Search Results (1,013)

This study uses an extrusion process to formulate blends based on recycled high-density and high-molecular-weight polyethylene (recHDPE, recHMWPE) for the manufacture of rainwater drainage pipes. The main objective of this project is to investigate the effects of incorporating graphene on the mechanical, thermal, and stress-cracking resistance properties of the recycled HDPE and HMWPE blends. Also, it aims to demonstrate that the addition of graphene may enable the use of different recycled polymers without compromising their properties. The effects of adding two amounts of graphene (0.5 and 1%) to recycled blends on the tensile and flexion properties, stress crack resistance (SCR) (using a notched crack ligament stress (NCLS) test), thermal behavior (using a differential scanning calorimeter (DSC) and a rheological plastometer) were investigated. The experimental results showed a significative enhancement when adding graphene in the SCR, some tensile properties (elongation at break and tensile strength), and flexural modulus. However, physical characterization showed that the samples containing 0.5% graphene exhibited lower crystallinity compared to the reference and, for the blend with 1% graphene, the fluidity also decreased for the blend filled with the graphene compared to the reference blend without any filler. Full article

Annual ryegrass (Lolium rigidum) is a problematic weed in winter crops and fallows in the southeastern cropping region (SCR) of Australia. This weed has evolved resistance to multiple herbicide groups, globally. In Australia, L. rigidum is more prevalent in the western and southern regions than in SCR. To assess the herbicide resistance status of L. rigidum, the response of five L. rigidum populations (collected from the SCR) to glyphosate, glufosinate, paraquat, haloxyfop-P-ethyl, and clethodim is determined using dose–response curves. Three parametric logistic models are used to determine the herbicide dose required to achieve 50% survival (LD₅₀) and 50% growth reduction (GR₅₀). The LD₅₀ values for 50% survival at 28 days after treatment range from 1702 g a.e. ha⁻¹ to 8225 g a.e. ha⁻¹ for glyphosate, 1637 g a.i. ha⁻¹ to 1828 g a.i. ha⁻¹ for glufosinate, 141 g a.i. ha⁻¹ to 307 g a.i. ha⁻¹ for paraquat, 11 g a.i. ha⁻¹ to 107 g a.i. ha⁻¹ for haloxyfop-P-ethyl, and 17 g a.i. ha⁻¹ to 48 g a.i. ha⁻¹ for clethodim. The resistance factor, based on GR₅₀ value, is highest in the S7 population (2.2 times) for glyphosate, the S11 population (2.3 times) for glufosinate, the S11 population (2.0 time) for paraquat, the S7 population (3.9 times) for haloxyfop-P-ethyl, and the S3 population (3.1 times) for clethodim, compared with the susceptible or less tolerant population. The S11 population is found to be resistant to five tested herbicides, based on resistance factors. Similarly, the S3 population is highly resistant to glyphosate, haloxyfop-P-ethyl, and clethodim compared with the W4 population. These results suggest that L. rigidum populations in the SCR exhibit resistance to multiple herbicide groups at labelled field rates. The findings highlight the necessity of adopting an integrated management approach, including the use of residual herbicides, tank mixing herbicides with different modes of action, and rotating herbicides in conjunction with cultural and mechanical control methods. Full article

