Found 197 results
Article
09 May 2025Modeling and Assessing Economical Feasibilities for Waste to Energy Conversion/Incineration Process in Context of Municipal Solid Waste
At the time of the study, most of the municipal waste, including solid municipal waste, in the city of St. Petersburg and in the connected larger Leningrad region is processed by landfilling. This sort of waste processing in open landfills causes environmental damage, uncontrollable landfill fires, bad and dangerous odors, nearby rivers/streams, groundwater pollution, CH4 and CO2 emissions, to mention a few. Additionally, landfilling is a waste of energy and material resources present in the content dumped into landfills. In this context, Waste-to-Energy (WtE) incineration is a process that we use to recover the energy the materials have back to usable form, which we use in the form of heat and electricity. Even though a lot of resources and energy are available in the (municipal solid) waste, it does not mean that recovering it would always make sense. Our study analyses and estimates the profitability of a WtE incineration plant(s) in the city of St. Petersburg and the connected Leningrad region. With the available data and following analysis, we have concluded that the WtE incineration is economically feasible in this specific region and city areas, given that the implementations follow more traditional (economically less expensive and easier) technical and process model solutions. As a note of results stability, it needs to be pointed out that the changes in estimates of gate fees, cost of electricity and heat, and so on do impact the economic feasibility a lot, and larger scale changes in the assumed revenues would have a high impact on the outcome of repeatability of the results.
Article
08 May 2025Vulnerability Assessment of Food Crop Production and Climate Change: Implication for Agricultural Productivity and Development in Nigeria
Climate change poses significant challenges to agriculture, particularly in developing nations like Nigeria, where the sector is highly dependent on vulnerable rain-fed farming systems. Extreme weather events such as prolonged droughts, erratic rainfall, flooding, and rising temperatures threaten agricultural productivity, food security, and rural livelihoods. This study examines the vulnerability of food crops to climate change, focusing on smallholder farmers’ perceptions and adaptation strategies. Using a multistage sampling technique, data were collected from 480 smallholder farmers across selected agro-ecological zones in Nigeria. The study employed descriptive statistics and a crop vulnerability scale to assess the susceptibility of key food crops—maize, cassava, sorghum, rice, millet, soybean, and yam—to climate extremes. Findings reveal that drought is the most critical climate-induced stressor affecting food crops, with maize and cassava exhibiting the highest vulnerability indices. Flooding also presents a substantial risk, particularly to maize, while temperature fluctuations have relatively less severe immediate impacts. The study highlights the importance of climate information dissemination, cooperative memberships, and extension services in enhancing farmers’ resilience. However, limited access to climate information remains a significant barrier to adaptation. Given the observed variability in crop vulnerability, it is recommended to implement targeted climate adaptation strategies such as drought-resistant crop varieties, improved drainage systems, and early warning mechanisms. This study underscores the urgent need for climate-smart agricultural policies and resilience-building measures to safeguard food production and rural livelihoods in Nigeria amid escalating climate change threats.
Article
08 May 2025Evaluating Orthophoto Mosaic Accuracy Using RTK UAVs and AeroPoints 2 Ground Control Points: A User’s Perspective
With the growing use of Real Time Kinematics (RTK) Unmanned Aerial Vehicles (UAVs) and advancements in ground control points (GCPs), assessing positional accuracy of UAV derived orthophoto mosaics is crucial. This study aimed to improve UAV aerial image accuracy for more reliable orthophoto mosaics by examining the positional accuracy of orthophoto mosaics derived with (1) an RTK UAV; and (2) an RTK UAV combined with AeroPoints 2 GCPs. We tested two GPS base station methods for the RTK UAV: self-determined and manually assigned coordinates. The manually assigned coordinates resulted in significantly lower root mean square error (RMSE = 0.0729 m) compared to the self-determined method (RMSE = 1.9762 m), indicating improved accuracy. For the AeroPoints 2 GCPs, we recorded coordinates from a central GCP at a known location and four additional GCPs placed in each cardinal direction. The AeroPoints 2 system showed lower RMSE at all points compared to the RTK, with the central GCP at 0.0136 m, indicating high accuracy. These findings suggest that while RTK UAVs improve accuracy with manual base station assignment, incorporating AeroPoints 2 GCPs provides consistently higher precision across multiple locations. The study highlights the potential of AeroPoints 2 GCPs and suggests further research opportunities to enhance RTK UAV accuracy in areas lacking GPS correctional networks.
