Search Results (131)

Steroidal pharmaceutical wastewater, such as stock liquid and cell lysate, is conventionally treated at a high cost due to its complex composition and high organic content. To treat steroidal pharmaceutical wastewater, make it harmless, and utilize it as a resource, engineering exploration of large-scale biogas engineering was carried out based on its anaerobic digestion characteristics, and the microbial population in the digestion process was analyzed. The results showed that, at a medium temperature of 35 °C and a total solid percentage of 6.5% ± 0.5%, both stock liquid and cell lysate wastewater could be anaerobically fermented normally, with the potential for anaerobic digestion treatment. The cumulative biogas production of lysate gas from the supernatant could reach 758 mL/gVS, which was significantly better than that of traditional raw materials such as straw and feces. The methane content reached 78.9%, and the total VFAs reached 10,204 mg/L on the ninth day. Moreover, we found that co-digestion of steroidal pharmaceutical wastewater with corn straw (CS) significantly enhanced system stability and biogas production efficiency, with synergistic improvement reaching up to 42%. This approach effectively shortened the lag phase observed in the mono-digestion of steroidal pharmaceutical wastewater. Actual treatment in a large-scale biogas project revealed that, after the addition of two kinds of wastewater, the main and auxiliary reactors presented serious acidification problems. Of these, the total volatile fatty acids in the main reactor reached up to 21,000 mg/L, and the methane content in the biogas production decreased to 25%. Additionally, 16S rRNA high-throughput sequencing analysis showed that, after the addition of steroidal pharmaceutical wastewater, the archaea community in the anaerobic reactor changed significantly due to the stress of changes in the fermentation environment. Euryarchaeota became the absolute dominant bacteria, and the methanogenic pathway also changed to the hydrogen trophic methanogenic pathway with Methanothermobacter as the absolute dominant bacterium. This is the first successful industrial-scale application of biogas engineering for treating steroid wastewater, demonstrating its technical feasibility and energy recovery potential. These research outcomes provide critical engineering parameters and practical experience for large-scale resource recovery from similar wastewater streams, offering important reference values for advancing pharmaceutical wastewater treatment from compliance discharge to energy utilization. Full article

To reproduce successfully, non-parasitic brook lamprey must accumulate all nutrients needed for growth and reproductive development during a multi-year larval stage while feeding on low-quality detritus. We used total length and wet mass data of American brook lamprey (Lethenteron appendix) in 14 streams across four watersheds in southeastern Minnesota, USA, to examine Fulton’s condition factors (Fulton K = [g wet mass/mm TL³] × 10⁶) of both lamprey ammocoetes (or larvae, n = 717) and spawning adults (n = 154) and developed preliminary standard mass equations for both life stages to allow for calculations of relative weights, a first attempt for any lamprey species. Condition factors and relative weights were most variable through the first year or two of the larval stage, with both condition factors and relative weights rising slightly through the remainder of the larval phase. Relative weights of most late-stage larvae ranged from 90 to 110% with condition factors at or slightly above 1.5. The standard mass equation for American brook lamprey larvae based on the top 25% heaviest individuals across the length range was: log₁₀ wet mass (g) = 2.7078 log₁₀ total length (mm)—5.115. Adult male American brook lampreys were slightly but not significantly longer than females at most of the sites examined, and condition factors and relative weights differed between the sexes only at one site. Overall, adult condition factors averaged 2.0, and relative weights averaged 86.9% and did not change significantly across the total length range (137 to 214 mm). The standard mass equation for American brook lamprey adults based on the top 25% healthiest or fittest individuals across the length range was: log₁₀ wet mass (g) = 2.7411 log₁₀ total length (mm)—5.047. American brook lamprey adults and ammocoetes approaching metamorphosis generally exhibited good condition factors and relative weights. Both adult and ammocoete condition factors and relative weights, along with adult lengths, differed significantly among streams. Length-wet mass data are needed from more populations of American brook lamprey across its range to build a more robust relative weight model for the species. Full article