Currently, in dairy farming, there is growing concern for the welfare of calves during the critical period between the separation from their dams and weaning. During weaning, rationed feeding is a practice used to improve feed efficiency and control the calves’ growth, but it could also have negative consequences associated with hunger and feed restriction behavior. One such consequence could be the performance by calves of stereotyped behaviors indicative of poor welfare, such as non-nutritive oral behaviors. We hypothesized that making a Total Mixed Ration (TMR) available to calves, in addition to the standard pelleted starter diet, thanks to its structural and nutritional characteristics, could help to focus the oral behavior of the subjects towards nutritional activities and therefore limit the development of stereotyped behaviors, even when the amount of starter is restricted. To test this hypothesis, 30 female Holstein calves (equipped with an accelerometer based on an ear tag), were randomly assigned to one of three treatments: a control diet (CTR) with an ad libitum calf starter but without TMR; Treatment 1 (TRT1) with both ad libitum calf starter and ad libitum TMR; Treatment 2 (TRT2) with ad libitum TMR and a restricted amount of a calf starter (50% of the intake starter of the control group day by day). All animals were kept in individual cages equipped with a slow-flow teat bucket apparatus for milk feeding and with access to separated buckets (one for drinking water, one for the starter, and one for the TMR) placed on the outside of the front gate of each cage. Sucking behavior, as well as resting, ruminating and activity behavior, was recorded individually from 7 days of life to weaning (63 d of age) by an automated monitoring system based on ear-tag accelerometers (SCR eSense, Allflex, Irving, TX, USA). The results showed that in the CTR group, there was a greater sucking activity compared to the TRT1 group (26.25 min/head/day vs. 16.83 min/head/day, p = 0.0181), while the TRT2 group showed intermediate values (20.41 min/head/day). We hypothesized that this increased sucking activity may be explained by the oral activity directed at sucking the Milk Bar tube observed only in CTR calves after complete consumption of available milk and could indicate a higher stress level than in the TRT1 group. The time spent resting was significantly lower for the CTR group compared to the TRT1 group (9.20 h/day vs. 11.15 h/day, p = 0.0049) while the TRT2 group was in an intermediate situation (10.65 h/day). Furthermore, the increase in time dedicated to rest observed in TRT1, in light of the good vitality of the calves shown by the daily patterns of resting behavior and daily activity, also seems to suggest an improvement in welfare conditions compared to calves receiving pelleted starter alone. Based on these results, we can deduce that providing TMR ad libitum in the diet of weaning calves could be an effective strategy to improve calf welfare due to the reduction in stereotyped oral activity. However, further studies are needed to establish threshold values useful for distinguishing physiological from pathological resting times in weaning calves raised in individual cages. Full article

Selective catalytic reduction of nitrogen oxides (NO_x) with ammonia (NH₃-SCR) has been implemented in response to the regulation of NO_x emissions from stationary and mobile sources above 300 °C. However, the development of NH₃-SCR catalysts active at low temperatures below 200 °C is still needed to improve the energy efficiency and to cope with various fuels. In this review article, recent reports on low-temperature NH₃-SCR catalysts are systematically summarized. The redox property as well as the surface acidity are two main factors that affect the catalytic activity. The strong redox property is beneficial for the low-temperature NH₃-SCR activity but is responsible for N₂O formation. The multiple electron transfer system is more plausible for controlling redox properties. H₂O and SO_x, which are often found with NO_x in flue gas, have a detrimental effect on NH₃-SCR activity, especially at low temperatures. The competitive adsorption of H₂O can be minimized by enhancing the hydrophobic property of the catalyst. Various strategies to improve the resistance to SO_x poisoning are also discussed. Full article

A cross-disciplinary rapid scoping review was carried out, generally following the PRISMA-SCR protocol to examine historical racial and caste-based discrimination as structural determinants of health disparities in the 21st century. We selected 48 peer-reviewed full-text articles available from the University of Memphis Libraries database search, focusing on three selected case-study countries: the United States (US), Canada, and Nepal. The authors read each article, extracted highlights, and tabulated the thematic contents on structural health disparities attributed to racism or casteism. The results link historical racism/casteism to health disparities occurring in Black and African American, Native American, and other ethnic groups in the US; in Indigenous peoples and other visible minorities in Canada; and in the Dalits of Nepal, a population racialized by caste, grounded on at least four foundational theories explaining structural determinants of health disparities. The evidence from the literature indicates that genetic variations and biological differences (e.g., disease prevalence) occur within and between races/castes for various reasons (e.g., random gene mutations, geographic isolation, and endogamy). However, historical races/castes as socio-cultural constructs have no inherently exclusive basis of biological differences. Disregarding genetic discrimination based on pseudo-scientific theories, genetic testing is a valuable scientific means to achieve the better health of the populations. Epigenetic changes (e.g., weathering—the early aging of racialized women) due to the DNA methylation of genes among racialized populations are markers of intergenerational trauma due to racial/caste discrimination. Likewise, chronic stresses resulting from intergenerational racial/caste discrimination cause an “allostatic load”, characterized by an imbalance of neuronal and hormonal dysfunction, leading to occurrences of chronic diseases (e.g., hypertension, diabetes, and mental health) at disproportionate rates among racialized populations. Major areas identified for reparative policy changes and interventions for eliminating the health impacts of racism/casteism include areas of issues on health disparity research, organizational structures, programs and processes, racial justice in population health, cultural trauma, equitable healthcare system, and genetic discrimination. Full article

