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Records with Subject: Materials
2670. LAPSE:2023.11319
Dough Rheological Properties and Macronutrient Bioavailability of Cereal Products Fortified through Legume Proteins
February 27, 2023 (v1)
Subject: Materials
Keywords: cereal products, interactions between nutrients, legume protein, rheology
Cereal products are regarded as important protein providers, though they could feature poor nutritional quality due to their occasional imbalanced amino acid content. Cereal proteins are low in cysteine or tryptophan, and rich in methionine; however, while their combination with legume proteins makes them nutritionally more comprehensive, such a possibility must be addressed by the cereal processing industry. However, the incorporation of legume protein concentrates and isolates might also influence the functionality and bioavailability of some cereal constituents. Therefore, the objective of the present review is to gain insights into the effects of cereal products incorporated with legume protein isolates/concentrates, knowing that both the cereals and the protein extracts/isolates are complex structural matrices, and besides the final products acceptability they should efficiently promote the health condition of consumers. The combination of legume proteins with cereals will bring a... [more]
2671. LAPSE:2023.11314
Mechanical Properties and Water Resistance of Magnesium Oxychloride Cement−Solidified Residual Sludge
February 27, 2023 (v1)
Subject: Materials
Keywords: magnesium oxychloride cement, residual sludge, solidification, unconfined compression strength
As a solid waste, the amount of residual sludge produced by the municipal wastewater treatment process is escalating. How to dispose it properly is attracting much attention in society. Herein, solidifying residual sludge using magnesium oxychloride cement (MOC) is promising for converting it into building materials. Various factors of mass ratio (RW/S) of liquid to solid, molar ratio (Rn) of MgO to MgCl2 in MOC, mass ratio (Rm) of residual sludge to MOC, the mass concentration of Na2SiO3 (DNa2SiO3), and dosage of fly ash (DF) influenced the unconfined compression strength (RC) of the as−obtained MOC−solidified residual sludge, and it was characterized using SEM and XRD analysis. The results show that the value of RC for MOC−residual sludge solidified blocks increased initially and then decreased as Rn and Rm increased, respectively, for 60−day curing. At 10−day curing, equilibrium RC was reached at all RW/S values except 1.38, and at 60−day curing, RC decreased with RW/S increasing. T... [more]
2672. LAPSE:2023.11307
The Effect of Organic Fillers on the Mechanical Strength of the Joint in the Adhesive Bonding
February 27, 2023 (v1)
Subject: Materials
Keywords: adhesive bonding, mechanical strength, organic filler, the single lap joint, waste material
The most important advantages of adding additives to adhesives are increasing the bonding strength and reducing the adhesive cost. The desire to reduce costs as well as the need for environmentally friendly and health-friendly products have paved the way for the recycling of waste materials and the use of cheaper natural materials as additives. In this study, mussel, olive pomace, and walnut powders in different ratios (5%, 15%, and 30% by weight) and in different sizes (38 and 45 µm) were added to an epoxy adhesive. The steel materials were joined in the form of single-lap joints by using the obtained adhesives with additives. These joints were subjected to the tensile test and the strengths of these joints were examined. SEM images of the bonding interface were taken, and the distribution of the powders was examined. When the powder size was 45 µm, bond strengths increased in all additive ratios compared to the pure adhesive, while for 38 µm powders, the strength value increased only... [more]
2673. LAPSE:2023.11306
Investigations on Microstructure and Mechanical Properties of AZ91 Alloy Processed by Single Pass Rolling with Varied Rolling Reductions
February 27, 2023 (v1)
Subject: Materials
Keywords: mechanical properties, metals and alloys, microstructure, rolling reduction, single pass rolling (SPR)
In this study, single pass rolling (SPR) with varied rolling reductions was conducted on pre-homogenized AZ91 alloys (H alloys) and ECAP-processed AZ91 alloys (HE alloys). The effects of rolling reduction on the microstructures and mechanical properties of HR alloys (pre-homogenized and rolled) and HER alloys (ECAP-processed and rolled) were investigated. The results showed that the HER alloys possessed much finer microstructures and superior mechanical properties than the HR alloys, which were significantly influenced by the rolling reduction. The microstructures of the HER alloys became bimodal, and the strength and elongation markedly improved with the increase in the rolling reduction. When the rolling reduction reached 70%, the HER alloys acquired a typical bimodal structure, contributing to their excellent comprehensive mechanical properties.
