Month: July 2024

Climate change impact assessment on the water resources of the Upper Yamuna River Basin in India

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Abstract

Climate change has ability to intensify the magnitude of flood and drought episodes, as well as their amplitude; also it has the potential to exacerbate hydrological extremes. It is crucial to forecast changes to hydrological regimes and determine the level of uncertainty around them to increase resilience and prepare for future changes. In order to enlighten long-term estimates, an attempt has been made to sustain the available water resources through Calibration and Validation of river discharge data using SWAT model for Upper Yamuna River Basin. Spatial climatic data were further crystallized to forecast climatic projection scenarios for Base line period, Mid-Century and End Century considering RCPs 2.6, 4.5 and 8.5. Result reveals that the average annual minimum temperature is estimated to be increased 1.4 °C in Mid-Century and 2.2 °C in End Century from the Base line Scenario while the average annual maximum temperature is found to be increased 1.5 °C in Mid-Century and 2.1 °C in End Century from the Base line Scenario. Further, while analyzing the hydrological components, Soil water percentage is expected to be increased in Mid-Century, whereas Percolation rate is found to be increased for all scenarios other than BL-MC (4.5) which is an indication of rise in Ground water. In addition to it, Surface flow is observed as a considerable increase from 4.33 to 72.69% in all scenarios. Also the Surface flow is more in case of End Century as compared to the Mid-Century. The estimated Ground water flow is found to be increased except BL-MC (4.5 & 8.5). Overall water yield has been estimated as a relative change from 7.06 to 18.70% based upon the specified conditions. The prediction for Evapotranspiration values is found as decreased in all scenarios except BL-MC (4.5 & 8.5). The outcome of the present study is very useful for planning of development strategies in the project area.

Temporal and spatial evolution of net primary productivity in the Three-River Headwaters Region under phenological changes and anthropogenic influence

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Abstract

Understanding the spatiotemporal changes in net primary productivity (NPP) and the driving factors behind these changes in climate-vulnerable regions is crucial for ecological conservation. This study simulates the actual NPP (NPPA) and climate potential NPP (NPPC) in the Three-River Headwaters Region from 2000 to 2020. The Theil–Sen Median method and Mann–Kendall mutation analyses are employed to explore their spatiotemporal variation patterns, while geographic weighted regression and machine learning are used to investigate the influence of anthropogenic activities and climatic factors on NPPA, the results indicate that the average NPPA across the entire region over multiple years is 382.506 \(gC{m}^{-2}{yr}^{-1}\) , which is 0.132 times the average annual NPPC over the past 21 years, showing an overall distribution pattern of low in the northwest and high in the southeast. The annual increase in NPPA from 2000 to 2020 is approximately 1.034 \(gC{m}^{-2}{yr}^{-1}\) . The source region of the Yangtze River shows the largest improvement in vegetation, with 74.1% of the area showing improvement. Between 2002 and 2003, the annual NPPA in the Three-River Headwaters Region experienced a sudden change, lagging behind the NPPC change by 1 year, and after 2005, the upward trend in NPPA became more pronounced. The impact of anthropogenic activities on NPPA shifted from positive to negative to positive from 2000 to 2020, with significant impact areas mainly concentrated in the northeast and a few areas in the central and southern parts. The proportion of areas with extremely significant impact increased from 1.9% in 2000 to 3.7% in 2020. Over the past 21 years, the main factors influencing NPPA changes in the Three-River Headwaters Region have been soil moisture and precipitation, with the influence of different climate factors on NPP changing over time. Additionally, NPP is more sensitive to changes in altitude in low-altitude areas. This study can provide more accurate theoretical support for ecological environment assessment and subsequent protection efforts in the Three-River Headwaters Region.

Implementation of efficient surface discretisation algorithms adapted to geometric models specific to the footwear industry

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Abstract

In 3D modelling, a surface mesh is a collection of vertices, edges, and faces that define the shape of a 3D object. The surface mesh is typically used to represent the outer surface of an object, as opposed to the internal structure. A surface mesh is usually defined as a polygon mesh, which is a collection of polygons (triangles or quadrilaterals are the most common) that are connected at their vertices. The vertices of the mesh define the shape of the object, and the edges and faces provide the topological information that describes how the vertices are connected. Surface meshes are often used in 3D modelling software to create 3D objects for animation, video games, and other purposes. Although triangular meshes are the most widely used in various fields, they have a series of disadvantages that quad meshes solve in most cases. This article presents a set of algorithms capable of generating quad meshes from any type of input triangular mesh, preserving the geometric characteristics of the initial model. This process is known as ‘remeshing’. The results obtained by these algorithms on a large number of models related to the footwear industry have been compared, as well as analysing the advantages and disadvantages of each one of them applied to geometric models commonly used in footwear industry.

