Search Results (7,037)

Five series of rigid polyurethane–polyisocyanurate (RPU/PIR) foams were obtained. They were modified by ashes from burning paper (P) and wood: conifers (pine—S, spruce—S’) and deciduous trees (oak—D, birch—B). The ash was added to rigid polyurethane–polyisocyanurate foams (PU/PIR). In this way, five series of foams with different ash contents (from 1 to 9% wt.) were obtained: PP, PS, PD, PS’, PB. The model foam (reference—W) was obtained without filler. The basic properties, physico-mechanical, and thermal properties of the ashes and obtained foams were examined. It was specified, among other things, the cellular structure by scanning electron microscopy (SEM), and changes in chemical structure by Fourier-transform infrared spectroscopy (FTIR) were compared. The obtained foams were also subjected to thermostating in a circulating air dryer in increased temperature (120 °C) for 48 h. Ash tests showed that their skeletal density is about 2.9 g/cm³, and the pH of their solutions ranges from 9 to 13. The varied color of the ashes affected the color of the foams. SEM-EDS tests showed the presence of magnesium, calcium, silicon, potassium, aluminum, phosphorus, sodium, and sulfur in the ashes. Foam tests showed that pine ash is the most beneficial for foams, because it increases their compressive strength three times compared to W foam and improves their thermal stability. All ashes cause the residue after combustion of the foams (retention) to increase and the range of combustion of the samples to decrease. Full article

When a 35 kV distribution network has the problem of insufficient reactive power, the input of a shunt reactor is a common compensation method. Vacuum circuit breakers are widely used in 35 kV distribution networks because of their superior arc extinguishing performance and convenient maintenance. However, in recent years, accidents involving vacuum circuit breakers breaking shunt reactors have occurred more frequently in China, such as high-frequency phase-to-phase short circuits, inter-turn burning losses, bus outlet short circuits, etc., which can cause serious damage and pose a greater threat to the safety of the power system. This paper focuses on the switching overvoltage generated by the vacuum circuit breaker cutting off the shunt reactor. Firstly, the mechanism of overvoltage generation is analyzed theoretically. It is concluded that the equivalent chopping current of the other two phases caused by the continuous reignition of the first open phase is the root cause of the high-amplitude interphase overvoltage. Based on the MODELS custom programming module in EMTP/ATP, according to the process of breaking and reigniting the circuit breaker, this paper uses Fortran language to compile the program and establishes a model of a vacuum circuit breaker, including power frequency current interception, high-frequency current, zero-crossing, breaking, and arc reignition modules. The vacuum circuit breaker is simulated for hundreds of continuous reignitions in milliseconds. Finally, a simulation study on the overvoltage suppression measures of a 35 kV shunt reactor is carried out. The comprehensive comparison of various suppression measures provides a reference for the reasonable selection of actual engineering conditions. Full article

Zen/Chan Buddhism, as a profound spiritual tradition, has witnessed the emergence and development of a unique phenomenon known as “老婆禪 Granny Chan”, which is deeply intertwined with the spiritual pursuits of Buddhist women throughout history. This proposed research aims to expound and interrogate the hidden treasures of Zen wisdom amassed by these remarkable women, thereby shedding new light on the often-overlooked contributions within the Zen domain. To begin with, by scouring ancient Zen texts, anecdotes, and historical records, we will trace the roots and evolutionary path of “Granny Chan”. These sources are replete with accounts of nameless “grannies” engaging in profound dialogs and encounters with Zen masters. Their sharp insights and spontaneous responses during dharma exchanges, as exemplified in classic koans like “婆子點心 The Granny’s Dimsum” and “婆子燒庵 The Granny Burning the Hermitage”, reveal a depth of understanding that belies their marginalized status in traditional religious narratives. Subsequently, this study will focus on dissecting the distinct ways in which their Zen wisdom was manifested within the cultural context of Zen. Their approach, characterized by simplicity, directness, and a deep connection to life’s realities, not only added a refreshing dimension to Zen teachings but also subtly challenged the male-dominated paradigm prevalent in the religious fields. By highlighting these expressions, we can appreciate how Buddhist women’s insights became an integral part of Zen’s cultural fabric. In the contemporary context, this research holds multiple implications. It serves as a corrective to the historical neglect of Buddhist women’s spiritual achievements, providing a source of inspiration and empowerment for modern female practitioners. Moreover, it prompts a rethinking of gender equality within religious traditions, advocating for a more inclusive and equitable recognition of women’s roles in the Zen community and beyond. Overall, through the exploration of “Granny Chan”, we anticipate contributing to a better understanding of Zen Buddhism’s historical, cultural, and spiritual dimensions, bridging the gender gap and enriching the ongoing discourse on religious wisdom. Full article

