Glass Shell Research Articles

Air to liquid heat transfer coefficient experimental comparison between silicon carbide and glass shell and tube heat exchangers in a pilot plant scale

ABSTRACT Instead of the expected 3.8–5.4% increase in the heat transfer coefficient due to the better thermal conductivity of silicon carbide tubes compared to glass tubes, the observed increase was 18–22% for 150–275 kg·h−1 airflow and 6 kg·s−1 propane-1,2-diol coolant in tubes. This additional 15–17% increase is probably due to local flow turbulisation due to the roughness of the sintered carbide of 4–10 µm, which unfortunately also causes a 17–24% higher air pressure drop. The hand calculation model used underestimates the heat transfer coefficient by −2% to 10%, which is better than CHEMCAD 8 modeling results.

High creep resistance in amorphous/crystalline dual-phase nanostructured CoCrFeNiMn high entropy alloys

Amorphous/crystalline dual-phase metallic materials received great attention owing to their synergistic combination of strength and ductility. However, the mechanisms governing creep deformation in these dual-phase materials are largely elusive. In the present letter, the creep deformation of amorphous/nanocrystalline CoCrFeNiMn high-entropy alloy (HEA) films is investigated through nanoindentation creep testing. It is suggested that dual-phase HEAs exhibit reduced creep strain compared to their monophase counterparts, and even surpass the performance of coarse-grained variants. This behavior arises from diffusion processes within the amorphous phase and the capacity for nucleation/annihilate of dislocations at amorphous/nanocrystalline interfaces. Furthermore, it is proposed that the presence of glass shell significantly influences the creep behavior of dual-phase HEAs.

Mitigating rim bending in fused silica micro shell resonators by a chamfered mold

In this work, we addressed the bending of a micro shell resonator’s rim toward the stem during glass-blowing process. This phenomenon occurs due to increased heat loss at the mold’s edge and reduced heat flux at the side of the Gaussian heat source. To mitigate rim bending and the subsequent reduction in capacitance between the rim and 3D electrodes, which can degrade performance in micro glass-blown shell resonators for gyroscopes, we propose two potential mold solutions, using short-stem mold and chamfered mold. To quantitatively compare resonators created by these two types of molds, we calculated the noise factor for predicting its gyroscope performance. From these calculations, we find out that using the chamfered mold enables us to increase in the resonator’s effective mass, eigenfrequency, angular gain, and quality factor, consequently reducing the noise factor compared to using the short-stem mold. We also demonstrated these results by manufacturing shell resonators and measuring its vibrational characteristics. After metalization of the glass shell resonator, Q factor and eigen frequency of n = 2 vibration mode along the primary (secondary) axis were measured to 622,466 ± 6,427 (619,793 ± 6,402) and 4,343 ± 40 Hz (4,350 ± 40 Hz), respectively. This simulation process will assist us in getting insight into understanding a shell resonator as a gyroscope, designing a mold and determining experimental conditions.

Low-carbon UHPC with glass powder and shell powder: Deformation, compressive strength, microstructure and ecological evaluation

Waste glass and shells are by-products generated in the production process of the construction industry and aquaculture respectively. The high-value treatment of these materials presents a global challenge. Converting waste glass and shells into solid waste-based ultra-high performance concrete (UHPC) mixtures is an eco-friendly strategy. In this study, glass powder (GP) and oyster shell powder (OSP) were mixed to prepare composite supplementary cementitious materials (GOS) and partially replace cement. The compressive strength, drying shrinkage, microstructure, and environmental impact of GOS-containing UHPC were investigated. Results indicate that adding GOS reduces the fluidity of UHPC mixtures, with further decreases as GOS content increases. Replacing cement with an appropriate amount of GOS (10 wt%-20 wt%) enhances the compressive strength of UHPC, though higher GOS levels reduce its strength. Meanwhile, the drying shrinkage deformation of UHPC decreases significantly as the GOS substitution level increases. The 28-d drying shrinkage deformation of the specimen added with 20 wt% GOS is 574 μm/m, which is 61.96 % lower than the control group. Additionally, the specimen added with 20 wt% GOS shows significantly improved compactness and enhanced bonding at the interfacial transition zone. Compared with traditional UHPC, GOS-containing UHPC has lower carbon emissions and costs, effectively utilizes waste, and promotes sustainable development.