Rural landscapes are changing rapidly, yet many assessments remain descriptive and weakly connected to planning instruments. This study connects rural landscape analysis with planning and management by examining post-earthquake transformations in Topaktaş (Tuşba, Van), a village redesigned and relocated after the 2011 events. Using ArcGIS 10.8 and the Analytic Hierarchy Process (AHP), we integrate DEM, slope, aspect, CORINE land cover Plus, surface-water presence/seasonality, and proximity to hazards (active and surface-rupture faults) and infrastructure (Karasu Stream, highways, village roads). A risk overlay is treated as a hard constraint. We produce suitability maps for settlement, agriculture, recreation, and industry; derive a composite optimum land-use surface; and translate outputs into decision rules (e.g., a 0–100 m fault no-build setback, riparian buffers, and slope thresholds) with an outline for implementation and monitoring. Key findings show legacy footprints at lower elevations, while new footprints cluster near the upper elevation band (DEM range 1642–1735 m). Most of the area exhibits 0–3% slopes, supporting low-impact access where hazards are manageable; however, several newly designated settlement tracts conflict with risk and water-service conditions. Although limited to a single case and available data resolutions, the workflow is transferable: it moves beyond mapping to actionable planning instruments—zoning overlays, buffers, thresholds, and phased management—supporting sustainable, culturally informed post-earthquake reconstruction. Full article

With rising global temperatures and increasing sustainability demands, the need for advanced pavement solutions has never been greater. This study breaks new ground by integrating phase change materials (PCMs), including paraffin-based wax (Rubitherm RT55), hydrated salt (Climator Salt S10), and fatty acid (lauric acid), as binder modifiers within warm mix asphalt (WMA) mixtures. Moving beyond the traditional focus on binder-only modifications, this research utilizes recycled cigarette filters (CFs) as a dual-purpose fiber additive, directly reinforcing the asphalt mixture while simultaneously transforming a major urban waste stream into valuable infrastructure. The performance of the developed WMA mixture has been evaluated in terms of stiffness behavior using an Indirect Tensile Strength Modulus (ITSM) test, permanent deformation using a static creep strain test, and rutting resistance using the Hamburg wheel-track test. Laboratory tests demonstrated that the incorporation of PCMs and recycled CFs into WMA mixtures led to remarkable improvements in stiffness, deformation resistance, and rutting performance. Modified mixes consistently outperformed the control, achieving up to 15% higher stiffness after 7 days of curing, 36% lower creep strain after 4000 s, and 64% reduction in rut depth at 20,000 passes. Cost–benefit analysis and service life prediction show that, despite costing USD 0.71 more per square meter with 5 cm thickness, the modified WMA mixture delivers much greater durability and rutting resistance, extending service life to 19–29 years compared to 10–15 years for the control. This highlights the value of these modifications for durable, sustainable pavements. Full article

Hydrological processes in river systems are changing due to climate variability and human activities, making it crucial to understand and quantify these changes for effective water resource management. This study examines long-term trends in hydroclimate variables (1990–2022) and land use/land cover (LULC) changes (1988, 2002, and 2022) within the Continental Reach of the Gambia River Basin (CGRB). Trend analyses of the Standardized Precipitation-Evapotranspiration Index (SPEI) at 12-month and 24-month scales, along with river discharge at the Simenti station, reveal a shift from dry conditions to wetter phases post-2008, marked by significant increases in rainfall and discharge variability. LULC analysis revealed significant transformations in the basin. LULC analysis highlights significant transformations within the basin. Forest and savanna areas decreased by 20.57 and 4.48%, respectively, between 1988 and 2002, largely due to human activities such as agricultural expansion and deforestation for charcoal production. Post-2002, forest cover recovered from 32.36 to 36.27%, coinciding with the wetter conditions after 2008, suggesting that climatic shifts promoted vegetation regrowth. Spatial analysis further highlights an increase in bowe and steppe areas, especially in the north, indicating land degradation linked to human land use practices. Bowe areas, marked by impermeable laterite outcrops, and steppe areas with sparse herbaceous cover result from overgrazing and soil degradation, exacerbated by the region’s drier phases. A notable decrease in burned areas from 2.03 to 0.23% suggests improvements in fire management practices, reducing fire frequency, which is also supported by wetter conditions post-2008. Agricultural land and bare soils expanded by 14%, from 2.77 to 3.07%, primarily in the northern and central regions, likely driven by both population pressures and climatic shifts. Correlations between precipitation and land cover changes indicate that wetter conditions facilitated forest regrowth, while drier conditions exacerbated land degradation, with human activities such as deforestation and agricultural expansion potentially amplifying the impact of climatic shifts. These results demonstrate that while climatic shifts played a role in driving vegetation recovery, human activities were key in shaping land use patterns, impacting both precipitation and stream discharge, particularly due to agricultural practices and land degradation. Full article