Background: Percutaneous nephrolithotomy (PCNL) is associated with a wide range of complications. This review aims to explore how recent technological advancements and personalized medicine can help prevent or predict these complications. Methods: A scoping review was conducted according to the PRISMA-SCR guidelines and registered on the Open Science Framework in April 2024. A literature search was performed on PUBMED, Web of Science, and Scopus databases. This review focused on predictive AI models, 3D surgical models, intrasurgical image guidance, and biomarkers. Articles meeting the following criteria were included: publication between 2019 and 2024, written in English, involving human participants, and discussing technological advancements or personalized medicine in the context of complications in PCNL. Results: Of the 11,098 articles searched, 35 new studies were included. We identified a few articles on predictive AI models. Several studies demonstrated that 3D presurgical models and virtual models could enhance surgical planning and reduce complications. New intrasurgical image and guidance systems showed the potential in reducing bleeding and radiation exposure. Finally, several biomarkers were identified as predictors of sepsis and other complications. Conclusion: This scoping review highlights the potential of emerging technologies in reducing and predicting PCNL complications. However, larger prospective studies are required for validation. Full article

To improve the electrochemical activity and discharge performance of an aluminum-air (Al-air) battery, a commercial 6061 alloy (Al6061) was selected as the anode, and CeO₂ was also added inside the anode to enhance its performance. The CeO₂/Al6061 composite was prepared using selective laser melting (SLM) technology. The influence of hatch spacing on the forming quality, corrosion resistance, and discharge performance of the anode was studied in detail. The results showed that with an increase in hatch spacing, the density, corrosion resistance, and discharge performance of the anode first increased and then decreased. When the hatch spacing is 0.13 mm, the anode has the best forming quality. At this point, the density reaches 98.39%, and the self-corrosion rate (SCR) decreases to 2.596 × 10⁻⁴ g·cm⁻²·min⁻¹. Meanwhile, the anode exhibits its highest electrochemical activity and discharge voltage, which is up to −1.570 V. The change in anode performance is related to the defects generated during the SLM forming process. For samples with fewer defects, the anode can dissolve uniformly, while for samples with more defects, the electrode solution is prone to penetrate the defects, causing uneven corrosion and reducing electrochemical and discharge activity. Full article

This paper presents an application of a fractional-order system on modeling an industrial process system with large inertia and time delay. The traditional integer-order model of the process system is extended to a fractional-order one in this work. To identify the parameters of the proposed fractional-order model, an output-error identification algorithm is presented. Based on the experimental step response data of the selective catalytic reduction (SCR) denitrification process in a power plant, this proposed fractional-order model shows a better fitting result compared with the typical integer-order models. An integer-order proportional–integral (PI) controller is designed for the process plant using a simple scheme according to the identified fractional-order and integer-order models, respectively. Validation tests are performed based on the obtained fractional-order and integer-order models, demonstrating the advantages of the proposed fractional-order model with the corresponding system identification approach for industrial processes with large inertia and time delay. Full article

