Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (30)

Search Parameters:
Keywords = grey seals

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
17 pages, 4108 KiB  
Article
Vulnerability of Grey Seal Pups (Halichoerus grypus) to Storm Disturbances in the Context of Climate Change: A British Isles Case Study
by Keely Saville, Laetitia Nunny, Daniel Jarvis, Sue Sayer, Laszlo Talas and Mark P. Simmonds
Oceans 2025, 6(2), 19; https://doi.org/10.3390/oceans6020019 - 8 Apr 2025
Viewed by 1906
Abstract
Marine mammals may be particularly vulnerable to climate change. While some climate-change-induced impacts on these species have been recognised, the potential consequences of storminess have been less well-defined, and understanding of its significance largely relies on anecdotal evidence. To quantify the relationship between [...] Read more.
Marine mammals may be particularly vulnerable to climate change. While some climate-change-induced impacts on these species have been recognised, the potential consequences of storminess have been less well-defined, and understanding of its significance largely relies on anecdotal evidence. To quantify the relationship between storminess and its possible impacts on grey seal pups (Halichoerus grypus), data from marine wildlife rescue databases and hospitalisation records (2015–2024) within the British Isles were examined (n = 20,686). Daily mean windspeed was used as a proxy for storminess. Significant relationships were found between storminess and pups presenting with malnourishment, head trauma, flipper injury, other wounds, and infections. This study provides the first empirical evidence of the explicit impacts of storminess on seal pup health, with all the presenting conditions increasing and higher rates of call-outs and pup admissions to rescue centres following stormy weather also recorded. Given the predicted increase in storm severity, these findings will aid rescue and rehabilitation planning by helping to predict when rescuers can anticipate increased admissions and the potential injuries that pups may experience following storms. The potential significance to the long-term conservation of the species is also highlighted. Full article
(This article belongs to the Special Issue Marine Mammals in a Changing World, 2nd Edition)
Show Figures

Figure 1

12 pages, 602 KiB  
Article
Endoparasites in Grey Seals (Halichoerus grypus) By-Caught in Latvian Commercial Coastal Fishery
by Maija Selezņova, Aivars Cīrulis, Maira Mateusa, Ēriks Krūze, Loreta Rozenfelde, Inga Pigiņka-Vjačeslalova, Lilija Geine-Romanova, Didzis Ustups and Gunita Deksne
Animals 2025, 15(1), 45; https://doi.org/10.3390/ani15010045 - 27 Dec 2024
Viewed by 1008
Abstract
The grey seal (Halichoerus grypus) is a fish-eating mammal and an apex predator in the Baltic Sea. It serves as the definitive host for several parasite species that utilize fish as intermediate or paratenic hosts. This study aimed to determine the [...] Read more.
The grey seal (Halichoerus grypus) is a fish-eating mammal and an apex predator in the Baltic Sea. It serves as the definitive host for several parasite species that utilize fish as intermediate or paratenic hosts. This study aimed to determine the endoparasite fauna of grey seals by-caught in the Latvian commercial coastal fishery and to analyze the impact of parasites on the seals’ nutritional status. A total of 59 grey seals were collected for parasitological analysis. Six parasite species were identified, with all seals infected by Contracaecum sp. and Corynosoma semerme. High prevalence rates were observed for Corynosoma strumosum (69.4%), Parafilaroides gymnurus (44.8%), and Pseudamphistomum truncatum (27.1%). Giardia duodenalis was detected in two animals, marking its first report in the Baltic Sea grey seals. A significant negative correlation was found between the infection intensity of C. semerme (Rs = −0.324, p = 0.013) and the nutritional status of the grey seals. Full article
(This article belongs to the Section Aquatic Animals)
Show Figures