2674. LAPSE:2023.11305
Diagnosis of Osteoarthritis at an Early Stage via Infrared Spectroscopy Combined Chemometrics in Human Serum: A Pilot Study
February 27, 2023 (v1)
Subject: Materials
Keywords: ATR-FTIR, biomarkers, blood testing, chemometrics, infrared spectroscopy, osteoarthritis, serum diagnostics
Methods applied for early diagnosis of osteoarthritis (OA) are limited. Early prevention and treatment can effectively reduce the pain of OA patients and save costs. The present study aimed to develop a rapid non-destructive detection method for early diagnosis of OA by evaluating infrared (IR) spectroscopy combined chemometrics. Our cohort consisted of (a) 15 patients with osteoarthritis (OA) and (b) 10 without clinical signs of the disease and they were used as controls. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was used to investigate serum samples (50 µL) collected from these patients. A supervised classification algorithm namely discriminant analysis (DA) was applied to evaluate the diagnostic accuracy spectral processing and chemometrics analysis allowed for detecting spectral biomarkers that discriminated the two cohorts. About 250 infrared spectra were statistically important for separating the groups. Peaks at 1000 cm−1 in OA serum were ass... [more]
2675. LAPSE:2023.11296
Polycaprolactone with Glass Beads for 3D Printing Filaments
February 27, 2023 (v1)
Subject: Materials
Keywords: 3D printing, biocompostable, biodegradable, cheap material, composite, glass beads, poly (ε-caprolactone)
At present, 3D printing is experiencing a great boom. The demand for new materials for 3D printing is also related to its expansion. This paper deals with manufacturing innovative polymer composite filaments suitable for the Fused Filament Fabrication method in 3D printing. As a filler, common and uncostly glass beads were used and mixed with biocompatible and biodegradable poly (ε-caprolactone), as a polymer matrix. This material was characterized via several physical-chemical methods. The Youngs modulus was increasing by about 30% with 20% loading of glass beads, and simultaneously, brittleness and elongations were decreased. The glass beads do not affect the shore hardness of filaments. The rheological measurement confirmed the material stability in a range of temperatures 75−120 °C. The presented work aimed to prepare lightweight biocompatible, cheap material with appropriate mechanical properties, lower printing temperature, and good printing processing. We can assess that the goa... [more]
2676. LAPSE:2023.11294
Brown Seaweed Sargassum-Based Sorbents for the Removal of Cr(III) Ions from Aqueous Solutions
February 27, 2023 (v1)
Subject: Materials
Keywords: Cr(III) ions sorption, Extraction, nanoparticles biosynthesis, seaweed, Wastewater
In this study, zinc oxide nanoparticles (ZnO NPs) were biosynthesized with the use of an extract derived from seaweed (Sargassum sp.) and used as a sorbent for the removal of Cr(III) ions from wastewater. The biosorption properties of the seaweed itself as well as of the post-extraction residue were investigated for comparison. ZnO NPs were characterized with UV−vis, ICP-OES, FTIR, XRD, and SEM techniques. The sorption capacity of the (bio)sorbents was investigated as a function of contact time at different pH values and initial concentrations of metal ions. Sorption kinetics and isotherms were studied in order to comprehend the sorption nature and mechanism. The sorption kinetic data were well-fitted with the pseudo-second-order model, and the highest sorption capacity was calculated for ZnO NPs (137 mg/g), whereas those calculated for Sargassum sp. (82.0 mg/g) and the post-extraction residue (81.3 mg/g) were comparable (at pH 5 and 300 mg of Cr(III) ions/L). The adsorption isotherms... [more]
2677. LAPSE:2023.11293
Growth of (Ag,Cu)(In,Ga)Se2 Absorbers under Band Gap Variation and Characterization with a Focus on Optical Spectroscopy