Preparation of large diameter/thickness ratio glass shells and “In situ” high temperature infrared spectroscopy study

The millimeter-sized glass (SiO2) shells play key roles in inertial confinement fusion (ICF) experiments, especially for the so-called "direct-drive" configuration. The preparation of large diameter/thickness ratio glass shells and the exploration of transformation mechanisms for silicon-doped glow discharge polymer (Si-GDP) to SiO2 still face challenges. Here, we prepared large diameter/thickness ratio glass shells with the diameter of ∼1200 μm and shell thickness of ∼5 μm by increasing the Si contents in Si-GDP precursors. The influence of Si contents in Si-GDP shells on the compositions, morphologies and geometrical properties of glass shells were carefully investigated. The formability and uniformity of micro morphologies of the glass shells will improve with the increase of Si contents in precursors. The chemical composition of the prepared glass shells is SiO2 with some carbides adsorbed on their surfaces and the compositions present negligible relationship with the Si contents. The sphericity, thickness uniformity and surface quality will increase with the increase of Si contents in precursors. Besides, the oxidation mechanisms for Si-GDP to SiO2 were explored by the combination of an in situ high temperature infrared spectroscopy and a simultaneous thermal analyzer.

Magnetic-Domain Structure of Iron-Based Microwires after Removal of the Glass Shell by Chipping and Chemical Etching

Magnetic-Domain Structure of Iron-Based Microwires after Removal of the Glass Shell by Chipping and Chemical Etching

Magnetic domain structure of iron-based microwires after removal of the glass shell by chipping and chemical etching

The magnetic domain structure of the surface of microwires with composition Fe73.9B13.2Si10.9C2 was studied by magnetic force microscopy. It has been found that the removal of glass shell by chipping leads to distortion of the original magnetic domain structure. Chemical etching of the glass shell makes it possible to observe the magnetic domain structure due to the stresses that have arisen due to the microwire production. In the absence of an applied magnetic field, a magnetic domain structure of the surface layer is observed, consisting of domain layers inclined to the microwire axis by 45 or 135 degrees. This structure has a shape close to a zigzag. The thickness of the domain layers is not constant and varies from 3 to 5 μm. It has been found that the application of a constant magnetic field along the microwire axis causes the formation of ring domain layers of various thicknesses (from 1 to 5 μm) with different orientations of the magnetic moment relative to the microwire surface. In a field of 60 oersteds along the axis of the microwire, the domain magnetic structure consists of only ring layers of domains. Magnetic field inversion leads to almost complete inversion of the observed domain structure. In this case, the complete removal of the magnetic field leads to the formation of a new domain structure of the surface layer. Such a structure is close in shape and position of the domains to the original one, but does not repeat it.

Quality Factors in Borosilicate Glass Shell Resonators

Quality Factors in Borosilicate Glass Shell Resonators

Дисперсное армирование цементных систем аморфной стеклометаллической фиброй

The fiber was made from an amorphous microwire of the Co69Fe4Cr4Si12B11 alloy in a glass shell of two sizes: diameter D = 17 and 50 μm, length is 7 and 15 mm, respectively. The influence of its geometric parameters, concentration (0.5—3%) and method of introduction on mobility, average density, bending strength and compression of cement systems (solutions) have been studied. The 54% increase in the flexural strength of the cement system was established in the case of its reinforcement with amorphous glass-metal fiber with D = 17 μm in an amount of 0.5% by weight of Portland cement and 22% one in the case of reinforcement with fiber with D = 50 μm in an amount of 1%. In this case, the compressive strength changes slightly. The introduction of fiber increases the crack resistance coefficient of the studied cement systems from 0.098 to 0.116—0.164.

Description, life cycle, and phylogenetics of Proterometra wigglewomble n. sp. (Digenea: Azygiidae) from the Cahaba River, Alabama, U.S.A.

We herein describe Proterometra wigglewomble n. sp. (Digenea: Azygiidae: Azygiinae) from the Cahaba River, Alabama, USA, which asexually reproduces in the compact elimia, Elimia showalteri (Lea, 1860) (Cerithioidea: Pleuroceridae) and matures in the oesophagus of the blackbanded darter, Percina nigrofasciata (Agassiz, 1854) (Perciformes: Percidae). Adults of the new species differ from congeners by having a small body and eggs having a wholly fimbriated surface that appears as a cilia-like brush border. Live naturally-shed cercariae of the new species differ from those of its congeners by having a strongly claviform tail stem bearing aspinose mammillae, a single furca, excretory pores that open on the posterior margin of the single furca, and few eggs in the cercarial distome. The behaviour of the cercaria further differentiates the new species. Naturally-shed cercariae of P. wigglewomble secrete a jelly-like adhesive that coats the surface of the furca and evidently facilitates attachment to the surface of glass, plastic, and snail shell. Attached cercariae vigorously wiggle and thrash about once attached, as if mimicking the larva of a stream insect so as to lure the blackbanded darter to eat it. Phylogenetic analyses recovered monophyletic Azygiidae, comprising monophyletic Leuceruthrinae Goldberger, 1911 and polyphyletic Azygiinae Lühe, 1909. The present study is the largest taxon sampling for Azygiidae and the first to include 28S sequences of Leuceruthrus. Compact elimia and blackbanded darter are new host records for Proterometra. The new species is the 3rd congener reported from the Cahaba River, a region renowned for its fish and snail endemic biodiversity.