Figure 1

21 pages, 3075 KiB  
Article
Investigations on the Health Status and Infection Risk of Harbour Seals (Phoca vitulina) from Waters of the Lower Saxon Wadden Sea, Germany
by Ursula Siebert, Jan Lakemeyer, Martin Runge, Peter Lienau, Silke Braune, Edda Bartelt, Miguel L. Grilo and Ralf Pund
Animals 2024, 14(20), 2920; https://doi.org/10.3390/ani14202920 - 10 Oct 2024
Cited by 1 | Viewed by 1880
Abstract
Harbour seals (Phoca vitulina) are the most common pinniped species in the Wadden Sea of Schleswig-Holstein, Hamburg and Lower Saxony, Germany. Their numbers have recovered after significant depletion due to viral outbreaks and effects of anthropogenic activities like pollution and habitat [...] Read more.
Harbour seals (Phoca vitulina) are the most common pinniped species in the Wadden Sea of Schleswig-Holstein, Hamburg and Lower Saxony, Germany. Their numbers have recovered after significant depletion due to viral outbreaks and effects of anthropogenic activities like pollution and habitat disturbance. Within the Wadden Sea National Park of Lower Saxony the harbour seal is protected. As a top predator in the Wadden Sea ecosystem, the harbour seal is a sentinel species for the state of the environment. Between 2015 and 2017, a total of 80 stranded dead harbour seals were collected along the coastline of Lower Saxony and submitted for pathological investigations. Of these, 70 seals were born in the same year (0–7 months, age group 1) and eight in the previous year (8–19 months, age group 2), due to high mortality rates in these age groups. However, two perennial animals were also available for examination during this period, one of which was in good nutritional condition. Many of the seals that had been mercy-killed and found dead were in poor nutritional status. Histopathological, microbiological, parasitological and virological examinations were conducted on 69 individuals (86% (69/80)) in a suitable state of preservation. Respiratory tract parasitosis, cachexia, and bronchopneumonia were the most common causes of death or disease. Overall, there was no evidence of a relapse of a viral disease outbreak. Macrowaste, such as plastic waste or fishery-related debris, were not found in any gastrointestinal tract of the animals examined. There was also no evidence of grey seal predation. Weakness and cachexia were prominent causes of disease and death in harbour seals found within a few weeks after birth, but bronchopneumonia and septicaemia also developed in slightly older animals. Frequently found microbial pathogens in seals from Lower Saxony were similar to those found in other studies on seals from the Wadden Sea region in Schleswig-Holstein, for example streptococci and Escherichia coli/v. haemolytica, Brucella spp. and Erysipelothrix rhusiopathiae, potentially human pathogenic germs. The results of the examinations of dead harbour seals from Lower Saxony show that pathological investigations on a representative number of animals deliver urgently needed information on the health status of the population. The results represent an important contribution to the state of the top predators of the Wadden Sea as part of the obligations within the Trilateral Wadden Sea Agreement, Oslo and Paris Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the Marine Framework Directive. The investigations should be continued as a matter of urgency and the stranding network should be expanded. Full article
(This article belongs to the Special Issue Wildlife Diseases: Pathology and Diagnostic Investigation)
Show Figures

Figure 1

28 pages, 9870 KiB  
Article
The Role of Play in the Social Development of Grey Seal (Halichoerus grypus) Pups with Comparative Notes on the Harbour Seal (Phoca vitulina)
by Susan C. Wilson
Animals 2024, 14(14), 2086; https://doi.org/10.3390/ani14142086 - 17 Jul 2024
Cited by 1 | Viewed by 1611
Abstract
Juvenile grey seals are known to be highly social, interacting with contact behaviours interpreted as gentle play. However, minimal sociality of pups with their mothers and among weaned pups has been suggested. The present study aimed to observe the natural social interactions of [...] Read more.
Juvenile grey seals are known to be highly social, interacting with contact behaviours interpreted as gentle play. However, minimal sociality of pups with their mothers and among weaned pups has been suggested. The present study aimed to observe the natural social interactions of pups to track the early ontogeny of their sociality. Pup behaviour at a salt marsh colony on the east coast of England was video-recorded. Pups interacted with their mothers around suckling bouts and after weaning as they gathered around pools. The records were transcribed to spreadsheets in 30 s time segments to estimate the frequency and co-occurrence of different behaviours. Mother-pup interaction comprised nosing contacts and sometimes contact play, involving one laying the head and fore-flipper over the other. Initial weaned pup encounters involved tentative nosing and defensive splashing, indicating contact shyness. However, socially orientated locomotor play, supine posturing, and exaggerated raising of fore- and hind-flippers led to reduced shyness and pups following one another towards the sea. Archive data on subadult interactions and on harbour seal behaviours were re-analysed. Gentle play-like contact between mother–pup, juvenile, and adult pairs is interpreted here as a universal mode of social bonding, underscoring the social structure of both grey and harbour seals. Full article
(This article belongs to the Special Issue Animal Ontogeny, Plasticity and Ecology)
Show Figures