The development of a soft crawling robot (SCR) capable of quick folding and recovery has important application value in the field of biomimetic engineering. This article proposes an origami-inspired vacuum-actuated foldable soft crawling robot (OVFSCR), which is composed of entirely soft foldable mirrored origami actuators with a Kresling crease pattern, and possesses capabilities of realizing multimodal locomotion incorporating crawling, climbing, and turning movements. The OVFSCR is characterized by producing periodically foldable and restorable body deformation, and its asymmetric structural design of low front and high rear hexahedral feet creates a friction difference between the two feet and contact surface to enable unidirectional movement. Combining an actuation control sequence with an asymmetrical structural design, the body deformation and feet in contact with ground can be coordinated to realize quick continuous forward crawling locomotion. Furthermore, an efficient dynamic model is developed to characterize the OVFSCR’s motion capability. The robot demonstrates multifunctional characteristics, including crawling on a flat surface at an average speed of 11.9 mm/s, climbing a slope of 3°, carrying a certain payload, navigating inside straight and curved round tubes, removing obstacles, and traversing different media. It is revealed that the OVFSCR can imitate contractile deformation and crawling mode exhibited by soft biological worms. Our study contributes to paving avenues for practical applications in adaptive navigation, exploration, and inspection of soft robots in some uncharted territory. Full article

Nitrogen oxides (NO_x), pivotal atmospheric pollutants, significantly threaten the environment and human health. The CH₄-SCR process, leveraging the abundance and accessibility have methane, emerges as a promising avenue for NO_x abatement. Previous studies have demonstrated that zeolite support with twelve-membered ring (12-MR) and five-membered ring (5-MR) structures are susceptible to framework collapse in the presence of H₂O, leading to catalyst deactivation. Consequently, there is a necessity to explore novel zeolites with enhanced hydrothermal stability for application in CH₄-SCR processes. This research introduced for the first time an investigation into a novel In/H-SSZ-39 catalyst, which was synthesized via ion exchange and meticulously optimized for preparation conditions, including calcination temperature and In ions concentration, and reaction conditions, including CH₄/NO ratio, O₂ concentration, H₂O content, and Gas Hourly Space Velocity (GHSV). Furthermore, long-term operation tests and stability tests were conducted on the In/H-SSZ-39 catalyst. In addition, a series of characterizations were conducted to delve into the reasons behind how preparation conditions influence catalytic activity, as well as to investigate the changes in physicochemical properties during the reaction process. Full article

A direct bidirectional current discharge path between the input/output (I/O) and ground (GND) is essential for the robust protection of charging device models (CDM) in the tightly constrained design parameters of advanced low-voltage (LV) processes. Dual-direction silicon controlled rectifiers (DDSCRs) serve as ESD protection devices with high efficiency unit area discharge, enabling bidirectional electrostatic protection. However, the high trigger voltage of conventional DDSCR makes it unsuitable for ASICs used for the preamplification of biomedical signals, which only operate at low supply voltage. To address this issue, a self-biased triggered DDSCR (STDDSCR) structure is proposed to further reduce the trigger voltage. When the ESD pulse comes, the external RC trigger circuit controls the PMOS turn-on by self-bias, and the current release path is opened in advance to reduce the trigger voltage. As the ESD pulse voltage increases, the SCR loop opens to establish positive feedback and drain the amplified current. Additionally, the junction capacitance is decreased through high-resistance epitaxy and low-concentration P-well injection to further lower the trigger voltage. The simulation results of LTspice and TCAD respectively demonstrate that ESD devices can clamp transient high voltages earlier, with low parasitic capacitance and leakage current suitable for ESD protection of high-speed ports up to 1.5 V under normal operating conditions. Full article

