Search Results (30)

Compared to single-decker ball bearings, double-decker ball bearings offer advantages such as higher speed limits, greater load capacity, and better impact performance. However, the inclusion of an additional bearing and adapter ring structure increases its overall mass, limiting its applications. This study addresses the challenges of achieving lightweight design and impact resistance in double-decker ball bearings. Using bionic principles, this study analyzes the internal spatial structure and fiber distribution of loofah to guide the bionic design of the adapter ring in the double-decker ball bearing. A new bearing structure inspired by loofah characteristics is proposed, and a finite element model for its mechanical analysis is developed. The structural response of both the new and traditional double-decker ball bearings is analyzed under varying speeds and impact excitation conditions. The results indicate that the mass of the new adapter ring is reduced by 25.26%, with smaller stress variation and more uniform stress distribution in the bionic design. The overall performance of the new double-decker ball bearing outperforms the traditional design in terms of deformation, equivalent stress, equivalent strain, and contact stress. The proposed bionic loofah-inspired double-decker ball bearing meets both lightweight and impact resistance requirements. The findings provide a theoretical foundation for applying double-decker ball bearings in high-impact and lightweight applications. Full article

Loofah is deemed a promising candidate for the purification of oily fumes. Our research utilized H₃PO₄ for initial activation of loofah (TCS), producing loofahderived carbon (TGSC-0). Subsequently, Fenton’s reagent was utilized for further modification to yield loofah-derived carbon (TGSC-1). TGSC-1 was used in the form of an adsorption column to simultaneously treat multiple pollutants from oily fumes, with surface Fe³⁺, Fe²⁺, and H₂O₂ catalyzing ·OH and ·OOH generation to enhance adsorption of the oils and non-methane hydrocarbon (NMHC). Characterization showed that the specific surface area of TGSC-1 was 427.97 m²/g and pore sizes ranged from 0.50 to 3.50 nm. The rich mesoporous and macroporous structures of TGSC-1 enhanced the capability of carbon layer adsorption. Langmuir adsorption kinetics suggested that adsorption proceeded via monolayer adsorption pathways, while L-τ lines revealed shorter protective effect times for adsorbing PM₁₀ and PM_2.5 than for oils and NMHC. The results indicated that TGSC-1 exhibited maximum saturated adsorption capacities of 25.79, 13.02, 9.82, and 15.99 mg/g for oils, NMHC, PM_2.5, and PM₁₀, respectively. Increasing resistance of the adsorption column exhibited a notable synergistic effect of filtration and adsorption in treating oily fumes. It combines renewable materials with low-energy processing, delivering eco-economic benefits for sustainable development and application. Full article

This research investigates suitable bio-carriers for the anaerobic ammonium oxidation (anammox) process. This study evaluates the efficiency of the anammox process by assessing nitrogen removal efficiency using five different bio-carriers: fine and coarse polyurethane (PU) sponges, a melamine sponge, Scotch Brite, and a loofah. Among the tested carriers, the reactor of the fine PU sponge media exhibited the highest nitrogen removal efficiency, achieving an 87% removal rate. This high efficiency was attributed to the substantial biomass containment, evidenced by a measured mixed liquor volatile suspended solids (MLVSS) amount of 1414 mg/L. Subsequently, the fine PU sponge, exhibiting the highest efficiency, was selected for further modification with a polyvinyl alcohol–sodium alginate (PVA-SA) gel coating to study the impact of methanol inhibition on nitrogen removal efficiency. An optimal modification condition was determined, utilizing concentrations of 8% PVA and 1.8% SA for the fine PU sponge media. The modified PU reactor exhibited the highest resistance to methanol inhibition, followed by the attached growth fine PU sponge reactor and suspended growth reactor. These findings suggest that there are benefits to using modified PU media for the anammox process in the field. Full article

This study evaluated the successful establishment of sponge gourds (Luffa cylindrica) through direct seeding under open-field conditions in a subtropical climate in Mexico. Three experimental sites, E1, E2, and E3, located in different rural communities with distinct altitudes and soil types (Luvisol and Andosol) were evaluated. E1 was enhanced with an organo-mineral substrate (SOM), while E2 and E3 served as controls without SOM application. Seeds from a single fruit were used for planting following standardized cultivation practices. Each experimental plot contained a total of 10 plants arranged in 10 rows with one plant per row. Yield variables, such as fruit count, length, diameter, weight, and seed quantity, were measured. E-1 exhibited superior growth, yielding 5–20 fruits per plant, with lengths of 9–15 cm, diameters up to 6.2 cm, and weights reaching 370 g, significantly surpassing E-2 and E-3. Kruskal-Wallis tests confirmed significant differences among the plots, indicating that seed germination enhanced by SOM in E-1 promoted improved growth characteristics. The production cost per fruit was $8.40 MXN in E-1, compared to $12.70 in E-2, and $13.60 MXN in E-3. These results support sponge gourds as a viable crop option for small- and medium-scale farmers in subtropical areas, offering both economic and environmental benefits. Full article