Figure 1

18 pages, 10152 KiB  
Article
Characteristics and Sources of CBM Well-Produced Water in the Shouyang Block, China
by Bing Zhang, Gang Wang, Wei Li and Xinglong Jiao
Appl. Sci. 2024, 14(10), 4218; https://doi.org/10.3390/app14104218 - 16 May 2024
Cited by 2 | Viewed by 1156
Abstract
The Shouyang Block was selected as the research subject. Comprehensive analysis was conducted using coalbed methane (CBM) well production data, geochemical test data on water produced from the coalbed methane well, and fundamental geological information. The findings reveal the water dynamics in the [...] Read more.
The Shouyang Block was selected as the research subject. Comprehensive analysis was conducted using coalbed methane (CBM) well production data, geochemical test data on water produced from the coalbed methane well, and fundamental geological information. The findings reveal the water dynamics in the Shouyang Block are characterized by weak groundwater runoff or retention in most areas. The groundwater head height exhibits a gradual decrease from the north to south, which is closely associated with the monoclinic structure of the Shouyang Block. Overall, water production is relatively high. As the average water production increases, the average gas production gradually decreases. A concentration of high water production wells is observed in the northern part of the Shouyang Block, which gradually increases towards the southeast direction. A comprehensive analysis was conducted on the factors influencing water production, including total water content of coal seams, coal seam porosity, groundwater stability index, groundwater sealing coefficient, D value of the fracture fractal dimension, fault fractal dimension, and sand–mud ratio. The correlation degree was calculated and ranked in order of magnitude through grey correlation analysis. The order of factors that influence water production, from strongest to weakest, is as follows: sand–mud ratio > porosity > fractal dimension of fault > fracture fractal dimension D value > groundwater sealing coefficient > groundwater stability index > total water content of coal seams. The dissolution amounts of carbonate and sulfate are both small, and the water source may mainly come from the sandstone aquifer. Attention should be paid to the distribution and lithological combination of sandstone aquifers in coal-bearing strata in the future exploration and development process of the Shouyang Block. This will help to avoid the potential influence of fault structures and enable the identification of favorable areas for low water and high gas production. Full article
(This article belongs to the Special Issue Advances in Unconventional Natural Gas: Exploration and Development)
Show Figures

Figure 1

18 pages, 3717 KiB  
Article
Innovative Closed Cavity Façades (CCF) with Inner Shading and Advanced Coatings for Enhancing Thermal Performance in the Tropics
by Nedhal Al-Tamimi, Ahmad Fadel Al Kahlout, Abdultawab M. Qahtan and Anas A. M. Alqanoo
Buildings 2024, 14(3), 603; https://doi.org/10.3390/buildings14030603 - 24 Feb 2024
Cited by 2 | Viewed by 2654
Abstract
In its simplest terms, a closed-cavity façade (CCF) is a sealed, unventilated enclosure equipped with motorized shading devices, internal double or triple glazing, and external single glazing. This technology effectively controls solar energy and daylight entry into buildings. This research aims to enhance [...] Read more.
In its simplest terms, a closed-cavity façade (CCF) is a sealed, unventilated enclosure equipped with motorized shading devices, internal double or triple glazing, and external single glazing. This technology effectively controls solar energy and daylight entry into buildings. This research aims to enhance the thermal efficiency of CCFs in tropical climates using Venetian blinds (VB) and advanced glass coatings. EnergyPlus and DesignBuilder were employed to assess various CCF designs and compare them to a single glazing unit (SGU) with grey coatings. This was inspired by a residential case study on Penang Island, Malaysia. The findings indicate that CCFs surpass SGUs in thermal performance and occupant comfort, particularly in Malaysia’s humid tropical climate. CCFs reduced operating temperatures by a monthly percentage ranging from 33.5% to 68.75% in all operations. On an annual basis, temperature reductions ranged from 27.5% to 80.25%, with maximum decreases between 2 °C and 4 °C and minimum decreases between 0.5 °C and 1 °C compared to SGU units. The results show that CCFs outperform SGUs in thermal performance and comfort, reducing operating temperatures by 33.5% to 68.75% monthly and 27.5% to 80.25% annually. Temperature reductions ranged between 2 °C and 4 °C at maximum and 0.5 °C and 1 °C at minimum compared to SGU. Notably, Venetian blinds with nano-coatings (83/58) and low-E coatings (83/23) (Tvis/Tsol) were the most effective. This study highlights the importance of selecting appropriate coatings for CCFs, and demonstrates their potential in enhancing interior temperatures and comfort in Malaysia’s climate. The findings emphasize the significant impact of innovative glazing technologies on improving operational temperatures and occupant comfort using closed-cavity façades in the tropics. Full article
(This article belongs to the Section Building Energy, Physics, Environment, and Systems)
Show Figures