Rocky land cover provides vital habitat for many different species, including endemic, vulnerable, or threatened plants and animals; thus, various land management organizations prioritize the conservation of rocky habitat. Despite its importance, land cover classification maps rarely classify rocky land cover explicitly, and if they do, they are limited in spatial resolution or extent. Consequently, we used random forest models in Google Earth Engine (GEE) to classify rocky land cover at a high spatial resolution across a broad spatial extent in the Cascade Mountains and Columbia River Gorge in Washington, USA. The spectral indices derived from Sentinel-2 satellite data and NAIP aerial imagery, the specialized multi-temporal predictors formulated using time series of normalized burn ratio (NBR) and normalized difference in vegetation index (NDVI), and topographical predictors were especially important to include in the rocky land cover classification models; however, the predictors’ relative variable importance differed regionally. Beyond evaluating random forest models and developing classification maps of rocky land cover, we conducted three case studies to highlight potential avenues for future work and form connections to land management organizations’ needs. Our replicable approach relies on open-source data and software (GEE), aligns with the goals of land management organizations, and has the potential to be elaborated upon by future research investigating rocky habitats or other rare habitat types. Full article

Rice straw is an agricultural waste that is difficult to manage and has traditionally been burned or buried, leading to environmental problems. Because of this, the introduction of rice straw into concrete has been proposed to revalue this residue. This investigation shows experimental work carried out to prepare rice straw fibers and introduce them into a concrete mix as macrofibers. In addition, three fiber treatments were compared: two alkaline and one thermal. Four concrete mixes were studied: a reference mix, two concrete mixes with untreated rice straw fibers in two dosages, 10 kg/m³ and 15 kg/m³, and a fourth concrete mix with 10 kg/m³ of fiber treated with sodium hydroxide. The properties analyzed are workability, compression flexural strength, and shrinkage. The results show that the rice straw fiber used in this work improves concrete flexural strength at the peak but does not provide post-crack residual flexural strength. The sodium hydroxide treatment was effective in obtaining a more cohesive mix and lower setting time delay and slightly improved the performance of the rice straw fiber at the flexural strength peak. In summary, concrete can be used to encapsulate this agricultural waste material, providing enough strength for several engineering applications (>30 MPa). Full article

Droughts present a significant global challenge, particularly to forest ecosystems in regions such as eastern New South Wales, Australia, which is known for its dry climate and frequent, intense droughts. Recent studies have indicated a notable increase in tree mortality and canopy browning across this area, especially during the recent extreme drought period culminating in the Black Summer of 2019–2020. Our study investigates the impacts of drought on eucalypt forests by leveraging remote sensing and field observation data to detect and analyse vegetation health and stress indicators. Utilising data from Sentinel-2, alongside historical Landsat observations, we applied multiple spectral vegetation indices, namely the Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), Normalized Burn Ratio (NBR), and Tasseled Cap Transformation, to assess the extent of drought impacts. We found NBR to show the most consistent agreement with ground-based observations of drought-related tree mortality. Additionally, by integrating ground-based data from the “Dead Tree Detective” citizen science project, we were able to validate the remote sensing outcomes with a 90.22% consistency, providing confirmation of the extensive spatial distribution and severity of the inferred impacts. Our findings reveal that 13.16% of eucalypt forests and woodlands across eastern New South Wales experienced severe stress associated with drought during the 2019–2020 Black Summer drought. This study demonstrates the utility of satellite-derived drought indicators in monitoring forest health and highlights the necessity for continuous monitoring and research to understand the factors that trigger tree vitality loss. Full article