February 27, 2023 (v1)
Subject: Materials
Keywords: (Ag,Cu)(In,Ga)Se2, band gap widening, raman spectroscopy, silver chalcopyrite, transparency
Whilst Cu(In,Ga)Se2 (CIGSe) is an extremely promising material for solar cell fabrication, the widening of the band gap beyond the standard 1.1 eV is highly desirable for semitransparent applications. By replacing Cu with Ag and increasing the Ga content, we fabricate ACIGSe absorbers with band gaps ranging from 1.27−1.55 eV. An Ag/(Ag + Cu) ratio from 0.36−1.00 is chosen, as well as a Ga/(Ga + In) ratio from 0.25−0.59. The larger Ag and Ga contents lead to the expected band gap widening, which is, together with high sub-gap transparency, essential for semitransparent applications. The crystalline properties are confirmed by Raman spectroscopy and X-ray diffraction, which both reveal peak shifts according to the composition variations: a higher Ag content results in lower Raman shifts as well as in lower angles of X-ray diffraction for the main peaks due to the larger mass of Ag compared to Cu and the larger lattice constant of Ag-rich compounds. Increased open circuit voltages and dec... [more]
2678. LAPSE:2023.11276
In-Situ Hydrothermal Synthesis of Ag3PO4/g-C3N4 Nanocomposites and Their Photocatalytic Decomposition of Sulfapyridine under Visible Light
February 27, 2023 (v1)
Subject: Materials
Keywords: Ag3PO4, g-C3N4, photocatalysis, sulfapyridine, visible light
Highly efficient visible-light-driven heterogeneous photocatalyst Ag3PO4/g-C3N4 with different weight ratios from Ag3PO4 to g-C3N4 were synthesized by a facile in situ hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), photoluminescence spectra (PL), UV−vis diffuse reflectance spectra (UV-Vis), and electrochemical impedance spectra (EIS). Under visible light irradiation, Ag3PO4/g-C3N4 showed very excellent photocatalytic activity for sulfapyridine (SP) which is one of the widely used sulfonamide antibiotics. When the ratio from Ag3PO4 to g-C3N4 was 1:2, the degradation rate of SP at 120 min was found to be 94.1%, which was superior to that of pure Ag3PO4 and pure g-C3N4. Based on the experimental results, the possible enhanced photocatalytic mechanism of Ag3PO4/g-C3N4 was proposed.
2679. LAPSE:2023.11253
Chemical Behaviour of Copper in the Application of Unconstrained Cr-Ni-Al-Cu Metal Powders in Submerged Arc Welding: Gas Phase Thermodynamics and 3D Slag SEM Evidence
February 27, 2023 (v1)
Subject: Materials
Keywords: aluminium deoxidiser, chromium, copper, nickel, partial oxygen pressure, powder, pyrometallurgy, welding
Unconstrained metal powders of Cu, Cr, Ni and Al were applied to submerged arc welding (SAW) to clarify the chemical behaviour of copper in this modified SAW process. Aluminium metal is avoided in SAW because it is easily oxidised. Excessive aluminium oxides in the form of slag or inclusions in the weld metal will lead to poor weld metal materials properties. Aluminium is an effective deoxidiser and can be used to prevent Cr and Ni loss to the slag by preventing oxidation of these metals. The results show that carbon steel was alloyed to 5.3% Cr, 5.3% Ni, 3.6% Al and 5.2% Cu at 80% Cr yield, 81% Ni yield, 54% Al yield and 79% Cu yield. BSE (backscattered electron) images of the three-dimensional (3D) post-weld slag sample show 3D structures within the slag dome. The 3D structures contain features of vapour formation and recondensation. In addition, nano-strands appear in the 3D structures and confirm the vaporisation and recondensation of fluorides. The chemical behaviour of copper met... [more]
2680. LAPSE:2023.11237
Innovative Materials and Processes for Removal of Biopersistent Pollutants
February 27, 2023 (v1)
Subject: Materials
The aim of this Special Issue “Innovative Materials and Processes for Removal of Biopersistent Pollutants” (https://www [...]