The loofah sponge has a complex, three-dimensional, porous mesh fiber structure characterized by markedly low density and excellent vibration isolation properties. In this study, loofah sponges made from dried Luffa cylindrica were divided into two components: the core unit and the shell unit, which were further subdivided into five regions. Static compression performance tests and vibration isolation analysis were conducted on the loofah sponge and its individual parts. Scanning models of the loofah sponge were generated using the RX Solutions nano-CT system in France, and finite element analysis was performed using the ANSYS Workbench. This study focused on the vibration isolation performance of the loofah sponge, examining energy absorption and isolation, as well as the vibrational strength of its isolation performance. The goal was to explore the functions and vibration isolation mechanisms of its different components. The results demonstrated that the loofah sponge structure exhibits rigid–flexible coupling, with the coordinated action of multiple parts producing highly effective energy absorption and isolation of the vibration intensity effect. Specifically, the core unit of the loofah sponge provides the best isolation effect of axial vibration intensity, with an acceleration vibration transfer of −60 dB at 300 Hz. Furthermore, both the core and shell unit structures combine to provide multidirectional low-frequency vibration isolation. This study of the loofah sponge’s vibration isolation mechanism provides a theoretical foundation and new insights for the design of bionic low-frequency vibration isolation devices. Full article

Enzyme immobilization is a crucial method in biotechnology and organic chemistry that significantly improves the stability, reusability, and overall effectiveness of enzymes across various applications. Lipases are one of the most frequently applied enzymes in food. The current study investigated the potential of utilizing selected agri-food and waste materials—buckwheat husks, pea hulls, loofah sponges, and yerba mate waste—as carriers for the immobilization of Sustine^® 121 lipase and Yarrowia lipolytica yeast biomass as whole-cell biocatalyst and lipase sources. Various lignocellulosic materials were pretreated through extraction processes, including Soxhlet extraction with hexane and ethanol, as well as alkaline and acid treatments for loofah sponges. The immobilization process involved adsorbing lipases or yeast cells onto the carriers and then evaluating their hydrolytic and synthetic activities. Preparations’ activities evaluation revealed that alkaline-pretreated loofah sponge yielded the highest hydrolytic activity (0.022 U/mg), while yerba mate leaves under brewing conditions demonstrated superior synthetic activity (0.51 U/mg). The findings underscore the potential of lignocellulosic materials from the agri-food industry as effective supports for enzyme immobilization, emphasizing the importance of material selection and pretreatment methods in optimizing enzymatic performance through giving an example of circular economy application in food processing and waste management. Full article

Membrane filtration is one of the preferred choices for petroleum wastewater disposal due to its simplicity and low energy consumption. In this paper, a biodegradable superhydrophobic membrane based on loofah and rice straw (LF-RS) was prepared and modified with dodecyltriethoxysilane to improve its stability, morphology, and performance. The membrane showed an efficiency of 99.06% for oil/water separation with an average water flux of 2057.37 Lm⁻²h⁻¹ and a tensile strength of 11.19 MPa. The tensile strength of the LF-RS membrane was 322.47% higher than that of the PVDF membrane and 126.58% higher than that of the commercially available nitrocellulose membrane. Through molecular simulations, we showed a 96.3% reduction in interaction energy between water and membrane post-modification, which is beneficial for increasing the contact angle and separation performance. This study provides an option for the large-scale, cost-effective fabrication of eco-friendly membranes for pollutant removal. Full article

Soil salinization severely limits the quality and productivity of economic crops, threatening global food security. Recent advancements have improved our understanding of how plants perceive, signal, and respond to salt stress. The discovery of the Salt Overly Sensitive (SOS) pathway has been crucial in revealing the molecular mechanisms behind plant salinity tolerance. Additionally, extensive research into various plant hormones, transcription factors, and signaling molecules has greatly enhanced our knowledge of plants’ salinity tolerance mechanisms. Cucurbitaceae plants, cherished for their economic value as fruits and vegetables, display sensitivity to salt stress. Despite garnering some attention, research on the salinity tolerance of these plants remains somewhat scattered and disorganized. Consequently, this article offers a review centered on three aspects: the salt response of Cucurbitaceae under stress; physiological and biochemical responses to salt stress; and the current research status of their molecular mechanisms in economically significant crops, like cucumbers, watermelons, melon, and loofahs. Additionally, some measures to improve the salt tolerance of Cucurbitaceae crops are summarized. It aims to provide insights for the in-depth exploration of Cucurbitaceae’s salt response mechanisms, uncovering the roles of salt-resistant genes and fostering the cultivation of novel varieties through molecular biology in the future. Full article