Waste tires (WTs) pose significant environmental challenges due to their massive volume, with millions of tons generated globally each year. Improper disposal methods, such as illegal burning, further aggravate these issues by releasing substantial quantities of greenhouse gases (GHGs) and toxic pollutants into the atmosphere. To mitigate these impacts, the adoption of environmentally friendly resource recovery technologies and a thorough evaluation of their environmental benefits are crucial. Against this backdrop, this research reviews life cycle assessment (LCA)-based analyses of WT recycling technologies, focusing on their environmental performance and contributions to GHG emission reduction. Key recycling pathways, including pyrolysis, rubber reclaiming, and energy recovery, are evaluated in terms of their carbon emissions, alongside an in-depth analysis of carbon reduction opportunities across various stages of the recycling process. Based on these findings, this paper proposes feasible recommendations and identifies future trends for advancing WT resource recovery. The objectives are to (1) systematically review the existing LCA research findings and technological pathways for WT resource recovery; (2) evaluate the advantages and disadvantages of current technologies from the perspective of carbon emission reduction; and (3) explore future trends, proposing optimization pathways and recommendations for technological development. Full article

Many barriers prevent ranchers from supporting prescribed fire on grazing leases or their own land. Barriers include negative perceptions of fire resources limitations, and fear of liability. We surveyed ranching landowners around four National Grasslands in North and South Dakota—public grazinglands managed by the USDA Forest Service—to assess landowner attitudes towards prescribed fire and provide insight into the barriers to using prescribed burning on the National Grasslands. Respondents reported being motivated by an interest in stewardship and want managers to prioritize sound science in decision-making on the National Grasslands. But respondents generally had negative perceptions of fire and reported little awareness of potential benefits. With respect to prescribed fire, specifically, respondents reported their greatest degree of trust in prescribed fire activity and/or information of Pheasants Forever and county Extension, and their lowest trust in the USDA Forest Service. Despite their proximity to public grazingland, where the risk and resource barriers for prescribed burning would be borne by the USDA Forest Service, respondents disagreed that prescribed fire use on the Grasslands should be increased and stated a lack of readiness to conduct prescribed burns on their own ranches. As the primary barriers to prescribed fire use in these communities appear to be negative perceptions, educational materials from trusted sources and opportunities to engage with burning might help explain where and when prescribed fire use would be appropriate on the landscape and aid understanding between entities that would like to use prescribed fire and those who are concerned about prescribed fire use. Full article

This study investigated the effects of different calcium levels on the nutritional quality and stress resistance of mini Chinese cabbage, focusing on the ‘QYH’ calcium-sensitive cultivar and the ‘HN’ calcium-tolerant cultivar. Plants were treated with five calcium levels (0, 2, 4, 6, and 8 mmol/L) to analyze the incidence of tip-burn, tissue calcium content, mineral accumulation, amino acid composition, and phenolic and flavonoid compound contents. The results showed that appropriate calcium levels significantly reduced tip-burn incidence. Specifically, ‘QYH’ exhibited no tip-burn symptoms at 6 mmol/L calcium, while ‘HN’ was tip-burn free at 4 mmol/L. Appropriate calcium levels also significantly increased the contents of soluble sugars, proteins, and ascorbic acid while reducing nitrate levels in both cultivars. For example, the soluble sugar content in ‘QYH’ increased by 119.05% under the 6 mmol/L calcium treatment. Similarly, ‘HN’ showed significant increases in soluble sugars, proteins, and ascorbic acid at 4 mmol/L. Amino acid and phenolic compound levels peaked at 6 mmol/L calcium in ‘QYH’, with rutin content in ‘QYH’ increasing by 181.58%. In ‘HN’ these compounds peaked at 4 mmol/L. Additionally, high calcium levels did not antagonize key minerals but reduced manganese accumulation. These findings highlight calcium’s critical role in enhancing the nutritional quality of mini Chinese cabbage and provide a scientific basis for optimizing calcium fertilizer application for both ‘QYH’ and ‘HN’ cultivars. Full article

