Search Results (30)

The quantification of solid debris in used lubricating oil is essential for assessing transmission system wear and optimizing maintenance strategies. This study introduces a low-cost capacitive proximity sensor for monitoring total solid particle contamination in lubricants, with a focus on ferrous (Fe), non-ferrous (Al), and non-metallic (SiO₂) debris. Controlled tests were performed using five mixing ratios of large-to-small particles (100:0, 75:25, 50:50, 25:75, and 0:100) at a fixed debris mass of 0.5 g per 25 mL of SAE 85W-140 automotive gear oil. Cubic regression analysis yielded high predictive accuracy, with average R² values of 0.994 for Fe, 0.943 for Al, and 0.992 for SiO₂. Further dimensionality reduction using Principal Component Analysis (PCA), along with Linear Discriminant Analysis (LDA) of multivariate statistical analysis, effectively classifies debris types and enhances interpretability. These results demonstrate the potential of capacitive sensing as an offline, non-invasive alternative to traditional techniques for wear debris monitoring in transmission systems. These results confirm the potential of capacitive sensing, supported by statistical modeling, as a non-invasive, cost-effective technique for offline classification and monitoring of wear debris in transmission systems. Full article

A new high-temperature allothermal gasification technology is used to process three types of oil waste: ground oil sludge (GOS), tank oil sludge (TOS), and petcoke. The gasifying agent (GA), mainly composed of H₂O and CO₂ at a temperature above 2300 K and atmospheric pressure, is produced by pulsed detonations of a near-stochiometric methane-oxygen mixture. The gasification experiments show that the dry off-gas contains 80–90 vol.% combustible gas composed of 40–45 vol.% CO, 28–33 vol.% H₂, 5–10 vol.% CH₄, and 4–7 vol.% noncondensable C₂–C₃ hydrocarbons. The gasification process is accompanied by the removal of mass from a flow gasifier in the form of fine solid ash particles with a size of about 1 μm. The ash particles have a mesoporous structure with a specific surface area ranging from 3.3 to 15.2 m²/g and pore sizes ranging from 3 to 50 nm. The measured wall temperatures of the gasifier are in reasonable agreement with the calculated value of the thermodynamic equilibrium temperature of the off-gas. The measured CO content in the off-gas is in good agreement with the thermodynamic calculations. The reduced H₂ content and elevated contents of CH₄, CO₂, and C_xH_y are apparently associated with the nonuniform distribution of the waste/GA mass ratio in the gasifier. To increase the H₂ yield, it is necessary to improve the mixing of waste with the GA. It is proposed to mix crushed petcoke with oil sludge to form a paste and feed the combined waste into the gasifier using a specially designed feeder. Full article

The solid phase composition in oily sludge (OS) is a key factor affecting the oil–solid separation of OS. In this paper, the effects and mechanisms of solid-phase particle factors on the oil content of residue phase were investigated in order to improve the oil–solid separation efficiency. Flotation experiments were carried out on single-size sand and mixed-size sand OS consisting of three particle sizes at room temperature without adding flotation reagents. The effects of different-size particles as solid phase composition of OS and flotation parameter settings such as flotation temperature (Tp), flotation time (Tt), impeller speed (Rs) and liquid-solid ratio (L/OS) on the oil–solid separation efficiency were investigated. The experimental results showed that the oil content of residue phase decreased with the increasing of solid-phase particle size for single-size sand OS, and the optimal flotation conditions were Tp of 50 °C, Tt of 25 min, Rs of 1450 r/min and L/OS of 12:1. The oil–solid separation was more pronounced for mixed-size sand OS with a complex particle composition, while different particle compositions of the solid phase in OS promoted oil–solid separation. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) characterisation of OS before and after flotation confirmed the relative advantage of coarse particle OS in the oil–solid separation process. The classical first-order model was well fitted to the flotation kinetic process of single-size sand and mixed-size sand OS. The response surface methodology (RSM) method was used to determine the Rs as the main control factor of the flotation process, and the oil content of residue phase in mixed-size sand OS was optimised to 2.63%. This study provides important process parameters and theoretical basis for the efficient treatment of OS. Full article

