Transition Area Research Articles

Design, preparation and mechanical properties of novel glass fiber reinforced polypropylene bending bars

Fiber reinforced thermoplastic composite bars offered the advantages of repeated molding, high toughness, and recyclability, making them a promising alternative to steel bars. For the stirrups applications in concrete structures, it was essential to develop efficient bending technologies for producing high-quality thermoplastic bending bars. In the present paper, the bending properties of glass fiber reinforced polypropylene (GFRPP) composite bars were investigated by experimental and theoretical methods. A novel bending fixture of GFRPP bars was specifically designed for GFRPP bars to ensure the reliable bending of the bars. Finite element simulation was employed to analyze the stress distribution of GFRPP bars, providing valuable insights into their mechanical behavior. Additionally, a bending strength model was developed based on the material mechanics, offering a theoretical framework for understanding and predicting the bending strength of GFRPP bars. Finally, the bending mechanism of bars was further revealed according to experimental and theoretical findings. The results of the study demonstrated that the specially designed bending fixture was successful in minimizing damage to the bending section of the GFRPP bars, leading to a significant improvement in bending strength retention of up to 43.2 %. Furthermore, the theoretical results and experimental test have a good agreement in terms of stress distribution and failure mode. The maximum strain in the transition zone between the straight section and the bending section of the GFRPP bars was nearly double that of the straight section at the same stress levels. With the increase of bending radius to diameter ratio from 3.0 to 7.0, the tensile strength of GFRPP bending bars increased by ∼7.9 %. The study identified the transition area between the bending section and straight section of GFRPP bars as the most critical failure point. The strength degradation mechanism during the bending were attributed to the shrinkage and torsion of inner fibers owing to the compression caused the local stress concentration, which caused the inner resin matrix to crack and interface debonding of fiber/resin, leading to the premature tensile failure.

Microstructure homogeneity and its role in the mechanical properties of the magnetic pulse welded steel/Al tubular joint

The steel and aluminum alloy tubes were successfully joined by magnetic pulse welding (MPW). Part of the joints fractured at the interface, yet part of them fractured at the base metal (BM) of aluminum alloy. The tensile test results revealed a fluctuation of the mechanical properties of the steel/Al MPW joints, demonstrating the microstructure inhomogeneity of the MPW joints. The typical wavy interfacial morphology could be observed at the interface of the MPW joints. The element transition zone composed of elements Fe and Al were detected while no obvious intermetallic compound (IMC) layer could be traced. The good mechanical properties of steel/Al MPW joints could be attributed to the longer effective bonding length and larger element transition area. Besides, the grain refinement was observed at the interface of the MPW joint, which explained its microhardness increase.

Dialectometry-based classification of the Central–Southern Italian dialects

Abstract This paper provides a new classification of Central–Southern Italian dialects using dialectometric methods. All varieties considered are analyzed and cast in a data set where homogeneous areas are evaluated according to a selected list of phonetic features. Using numerical evaluation of these features and the Manhattan distance, a linguistic distance rule is defined. On this basis, the classification problem is formulated as a clustering problem, and a k-means algorithm is used. Additionally, an ad-hoc rule is set to identify transitional areas, and silhouette analysis is used to select the most appropriate number of clusters. While meaningful results are obtained for each number of clusters, a nine-group classification emerges as the most appropriate. As the results suggest, this classification is less subjective, more precise, and more comprehensive than traditional ones based on selected isoglosses.

РАССМОТРЕНИЕ УСТРОЙСТВ И СПОСОБОВ УПРОЧНЕНИЯ ГАЛТЕЛЕЙ ТЕЛ ВРАЩЕНИЯ ППД, ИХ КЛАССИФИКАЦИЯ И РАЗРАБОТКА РЕКОМЕНДАЦИЙ ПО СОВЕРШЕНСТВОВАНИЮ