2681. LAPSE:2023.11227
Catalytic Hydrothermal Liquefaction of Brachychiton populneus Biomass for the Production of High-Value Bio-Crude
February 27, 2023 (v1)
Subject: Materials
Keywords: Brachychiton populneus, catalytic HTL, energy recovery, hydrothermal liquefaction
The current study focused on the heterogenous catalytic hydrothermal liquefaction (HTL) of Brachychiton populneus biomass seed, using Ni as hydrogenation catalyst and Fe as active hydrogen producer. The activity of Ni metal and of Ni/Al2O3 in the HTL of seed (BS) and of a mixture of seed and shell (BM) was studied. To establish the best operating process conditions, the influence of variation of temperature and reaction time on the product yields was also examined. The highest bio-crude yields of 57.18% and 48.23% for BS and BM, respectively, were obtained at 330 °C and 10 min of reaction time, in the presence of Ni/Al2O3 as catalyst and Fe as hydrogen donor. Elemental analysis results showed that at these operative conditions, an increase of the higher heating value (HHV) from 25.14 MJ/kg to 38.04 MJ/kg and from 17.71 MJ/kg to 31.72 MJ/kg was obtained for BS and BM biomass, respectively, when the combination of Fe and Ni/Al2O3 was used. Gas chromatography−mass spectrometry (GC-MS) and... [more]
2682. LAPSE:2023.11226
Quantitative Characterization of Shallow Marine Sediments in Tight Gas Fields of Middle Indus Basin: A Rational Approach of Multiple Rock Physics Diagnostic Models
February 27, 2023 (v1)
Subject: Materials
Keywords: Lower Goru formation, rock physics diagnostics, rock physics template, shallow marine sediments, tight gas sand reservoir
For the successful discovery and development of tight sand gas reserves, it is necessary to locate sand with certain features. These features must largely include a significant accumulation of hydrocarbons, rock physics models, and mechanical properties. However, the effective representation of such reservoir properties using applicable parameters is challenging due to the complicated heterogeneous structural characteristics of hydrocarbon sand. Rock physics modeling of sandstone reservoirs from the Lower Goru Basin gas fields represents the link between reservoir parameters and seismic properties. Rock physics diagnostic models have been utilized to describe the reservoir sands of two wells inside this Middle Indus Basin, including contact cement, constant cement, and friable sand. The results showed that sorting the grain and coating cement on the grain’s surface both affected the cementation process. According to the models, the cementation levels in the reservoir sands of the two w... [more]
2683. LAPSE:2023.11216
Fluidized Bed Spray Coating for Improved Mechanical Properties of Particles
February 27, 2023 (v1)
Subject: Materials
Keywords: crash absorber, energy dissipation, fluidized bed, mechanical properties, particle coating
When designing crash absorber particles for application as a filling material in the double-hull of ships, the main goal is to achieve an optimal mechanical performance, in combination with a low-density particle structure, while fulfilling several additional requirements regarding, for example, non-toxic and hydrophobic behavior. In this study, a fluidized bed was used to coat Poraver® glass particles with Candelilla wax and silicone to attain these specifications. A uniform coating was achieved with wax, but the process turned out to be far more challenging when using silicone. To evaluate the suitability of coated particles as a granular filling material, and to compare their performances with that of untreated Poraver® particles, several mechanical tests, as well as structural investigations, were conducted. While no notable improvement in mechanical behavior was observed on the single-particle level, bulk tests showed promising results regarding compressibility and abrasion resist... [more]
2684. LAPSE:2023.11207
Anticancer and Antimicrobial Activity of Silver Nanoparticles Synthesized from Pods of Acacia nilotica
February 27, 2023 (v1)
Subject: Materials
Keywords: Acacia nilotica, antibacterial activity, cytotoxicity, gene expression, silver nanoparticles