Slender defect segmentation network of workpiece surface based on deep learning

As a key part of the workpiece production process, workpiece surface defect segmentation detection plays an important role in the quality assurance of the workpiece. Aiming at the problem of low accuracy of workpiece surface slender defect segmentation, we propose a slender defect segmentation network based on feature enhancement module (FEM) and feature fusion module (FFM). Firstly, the ConvNeXt is improved and used as the backbone network. Then, the FEM is designed to obtain rich defect features. Finally, the FFM is designed to expand the receptive field and fuse shallow features with deep features to enhance the features of slender defects. The proposed method improves the segmentation accuracy of slender defects. The mean pixel accuracy) of slender defect segmentation on the self-built diode glass shell dataset and public magnetic sheet dataset is 97.87% and 94.86%, respectively. The mean Intersection over Union of slender defect segmentation is 94.32% and 83.89%, respectively. The segmentation speed reaches 43FPS, and the parameter is 7.12 M, which balances the segmentation accuracy, speed and model size.

Light-Density Hollow-Glass-Beads Drilling Fluid Achieves High Solids-Control Efficiency

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 212470, “Full-Scale Solids-Control Testing of a Light-Density Hollow-Glass-Beads Drilling Fluid,” by Nikolay Kostov, ExxonMobil; Glenn Penny, SPE, Contractor for ExxonMobil; and James White, NOV, et al. The paper has not been peer reviewed. _ Light-density drilling fluids with hollow glass beads (HGBs) are being used increasingly in applications for drilling depleted formations with minimal losses and increasing rates of penetration. Studies about how best to use typical solids-control equipment are lacking, however, because current practices and procedures based on barite-weighted muds are inefficient. In the complete paper, the authors report a systematic full-scale test program to study and optimize solids-control efficiency with such fluids using centrifuges, hydrocyclones, and shale shakers. HGB Fluid Formulation The fluid formulation developed for the field test had a target design density of 7.2 lbm/gal. Significant effort was put into developing an HGB fluid that matched or exceeded all design requirements for the existing drilling fluid used to drill a production hole interval in a depleted field. The HGB drilling fluid showed excellent fluid loss and rheology. An overview of the composition and some of the fluid properties is provided in the complete paper. HGB 19K46 is a product with a nominal hydrostatic collapse pressure rating of 19,000 psi and a density of 0.46 g/cm3 (approximately 3.8 lbm/gal). The HGBs are almost perfectly round spheres made up of a thin shell of borosilicate glass a few micrometers thick. The glass density is approximately 2.50–2.55 SG. The hardness is approximately 5 on the Mohs scale, in between barite (3.5) and quartz (7.0). HGB Large-Batch Mixing Based on the testing time to reach steady conditions and the tanks available at the test facility, it was determined that a volume of approximately 40 bbl was required for the field-scale solids-control testing. A mixing plant was used, and the fluid was mixed over a period of 3 days. Good agitation is crucial to mix the additives and HGBs effectively into the base oil. With the exception of the process used to add HGBs, however, no special equipment or modified procedures are needed to mix the HGB fluid. For adding the HGBs, a hopper was used and an efficient additive process developed while dust was eliminated. A 100-bbl mixing tank unit mounted on a trailer was used to generate the HGB fluid for testing (Fig. 1). The unit consists of a multicompartment 100-bbl tank, a diesel-engine-driven centrifugal pump, a hopper, and a series of control valves for directing the fluid flow. One specific modification to the tank was the installation of large eductors at the ends of the feeding pipe. This ensured good circulation of the fluid in the tank, promoted good mixing, and eliminated any dead zones where fluid could become stagnant. The large-scale mixing resulted in approximately 43 bbl of HGB drilling fluid. Samples were collected, and properties were measured. All properties were within the specification window, confirming a successful operation.