Therapeutic management during the acute phase of traumatic brain injury (TBI) relies on continuous multimodal cerebral physiologic monitoring to detect and prevent secondary injury. These high-resolution data streams come from various invasive/non-invasive sensor technologies and challenge clinicians, as they are difficult to integrate into management algorithms and prognostic models. Data reduction techniques, like moving average filters, simplify data but may fail to address statistical autocorrelation and could introduce new properties, affecting model utility and interpretation. This study uses the CAnadian High-Resolution TBI (CAHR-TBI) dataset to examine the impact of temporal resolution changes (1 min to 24 h) on autoregressive integrated moving average (ARIMA) modeling for raw and derived cerebral physiologic signals. Stationarity tests indicated that the majority of the signals required first-order differencing to address persistent trends. A grid search identified optimal ARIMA parameters (p,d,q) for each signal and resolution. Subgroup analyses revealed population-specific differences in temporal structure, and small-scale forecasting using optimal parameters confirmed model adequacy. Variations in optimal structures across signals and patients highlight the importance of tailoring ARIMA models for precise interpretation and performance. Findings show that both raw and derived indices exhibit intrinsic ARIMA components regardless of resolution. Ignoring these features risks compromising the significance of models developed from such data. This underscores the need for careful resolution considerations in temporal modeling for TBI care. Full article

PVC has become an indispensable material worldwide. However, its production method (suspension) presents significant sustainability challenges, such as negative environmental impacts and high operational costs due to energy consumption. For this reason, a combined analysis was conducted involving energy integration using Aspen Energy Analyzer™ V14 software and a technical process analysis. This methodology aims to reduce industrial utility consumption and assess the sustainability performance of this alternative. The integration through pinch analysis revealed that it is possible to reduce the energy consumption of the process by 29% in heating utilities and 6% in cooling utilities. The minimum utility requirements were 21 GJ/h for heating (down from 29 GJ/h) and 131 GJ/h for cooling (down from 139 GJ/h). This reduction resulted in approximately a 41% decrease in utility costs. Additionally, the reduction in burner energy consumption led to lower greenhouse gas emissions, with a decreased natural gas consumption of approximately 279 m³. However, only two streams could be integrated due to technical process limitations; therefore, it is recommended to explore integrations with complex operations such as reactors and phase-change processes. In addition to this, the WEP technical evaluation yielded promising results showing a decrease in the specific energy intensity by 3219.506 MJ/t (being 4681.8 MJ/t), which represents an economic saving in industrial services (energy purposes) of approximately USD 886.000 per year, satisfying the optimization of the process despite the limitations when integrating it energetically. Finally, a more in-depth analysis should be conducted to further integrate other streams of the process to reduce utilities consumption. Full article