The substitution of ethyl acetate for ammonia in NH₃-SCR provides a novel strategy for the simultaneous removal of VOCs and NO. In this study, three distinct types of biochar were fabricated through pyrolysis at 700 °C. MnO_x and TiO₂ were sequentially loaded onto these biochar substrates via a hydrothermal process, yielding a family of biochar-based catalysts with optimized dosages. Upon exposure to xenon lamp irradiation at 240 °C, the biochar catalyst designated as 700-12-3GN, derived from Ginkgo shells, demonstrated the highest catalytic activity when contrasted with its counterparts prepared from moso bamboo and loofah. The conversion efficiencies for NO and ethyl acetate (EA) peaked at 73.66% and 62.09%, respectively, at a catalyst loading of 300 mg. The characterization results indicate that the 700-12-3GN catalyst exhibits superior activity, which can be attributed to the higher concentration of Mn⁴⁺ and Ti⁴⁺ species, along with its superior redox properties and suitable elemental distribution. Notably, the 700-12-3GN catalyst has the smallest specific surface area but the largest pore volume and average BJH pore size, indicating that the specific surface area is not the predominant factor affecting catalyst performance. Instead, pore volume and average BJH pore diameter appear to be the more influential parameters. This research provides a reference and prospect for the resource utilization of biochar and the development of photothermal co-catalytic ethyl acetate and NO at low cost. Full article

The arrangement of layers of natural long fibers that compose a polymeric composite can result in a final material with greater mechanical strength, in addition to replacing synthetic glass and carbon fibers. This study proposed different configurations of layers of loofah fibers (Luffa cylindrica) to produce reinforced polymeric–polyester composites, determining their potential mechanical properties such as flexural strength and Rockwell hardness. The layers were arranged by varying parallel and perpendicularly the direction of the loofah fibers pieces. The reinforcement decreased the density of all composites, with the lowest value, 1.03 g cm⁻³, indicated by the configuration 90°/0°/90°. The composites in the configuration 0°/90°/0° presented the highest value among the reinforced compositions (10.8 MPa), in addition to the highest rigidity value during bending tests (774.8 MPa). In the Rockwell hardness tests, the treatment reinforced with fibers in the configuration 90°/90°/90° had the highest value among all experimental treatments with a value of 86.9 HHR. The configuration angle of the loofah layers has a significant impact on the mechanical performance of the composites and should be taken into account in their confection. Furthermore, composites reinforced with loofah fibers in different configurations have physical–mechanical properties that qualify them for non-structural applications in indoor environments. Full article

Multifunctional wearable electronic sensors exhibit significant potential for applications in health management, motion tracking, intelligent healthcare, etc. In this study, we developed a novel assembly method for a polymeric silver nanowire (Ag NW)/transition metal carbide/nitride (MXene) @Loofah device using a facile solution dip-coating technique. During the pretreatment phase, the loofah was conditioned with polydiallyldimethylammonium chloride (PDAC), promoting the self-assembly of MXene layers and bolstering device stability. Then, the Ag NWs/MXene@Loofah was packaged with polyurethane to form a piezoresistive pressure sensor, which demonstrated superior pressure-sensing capabilities and was adept at registering movements of human joints and even subtle pulses. The design strategy presents a novel and rational approach to developing efficient pressure sensors. Full article