Figure 1

26 pages, 7407 KiB  
Article
Static Acoustic Monitoring of Harbour (Phoca vitulina) and Grey Seals (Halichoerus grypus) in the Malin Sea: A Revolutionary Approach in Pinniped Conservation
by Yaiza Pilar Pozo Galván, María Pérez Tadeo, Morgane Pommier and Joanne O’Brien
J. Mar. Sci. Eng. 2024, 12(1), 118; https://doi.org/10.3390/jmse12010118 - 7 Jan 2024
Viewed by 3635
Abstract
Harbour and grey seals rely on acoustic signals to mate, socialise and defend their territory. Previous studies have focused on their behaviour, movements and communication from the coast, leaving a knowledge gap in the offshore environments, and therefore being unable to determine the [...] Read more.
Harbour and grey seals rely on acoustic signals to mate, socialise and defend their territory. Previous studies have focused on their behaviour, movements and communication from the coast, leaving a knowledge gap in the offshore environments, and therefore being unable to determine the proper use they give to those areas and the risks they face around them. Acoustic data collected with a SoundTrap were analysed to assess the detectability of both species in the Malin Sea. Vocalisations were classified based on aural and visual features, as well as using non-parametric classification trees. Differences in the vocalisation rate of grey seals per diel, season and tidal state were also assessed through Generalised Linear Mixed Models, obtaining significant results, and finding similarities in the vocalisations of grey seals with the Scottish and Irish populations. A small sample of adult and pup harbour seals was detected, and differences in call type and number of detections per type were found across the seasons. These results show the importance of the area for both species, and lay the foundations for future studies, which will help to implement proper conservation measures such as Marine Protected Areas. Full article
(This article belongs to the Special Issue Research on Marine Mammals Acoustic Ecology)
Show Figures

Figure 1

26 pages, 370 KiB  
Review
A Legal Framework for Energy-Conscious Urban Planning in Poland and Germany
by Olga Sachanbińska-Dobrzyńska
Energies 2023, 16(18), 6428; https://doi.org/10.3390/en16186428 - 5 Sep 2023
Cited by 2 | Viewed by 1589
Abstract
This work seeks to answer the question as to whether the legal orders of Poland and Germany provide an effective framework for energy-efficient and climate-resilient urban space management. To this end, it verifies what similarities and differences exist between certain areas and whether [...] Read more.
This work seeks to answer the question as to whether the legal orders of Poland and Germany provide an effective framework for energy-efficient and climate-resilient urban space management. To this end, it verifies what similarities and differences exist between certain areas and whether they need reform. The starting point is the belief that legal instruments for environmentally friendly space management are a cross-border issue. Comparative studies are important because effective environmental protection knows no borders, and a lower level of protection in one country or geographic region can affect neighbouring countries and regions. The analysis of legal norms affecting such issues as passive energy construction; prevention of soil sealing and adequate ventilation; reduction of CO2 emissions; promotion of green areas; proper water management; reduction of so-called “grey energy” associated with new construction; the compact city; and a reduction of light pollution has enabled us to synthesise findings into specific conclusions and to propose postulates and directions for further research. However, this does not change the overall assessment that the legal systems of Poland and Germany enable environmentally friendly space management at a similar level, while at the same time, certain additions to the regulations and a further discussion of possible improvements are most welcome and needed. Full article
27 pages, 12080 KiB  
Article
Multi-Response Optimization of High-Performance Low-pH Grouting Materials by Using Taguchi-Based Grey Relational Analysis
by Zengzeng Ren, Weiquan Zhao, Ju Wang, Jinjie Zhang, Liang Chen and Yonghui Li
Materials 2023, 16(10), 3891; https://doi.org/10.3390/ma16103891 - 22 May 2023
Cited by 1 | Viewed by 1885
Abstract
The most accepted approach to sealing in high-level radioactive waste repositories (HLRWs) is to develop a low-pH grouting material with a pH of the pore solution of less than 11. Currently, the most widely used binary low-pH grouting material is MCSF64, which comprises [...] Read more.
The most accepted approach to sealing in high-level radioactive waste repositories (HLRWs) is to develop a low-pH grouting material with a pH of the pore solution of less than 11. Currently, the most widely used binary low-pH grouting material is MCSF64, which comprises 60% microfine cement (MC) and 40% silica fume (SF). In this study, a high-performance MCSF64-based grouting material was developed by incorporating naphthalene superplasticizer (NSP), aluminum sulfate (AS), and united expansion agent (UEA) to enhance the slurry’s shear strength, compressive strength, and hydration process. Orthogonal experiments were conducted to measure the flow time, yield stress, plastic viscosity, initial setting time, shear strength, and compressive strength of the MCSF64-based slurry, and the optimal mix proportion was determined using the Taguchi–Grey relational analysis method. The pH variation of the pore solution, shrinkage/expansion, and hydration products of the optimal hardened slurry were evaluated using simplified ex-situ leaching (S-ESL), a length comparometer, and scanning electron microscopy (SEM), respectively. The results demonstrate that the Bingham model effectively predicted the rheological properties of the MCSF64-based slurry. The optimum ratio for the MCSF64-based slurry was water/binder (W/B) ratio of 1.4, and the contents of NSP, AS and UEA by mass of binder were 1.9%, 3.6% and 4.8%, respectively. The optimal mix exhibited a pH value below 11 after curing for 120 days. The addition of AS and UEA facilitated hydration, shortened the initial setting time, improved early shear strength, and enhanced the expansion ability of the optimal mix under water curing conditions. Full article
Show Figures