The Syrdarya Delta, located in semi-arid and arid Central Asia, is an important water source for fertile landscapes. The environmental history of the Syrdarya Delta (SD) during the 19th and 20th centuries is a diverse and understudied subject, and its natural and anthropogenic aspects changed drastically during this period. As a result of the Syrdarya Delta’s location, on the shores of the former Aral Sea, there is a vital need to expand our understanding of the phases and policies that led to the current condition. This study argues that by integrating methods from social and natural sciences and applying them to selected historical materials, among them, former classified materials from the Cold War period, we can expand our understanding regarding the extent and types of disruptions in the Syrdarya Delta ecological system. The main findings of this study show that between the second part of the 19th and the 21st centuries, a period of roughly a hundred and fifty years, the SD changed drastically in aspects of urban areas, which increased during the Soviet period, changes in land use and hydrography, with changes in the amounts, size and flowing directions of water streams in the SD. The findings also present changes in vegetative cover and amounts parallel to salinization of the soil, which increased in the 1970s–1980s, and changes in the meeting point of the former Aral Sea with the SD. The findings of the study indicate that most of these changes can be attributed to anthropogenic factors, which have taken place mainly since the 1960s–1970s under the USSR regime. As this study presents, such materials can assist in reconstructing land use and land cover from the years to which our data are limited by integrating them with modern satellite image analysis, thus being able to quantify and estimate the amounts and types of these changes regarding salinization, land use and land cover and hydrology, which are crucial for studying deltas located in arid and semi-arid landscapes, such as the SD. This study presents evidence and argues that these data are of pivotal importance and should be used when attempting to rehabilitate and manage today’s Syrdarya Delta landscapes and hydrology. Full article

This paper proposes an accuracy enhancement method for fiber-longitudinal power profile estimation (PPE) based on convolutional neural networks (CNN). Two types of CNNs are designed. The first network treats different polarization streams identically and is denoted as CNN. The second network considers the difference between the contributions of different polarization streams to the nonlinear phase shift and is denoted as enhanced CNN (ECNN). The numerical simulation results confirm the effectiveness of the method for a 64 Gbaud/s quadrature phase-shift keying (QPSK) polarization-division-multiplexed (PDM) coherent optical communication system with a fiber length of 320 km. The effects of finite impulse response (FIR) filter length, power into the fiber, and polarization mode dispersion on the PPE accuracy are examined. Finally, the results of the proposed method are monitored in the presence of several simultaneous power attenuation anomalies in the fiber optic link. It is found that the accuracy of the PPE substantially improves after using the proposed method, achieving a relative gain of up to 71%. When the modulation format is changed from QPSK to 16-ary quadrature amplitude modulation (16-QAM), and the fiber length is increased from 360 km to 480 km, the proposed method is still effective. This work provides a feasible solution for implementing fiber-longitudinal PPE, enabling significantly improved estimation accuracy in practical applications. Full article

Atmospheric jets are pivotal components of atmospheric circulation, profoundly influencing surface weather patterns and the development of extreme weather events such as storms and cold waves. Accurate detection of the jet stream axis is indispensable for enhancing weather forecasting, monitoring climate change, and mitigating disasters. However, traditional methods for delineating atmospheric jets are plagued by inefficiency, substantial errors, and pronounced subjectivity, limiting their applicability in complex atmospheric scenarios. Current research on semi-supervised methods for extracting atmospheric jets remains scarce, with most approaches dependent on traditional techniques that struggle with stability and generalization. To address these limitations, this study proposes a semi-supervised jet stream axis extraction method leveraging an enhanced U-Net++ model. The approach incorporates improved residual blocks and enhanced attention gate mechanisms, seamlessly integrating these enhanced attention gates into the dense skip connections of U-Net++. Furthermore, it optimizes the consistency learning phase within semi-supervised frameworks, effectively addressing data scarcity challenges while significantly enhancing the precision of jet stream axis detection. Experimental results reveal the following: (1) With only 30% of labeled data, the proposed method achieves a precision exceeding 80% on the test set, surpassing state-of-the-art (SOTA) baselines. Compared to fully supervised U-Net and U-Net++ methods, the precision improves by 17.02% and 9.91%. (2) With labeled data proportions of 10%, 20%, and 30%, the proposed method outperforms the MT semi-supervised method, achieving precision gains of 9.44%, 15.58%, and 19.50%, while surpassing the DCT semi-supervised method with improvements of 10.24%, 16.64%, and 14.15%, respectively. Ablation studies further validate the effectiveness of the proposed method in accurately identifying the jet stream axis. The proposed method exhibits remarkable consistency, stability, and generalization capabilities, producing jet stream axis extractions closely aligned with wind field data. Full article