Article
29 April 2025Application of recovered Carbon Black (rCB) by Waste Tire Pyrolysis as an Alternative Filler in Elastomer Products
The increasing global accumulation of End-of-Life (EoL) tires and the growing demand for fossil industrial Carbon Black (CB) call for sustainable alternative solutions. In this context, tire pyrolysis and the resulting recycled raw material recovered Carbon Black (rCB), are considered potential alternatives. In the study, various rCBs were incorporated into new elastomer compounds using a laboratory internal mixer and their properties were investigated. The compounds were selected based on examples of applications such as bicycle inner tubes and hydraulic membranes. By comparing the in-rubber properties of rCB-based compounds with CB reference compounds, an initial assessment of the potential use of rCB for the chosen products was derived. Compared to industrial carbon black, the use of rCB leads to a reduction in performance. Although increasing the filler content partially compensated for the mineral content in rCB and led to a slight improvement, it could not fully offset the performance loss.
Article
28 April 2025Production and Characterization of Recovered Carbon Black (rCB) by Waste Tire Pyrolysis as a Potential Carbon Black (CB) Substitute
Recovered Carbon Black (rCB) from scrap tire pyrolysis offers a potential alternative to fossil-based virgin Carbon Black (CB) in the context of a circular economy. This study investigated the influence of pyrolysis process parameters on rCB yield and quality at laboratory and semi-industrial scales. The resulting rCBs were characterized and found to have surface and structural properties comparable to N500 and N600 series CBs, but with higher mineral and volatile contents. The quality of rCB is influenced by the feedstock composition, particularly the ratio of organic to inorganic components as well as key process parameters such as heating rate, pyrolysis temperature and residence time. Higher heating rates accelerate degradation and shift product distribution toward increased oil yield and reduced rCB formation, while higher pyrolysis temperatures lead to lower volatile content in rCB. Additionally, reactor and process design affect heat distribution, transfer efficiency, and mixing behavior, further shaping rCB properties. However, further testing is required to evaluate the actual in-rubber properties of rCBs. Therefore, additional tests are planned, incorporating rCB into butyl and nitrile rubber-based elastomer compounds, which will be addressed in a follow-up study. In addition, data from the current experiments will support a comprehensive Life Cycle Assessment (LCA) to evaluate the environmental impacts of tire pyrolysis and rCB production compared to other recycling methods, with details to follow in a future publication.
Article
27 April 2025The Impact of Pacemaker Programming on Morbidity in Heart Transplant Recipients
Pacemaker programming recommendations in patients post-heart transplant include a higher lower rate limit, activating rate response mode, maximising battery longevity and minimising ventricular pacing in patients without atrioventricular block. This study sought to investigate how variability in pacemaker programming following orthotopic heart transplant affects morbidity. We conducted a retrospective analysis of heart transplant recipients at a single transplant centre between 1991 and 2023. Patients requiring pacemaker implantation following transplantation were matched with non-pacemaker recipients by age, sex and height. Patient and device characteristics were reviewed. Clinical outcomes, programming and physiological parameters were compared within the pacemaker group and between subject and comparator groups. Forty-five heart transplant recipients were included: 15 with pacemakers and 30 without. Within the pacemaker group, 20% were programmed with LRL > 60 bpm, rate-response mode in 47% and algorithms minimising ventricular pacing in 27%. Fifty-three percent were NYHA class I, and 46% NYHA class II; resting heart rate was similar between the groups (85 (SD14.9) and 79 (SD8) bpm: p = 0.33). NYHA class I group achieved a higher workload (METS 9 (SD2.7) vs. 6.9 (SD1) mL/kg/min: p = 0.21), and peak heart rate (135 (18.8) vs. 123 (14.8) bpm: p = 0.29) during exercise stress echocardiogram (ESE). The pacemaker group was more symptomatic than the comparator group (NYHA class II 46% vs. 10%: p = 0.016) and exhibited higher rates of cardiac allograft vasculopathy (53% vs. 10%: p = 0.005). There is substantial variability in pacemaker programming in heart transplant recipients. Patients who require a pacemaker have a greater symptom and comorbidity burden than those without. No identifiable physiological or programming differences stratified the greater morbidity within the pacemaker cohort.