Figure 1

24 pages, 12069 KiB  
Article
Exploring the Use of Orthophotos in Google Earth Engine for Very High-Resolution Mapping of Impervious Surfaces: A Data Fusion Approach in Wuppertal, Germany
by Jan-Philipp Langenkamp and Andreas Rienow
Remote Sens. 2023, 15(7), 1818; https://doi.org/10.3390/rs15071818 - 29 Mar 2023
Cited by 9 | Viewed by 3684
Abstract
Germany aims to reduce soil sealing to under 30 hectares per day by 2030 to address negative environmental impacts from the expansion of impervious surfaces. As cities adapt to climate change, spatially explicit very high-resolution information about the distribution of impervious surfaces is [...] Read more.
Germany aims to reduce soil sealing to under 30 hectares per day by 2030 to address negative environmental impacts from the expansion of impervious surfaces. As cities adapt to climate change, spatially explicit very high-resolution information about the distribution of impervious surfaces is becoming increasingly important for urban planning and decision-making. This study proposes a method for mapping impervious surfaces in Google Earth Engine (GEE) using a data fusion approach of 0.9 m colour-infrared true orthophotos, digital elevation models, and vector data. We conducted a pixel-based random forest (RF) classification utilizing spectral indices, Grey-Level Co-occurrence Matrix texture features, and topographic features. Impervious surfaces were mapped with 0.9 m precision resulting in an Overall Accuracy of 92.31% and Kappa-Coefficient of 84.62%. To address challenges posed by high-resolution imagery, we superimposed the RF classification results with land use data from Germany’s Authoritative Real Estate Cadastre Information System (ALKIS). The results show that 25.26% of the city of Wuppertal is covered by impervious surfaces coinciding with a government-funded study from 2020 based on Sentinel-2 Copernicus data that defined a proportion of 25.22% as built-up area. This demonstrates the effectiveness of our method for semi-automated mapping of impervious surfaces in GEE to support urban planning on a local to regional scale. Full article
(This article belongs to the Special Issue Urban Planning Supported by Remote Sensing Technology)
Show Figures

