perturbation endured by major elements, we identify the extent of environmental alteration and describe how different elements and matrices can respond differently to the archaeological environment, leading to various corrosion behaviors. For such samples LA-ICP-MS is shown to be an advantageous tool to provide archaeologically relevant information, or to probe artifact conditions for conservation purposes. A good understanding of sample conditions, and close attention to the experimental and calibration process are required to overcome inhomogeneity when tackling archaeological glass. [ABSTRACT FROM AUTHOR]

The aim of this work was to coat glass beads with chitosan and cyanoguanidine-crosslinked chitosan and, afterward, to verify the potential of the coated beads as adsorbent for the FD&C Red 40 dye in fixed bed column. The coating was realized in eight experimental conditions, varying the technique (dip coating or casting) and the coating solution composition (different proportions of chitosan, cyanoguanidine, glycerol, sorbitol, sodium alginate, NaOH and CaCl2). The beads coated in the eight experimental conditions were then applied to adsorb FD&C Red 40 in a fixed bed column, from aqueous solutions at pH 3.0 and 6.0. The breakthrough curves were fitted according to Thomas and Yoon-Nelson dynamic models. The coating was dependent of the solution composition. The casting technique presented coating percentage values of 92%, while the dip coating technique presented only 43%. The breakthrough curves revealed that the use of glass beads coated with cyanoguanidine-crosslinked chitosan had good performance, attaining adsorption capacity values higher than 80 mg g−1. Thomas and Yoon-Nelson models were able to predict the breakthrough curves in all conditions. [ABSTRACT FROM AUTHOR]

For many powder processes, the particle size distribution (PSD) is a key quality attribute of the flow properties of the process powders. This paper presents a method for estimating the PSD with acoustic emissions (AE) by implementing a time domain-based threshold approach followed by the extraction of the amplitude mean from each set threshold and correlation to particle size. The experiments were carried out using a powder-free fall experimental rig, and a set of glass beads, while the acquired data were analyzed with a designed signal analysis method. The results of the experiments showed that the PSD of the particle mixtures being investigated could be identified with an average absolute error of 10%. The main advantage of the designed signal analysis method was identified as the requirement for a low hardware complexity due to a simpler algorithm than its predecessors. In an attempt to benchmark the performance of the system, the performance of the designed approach was compared to a wavelet-based analysis designed by Ren et al. From this it was seen that the approach used by Ren et al. is reliant on a tuning process to aid the algorithm in making the size estimation, suggesting that Ren's approach would prove to be inefficient in a process where powder segregation occurred due to poor mixing. [ABSTRACT FROM AUTHOR]

In the papers assembled here, five scholars focus on shell beads at site, watershed, and regional scales. Themes include manufacturing techniques such as bore size discussions, changes in bead preferences over time and geography, the appearance of beaded regalia, and shell bead meaning. Claassen's paper addresses the beads at Late Archaic Indian Knoll; Connaway discusses shell beads in northwestern Mississippi; Pearson looks at beads from coastal Georgia; and Webster and King examine beads before and after European contact in the Potomac basin. [ABSTRACT FROM AUTHOR]

This article examines over 7,500 beads from eight Native archaeological sites located in the lower Potomac River valley in order to understand how changes in bead assemblages between AD 1300 and 1712 expressed an ever-evolving Chesapeake cultural landscape. This analysis demonstrates clear differences in the types and distributions of beads from mortuary and domestic/nonmortuary contexts. Ossuary contexts contained the highest frequency of beads with the number of beads increasing over time. Following the arrival of English settlers in the 1620s, glass beads begin to appear in ossuary contexts. Beads from domestic or nonmortuary contexts are fewer in number, and those present were manufactured using local materials, including bone and clay, as well as shell. However, after 1680, there is a shift from shell beads being predominate on Native sites, to sites containing exclusively glass beads, red and black glass beads in particular. Post-1680 sites appear to reflect Piscataway displacement and the disruption of indigenous trade routes, leading Natives to obtain beads from colonial vendors. The distribution of bead color, an important attribute for communicating Native states of being, also shifts after 1680, with assemblages once dominated by white shell beads now dominated by black and red glass beads. [ABSTRACT FROM AUTHOR]

Experimental and modeling studies have been performed to determine mixing characteristics of binary mixtures in a spout-fluid bed. Spherical glass beads of diameters (3.075, 1.7, 1.2, and 0.75 mm) and air as fluidizing medium have been used in the study. Effect of various system parameters, namely, initial static bed height, gas velocity, diameter ratio, mixture composition, and sampling time on mixing of binary particles has been experimentally investigated. A dimensionless correlation has been developed for mixing index. Mixing behavior has been modeled using artificial neural networks (ANNs). Training of ANN was performed using the Levenberg–Marquardt (LM) backpropagation algorithm to predict the mixing index. The predictions of the ANN were found to be in good agreement with the experimental results and predictions from developed correlations. [ABSTRACT FROM AUTHOR]