Permeation and photo-induced outgassing of deuterium in hollow glass microspheres doped with titanium

The influences of titanium (Ti) doping on the gas retention capacity and photo-induced outgassing behavior of hollow glass microspheres (HGMs) were investigated. It was found that the addition of Ti4+ did not significantly impact the permeability of HGMs, which exhibited a pressure half-life over 100 days. The Kp of Ti3+-doped HGMs was found to be 3–8 times higher than that of Ti4+-doped HGMs, where oxygen vacancies and phase interfaces in the glass shell act as gas diffusion passages. Fortunately, these defects can be eliminated by heat treatment at 600 °C to improve the gas retention capacity. Moreover, photo-induced outgassing was observed in Ti3+-doped HGMs due to the absorption of light in the range of 400–2400 nm, while no absorption or response to illumination was observed in Ti4+-doped HGMs. Notably, the photo-induced outgassing was found to be controllable and repeatable without attenuation of response rate or intensity over four trials.

Ceramic matrix composite reinforced with glass and walnut shell filler: Influence of mesh size on its mechanical properties

Fillers are added in the composite in order to not only enhances the properties enhancement but also reduces the fabrication cost. In this regard, various fillers are added in polymers to achieve optimized properties of composite. Walnut shell in the form of powder is now being utilizes as a filler reinforcement in the polymer matrix. The size of the walnut shell filler is one of the vital factors that influences greatly the mechanical properties of the composite. The present study thus shed lights on the reinforcement of walnut shell filler (WSF) of two categories of mesh size viz: 160–180 µm and 280–300 µm in the glass fiber-polyester composite. The weight fraction of WSF was varied from 0 to 15 % with a difference of 5 % in every reinforcement. Samples were fabricated as per ASTM standards and a comparison was made for mechanical properties. It was found that WSF with mesh size 160–180 µm performed well for tensile, flexural and impact behavior whereas WSF with mesh size 280–300 µm showed better improvement in hardness.

Performance analyses of supercritical carbon dioxide-based parabolic trough collectors with double-glazed receivers

Supercritical carbon dioxide is becoming a hot research topic as a potential heat transfer fluid in parabolic trough concentrators since it enables operating the solar system at high temperatures for a higher quality of energy. However, the corresponding inflated thermal losses necessitate alternative receiver designs. This work examines four double-glazed receivers, with each annular space being evacuated or non-evacuated, in terms of the absorber tube's diameter (53–80 mm) and the diameter ratios of the two glass shells (1.2–2.0). An analytical model is developed and validated for this purpose, and the four designs are further examined using ground-level solar and meteorological measurements. The results demonstrate higher performance in the case of fully evacuating the receiver and using the smallest possible diameters of the three concentric cylinders, where the energy and exergy efficiencies reach 65.3 and 40.3%, respectively. Yet, evacuating only the inner annular space is sufficient to achieve virtually the same performance level. This energy efficiency decreases to 62% in case of increasing the tube diameter to 80 mm. As the operating temperature increases from 423 to 850 K, the specific thermal losses increase by 3.98–4.34 folds, depending on the receiver design. Double glazing the receivers is favorable only at high operating temperatures of sCO2, where the reduction in thermal losses overcomes the drop in optical efficiency. For an inlet sCO2 temperature of 850 K, thermal losses are reduced by 33.64 and 53.92%, compared to evacuated and non-evacuated single-glazed receivers, respectively. Throughout the year, the fully evacuated and fully non-evacuated double-glazed receivers have energy efficiencies of 54.96 and 52.39%, exergy efficiencies of 33.64 and 32.06%, and thermal losses of 348.8 and 402.5 W/m, respectively.

Mechanistic Formulation Design of Spray-Dried Powders

Spray drying is gaining traction in the pharmaceutical industry as one of the processing methods of choice for the manufacture of solid dosage forms intended for pulmonary, oral, and parenteral delivery. This process is particularly advantageous because of its ability to produce engineered particles with improved efficacy and stability by combining active pharmaceutical ingredients or biologics with appropriate excipients. Moreover, due to its high throughput, continuous operation, and ability to produce thermostable solid powders, spray drying can be a manufacturing method of choice in the production of drugs and other formulations, including vaccines, for global distribution. Formulation design based on a mechanistic understanding of the different phenomena that occur during the spray drying of powders is complicated and can therefore make the use of available particle formation models difficult for the practitioner. This review aims to provide step-by-step guidance accompanied by critical background information for the successful formulation design of spray-dried microparticles. These include discussion of the tools needed to estimate the surface concentration of each solute during droplet drying, their times and modes of solidification, and the amount of glass stabilizers and shell formers required to produce stable and dispersible powders.