Ice cream is popular but contains high amounts of saturated fats and few health-promoting ingredients. In the presence of xanthan gum (0.25%), blueberry peel particles prepared through ball-milling treatment (BMPs) were used to prepare ice cream containing camellia oil as a fat replacer. The BMPs possessed smaller particle sizes, larger contact angles, and higher contents of anthocyanin aglycone compared with commonly milled blueberry peel particles. BMPs with the largest contact angle (66.30°) were obtained by ball-milling the blueberry peel at 15 Hz for 6 h (BMP_15Hz6h). The ice cream mixes were depicted as linear viscoelastic gel-like solids, and their apparent viscosity, G′ and G′, increased with the increase in the BMP_15Hz6h concentration. Ice cream with strong antioxidant activity and good freeze–thaw stability was acceptable and desirable in the presence of 0.5% BMP_15Hz6h. Full article

Background: Voriconazole is an antifungal drug, which is classified under Bio-Classification System-II and has low water solubility (0.71 mg/mL) and high permeability. Hardly any endeavors have been made to increase the bioavailability of voriconazole. Objective: To develop and evaluate a solid SMEDDS (self-microemulsifying drug delivery system) for antifungal activity. Methods: Based on solubility studies of Labrafil-M 1994 CS (oil), Cremophor-RH 40 (a surfactant) and Transcutol-HP (a co-surfactant) were selected as components of the SMEDDS and a pseudo-ternary phase diagram was prepared. Thereafter, the oil, surfactant, and co-surfactant were mixed with altered weight ratios (1:1/1:2/2:1) and evaluated through various in vitro, in vivo analyses. Results: The particle size of the optimized formulation was observed to be 19.04 nm and the polydispersity index (PDI) value was found to be 0.162 with steady-state zeta potential. The optimized liquid SMEDDS was converted into a solid SMEDDS. Various adsorbents, such as Aerosil-200, Avicel-PH101, Neusilin-US2, and Neusilin UFL2 were screened to better detect the oil-absorbing capacity and flow properties of the powder. Neusilin UFL2 was selected as an adsorbent due to its better oil-absorbing capacity. DSC, X-ray diffraction, and dissolution studies were carried out to characterize the formulation. Further, the Pharmacokinetic profile was also studied in Wistar rats and the Cmax, tmax, and AUC0→t were calculated. The Cmax and AUC0→t plasma concentration is considerably better for the SMEDDS than for the pure drug and marketed formulation. Conclusions: This investigation clearly reveals the potential of developing a solid SMEDDS for candidiasis and invasive aspergillosis treatment, with better efficacy as compared to the commercially available marketed formulation. Full article

Chronic inflammatory bowel disorders (IBDs) are characterized by altered intestinal permeability, prompting inflammatory, oxidative stress, and immunological factors. Gut microbiota disorders impact brain function via the bidirectional gut–brain axis, influencing behavior through inflammatory cascades, oxidative stress, and neurotransmitter levels. This study highlights the potential effect of integrating lyophilized milk kefir alone and lyophilized milk kefir as solid carriers loaded with a self-nanoemulsifying self-nanosuspension (SNESNS) of licorice extract on an induced chronic IBD-like model in rats. Licorice-SNESNS was prepared by the homogenization of 30 mg of licorice extract in 1 g of the selected SNEDDS (30% Caraway oil, 60% Tween 20, and 10% propylene glycol (w/w)). Licorice-SNESNS was mixed with milk kefir and then freeze-dried. Dynamic TEM images and the bimodal particle size curve confirmed the formation of the biphasic nanosystems after dilution (nanoemulsion and nanosuspension). Daily oral administration of lyophilized milk kefir (100 mg/kg) loaded with SNESNS (10 mg/kg Caraway oil and 1 mg/kg licorice) restored normal body weight and intestinal mucosa while significantly reducing submucosal inflammatory cell infiltration in induced rats. Importantly, this treatment demonstrated superior efficacy compared to lyophilized milk kefir alone by leading to a more significant alleviation of neurotransmitter levels and improved memory functions, thereby addressing gut–brain axis disorders. Additionally, it normalized fecal microbiome constituents, inflammatory cytokine levels, and oxidative stress in examined tissues and serum. Moreover, daily administration of kefir-loaded SNESNS normalized the disease activity index, alleviated histopathological changes induced by IBD induction, and partially restored the normal gut microbiota. These alterations are associated with improved cognitive functions, attributed to the maintenance of normal neurotransmitter levels and the alleviation of triggered inflammatory factors and oxidative stress levels. Full article