Orofacial pain (OFP) includes chronic pain conditions categorized into musculoskeletal (MS), neurovascular (NV), and neuropathic (NP) pain types, encompassing temporomandibular disorders (TMD), migraines, trigeminal neuralgia (TN), post-traumatic neuropathies, and burning mouth syndrome (BMS). These conditions significantly affect quality of life; yet, their underlying metabolic disruptions remain inadequately explored. Salivary metabolomics provides a non-invasive method to investigate biochemical alterations associated with OFP subtypes. This study aimed to identify pain-specific salivary metabolites across chronic OFP types and examine their correlations with clinical characteristics. Saliva samples from 63 OFP patients (TMD, migraines, TN, post-traumatic neuropathies, BMS) and 37 pain-free controls were analyzed using liquid chromatography–mass spectrometry (LC-MS) targeting 28 metabolites linked to pain. Statistical analyses determined significant metabolite changes and associations with pain subtypes and patient characteristics. Among the 28 analyzed metabolites, 18 showed significant differences between OFP patients and controls. Key amino acids, including DL-glutamic acid, DL-aspartic acid, DL-citrulline, spermidine, and DL-ornithine, were significantly elevated in MS, NV, and NP pain types compared to controls. Additionally, DL-glutamine, DL-valine, and DL-phenylalanine were distinctively elevated in TMD and migraine patients. BMS displayed fewer alterations, with significantly lower levels of DL-proline, DL-tryptophan, DL-glutamic acid, DL-asparagine, and DL-aspartic acid compared to other pain types but elevated spermidine levels relative to controls. Salivary metabolomics revealed distinct metabolic alterations in OFP subtypes, providing insights into potential biomarkers for diagnosis and monitoring. These findings offer a foundation for personalized approaches in OFP management, although further research is required to validate and expand these results. Full article

The most common aftereffect of severe burns in patients is hypertrophic scarring. Hypertrophic scars typically form following severe burns; it refers to excessive collagen production in the dermal layer during the healing process, resulting in an abnormal raised scar. Currently, practical treatments for suppressing hypertrophic scars include laser therapy, pressure therapy, and the application of silicone sheets for moisture retention. The most extensively used treatment involves compression therapy using specially designed garments for the affected areas. However, this method has limitations when applied to curved surfaces like the face. To address this issue, three-dimensional (3D) scanning and 3D printing techniques have been actively developed for face masks and have shown promising clinical results. Unfortunately, current facial masks under development lack a sensor system to measure pressure, making it difficult to ensure consistent and appropriate pressures during clinical trials. In this study, we have developed a burn pressure mask capable of real-time pressure monitoring. The facial mask developed in this study utilizes an FSR-type sensor to measure the pressure applied to the skin. We have also embedded electrical wires within the mask to enhance its comfort and wearability. For this study, two patients wore the facial mask with real-time pressure measurement capabilities for 4 weeks in 12 h per day on average. We evaluated whether the mask maintained the appropriate pressure range (15–25 mmHg) throughout the clinical trial and whether it effectively inhibited scar formation. Through the analysis of recorded pressure signal data, we confirmed that the patients consistently maintained the appropriate pressure while wearing the mask during the clinical trial. Additionally, we observed significant differences in skin moisture levels, transepidermal water loss, and scar thickness before and after the experiment. These findings suggest that the facial mask, featuring real-time monitoring capabilities, effectively prevents the formation of hypertrophic scars. Full article

The key challenge in polymer science is developing sustainable synthesis methods using renewable feedstocks. This study explores plant-derived diarylheptanoids with various structures as the building blocks for polyurethane (PU) materials. Diarylheptanoid glucosides isolated from black alder (Alnus glutinosa) bark were hydrolyzed and fractionated to remove sugar moieties. The resulting diarylheptanoids, along with unhydrolyzed analogues and curcumin, were used as biomass-based polyols to synthesize model PU films. Incorporating diarylheptanoids enhanced the mechanical strength and reduced the flexibility of PU due to increased crosslinking, with effects proportional to the OH functionality of the biomass-based polyols. Weight loss, FTIR, and Py-GC-MS/FID analyses revealed that the catechol moieties and the glucosidic bonds are biodegradable structural subunits of diarylheptanoids incorporated into PU films. Rigid polyurethane foams (PURs) incorporating high-OH-functionality diarylheptanoid glucosides such as oregonin demonstrated significantly higher compression strength and less weight loss during non-isothermal thermal analysis in air compared to those of commercial polyol-based foams. A cone calorimeter test showed that the PUR foam with diarylheptanoid derivatives had a lower degradation rate, a longer flame-burning time, 30% less heat emission, and 25% less smoke, indicating improved flame retardancy. Adding 1–2% oregonin-enriched black alder bark extracts to commercial Elastopir 1132/509/0 PUR foam significantly improved its resistance to thermal oxidative aging, outperforming the commercial antioxidant Irganox. Full article