Effect of temperature on magnetoimpedance in amorphous microconducts Co-=SUB=-27.4-=/SUB=-Fe-=SUB=-5-=/SUB=-Ni-=SUB=-43.08-=/SUB=-B-=SUB=-12.26-=/SUB=-Si-=SUB=-12.26-=/SUB=-

A study of the temperature behavior of high-frequency magnetoimpedance (MI) in amorphous microcircuits in a glass shell up to the Curie temperature TC has been carried out. Samples from the alloy Co27.4Fe5B12.26Si12.26Ni43.08 with a low Curie temperature (TC~48oC) and negative magnetostriction were used. Near TC, the impedance curves retain their characteristic behavior for materials with circular anisotropy, but the sensitivity of MI with respect to the field decreases sharply. The change in impedance with temperature becomes significant only in the presence of an external magnetic field. With an increase in temperature from room temperature to TC, the relative change in impedance can reach 140-275% in the frequency range 0.1-0.9 GHz and a magnetic field of ~10 Oe. Taking into account the location of TC in an almost important temperature region, the results obtained are interesting for the development of miniature temperature sensors, including contactless embedded sensors. Keywords: amorphous alloys, MI-effect, circular anisotropy, spin-orientation transition.

Prospects for using amorphous ferromagnetic alloy microwire for reinforcement of cement mortar

Traditionally, fibers for fiber-reinforced concrete are made of metal, polypropylene, basalt or glass. На сегодняшний день для строительства актуально использование волокон с уникальными электрофизическими свойствами. The possibilities of using a microwire made of an amorphous ferromagnetic alloy based on cobalt with a shell of borosilicate glass in concrete technologies are studied in this paper. The influence of the content of fibers of different sizes (length 7 and 15 mm) on the rheological and physico-mechanical properties of the solution was established. The deterioration of the workability of mixtures and the average density of the composite with the introduction of the studied fiber is shown. It has been established that the spread diameter of the mortar mixture with a fiber content of 0.5...3.0 % by weight of Portland cement is reduced by 9.8...26.1% compared to the control composition. It is shown that the short fiber (7 mm) at the maximum content (3 %) leads to a more significant decrease in the average density (up to 9.6 %) compared to the long fiber (15 mm) of the same concentration (reduction is no more than 4 %). A positive effect on the flexural strength and crack resistance of the solution was established. The increment of flexural and compressive strength ranges from 1.11 to 1.54 and from 0.99 to 0.78 respectively with increasing fiber concentration. The presence of fiber in the composition of the solution allows you to increase the crack resistance from 0.098 to 0.164. The increase in the crack resistance coefficient for compositions with a fiber 7 mm long is 51...68 % and compositions with a fiber 15 mm long is 22...37 %. The possibility of using such microwire based on a ferromagnetic alloy for dispersed reinforcement of cement solutions opens up prospects for the creation of “smart” materials.

Surface crystallization of amorphous Fe-=SUB=-73.8-=/SUB=-Si-=SUB=-13-=/SUB=-B-=SUB=-9.1-=/SUB=-Cu-=SUB=-1-=/SUB=-Nb-=SUB=-3.1-=/SUB=- and Fe-=SUB=-77.5-=/SUB=-Si-=SUB=-13.5-=/SUB=-B-=SUB=-9-=/SUB=- microwires

Amorphous microwires of Fe73.8Si13B9.1Cu1Nb3.1 andFe77.5Si13.5B9 composition fabricated by the Ulitovsky--Taylor method were studied. The samples with the glass shell removed were heated at temperatures of 753 K and 703 K for 20 min, afterwards, their structure was examined using X-ray diffraction. Subsequently, the thermally treated samples were chemically etched and X-ray diffraction study of the structure was again carried out. Experimental results on the predominant crystallization of near-surface regions were discussed assuming that mechanical stresses affect the nucleation and growth of nanocrystals. Keywords: amorphous materials, stress distribution, nanocrystallization, X-ray diffraction.

Поверхностная кристаллизация аморфных микропроводов состава Fe-=SUB=-73.8-=/SUB=-Si-=SUB=-13-=/SUB=-B-=SUB=-9.1-=/SUB=-Cu-=SUB=-1-=/SUB=-Nb-=SUB=-3.1-=/SUB=- и Fe-=SUB=-77.5-=/SUB=-Si-=SUB=-13.5-=/SUB=-B-=SUB=-9-=/SUB=-

Amorphous microwires of Fe73.8Si13B9.1Cu1Nb3.1 and Fe77.5Si13.5B9 composition fabricated by the Ulitovsky–Taylor method were studied. The samples with the glass shell removed were heated at temperatures of 753 K and 703 K for 20 minutes, afterwards, their structure was examined using X-ray diffraction. Subsequently, the thermally treated samples were chemically etched and X-ray diffraction study of the structure was again carried out. Experimental results on the predominant crystallization of near-surface regions were discussed assuming that mechanical stresses affect the nucleation and growth of nanocrystals.