Graphical abstract

13 pages, 1195 KiB  
Article
Screening for Influenza and Morbillivirus in Seals and Porpoises in the Baltic and North Sea
by Iben Stokholm, Christine Baechlein, Sara Persson, Anna Roos, Anders Galatius, Line Anker Kyhn, Signe Sveegaard, Charlotte Bie Thøstesen, Morten Tange Olsen, Paul Becher and Ursula Siebert
Pathogens 2023, 12(3), 357; https://doi.org/10.3390/pathogens12030357 - 21 Feb 2023
Cited by 6 | Viewed by 3620
Abstract
Historically, the seals and harbour porpoises of the Baltic Sea and North Sea have been subjected to hunting, chemical pollutants and repeated mass mortalities, leading to significant population fluctuations. Despite the conservation implications and the zoonotic potential associated with viral disease outbreaks in [...] Read more.
Historically, the seals and harbour porpoises of the Baltic Sea and North Sea have been subjected to hunting, chemical pollutants and repeated mass mortalities, leading to significant population fluctuations. Despite the conservation implications and the zoonotic potential associated with viral disease outbreaks in wildlife, limited information is available on the circulation of viral pathogens in Baltic Sea seals and harbour porpoises. Here, we investigated the presence of the influenza A virus (IAV), the phocine distemper virus (PDV) and the cetacean morbillivirus (CeMV) in tracheal swabs and lung tissue samples from 99 harbour seals, 126 grey seals, 73 ringed seals and 78 harbour porpoises collected in the Baltic Sea and North Sea between 2002–2019. Despite screening 376 marine mammals collected over nearly two decades, we only detected one case of PDV and two cases of IAV linked to the documented viral outbreaks in seals in 2002 and 2014, respectively. Although we find no evidence of PDV and IAV during intermediate years, reports of isolated cases of PDV in North Sea harbour seals and IAV (H5N8) in Baltic and North Sea grey seals suggest introductions of those pathogens within the sampling period. Thus, to aid future monitoring efforts we highlight the need for a standardized and continuous sample collection of swabs, tissue and blood samples across Baltic Sea countries. Full article
(This article belongs to the Special Issue Wildlife Hosts Pathogen Interaction)
Show Figures

Figure 1

16 pages, 2298 KiB  
Article
First Steps towards the Automated Detection of Underwater Vocalisations of Grey Seals (Halichoerus grypus) in the Blasket Islands, Southwest Ireland
by María Pérez Tadeo, Martin Gammell and Joanne O'Brien
J. Mar. Sci. Eng. 2023, 11(2), 351; https://doi.org/10.3390/jmse11020351 - 4 Feb 2023
Cited by 3 | Viewed by 2861
Abstract
Underwater vocalisations of grey seals (Halichoerus grypus) were recorded by static acoustic monitoring (SM2M, Wildlife Acoustics) in the vicinity of a colony located at White Strand beach on Great Blasket Island, southwest Ireland during the pre-breeding and breeding seasons. Grey seal [...] Read more.
Underwater vocalisations of grey seals (Halichoerus grypus) were recorded by static acoustic monitoring (SM2M, Wildlife Acoustics) in the vicinity of a colony located at White Strand beach on Great Blasket Island, southwest Ireland during the pre-breeding and breeding seasons. Grey seal vocalisations were first classified across nine different categories based on aural and visual characteristics of the spectrograms, providing an acoustic repertoire for grey seals. This classification was further investigated by applying a classification tree analysis, resulting in five of the initial nine groups being selected. Furthermore, a comparison of two common approaches for the detection and extraction of vocalisations from acoustic files was done using the software Raven Pro and PAMGuard. The outputs of this study will present an essential first step towards the development of a protocol for underwater acoustic monitoring of grey seals in Irish waters and elsewhere. Full article
(This article belongs to the Special Issue Research on Marine Mammals Acoustic Ecology)
Show Figures

Figure 1

15 pages, 2821 KiB  
Article
Greener or Greyer? Exploring the Trends of Sealed and Permeable Spaces Availability in Italian Built-Up Areas during the Last Three Decades
by Marco di Cristofaro, Elena Di Pirro, Marco Ottaviano, Marco Marchetti, Bruno Lasserre and Lorenzo Sallustio
Forests 2022, 13(12), 1983; https://doi.org/10.3390/f13121983 - 24 Nov 2022
Cited by 7 | Viewed by 2293
Abstract
Increasing the availability of greenspaces in built-up areas (GSB) is one of the main challenges to improving sustainability and livability in urban landscapes. Concurrently, the availability of brownfields and permeable spaces offers the chance to increase sustainability through the implementation of Nature-Based Solutions. [...] Read more.
Increasing the availability of greenspaces in built-up areas (GSB) is one of the main challenges to improving sustainability and livability in urban landscapes. Concurrently, the availability of brownfields and permeable spaces offers the chance to increase sustainability through the implementation of Nature-Based Solutions. This work aims to evaluate how land use/cover changes influenced the availability of permeable spaces in Italian built-up areas over the last three decades. These spaces were classified according to population density, vegetation type, and average size, to better characterize recent dynamics (2008–2016) and offer remarks and tips concerning ongoing soil sealing dynamics. According to the findings, despite an overall increase of 41.5% in built-up areas with respect to their 1990 extension, permeable spaces increased only by 25.2% during the same time-span, moving from 49.8% coverage in 1990 to 44.7% today, in relation to the whole national built-up area. Moreover, our in-depth analysis for the 2008–2016 period shows that forested spaces increased by 0.4%, while permeable unforested ones decreased by 0.7%, especially in thinly and intermediately populated areas. Overall, the scarcity of these spaces should be carefully considered when assigning residual vacant lots to new buildings and grey infrastructure, especially in densely populated areas. The proposed methodology provides reliable estimates and represents a starting point to develop advanced monitoring tools supporting sustainable urban policies. Full article
(This article belongs to the Section Urban Forestry)
Show Figures