Green synthesized silver nanoparticles (AgNPs) have been used against antibiotic-resistant bacteria and chemo-resistant cancer cells. We synthesized AgNPs from Acacia nilotica pods, evaluating their antibacterial activity against eight bacterial strains and anticancer efficiency against two colon cancer cell lines, SW620 and SW480. Expression levels of eight genes (β-catenin, APC, TP53, Beclin1, DKK3, Axin, Cyclin D1, and C-myc) were checked by a reverse transcription-polymerase chain reaction in cancer cells before and after treatment with A. nilotica extract and A. nilotica-AgNPs. Prepared nanoparticles were characterized through ultraviolet-visible (UV-vis), Zetasizer, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FTIR) was used to identify the functional group in extracts. At first, AgNPs were confirmed by a sharp peak of surface plasmon resonance at 375 nm. The Z-average size was 105.4 nm with a polydispers... [more]
2685. LAPSE:2023.11205
Enhancing Visible-Light Photodegradation of TC-HCl by Doping Phosphorus into Self-Sensitized Carbon Nitride Microspheres
February 27, 2023 (v1)
Subject: Materials
Keywords: antibiotic residue disposal, carbon nitride microsphere, phosphorus doping, self-sensitization
SSCN is a new type of self-sensitive photocatalyst. It consists of oxygenated carbon nitride-containing microspheres inside and polymerized triazine dye (TBO) formed on its surface by in situ polymerization. The presence of TBO endows SSCN with a wide range of optical responses. However, the TBO would self-degrade under light, making SSCN extremely unstable in photocatalytic reactions and limiting the practical application of SSCN. The introduction of phosphorus into the structure of SSCN significantly improved the electron−hole separation efficiency and reduced the self-degradation of surface TBO. Phosphorus-doped self-sensitive carbon nitride microspheres (P-SSCN) are easily synthesized by a one-pot solvothermal method—the phosphorus source was added to the precursor solution of SSCN. This resulting material was used for the photodegradation of tetracycline hydrochloride (TC-HCl) for the first time, giving improved visible light sensitivity and high stability in the photocatalytic pr... [more]
2686. LAPSE:2023.11203
The Pyrolysis Behaviors of Blended Pellets of Pine Wood and Urea-Formaldehyde Resin
February 27, 2023 (v1)
Subject: Materials
Keywords: pine wood, pyrolysis, urea-formaldehyde resin
TG-FTIR and PY-GC/MS were used to analyze the pyrolysis behaviors of pine wood, urea-formaldehyde resin (UF resin) and their blended pellets. The pyrolysis process was divided into three stages: water evaporation, devolatilization and pyrolysis residue decomposition. During the pyrolysis process of the blended pellets, with the increase of the addition ratio of UF resin, the peak value of the weight loss decreased in the decomposition stage of the pyrolysis residue, while the temperature shifted to the low-temperature region. This was mainly due to the structural stability of pyrolytic carbon produced by UF resin, which hindered the thermal decomposition of lignin-produced residues in pine. FTIR showed that CO2 was the main product of pyrolysis. For UF resin, nitrogen compounds accounted for a large proportion. With the addition of UF resin, the nitrogen in the blended pellets increased significantly. Since the synergistic effect promoted the further decomposition of the organic oxygen... [more]
2687. LAPSE:2023.11200
Characteristics and Significance of Acid-Soluble Organic Matter in Marine Carbonate Source Rocks
February 27, 2023 (v1)
Subject: Materials
Keywords: acid-soluble organic matter, carbonate rock, organic acid salt, source rock evaluation, TOC
Since the 1950s, major breakthroughs have been made in the field of carbonate oil and gas exploration, and large reservoirs have been found in carbonate strata in many countries; however, the validity of highly evolved carbonate source rocks has been controversial. Because of the loss of organic carbon during acid-solution processing in conventional total organic carbon (TOC) determination, we decided to use a new method of reducing acid-solution losses in order to more effectively quantify acid-soluble organic matter in carbonate rock samples. Different levels of acid-soluble organic matter were present in different types of samples, and there was no positive correlation between the content of acid-soluble organic matter and conventionally measured TOC values. However, the thermal evolutionary maturity of samples with high acid-soluble organic matter content is relatively low, and the high hydrocarbon generation conversion rate of acid-soluble organic matter and conventional TOC in ca... [more]