Modern engine bearing materials encounter the challenge of functioning under conditions of mixed lubrication, low viscosity oils, downsizing, start–stop engines, potentially leading to metal-to-metal contact and, subsequently, premature bearing failure. In this work, two types of polymer overlays were applied to the bearing surface to compensate for extreme conditions, such as excessive loads and mixed lubrication. Two different polymer overlays, created through a curing process on a conventional engine bearing surface with an approximate thickness of 13 µm, were investigated for their friction and wear resistances under a 30 N load using a pin-on-disc setup. The results indicate that the newly developed polymer overlay (NDP, PAI-based coating) surface has a coefficient of friction (COF) of 0.155 and a wear volume loss of 0.010 cm³. In contrast, the currently used polymer overlay (CPO) in this field shows higher values with a COF of 0.378 and a wear volume loss of 0.024 cm³, which is significantly greater than that of the NDP. It was found that, in addition to accurately selecting the ratios of solid lubricants, polymer resins, and wear-resistant hard particle additives (metal powders, metal oxides, carbides, etc.) within the polymer coating, the effective presence of a transfer film providing low friction on the counter surface also played a crucial role. Full article

This paper presents a new type of hydraulic clutch operating by means of magnetorheological (MR) fluids and the results achieved from both theoretical analysis and experimental measurement. A hydraulic clutch system with MR working fluid and a rotating magnetic field located was designed. The clutch was based on the principle of using a rotating magnetic field created by an alternating current electromagnet to set the MR fluid in motion. To test the hydraulic clutch with a rotating magnetic field, MR fluids were produced by our laboratory, consisting of solid iron particles of various diameters mixed with a silicone oil. With MR working fluid and a rotating magnetic core was designed. The rheological properties of the MR fluids were assessed on the basis of tests carried out with a Brookfield DV2T rheometer equipped with a magnetic device for generating a magnetic field. The characteristics of the hydraulic clutch were tested on a specially built test stand. It was found that the torque transmitted by the clutch increased with the rotational speed of the magnetic field and with a lower rotational speed of the beaker in which the working fluid was placed. It was also found that the greatest torque occurred with the working fluid with the highest iron content. Based on the analysis of the structure and characteristics of the clutch in which the magnetic field is used, it has been shown that the design of the developed clutch is similar to that of an induction clutch, and its characteristics correspond to the characteristics of the eddy current clutch. Therefore, the proposed new clutch with MR fluid and rotating magnetic field can be applied to stationary power transmission systems in a manner similar to an eddy current clutch. Full article

Guava (Psidium guajava L.) is an important economic crop grown widely in tropical and subtropical regions. Guava exhibits fast ripening and senescence as a climacteric fruit, causing a short shelf life and quality deterioration. Chitosan–essential oil nanoemulsions can be an edible coating used to improve postharvest quality attributes. In this study, chitosan was mixed with carvacrol to generate a nano-emulsoid solution containing 0.1 and 0.2% (v/v) carvacrol, using a sonic dismembrator. Guava fruit were coated with the above emulsion and postharvest quality parameters were measured during storage at 20 ± 1 °C and RH = 80 ± 5% for 8 days. The result illustrated that the particle size of the chitosan–carvacrol emulsions was nanoscale, and their high stability was demonstrated by the zeta potential and polydispersity index. Chitosan coating (2%, w/v, 310–375 kDa) containing 0.2% (v/v) carvacrol maintained postharvest quality compared to chitosan alone, with higher firmness, soluble solid content, total acid, and total phenol content, and lower weight loss and pericarp browning. The collective data were further verified by principal component analysis. A chitosan coating containing carvacrol can reduce postharvest losses. It can be applied as an effective strategy to improve postharvest fruit quality. Full article