The relative influence of climate and Indigenous cultural burning on past forest composition in southern New England, US, remains debated. Employing varied analyses, this study compared data on Indigenous settlements from over 5000 years before present (YBP) with relative tree abundances estimated from pollen and land survey records. Results suggested that fire-tolerant vegetation, mainly oak (Quercus spp.), was more abundant near Indigenous settlements from 4955 to 205 YBP (i.e., 86–91% fire-tolerant trees), and significantly (p < 0.05) higher from 3205 to 205 YBP; fire-tolerant vegetation was less abundant away from settlements, where it also experienced greater fluctuations. Correlative models showed that warmer temperatures and distance to Indigenous settlement, which are both indicators of fire, were important predictors in the 17th–18th centuries of fire-tolerant tree abundance; soil variables were less important and their relationships with vegetation were unclear. A marked increase in oak abundance occurred above 8 °C mean annual temperature and within 16 km of major Indigenous settlements. Pyrophilic vegetation was most correlated with distance to Indigenous villages in areas with 7–9 °C mean annual temperature, typical of higher latitudes and elevations that usually supported northern hardwoods. Widespread burning in warmer areas potentially weakened relationships between distance and pyrophilic abundance. Indigenous land use imprinted upon warmer areas conducive to burning created patterns in fire-tolerant vegetation in southern New England, plausibly affecting most low-elevation areas. Results imply that restoration of fire-dependent species and of barrens, savannas, and woodlands of oak in southern New England benefit from cultural burning. Full article

The association between hypothermia and poor outcomes in severe burn injury is well established. However, the significance of the core-peripheral temperature gradient has not previously been investigated. Institutional guidance at our burns centre advocates avoiding hypothermia and targeting a body temperature between 37.5 and 39.5 °C. The core-peripheral temperature gap should be ≤2 °C, based on expert opinion. Data from 61 patients admitted to the Intensive Care Unit (ICU) with severe burns between 2016 and 2022 were analysed. A higher core temperature at 48 h, avoidance of hypothermia and a core-peripheral temperature gap > 2 °C were associated with reduced odds of mortality. The mean core body temperature and core-peripheral temperature gap increased over the first 48 h (r = 0.5, p < 0.001). All non-survivors had a core-peripheral gap < 2 °C at 48 h. Survivors had a higher mean 48 h gap (1.6 [95%CI:1.3–1.9]) than non-survivors (0.8 [95%CI:0.2–1.4; p = 0.04]). Our findings support previous studies suggesting that avoiding hypothermia and achieving a higher target temperature are associated with reduced mortality. However, it challenges the previous expert consensus that a lower core-peripheral gap indicates better outcomes. Further research with a larger cohort of patients is required to identify whether a higher core-peripheral temperature gap predicts outcomes in critically ill patients with severe burns. Full article

Stearic acid was used to modify the surface of a mixed flame-retardant powder consisting of aluminum hydroxide and ammonium polyphosphate by an uneven nucleation method, aiming to improve its dispersion in a vinyl resin matrix. This study investigated the effect of stearic acid dosage on the powder’s surface modification, characterized by infrared spectroscopy, activation degree, and laser particle size distribution. The dispersion of the modified powder in the resin matrix was evaluated by measuring the system viscosity, scanning electron microscopy (SEM) images, and bending performance. The results indicated that when the stearic acid content was 1%, the powder exhibited the best overall coating effect, with a uniform particle size distribution and an activation degree of 73.6%. After the composite material was added to the resin, the system viscosity was 923 mPa·s, and SEM images showed good dispersion of the powder in the resin matrix. The cured resin demonstrated a bending strength of 41.86 MPa. However, the flame retardancy slightly decreased, with the limiting oxygen index (LOI) dropping from 24.6% for the unmodified sample to 24.0%. When the stearic acid content exceeded 1%, the powder’s particle size increased dramatically. Although the activation degree also increased, the improvement was not significant. The addition of the powder to the resin resulted in a higher system viscosity, and the flame retardancy deteriorated sharply, with the vertical burning rating dropping from FV-1 to FV-2. Considering flame retardancy, mechanical properties, and processing performance, the composite material with 1% stearic acid demonstrated the best overall performance. Full article