Fruit maturity is a crucial index for determining the optimal harvesting period of open-field loofah. Given the plant’s continuous flowering and fruiting patterns, fruits often reach maturity at different times, making precise maturity detection essential for high-quality and high-yield loofah production. Despite its importance, little research has been conducted in China on open-field young fruits and vegetables and a dearth of standards and techniques for accurate and non-destructive monitoring of loofah fruit maturity exists. This study introduces a real-time detection and maturity classification method for loofah, comprising two components: LuffaInst, a one-stage instance segmentation model, and a machine learning-based maturity classification model. LuffaInst employs a lightweight EdgeNeXt as the backbone and an enhanced pyramid attention-based feature pyramid network (PAFPN). To cater to the unique characteristics of elongated loofah fruits and the challenge of small target detection, we incorporated a novel attention module, the efficient strip attention module (ESA), which utilizes long and narrow convolutional kernels for strip pooling, a strategy more suitable for loofah fruit detection than traditional spatial pooling. Experimental results on the loofah dataset reveal that these improvements equip our LuffaInst with lower parameter weights and higher accuracy than other prevalent instance segmentation models. The mean average precision (mAP) on the loofah image dataset improved by at least 3.2% and the FPS increased by at least 10.13 f/s compared with Mask R-CNN, Mask Scoring R-CNN, YOLACT++, and SOLOv2, thereby satisfying the real-time detection requirement. Additionally, a random forest model, relying on color and texture features, was developed for three maturity classifications of loofah fruit instances (M1: fruit setting stage, M2: fruit enlargement stage, M3: fruit maturation stage). The application of a pruning strategy helped attain the random forest model with the highest accuracy (91.47% for M1, 90.13% for M2, and 92.96% for M3), culminating in an overall accuracy of 91.12%. This study offers promising results for loofah fruit maturity detection, providing technical support for the automated intelligent harvesting of loofah. Full article

The heavy metal adsorbents developed based on biomass resources have valuable application prospects due to the characteristics of rich sources, renewability and low cost. In the present work, a carboxyl functioned loofah fiber (LF@AA) was synthesized via UV-induced polymerization, and its adsorption capacity for cadmium (Cd²⁺) was investigated systematically. This modification resulted in the effective combination of a loofah fiber template and polyacrylic acid (PAA), which promoted its adsorption of Cd²⁺ to significantly increase to 339.3 mg·g⁻¹, and the applicable pH range was 4.0~7.0. Furthermore, the adsorbability of LF@AA remained stable at a high level after eight consecutive cycles. The adsorption kinetics and isotherm parameters revealed that the adsorption characteristics of cadmium conformed to the Weber–Morris and pseudo-second-order kinetics equations, and the adsorption process of cadmium conformed to Redlich–Peterson and Langmuir models. In addition, consequences of EDS, FTIR, and Zeta potential analysis reflected that the main adsorption mechanism should be ion exchange. Cd²⁺ was drawn to the adsorbent surface by electrostatic binding, and ion exchange occurred to form a bidentate chelate. This study suggests that it is reasonable and feasible to use natural biomass materials to develop efficient adsorbents to treat heavy metal pollution in wastewater. Full article

Luffa leaf (LL) is an agricultural waste produced by loofah. In this work, LL was used as biomass carbon source for biochars for the first time. After carbonization, activation, and chemical co-precipitation treatments, a magnetic lignocellulose-derived hierarchical porous biochar was obtained. The specific surface area and total pore volume were 2565.4 m²/g and 1.4643 cm³/g, and the surface was rich in carbon and oxygen functional groups. The synthetic dye rhodamine B (RhB) and the antibiotic tetracycline hydrochloride (TH) were selected as organic pollutant models to explore the ability to remove organic pollutants, and the results showed good adsorption performances. The maximum adsorption capacities were 1701.7 mg/g for RhB and 1755.9 mg/g for TH, which were higher than most carbon-based adsorbents. After 10 cycles of use, the removal efficiencies were still maintained at more than 70%, showing good stability. This work not only verified the feasibility of lignocellulose LL as a carbon source to prepare biochar but also prepared a magnetic hierarchical porous adsorbent with good performances that can better treat RhB and TH, which provided a new idea and direction for the efficient removal of organic pollutants in water. Full article

In the last decades, sorbent materials characterized by low selectivity have been developed for the removal of pollutants (in particular dyes) from wastewater. However, following the circular economy perspective, the possibility to selectively adsorb and desorb dyes molecules today represents an unavoidable challenge deserving to be faced. Herein, we propose a sequential treatment based on the use of PANI-modified loofah (P-LS) and loofah sponge (LS) to selectively adsorb cationic (rhodamine, RHB, and methylene blue, MB) and anionic (methyl orange, MO) dyes mixed in aqueous solution by tuning the adsorption pH (100% MO removal by P-LS and 100% and 70% abatement of MB and RHB, respectively, by LS). The system maintained high sorption activity for five consecutive cycles. A simple and effective regeneration procedure for the spent adsorbents permits the recovery of the initial sorption capability of the materials (81% for MO, ca. 85% for both RHB and MB, respectively) and, at the same time, the selective release of most of the adsorbed cationic dyes (50% of the adsorbed MB and 50% of the adsorbed RHB), although the procedure failed regarding the release of the anionic component. This approach paved the way to overcome the traditional procedure based on an indiscriminate removal/degradation of pollutants, making the industrial wastewater a potential source of useful chemicals. Full article