Drilling cuttings from the rock formation generated during the drilling process are generally smashed to fine particles through hydraulic cutting and grinding using a drilling tool, and then are mixed with the drilling fluid during circulation. However, some of these particles are too small and light to be effectively removed from the drilling fluid via solids-control equipment. These small and light solids are referred to as low gravity solids (LGSs). This work aimed to investigate the effect of LGSs on the performance of oil-based drilling fluid (OBDF), such as the rheological properties, high-temperature and high-pressure filtration loss, emulsion stability, and filter cake quality. The results show that when the content of LGSs reached or even exceeded the solid capacity limit of the OBDF, the rheological parameters including the plastic viscosity, gel strength, and thixotropy of OBDF increased significantly. Furthermore, the filtration of OBDF increases, the filter cake becomes thicker, the friction resistance becomes larger, and the stability of emulsion of OBDF also decreases significantly when the concentration of LGSs reached the solid capacity limit of OBDF (6–9 wt% commonly). It was also found that LGSs with a smaller particle size had a more pronounced negative impact on the drilling fluid performance. This work provides guidance for understanding the impact mechanism of LGSs on drilling fluid performance and regulating the performance of OBDF. Full article

The synergistic effect of different types of solid particles in liquid lubricants is of great interest. In this work, g-C₃N₄ nanosheets were initially prepared using a calcination method and then as-prepared, and h-BN were used as lubricating additives to the white oil. A comparison between the mixed additives and the single g-C₃N₄ or h-BN additives revealed that the base oil with the addition of g-C₃N₄ and h-BN showed the best lubricating properties. The results show a 12.3% reduction in friction coefficient, resulting in a 68.6% reduction in wear rate compared to the white oil when filled with 0.5 wt% g-C₃N₄ and h-BN (1:1 by weight). Moreover, the addition of g-C₃N₄ and h-BN improves the high-temperature lubrication properties of the white oil. However, the friction coefficient and wear rate increase with increasing oil temperature. The large contact area between g-C₃N₄ and its sliding counterpart and the strong adhesive force between h-BN and its sliding counterpart improve the film formation efficiency, leading to enhanced tribological properties under oil lubrication conditions. Full article

Filter media may encounter aerosols mixed with solid and oil ingredients from various sources, such as industries, transportation, and households, in the air purification process, while the influence such oil content has on the loading performance of single-stage and two-stage filtration systems is under-reported. Thus, this study aims to evaluate oil fraction effects on the loading performance of single-stage and two-stage filtration systems. First, to reveal the oil–solid mixed particle deposition mechanisms, the filter media parameters, i.e., specific cake resistance $\mathsf{\epsilon }$and cake porosity ${\mathrm{K}}_2,$were tested, indicating that a slight amount of oil can increase the dust holding capacity (DHC) of filters by forming a more porous cake, while an excess of oil results in reduced DHC by forming impermeable liquid films on the solid skeleton. Further two-stage experimental results indicate that the effectiveness of a pre-stage filter can be significantly affected by the properties of incoming aerosol and main-stage filters. The utilization of a pre-stage filter unintentionally deteriorated the service lifetime of the main-stage filter when challenged with contaminants with certain oil particles. This counter-intuitive negative phenomenon is due to the special loading behaviors of oil–solid mixed particles. The existing pre-stage filters allow a higher fine oil particle fraction to reach the main-stage downstream, while the induced cake filtration scenario leading to a film clogging scenario adversely reduced the lifetime of the main-stage filter. The findings suggest that the feasibility of a pre-stage in the filtration system requires compressive evaluations according to the specific oil-coated contaminants. Full article