Review
23 April 2025Research Progress on Offshore Wind Turbine Foundation Structures and Installation Technologies
Offshore wind power, as an important component of renewable energy, has gradually become one of the key technologies in global energy transition. The development of offshore wind power faces complex technical challenges, including strong wind, waves, currents, foundation bearing capacity, and installation technologies for wind turbines, among other issues. In recent years, with technological advancements, significant breakthroughs have been made in the design of offshore wind power foundation structures, installation technologies, and equipment. This paper provides a comprehensive review of the recent progress in offshore wind power technologies, deeply exploring innovative technologies in areas such as the overall development trends, foundation structures, installation technologies, and equipment of offshore wind power. Special attention is given to the design and safety analysis of wind turbine foundation structures under different foundation conditions, as well as installation technologies for wind power in complex sea conditions and deep-water areas. The paper argues that the applicable depth of fixed foundations is expected to extend beyond 50 m. The jacket foundation remains the mainstream choice for future large-scale wind turbines, with the potential to increase its applicable water depth to 100 m. Furthermore, floating foundations have significant potential for cost reduction and efficiency improvements. Developing entirely new foundation structures and installation technologies suitable for deep-water environments is also a key direction for future development.
Article
23 April 2025Evaluating Everyday Prospective Memory in School-Age Children through Parent- and Self-Reports: Validating Questionnaires and Examining Relations to Executive Functions and Autistic Traits
Prospective memory (PM) refers to the ability to remember to complete everyday tasks, and in adults, PM is often assessed using the Prospective and Retrospective Memory Questionnaire (PRMQ). However, this questionnaire has not been validated in children, and whether it is effective in detecting subtle PM and retrospective memory (RM) difficulties in subclinical populations remains unclear. Study 1 first validated the parent-reported PRMQ for children (PRMQC-p) and developed a self-reported version (PRMQC-s), and Study 2 examined the relationships among PM, executive functions, and autistic traits using parent-reported questionnaires. The study recruited 1127 children aged 6–12 years and their parents. Parents completed questionnaires assessing PM, executive functions, and autistic traits, while children completed the PRMQC-s. Confirmatory factor analysis indicated that both versions of PRMQC showed good reliability and supported the PM-RM correlated factor model. Preliminary norms were generated to allow quick evaluation of children’s everyday PM and RM performance. Importantly, higher autistic traits were associated with more frequent PM errors and executive functions completely mediated this relationship. These findings suggest that the PRMQC is a valid and useful tool for evaluating children’s everyday PM performance and emphasizes the critical role of executive functions in daily PM.
Article
18 April 2025Demographic History of Ancient Okunev People and Their Kin across Eurasia: A Patrilineal Perspective
The ancient Okunev culture in South Siberia is renowned for its mysterious artistic and cultural legacy and belief system. Many later, Eurasian steppe peoples are thought to have inherited elements of the Okunev culture, but its origins and evolution remain unclear. Previous research of ancient DNA (aDNA) indicated that the primary paternal lineage of the ancient Okunev people was Q-L330-YP761. In this study, we sequenced 25 modern samples from this haplogroup and analyzed them alongside 26 ancient samples and 10 modern samples from public sources. The updated, high-resolution phylogenetic tree shows paternal lineage Q-L330-YP761 expanded significantly during the Okunev culture. Its downstream subclade Y145421 was the main paternal type of the Chandman culture. Phylogeographic analysis indicates that Q-L330-YP761 largely integrated into the Xiongnu, Tiele, and Han Chinese populations after the Okunev culture. Many downstream branches of Q-L330-YP761 also migrated westward to Central Asia and Europe. In summary, Q-L330-YP761 is considered one of the genetic lineages that have migrated across the Eurasian steppe since the Bronze Age.
Article
18 April 2025Strata Use in a Canopy Beetle Community of a Lowland Neotropical Rainforest in Southern Venezuela
Stratification of tropical rainforests and their arthropods is highly pronounced. I hypothesize that the occurrence of rainforest canopy beetles in the understory is not random but related to the ecology of the taxa, such as feeding guilds and larval development. Therefore, the ecological characteristics of stratum generalists recorded in both the canopy and the lower understory were analyzed. Adult beetles were collected manually and with traps in the northern part of the Amazonian rainforest for a cumulative year. Seventy out of a total of 862 canopy beetle species from 45 families associated with 23 tree species were shared between both strata. The beetle families represented by most species in the canopy and ground samples were Curculionidae, Chrysomelidae, and Carabidae. For Elateridae and Scarabaeidae, the proportion of shared species between the strata was ≥20%. In contrast, the species-rich families (≥20 canopy species) Cerambycidae, Mordellidae, and Buprestidae did not comprise species sampled in both strata. Thus, beetle families comprising many stratum generalists are either largely predatory, or their larvae often develop in the soil.