2688. LAPSE:2023.11199
Pore Structure and Fractal Characteristics of Tight Sandstone: A Case Study for Huagang Formation in the Xihu Sag, East China Sea Basin, China
February 27, 2023 (v1)
Subject: Materials
Keywords: East China Sea Basin, fractal analysis, HPMI, NMR with centrifugation, pore structure, tight sandstone reservoir
Various experiments, including routine petrophysical measurements, thin section and scanning electronic microscope (SEM), high-pressure mercury intrusion (HPMI), and nuclear magnetic resonance (NMR), were performed to characterize the microscopic pore structure of tight sandstone in the Huagang Formation (E3h), Xihu Sag, East China Sea Basin, China. Specifically, NMR was used to investigate the dynamic variation of fractal dimensions during centrifugation, and the comparison of HPMI and NMR were used to clarify the difference of fractal dimensions. The results showed that there were four types of pores observed in thin section and SEM images: primary intergranular pores, intergranular dissolution pores, intragranular dissolution pores, and micropores within clay aggregates. The geometric shape and pore size of different pore types showed huge differences, indicating the formation of complex and diverse pore structures in the E3h formation. The flow capability of the reservoir was domin... [more]
2689. LAPSE:2023.11195
The Fractured Permian Reservoir and Its Significance in the Gas Exploitation in the Sichuan Basin, China
February 27, 2023 (v1)
Subject: Materials
Keywords: deep gas exploitation, fractured reservoir, seismic reservoir description, Sichuan basin, strike-slip fault, tight matrix reservoir
Large gas reserves have been found in the Permian platform margin of the Kaijiang-Liangping area of the Sichuan Basin in SW China. They are assumed to be a widely developed reef−shoal reservoir. However, the tight matrix reservoir cannot support high gas production using conventional development technology at deep subsurface. In this contribution, we analyze the fractured reservoirs along the strike-slip fault zones using the compiled data of cores, well logging, and production data, and provide a seismic description. It was shown that the fractures and their dissolution developed along the strike-slip fault zones. The porosity and permeability of the fractured reservoir could increase by more than one and 1−2 orders of magnitude, respectively. The seismic anisotropic energy found in the steerable pyramid process suggests that fractured reservoirs have a strong heterogeneity, with a localized fault damage zone. This fracturing has both positive and negative effects, showing varied rese... [more]
2690. LAPSE:2023.11190
Experimental Study of Frost Crystals Dendrite Growth on Two Neighboring Separate Frozen Water Drops on a Cryogenic Cold Surface under Natural Convection Conditions
February 27, 2023 (v1)
Subject: Materials
Keywords: cryogenic cold surface, dendrite growth, frost crystal, initial frost layer thickness
The effects of cold surface temperature, wet air state (temperature and humidity) and original drop size on frost dendrites growth of two neighboring separate frozen water drops of same size under natural convection conditions were investigated by quantitative measurement. It was determined that for different cold plate surface temperature conditions, i.e., the ordinary-low temperature and the cryogenic temperature range, the frost formation mechanism is different. Under the conditions that the air temperature is not too high and absolute humidity is not too excessive, the influence of frozen water drop size on the longest dendrite of frost crystals becomes more and more obvious with the decrease in cold plate temperature. The changes in air temperature and relative humidity both change air absolute humidity, so they have similar effects on the growth of dendrites. However, the effect of wet air state on the growth of frost dendrites is not monotonous, which needs to be considered comp... [more]
2691. LAPSE:2023.11186
Ceria−Zirconia-Supported Ruthenium Catalysts for Hydrogen Production by Ammonia Decomposition
February 27, 2023 (v1)
Subject: Materials
Keywords: ammonia decomposition, cerium–zirconium oxide, commercial supports, ruthenium, Temkin–Pyzhov kinetics