Given that rubber tires are almost immune to biological degradation, this vast amount of solid waste is a major environmental concern worldwide. Reuse of these waste tires in the construction industry is one of the strategies to minimize their environmental pollution and landfill problems, while contributing to more economical building design. Thus, we assessed the improved traits of rubberized concrete made by combining palm oil fuel ash (POFA) with tire rubber aggregates (TRAs). Studies on the effects of POFA inclusion on the durability properties of rubberized concrete with TRAs as the replacement agent for fine or coarse aggregates remain deficient. Herein, the rubberized concrete contained 20% POFA as ordinary Portland cement (OPC) substitute, and various amounts of TRAs (5, 10, 20 and 30%). The proposed mixes enclosing three types of TRAs (fiber, fine and coarse aggregates) were characterized to determine their durability and acoustic performance. The water absorption, fire endurance performance, chloride penetration, and acoustic properties of the proposed concrete were evaluated. The designed concrete showed a systematic increase in water absorption and chloride penetration with the increase in rubber amount and particle size. These POFA-modified rubberized concretes displayed a satisfactory performance up to 500 °C, and superior acoustic properties in terms of sound absorption. The presence of TRA as 30% coarse aggregate replacement was found to improve the sound absorption properties by as much as 42%. Full article

The biologically treated palm oil mill effluent (POME) urges further treatment to minimize the residual pollutant concentration for safe discharge in the nearest watercourse. In the present study, the post-treatment of biologically treated POME was conducted using ferrous sulfate monohydrate (FeSO₄·H₂O) as a coagulant. The influence of the FeSO₄·H₂O coagulation of POME was determined on the elimination of biochemical oxygen demand (BOD), suspended solids (SS), and chemical oxygen demand (COD) with varying flocculation time (min), slow mixing speed (rpm), coagulant doses (g/L) and pH. The FeSO₄·H₂O coagulation–flocculation experimental conditions were designed following the central composite design (CCD) of experiments and optimized by employing response surface methodology (RSM) based on the optimal SS, COD, and BOD elimination from POME. The maximum BOD, SS, and COD elimination achieved were about 96%, 97%, and 98%, respectively, at the optimized experimental condition. The surface morphology and elemental composition analyses of raw FeSO₄·H₂O and sludge generated after coagulation revealed that the FeSO₄·H₂O effectively removed the colloidal and suspended particles from POME. The well-fitted kinetic model equation was the pseudo-second-order kinetic equation to describe the FeSO₄·H₂O coagulation–flocculation behavior. The thermodynamics properties analyses revealed that the FeSO₄·H₂O coagulation of POME was non-spontaneous and endothermic. The residual SS, COD, and BOD in treated POME were determined to be 28.27 ± 5 mg/L, 147 ± 3 mg/L, and 6.36 ± 0.5 mg/L, respectively, lower the recommended discharged limits as reported by the Department of Environment (DoE), Malaysia. Full article

Solid-free drilling fluid has more advantages as a new type of drilling fluid compared with traditional drilling fluid, such as improving drilling efficiency, protecting oil and not having clay particles clog the oil and gas layer. In this study, Zn/Cu/Fe-doped magnesium–aluminum hydroxide (Mg-Al MMH) was prepared using the co-precipitation method and evaluated in solid-free drilling fluid. The inhibition mechanism of synthesized hydroxide was analyzed by X-ray diffraction, laser particle-size analysis and thermogravimetric analysis. The samples were directly used as drilling fluid base muds for performance evaluation. The results showed that the linear expansion rate of 4% M6-Fe was only 12.32% at room temperature within 2 h, that the linear expansion rate was 20.28% at 90 °C and that the anti-swelling rate was 81.16% at room temperature, indicating that it has a strong inhibition ability at both room temperature and at high temperatures. Meanwhile, the possibility of multi-mixed metal hydroxide as a drilling fluid base mud is discussed in this study. We found that 4% M6-Fe exhibited low viscosity, a high YP/PV ratio and high temperature resistance, and its apparent viscosity retention rate reached 100% rolled at 200 °C for 16 h, with a YP/PV ratio of 2.33. Full article