Figure 1

17 pages, 2517 KiB  
Article
Investigation of the High-Temperature and Rheological Properties for Asphalt Sealant Modified by SBS and Rubber Crumb
by Yafeng Gong, Shuzheng Wu, Yuwei Zhang, Yunze Pang and Yulin Ma
Polymers 2022, 14(13), 2558; https://doi.org/10.3390/polym14132558 - 23 Jun 2022
Cited by 21 | Viewed by 2789
Abstract
Crack sealing is an important measure for pavement maintenance. Hot-poured crack sealant is the most utilized material for crack sealing. However, its poor high-temperature and rheological properties seriously weaken the mechanical properties of repaired pavement. Thus, to overcome the disadvantage of the poor [...] Read more.
Crack sealing is an important measure for pavement maintenance. Hot-poured crack sealant is the most utilized material for crack sealing. However, its poor high-temperature and rheological properties seriously weaken the mechanical properties of repaired pavement. Thus, to overcome the disadvantage of the poor high-temperature and rheological properties of sealant, styrene–butadiene–styrene (SBS) and rubber crumb (CR) were utilized for modifying the asphalt-based sealants. Softening point tests, temperature tests, frequency scan tests, and multiple stress creep recovery tests (MSCR) were conducted to evaluate the high-temperature and rheological properties of the modified sealant. Additionally, the influence of SBS and CR on the high-temperature performance of the modified sealant was quantitatively analyzed by the grey relational analysis method. The results reveal that the SBS has a greater enhancement effect on the high-temperature performance of sealant than CR. Increasing the SBS and CR content in the sealant could enhance the sealant’s high-temperature performance, stiffness, and elasticity. Compared with asphalt-based sealant and one-component modified asphalt-based sealant, SBS/CR-modified asphalt sealant has greater viscosity and higher temperature deformation resistance. Additionally, SBS can increase the stress level of the sealant, thereby enhancing the resistance of the sealant to permanent deformation. Full article
Show Figures

Figure 1

16 pages, 9126 KiB  
Article
Simulation and Optimization of Connection-Strength Performance of Axial Extrusion Joint
by Jianguo Wu, Jingyu Zhai, Yangyang Yan, Hongwei Lin, Siquan Chen and Jianping Luo
Materials 2022, 15(7), 2433; https://doi.org/10.3390/ma15072433 - 25 Mar 2022
Cited by 2 | Viewed by 2335
Abstract
Axial extrusion-connection technology is one of the important connection technologies for hydraulic piping systems, with high sealing performance and mechanical strength. In this paper, the finite-element-modeling method is used to simulate the experimental process of the connection strength of the axial extrusion joint. [...] Read more.
Axial extrusion-connection technology is one of the important connection technologies for hydraulic piping systems, with high sealing performance and mechanical strength. In this paper, the finite-element-modeling method is used to simulate the experimental process of the connection strength of the axial extrusion joint. The generation mechanism and calculation method of the connection strength are analyzed. To optimize the joint strength, orthogonal testing and grey correlation analysis are used to analyze the influencing factors of joint strength. The key factors affecting joint strength are obtained as the friction coefficient μ1, μ2 between joint components and the groove angle θ1 of the fittings body. The back-propagation (BP) neural-network algorithm is used to establish the connection-strength model of the joint and the genetic algorithm is used to optimize it. The optimal connection strength is 8.237 kN and the optimal combination of influencing factors is 0.2, 0.4 and 76.8°. Compared with the prediction results of the neural-network genetic algorithm, the relative error of the finite-element results is 3.9%, indicating that the method has high accuracy. The results show that the extrusion-based joining process offers significant advantages in the manufacture of high-strength titanium tubular joints. Full article
Show Figures

Figure 1

Back to TopTop