Effects of process parameters and geometry on dimensional accuracy and surface quality of thin strut heart valve frames manufactured by laser powder bed fusion

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Abstract

Laser powder bed fusion (LPBF) is one of the most popular metal additive manufacturing technologies, which has found its applications in high-value sectors such as aerospace and biomedical devices. Some recent studies on the LPBF of stents have demonstrated its feasibility in the fabrication in thin strut structures including heart valve frames, as used in transcatheter aortic valve implantation (TAVI) for the treatment of severe aortic stenosis. The state of the art method of laser cutting TAVI frame limits the scope for novel concepts which are made possible by additive manufacturing. However, the surface quality and dimensional accuracy of LPBF parts are lower than that produced by laser cutting. To start the development of new TAVI concepts, the feasibility of manufacturing thin frames by LPBF has been investigated based on the SAPIEN 3 frame by Edwards Lifesciences. In this study, simplified frames with strut size from 0.3 to 0.5 mm have been successfully manufactured. The effects of strut size, strut angle, laser power and scan speed on the dimensional accuracy and surface quality were systemically studied. In addition, a representative SAPIEN 3 frame was manufactured and assessed with high-resolution X-ray CT scans. Good overall dimensional accuracy and low porosity were obtained for the SAPIEN 3 frame. However, inclined struts were found to have relatively low dimensional accuracy and poor surface quality.

Solderability of additively manufactured pure copper and the effect of surface modification

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Abstract

Additive manufacturing of copper enables enhanced design freedom which allows for improved performance of components in thermal management and electrical applications. Joining via soldering provides ideal electrical and thermal connections, but the solderability of complex additively manufactured surfaces is poorly understood. In the present work, the solderability of nominally pure copper coupons manufactured by three additive manufacturing techniques (laser powder bed fusion, laser engineered net shaping, and bound powder extrusion) was experimentally assessed using the wetting balance technique and pin pull testing. Coupons produced by each method were tested as built and after surface modification by dry electropolishing. Contact angles and wetting times were calculated from wettability testing. Peak tensile loads required to remove pins soldered to coupons were also recorded for each surface condition. The dipped coupons and solder joint fracture surfaces were examined with optical and scanning electron microscopes. It was found that nonuniform wetting and excessive wicking of solder can result in weak joints, and surface modification positively affected overall solderability in all cases. All surfaces were shown to be wettable, but bound powder extrusion was found to produce the most solderable copper surfaces among the additive manufacturing methods tested.

Strategies to improve postpartum engagement in healthcare after high-risk conditions diagnosed in pregnancy: a narrative review

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Abstract

Transition from antepartum to postpartum care is important, but often fragmented, and attendance at postpartum visits can be poor. Access to care is especially important for individuals diagnosed antepartum with conditions associated with longer-term implications, including gestational diabetes (GDM) and hypertensive disorders in pregnancy (HDP). Strategies to link and strengthen this transition are essential to support people to attend recommended appointments and testing. This narrative review evaluates what is known about postpartum transition of care after higher-risk antepartum conditions, discusses barriers and facilitators to uptake of recommended testing, and outlines strategies trialled to increase both postpartum attendance and testing. Barriers to attendance frequently overlap with general barriers to accessing healthcare. Specific postpartum challenges include difficulties with transport, coordinating breastfeeding and childcare access. Systemic challenges include inadequate communication to women around implications of health conditions diagnosed in pregnancy, and the importance of postpartum follow up. Uptake of recommended testing after a diagnosis of GDM and HDP is variable but generally suboptimal. Strategies which demonstrate promise include the use of patient navigators, focused education and specialised clinics. Reminder systems have had variable impact. Telehealth and technology are under-utilised in this field but offer promising options particularly with the expansion of virtual healthcare into routine maternity care. Strategies to improve both attendance rates and uptake of testing must be designed to address disparities in healthcare access and tailored to the needs of the community. This review provides a starting point to develop such strategies from the community level to the population level.

A farewell to the lone hero researcher: team research and writing

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Abstract

Criminology have long celebrated the lone hero researcher. Doing and writing up research in solitude has been the key to academic success and institutional promotions. However, the social sciences in general have increasingly moved towards more collaborative ways of doing research, and co-authorship has become more common. In this study, we summarize and discuss the pros and cons of working in teams when doing qualitative research. Drawing upon our own experiences from Mexico and Norway, we argue for a radical approach to team research and co-authorship, which we describe as team writing. Most importantly, we suggest opening up to include stakeholders and community partners, thus challenging the borders between researchers and those researched. This is arguably particularly important for research done in the academic, geographical and topical periphery of criminology. Team research and writing answers some of the critique of power inequality, representativity and lack of diversity in contemporary academic research. We also believe that team research, and writing, can make criminological research more multifaceted, reflexive, and thus better.