This paper investigates the effect of innovative cross-sectional configurations on Low-Cost Bamboo Composite (LCBC) structural members. The study employs both experimental and numerical methods with different resin matrices and bamboo species. In this study, LCBC short columns are designed with different innovative cross-sectional configurations in an attempt to overcome the costly production processes of engineered bamboo. This approach uses bundles of bamboo, both in culm and strip forms. A compatible, environmentally responsible, and economically justifiable resin matrix is used to fabricate an LCBC member. The production of LCBC members does not necessitate highly advanced technology. This capability enables the production of LCBC members in custom-designed cross-sectional shapes and lengths. This study introduces the Russian doll (RD), Big Russian doll (BRD), Hawser (HAW), and Scrimber (SCR) cross-sectional configurations. Extra-large, large, medium, and small sizes of bamboo are employed. Synthetic Epoxy (EXP), a Bio-based Experimental soft filler (BE1), Bio-Epoxy (BE2), Furan-based (PF1) matrices are applied. Furthermore, Moso, Guadua, Madake, and Tali bamboo species are incorporated. The results of this study reveal that the most efficient cross-sectional configuration for compressive strength is the HAW configuration, closely followed by the SCR configuration. LCBC members with bio-resins have shown excellent promise in competing in strength with those made with their synthetic counterparts. The maximum compressive strengths (MPa) were achieved by two specimens with synthetic epoxy closely followed by a specimen with bio-epoxy, namely HAW-EPX-M, RD-EPX-M, and RD-BE2-G specimens with 78 MPa, 75 MPa, and 72 MPa, respectively. In terms of the modulus of elasticity of LCBC with different resin matrices, the stiffest specimens were HAW-BE2-M1, HAW-EPX-M, and HAW-BE2-M2 with 3.89 GPa, 3.08 GPa, and 2.54 GPa, respectively. The theoretical and numerical modelling of the LCBC members showed excellent correlation with the experimental results, which provides the capacity to design LCBC for engineering projects. The LCBC design can be further developed with more bamboo and less resin content. Full article

In view of the flue gas characteristics of cement kilns in China, the development of low-temperature denitrification catalysts with excellent anti-poisoning performance has important theoretical and practical significance. In this work, a series of MnCeO_x@TiO₂ and tourmaline-containing MnCeO_x@TiO₂-T catalysts was prepared using a chemical pre-deposition method. It was found that the MnCeO_x@TiO₂-T2 catalyst (containing 2% tourmaline) exhibited the best low-temperature NH₃-selective catalytic reduction (NH₃-SCR) performance, yielding 100% NO_x conversion at 110 °C and above. When 100–300 ppm SO₂ and 10 vol.% H₂O were introduced to the reaction, the NO_x conversion of the MnCeO_x@TiO₂-T2 catalyst was still higher than 90% at 170 °C, indicating good anti-poisoning performance. The addition of appropriate amounts of tourmaline can not only preferably expose the active {001} facets of TiO₂ but also introduce the acidic SiO₂ and Al₂O₃ components and increase the content of Mn⁴⁺ and O_α on the surface of the catalyst, all of which contribute to the enhancement of reaction activity of NH₃-SCR and anti-poisoning performance. However, excess amounts of tourmaline led to the formation of dense surface of catalysts that suppressed the exposure of catalytic active sites, giving rise to the decrease in catalytic activity and anti-poisoning capability. Through an in situ DRIFTS study, it was found that the addition of appropriate amounts of tourmaline increased the number of Brønsted acid sites on the catalyst surface, which suppressed the adsorption of SO₂ and thus inhibited the deposition of NH₄HSO₄ and (NH₄)₂HSO₄ on the surface of the catalyst, thereby improving the NH₃-SCR performance and anti-poisoning ability of the catalyst. Full article

Conventional grid-forming control often destabilizes voltage source converters (VSCs) in stiff grids, and transient synchronization instability will occur in the grid fault condition. Therefore, power self-synchronization control (PSSC) is first introduced for enhancing the small-signal stability of grid-forming control in the case of a short circuit ratio ranging from 1 to infinity. Meanwhile, the transient synchronization instability for the grid-forming converter with PSSC in the grid fault condition is analyzed by the phase portrait, and a transient stability enhancement control (TSEC) scheme is combined with a PSSC-based VSC, which can efficiently eliminate the risk of losing synchronization in the arbitrary SCR. Finally, experimental results are provided to confirm the theoretical analysis. Full article

The Special Issue “Exclusive Papers of the Editorial Board Members and Topical Advisory Panel Members of Catalysts in Section “Catalytic Materials” contains 14 peer-reviewed research articles and 1 review paper (Contributions 1–15), which broadly focus on the field of homogeneous and heterogeneous catalysis, with an emphasis on synthesis, physico-chemical characterizations, and applications in several environmental protection reactions, such as CO₂ valorization, NOx SCR, removal of VOCs, photocatalysis [...] Full article