The transition from a perennial to an intermittent regime in newly intermittent rivers (nIRs) negatively affects both taxonomic and functional diversity, with significant repercussions on freshwater ecosystem processes and services. However, to better understand how changes in the natural flow regime may influence the structure and functioning of freshwater ecosystems, it is fundamental to assess variations in abiotic and biotic parameters throughout the hydrological phases characterizing nIRs. For these reasons, we evaluated the temporal changes in community structure and composition during the drying phase of a Central Apennines stream (Italy) over two consecutive drought years. We demonstrated that the different hydrological regime of the pre-drought phase profoundly affected the structure and composition of freshwater communities. The reduced discharge during the low-flow conditions of 2024 led to a transition from insect- to non-insect-dominated communities, with small-sized, lentic-adapted and generalist taxa replacing rheophile and more sensitive insect taxa. We also found marked interannual differences in temporal beta diversity. However, in both years, taxa richness did not exhibit a negative stepped response pattern during the sequence of channel contraction, flow cessation and pools formation. Consequently, we can assume that in newly intermittent Apennine rivers, the response of freshwater communities to drying is strictly dependent on the local and interannual variable hydrological context. This study emphasizes the need for further investigation to better understand the ecological impacts of increasing intermittence in formerly perennial streams and rivers. Full article

Aircraft engine turbine blades are covered with protective coatings. These coatings should have the best thermophysical convergence with the blade’s parent material. The aim is to create heat-resistant covering for aircraft engine turbine blades made of nickel superalloy. The results of tests on coatings are presented; the inner layer is an adhesive layer of the MeCrAlY type, applied to the blade by means of supersonic thermal spraying, and the outer layer is diffusion-aluminized in the first case using the Vapor Phase Aluminizing method, and in the second using the suspension method. The inner layer of the coating protects the blade material against high-temperature corrosion, and the outer layer against high-temperature fuel combustion product stream. The protective coatings applied to aircraft engine turbine blades were subjected to an engine test in test bench conditions and then to material tests. A protective coating with an internal layer of MeCrAlY type applied to the blade by supersonic spraying and an external layer aluminized by the Vapor Phase Aluminizing method protects the nickel superalloy against high-temperature diffusion changes, protects it against oxidation and provides it thermal insulation. Full article

The Qilian Mountains, located on the northeastern edge of the Qinghai–Tibet Plateau, are characterized by unique high-altitude and cold-climate terrain, where permafrost and seasonally frozen ground are extensively distributed. In recent years, with global warming and increasing precipitation on the Qinghai–Tibet Plateau, permafrost degradation has become severe, further exacerbating the fragility of the ecological environment. Therefore, timely research on surface deformation and the freeze–thaw patterns of alpine permafrost in the Qilian Mountains is imperative. This study employs Sentinel-1A SAR data and the SBAS-InSAR technique to monitor surface deformation in the alpine permafrost regions of the Qilian Mountains from 2017 to 2023. A method for spatiotemporal interpolation of ascending and descending orbit results is proposed to calculate two-dimensional surface deformation fields further. Moreover, by constructing a dynamic periodic deformation model, the study more accurately summarizes the regular changes in permafrost freeze–thaw and the trends in seasonal deformation amplitudes. The results indicate that the surface deformation time series in both vertical and east–west directions obtained using this method show significant improvements in accuracy over the initial data, allowing for a more precise reflection of the dynamic processes of surface deformation in the study area. Subsidence is predominant in permafrost areas, while uplift mainly occurs in seasonally frozen ground areas near lakes and streams. The average vertical deformation rate is 1.56 mm/a, with seasonal amplitudes reaching 35 mm. Topographical (elevation; slope gradient; aspect) and climatic factors (temperature; soil moisture; precipitation) play key roles in deformation patterns. The deformation of permafrost follows five distinct phases: summer thawing; warm-season stability; frost heave; winter cooling; and spring thawing. This study enhances our understanding of permafrost deformation characteristics in high-latitude and high-altitude regions, providing a reference for preventing geological disasters in the Qinghai–Tibet Plateau area and offering theoretical guidance for regional ecological environmental protection and infrastructure safety. Full article