The hormone melatonin (MT) is produced by the pineal gland in animals and can also be found in plants and algae. MT regulates not only sleep, reduces the effects of jet lag, and has anti-aging properties in animals, but also eliminates intracellular reactive oxygen species and promotes vegetative growth in plants. However, research on its biological function in microalgae is still rare. The present study involved the construction of the Chlamydomonas reinhardtii expression vector pDBle-AANAT, which harbours the gene of one of the enzymes of the MT synthesis pathway, aralkylamine N-acetyltransferase (AANAT). The AANAT gene was introduced into the genome of the model microalga C. reinhardtii via glass bead transformation. The AANAT transgenic algal strain was identified by resistance screening, culture, and molecular biology methods. Changes in MT content between transformed algal strain and nontransformed algal strains were detected and the antioxidant capacity of the AANAT overexpressing algal strain was analysed under salt stress. The results showed that genetically engineered algae can increase the content of MT in algal cells by overexpressing AANAT. Under salt stress conditions, this can help to improve the enzymatic activity of the antioxidant system of algal cells and reduce membrane damage to counteract the adverse external stress. This enhances the self-protection ability of C. reinhardtii. This study reveals the effects of MT overproduction on the physiological functions of C. reinhardtii. Additionally, the potential functions of MT in the response of C. reinhardtii to stress have been elucidated, thus broadening the functional scope of MT in plants. [ABSTRACT FROM AUTHOR]

Glass beads from the East African coast obtained through the Indian Ocean trade have been known for a half-century to have been taken into the interior of southern Africa. Zhizo Hill and Makuru, both situated in central Zimbabwe, were among the first Early Iron Age sites where such beads were recovered. Zhizo Hill subsequently became the name site for these beads and associated pottery, now called Zhizo. Makuru was among the very few mid-twentieth century sites with adequate charcoal from which the first radiocarbon dates associated with Zhizo beads and ceramics were obtained. Yet the beads from neither site have been analysed before this nor described in any adequate way. This paper presents the results of their analyses by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry along with reassessments of those first radiocarbon dates. It then considers the implications of these data and the complexities of interpretation regarding the beads in southern Africa still to be addressed. [ABSTRACT FROM AUTHOR]

This paper investigated the overall gas holdup characteristics in a cocurrent three-phase fluidized flotation column with liquid as the continuous phase. The air, water, and glass beads with a diameter of 3 mm were, respectively, used as the gas, liquid, and solid phases in the flotation column. The gas holdup studies were carried out in a plexiglass column with 0.05 m in internal diameter and 2.2 m in height. Bed pressure drop measurements were used to calculate the fractional gas holdup. During the measurements, the superficial gas and liquid velocities, respectively, varied from 0.42 to 2.55 cm/s and from 6.47 to 10.82 cm/s. Detailed experimental investigations were carried out to study the effects of static liquid height, initial static bed height, gas velocity, liquid velocity, and frother concentration on gas holdup in a cocurrent three-phase fluidized flotation column. It was found that the gas holdup increased with the flow rate of air and decreased with an increase in the water flow rate. Certain effect of the static bed height on gas holdup was observed when the gas velocity varied. But the increase in the static liquid height resulted in the decrease in gas holdup when the gas velocity varied. [ABSTRACT FROM AUTHOR]

Context:Recent findings indicating the anti-inflammatory action of silver preparations through modulation of the gut microbiota and apoptosis of inflammatory cells predestine silver use in inflammatory bowel disease (IBD). Objective:The aim of our study was to validate the possibility of effective silver release from silver-coated glass beads for anti-inflammatory local application in the lower sections of the gastrointestinal (GI) tract. Materials and methods:Silver-coated glass beads were prepared using magnetron method. Release of silver from the silver-coated glass bead surface was carried out in BIO-DIS reciprocating cylinder apparatus. Erosion of silver coating and indirect estimation of the silver release dynamics was assessed using scanning electron microscope. Rectal suppositories containing silver-coated glass beads were prepared using five different methods (M1–M5) and X-ray scanned for their composition. Results and discussion:The XR microanalysis and the chemical composition analysis evidenced for a rapid (within 30 min) release of nearly 50% of silver from the coating of the glass beads, which remained stable up to 24 h of incubation. The most homogeneous distribution of beads in the entire volume of the suppository was obtained for formulation M5, where the molten base was poured into mold placed in an ice bath, and the beads were added after 10 s. Conclusions:Our study is the first to present the concept of enclosing silver-coated glass beads in the lipophilic suppository base to attenuate inflammation in the lower GI tract and promises efficient treatment with reduced side effects. [ABSTRACT FROM PUBLISHER]