Mapmaking as visual storytelling: the movement and emotion of managing sex work in the urban landscape

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Abstract

This paper explores an interdisciplinary approach that researchers can use to understand how people feel about their movement in the cityscape and their risk-taking activities by visualizing it. Author 1, a visual artist, and Author 2, a criminologist, used a psychogeography method where participants hand-drew maps of their everyday operations in the sex marketplace. Researchers, artists, and activists have used mapmaking to elucidate how individuals conceptualize physical space and place or their subjective, emotional relationship to the city's geography. Psychogeographers Lynch and Debord have used it to understand how participants feel about moving, inhabiting, navigating risk, and subverting space in the metropolis. We use this method as a vehicle to show how sex market facilitators’ imagine the physical geographic space where they work in the nighttime economy, their embodiment in managing a business in the urban landscape, their emotions in this risk-taking activity, and how they feel rerouting city blocks and subverting formal capitalism. In addition, this technique enabled participants to feel and recall emotions of this lived experience, such as excitement, control, authenticity, shame, and freedom. Sixty participants who worked in New York City hand drew mental maps or visual depictions of where they worked within the city. This visual storytelling method provides an avenue for what O'Neill terms an ethno-mimetic process where images/performances make lived experiences palpable to viewers. In this case, we see a glimpse of the sensations of this high-risk activity in the sex marketplace, allowing us to understand participants' social relations, lived experiences, and motivations.

Combining genetic and environmental data to map and model regions of provenance for silver fir (Abies alba Mill.) in Italy

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Abstract

Regions of provenance for forest reproductive materials are the basis for wise use of forest resources in a changing climate. In this work a modelling framework is proposed for silver fir (Abies alba Mill.) in Italy where genetic clusters described by nuclear microsatellites were combined with high-resolution climatic data. When the genetic clusters were too large or had an uncertain ecological niche expression, an additional subregion division-was evaluated according to a climatic assessment. Subsequently each genecological group (Region of Provenance, RoP) was projected in geographic space separately using species distribution modelling (SDM) procedure under current (1991–2020) and a future climate scenario derived from the 6th assessment report for the period 2041–2070. The final division into nine RoPs was able to explain 77.41% of the total climatic variance, a good trade-off between statistical significance and practical usability. The modelling steps then showed a large degree of ecological overlap between RoPs with some of them occurring in similar ecological environments but characterized by a different genetic structure. When projected at the continental scale, the Italian RoPs were found to be suitable for almost all the current European range of silver fir, with potential expansion in Nordic countries in the future, beyond the current distribution range. The study showed that the combination of genetic and ecological data can be a robust way to proceed in areas where a strong genetic differentiation between populations occurs, such as in Italy. New markers such as SNPs can then be used to detect adaptive traits and drive the selection of provenances for common garden experiments in areas where the SDM modelscurrently extrapolate potential sites outside the current natural range.

Life cycle assessment of an upcoming nuclear power plant decommissioning: the Fessenheim case study from public data

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Abstract

Purpose

Historical French fleet of Nuclear Power Plants (NPP) is near end-of-life, with 14 NPPs planned to begin decommissioning by 2035. Despite decade-old calls for more research regarding these activities’ environmental impact, very few if any studies were conducted since. Due to the French fleet high-degree of standardization, a prospective investigation regarding the Fessenheim NPP—first large-scale plant to be decommissioned in France, starting 2026—is conducted to identify results of interest beyond this case study.

Methods

A life cycle assessment is realized, following ISO 14040/44, with a functional unit defined as “the decommissioning of the Fessenheim NPP.” The system boundaries encompass four unit-processes: dismantling of electromechanical equipment, clean-up of the structures, demolition of plant buildings, and transport of conventional and radioactive waste (RW). This last unit-process is investigated separately to make a clear comparison of conventional and radioactive waste. Pre-decommissioning activities, soil rehabilitation, and RW final storage are excluded. Primary data were obtained from the decommissioning public report of EDF (Electricity of France), with scaling based on the literature and third-party reports/documents. Background processes were modeled with the ecoinvent 3.8 database. Environmental impacts are estimated using the CML-IA baseline methodology to allow comparison with previous works based on CML2001.

Results and discussion

The “Metal cutting” sub-process is found to be the major contributor to environmental impacts during dismantling, clean-up, and demolition, results varying from 62.6 to 99.5% depending on the impact category. A sensitivity analysis explores the effect of variation in shares of thermal and mechanical cutting. It demonstrates the huge potential of impact reduction for the total system under study if thermal cutting use is limited as much as possible. Despite representing only 5% of the total mass of waste, RW scores 1.8–6.6 times higher than conventional waste during transport, due to much higher distances to cover and specific conditioning. Previous explorations of results transferability are found to be methodologically uncertain, and the NPP total power installed is evaluated as an unpromising transferability factor.

Conclusions

Decommissioning of nuclear power plants is still in need of thorough studies based on exhaustive and transparent datasets. Until then, state-of-the-art prospective assessments and transferability of LCA results to future studies are severely limited. Restraint in use of oxy-acetylene cutting is nevertheless highly recommended. French unique policy regarding very low-level waste needs further consideration, and decentralized storage sites are a promising research lead.