Commercial cerium−zirconium oxide supports (Ce0.5Zr0.5O2, Ce0.75Zr0.25O2, and Ce0.4Zr0.5Y0.05La0.05O2) were used to prepare Ru/CeZrOx catalysts. According to the XRD and IR spectroscopy data, the supports consist of ceria-based substitutional solid solutions. The specific surface areas of supports and catalysts are similar and range from 71−89 m2/g. As shown by TEM and XRD methods, the size of support particles equals 6−11 nm. According to the TEM data, the size of ruthenium particles does not exceed 1.3 nm. The catalyst activity in the ammonia decomposition process was studied. The Ru/Ce0.75Zr0.25O2 catalyst at temperature 500 °C and GHSV 120,000 h−1 demonstrated the highest hydrogen productivity of 53.3 mmol H2/(gcat·min) and compares well with the best results reported in the literature. The kinetics of ammonia decomposition reaction were calculated using the Temkin−Pyzhov exponential expression. The developed mathematical model well described the experimental data. The studied cata... [more]
2692. LAPSE:2023.11168
Effect of Temperature Conditions in Arctic Offshore Oil Fields on the Rheological Properties of Various Based Drilling Muds
February 27, 2023 (v1)
Subject: Materials
Keywords: barite-free muds, hydrocarbon-based muds, offshore drilling, rheological parameters, synthetic-based muds, water-based muds
During well drilling in offshore conditions beyond the North of the Arctic Circle, there are often problems associated with deviations in the rheological parameters of the drilling mud as the temperature changes. Mud temperature in the upper part of the well in most cases is in the range up to 20 °C, whereas in the productive formation it is up to 80 °C and more. For such conditions, it is necessary to estimate the influence of temperature on the rheological parameters of drilling fluids, which is done in this paper. Compositions of water-based and hydrocarbon-based muds that may be used in the conditions of the offshore hydrocarbon fields were considered. The paper presents the authors’ formula for a drilling mud that possesses more stable rheological parameters in the temperature conditions of the offshore oil field and is more environmentally friendly. The physical properties of the newly designed drilling mud were measured with laboratory equipment. Rheological investigations were... [more]
2693. LAPSE:2023.11158
Measurement of Gas Flow Rate at Gasification of Low-Melting Materials in a Flow-Through Gas Generator
February 27, 2023 (v1)
Subject: Materials
Keywords: combustion, flow-through gas generator, gasification, low-melting solid material
A semi-empirical method is proposed for determining the rate of gas production in a flow-through gas generator (GG) with the allocation of a part of the gas flow produced by gasification of a low-melting solid material (LSM) in the total gas flow rate through the GG. The method is verified by test fires with polypropylene sample gasification by hot air under conditions of incoming supersonic flow with Mach number 2.43, 2.94, and 3.81 and stagnation temperature 600−700 K. The mean flow rates of gasification products obtained in test fires were 0.08 kg/s at Mach 2.43, 0.10 kg/s at Mach 2.94, and 0.05−0.02 kg/s at Mach 3.81. For obtaining 1 kg of gasification products in the test fires there was a need of 1.61 to 2.86 kg of gasifying agent.
2694. LAPSE:2023.11150
Analysis of Micro-Contaminants in Solid Particles from Direct Injection Gasoline Vehicles
February 27, 2023 (v1)
Subject: Materials
Keywords: Euro 6, gasoline vehicles, micro-contaminants, particle number, particulate matter, solid particles, WLTP
Exhaust emissions from vehicles are the subject of numerous studies and legal acts. In the European Union, exhaust emissions are regulated by “Euro” emission standards, which limit emissions of gaseous pollutants such as CO, CO2, HC, and NOx, as well as the particulate matter (PM) and particle number (PN). Solid particles consist of a number of micro-contaminants, inter alia polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives. Despite their highly mutagenic and carcinogenic character, these micro-contaminants are not regulated in Euro emissions standards. This paper presents both a general discussion of the phenomenon of particulate formation in and emission from direct injection gasoline engines, as well as a wide range of results on the subject. The subject of the micro-contaminants in solid particles from modern gasoline vehicles is explored. The samples of solid particles were collected from 11 groups of vehicles according to the WLTP test methodol... [more]
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