When material objects are recovered in a place different from their presumed place of origin, archaeologists usually fix attention on those objects and places themselves. Material objects do not, in themselves, however, have intrinsic value, and underlying the material variables of objects and their loci of origin and deposition is a more fundamental actuality of their translocation, the regimes of value in which things were assessed and in which they moved. Fundamental to this is that things have exchange value as well as consumption value and may also have spiritual value in specific circumstances. I argue that these are particularly important considerations when material objects are translocated from a distinct socio-geographic region, with its internal regime of values, to another quite different region, with probably diverse local regimes of value, as is the case when Early--Middle Iron-Age (300-1300 CE) sumptuary goods, mainly glass beads, moved from the East African Indian Ocean sphere to interior southern Africa, which had its own distinct regimes of value. In this article, I present data for this movement and premises regarding regimes of value, to address the trajectory of such beads into the southern region. I suggest that marine gastropod shells, cowrie and conus, are equally significant markers of interior--coastal associations, and their presence at 7th-11th-century southern sites with no glass beads suggests that different regimes of value were held by southern African peoples. This offers clues to bead and shell distributions. Several concrete instances demonstrate the point. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the bond strength of different resin cements in lithium disilicate glass ceramics on which different surface treatments are used. For this study, 120 unit IPS e.max Press samples were prepared for the bond strength test. Samples were randomly divided into six groups. The following treatments were applied on ceramic surfaces: (1) control (no surface treatment), (2) hydrofluoric acid (HF), (3) sandblasting (Al2O3powder), (4) Co-Jet (silica-coated Al2O3powder), (5) Er:YAG (erbium-doped yttrium aluminium garnet) laser and (6) Nd:YAG laser (neodymium-doped yttrium aluminium garnet). SEM (scanning electron microscopy) was performed on one sample from each group. Dual-cure resin cement was stuck on half of the samples prepared, and self-cure resin cement was stuck on the other half of the samples, and shear strength was applied until breakage occurred. The data was analyzed with variance analysis (ANOVA). According to the results from the bond strength tests, dual-cure and self-cure resin cements showed statistically significantly higher bond strength in the samples on which Co-Jet was applied, while the least bond strength was observed in the samples in the control group. Additionally, self-cure resin cement showed significantly higher bond strength values than dual-cure resin cement. Different surface treatments affect the bonding of different resin cement to IPS e.max Press. [ABSTRACT FROM AUTHOR]

A set of artifacts, apparently associated with human remains (one tooth), from Pine Island, Alabama, was donated to the Yale Peabody Museum of Natural History in 1915. In preparation for repatriation, this collection was investigated extensively by a volunteer team. This paper reports the results of this analysis, focusing especially on a new type of trade gun and the glass beads. The goal of the research is to provide an accurate date for the collection to assist in identifying the Native American group represented. [ABSTRACT FROM PUBLISHER]

A series of micro hollow glass beads (HGB) filled castor oil-based polyurethane/epoxy resin graft interpenetrating polymer network (IPN) composites were prepared. The tensile and impact strengths, impact fractured surfaces, damping properties and thermal stability of the IPN composites were studied systematically in terms of composition. Results revealed that the addition of HGB into polyurethane/epoxy IPN can significantly improve not only the tensile strength but also the impact strength. The tensile strength was increased by 61% and at the same time the impact strength was increased by 25% when the HGB content was 1.5%. The damping properties were better than the composition of 0.5% or 2% HGB content when the HGB content was 1% or 1.5%. The thermal decomposition temperature was also slightly improved by the incorporation of HGB. It is suggested that the HGB reinforced polyurethane/epoxy resin IPN composites could be used as structural damping materials. [ABSTRACT FROM AUTHOR]

Particle–particle and bubble–particle-interactions in flotation systems are governed by physico-chemical and hydrodynamic conditions of pulp. Shape factor and roughness of particles significantly affect these interactions, and hence both grade and recovery in flotation. Although many studies have been conducted to understand morphological features of particles, the underlying mechanism of their effect on flotation recovery have not been clearly shown. Towards this aim, acombination of grinding and abrasion processes was applied to mimic grinding in terms of shape and roughness in order to get their corresponding flotation recoveries at different collector levels. For this purpose, glass beads representing smooth spherical particles of –150+106 µm in size along with ground and abraded glass particles of different shapes and roughness were used to evaluate the flotation efficiency of these particles in the absence and presence of amine collector. The dependence of the shape and roughness on the flotation recoveries at different hydrophobicities as monitored by different amine collector concentrations is demonstrated. Finally, the results are discussed to see if morphology ofparticles can be tuned through grinding to achieve maximum flotation efficiencies. [ABSTRACT FROM PUBLISHER]