Laser cladding has unique technical advantages, such as precise heat input control, excellent coating properties, and local selective cladding for complex shape parts, which is a vital branch of surface engineering. During the laser cladding process, the parts are subjected to extreme thermal gradients, leading to the formation of micro-defects such as cracks, pores, and segregation. These defects compromise the serviceability of the components. Ultrasonic vibration can produce thermal, mechanical, cavitation, and acoustic flow effects in the melt pool, which can comprehensively affect the formation and evolution for the microstructure of the melt pool and reduce the microscopic defects of the cladding layer. In this paper, the coupling model of temperature and flow field for the laser cladding of 45 steel 316L was established. The transient evolution laws of temperature and flow field under ultrasonic vibration were revealed from a macroscopic point of view. Based on the phase field method, a numerical model of dendrite growth during laser cladding solidification under ultrasonic vibration was established. The mechanism of the effect of ultrasonic vibration on the solidification dendrite growth during laser cladding was revealed on a mesoscopic scale. Based on the microstructure evolution model of the paste region in the scanning direction of the cladding pool, the effects of a static flow field and acoustic flow on dendrite growth were investigated. The results show that the melt flow changes the heat and mass transfer behaviors at the solidification interface, concurrently changing the dendrites’ growth morphology. The acoustic streaming effect increases the flow velocity of the melt pool, which increases the tilt angle of the dendrites to the flow-on side and promotes the growth of secondary dendrite arms on the flow-on side. It improves the solute distribution in the melt pool and reduces elemental segregation. Full article

A series of M(x)CoCeMgAlO mixed oxides with different transition metals (M = Cu, Fe, Mn, and Ni) with an M content x = 3 at. %, and another series of Fe(x)CoCeMgAlO mixed oxides with Fe contents x ranging from 1 to 9 at. % with respect to cations, while keeping constant in both cases 40 at. % Co, 10 at. % Ce and Mg/Al atomic ratio of 3 were prepared via thermal decomposition at 750 °C in air of their corresponding layered double hydroxide (LDH) precursors obtained by coprecipitation. They were tested in a fixed bed reactor for complete methane oxidation with a gas feed of 1 vol.% methane in air to evaluate their catalytic performance. The physico-structural properties of the mixed oxide samples were investigated with several techniques, such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), elemental mappings, inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction under hydrogen (H₂-TPR) and nitrogen adsorption–desorption at −196 °C. XRD analysis revealed in all the samples the presence of Co₃O₄ crystallites together with periclase-like and CeO₂ phases, with no separate M-based oxide phase. All the cations were distributed homogeneously, as suggested by EDX measurements and elemental mappings of the samples. The metal contents, determined by EDX and ICP-OES, were in accordance with the theoretical values set for the catalysts’ preparation. The redox properties studied by H₂-TPR, along with the surface composition determined by XPS, provided information to elucidate the catalytic combustion properties of the studied mixed oxide materials. The methane combustion tests showed that all the M-promoted CoCeMgAlO mixed oxides were more active than the M-free counterpart, the highest promoting effect being observed for Fe as the doping transition metal. The Fe(x)CoCeMgAlO mixed oxide sample, with x = 3 at. % Fe displayed the highest catalytic activity for methane combustion with a temperature corresponding to 50% methane conversion, T₅₀, of 489 °C, which is ca. 40 °C lower than that of the unpromoted catalyst. This was attributed to its superior redox properties and lowest activation energy among the studied catalysts, likely due to a Fe–Co–Ce synergistic interaction. In addition, long-term tests of Fe(3)CoCeMgAlO mixed oxide were performed, showing good stability over 60 h on-stream. On the other hand, the addition of water vapors in the feed led to textural and structural changes in the Fe(3)CoCeMgAlO system, affecting its catalytic performance in methane complete oxidation. At the same time, the catalyst showed relatively good recovery of its catalytic activity as soon as the water vapors were removed from the feed. Full article