The service life of heavily loaded shafts is largely determined by the degree of stress in the transition area from one diameter to another. There are a fairly large number of methods for reducing the stress concentration of these areas, but a special place in this case is occupied by strengthening the surfaces of non-profile, heavily loaded shafts. First of all, their fillets are subjected to hardening, which leads to the formation of uniformly distributed compressive stresses in the technological zone and, accordingly, an increase in the fatigue strength of such parts. The method has become especially widespread when hardening crankshafts. Along with this, surface hardening is applied to the abovementioned part to eliminate its bending. This technological process is especially important in the case of restoration of rotating parts. Meanwhile, existing work in this area does not solve existing issues. In this regard, it is necessary to give a critical analysis of the methods and designs for PPD fillets with the development of appropriate proposals, which determines the relevance of the work. The purpose of the study is to consider devices and methods for strengthening fillets of bodies of rotation of PPD, their classification and development of recommendations for improvement. To reveal the goal, the authors conducted a comprehensive review of the information available in the public domain regarding the strengthening of fillets by cold hardening. This made it possible to identify their advantages and disadvantages. First of all, this is the lack of a unified classification system, as well as methods for preventing the formation of a “wave of deformation”. Based on the analysis, a classification is proposed based on the factors that determine the properties of the shafts and the quality of their surface layers and the functional purpose of the processing. A proprietary scheme for processing SPD surfaces is proposed, which ensures the prevention of a “wave of deformation” in one pass of the working tool, which is based on the well-known principles of the theory of the introduction of a ball indenter into a solid.

The role of environmental gradients and microclimates in structuring communities and functional groups of lizards in a rainforest-savanna transition area.

Environmental heterogeneity poses a significant influence on the functional characteristics of species and communities at local scales. Environmental transition zones, such as at the savanna-forest borders, can act as regions of ecological tension when subjected to sharp variations in the microclimate. For ectothermic organisms, such as lizards, environmental temperatures directly influence physiological capabilities, and some species use different thermoregulation strategies that produce varied responses to local climatic conditions, which in turn affect species occurrence and community dynamics. In the context of global warming, these various strategies confer different types of vulnerability as well as risks of extinction. To assess the vulnerability of a species and understand the relationships between environmental variations, thermal tolerance of a species and community structure, lizard communities in forest-savanna transition areas of two national parks in the southwestern Amazon were sampled and their thermal functional traits were characterized. Then, we investigated how community structure and functional thermal variation were shaped by two environmental predictors (i.e., microclimates estimated locally and vegetation structure estimated from remote sensing). It was found that the community structure was more strongly predicted by the canopy surface reflectance values obtained via remote sensing than by microclimate variables. Environmental temperatures were not the most important factor affecting the occurrence of species, and the variations in ecothermal traits demonstrated a pattern within the taxonomic hierarchy at the family level. This pattern may indicate a tendency for evolutionary history to indirectly influence these functional features. Considering the estimates of the thermal tolerance range and warming tolerance, thermoconformer lizards are likely to be more vulnerable and at greater risk of extinction due to global warming than thermoregulators. The latter, more associated with open environments, seem to take advantage of their lower vulnerability and occur in both habitat types across the transition, potentially out-competing and further increasing the risk of extinction and vulnerability of forest-adapted thermoconformer lizards in these transitional areas.

Comparison of the connectivity of the posterior intralaminar thalamic nucleus and peripeduncular nucleus in rats and mice.

The posterior intralaminar thalamic nucleus (PIL) and peripeduncular nucleus (PP) are two adjoining structures located medioventral to the medial geniculate nucleus. The PIL-PP region plays important roles in auditory fear conditioning and in social, maternal and sexual behaviors. Previous studies often lumped the PIL and PP into single entity, and therefore it is not known if they have common and/or different brain-wide connections. In this study, we investigate brain-wide efferent and afferent projections of the PIL and PP using reliable anterograde and retrograde tracing methods. Both PIL and PP project strongly to lateral, medial and anterior basomedial amygdaloid nuclei, posteroventral striatum (putamen and external globus pallidus), amygdalostriatal transition area, zona incerta, superior and inferior colliculi, and the ectorhinal cortex. However, the PP rather than the PIL send stronger projections to the hypothalamic regions such as preoptic area/nucleus, anterior hypothalamic nucleus, and ventromedial nucleus of hypothalamus. As for the afferent projections, both PIL and PP receive multimodal information from auditory (inferior colliculus, superior olivary nucleus, nucleus of lateral lemniscus, and association auditory cortex), visual (superior colliculus and ectorhinal cortex), somatosensory (gracile and cuneate nuclei), motor (external globus pallidus), and limbic (central amygdaloid nucleus, hypothalamus, and insular cortex) structures. However, the PP rather than PIL receives strong projections from the visual related structures parabigeminal nucleus and ventral lateral geniculate nucleus. Additional results from Cre-dependent viral tracing in mice have also confirmed the main results in rats. Together, the findings in this study would provide new insights into the neural circuits and functional correlation of the PIL and PP.

Strategy for Implementing the Tiatiki Concept in Conservation Resource

Strategy is a plan that is intended to achieve the desired goal, or in other words, Strategy is a long-term plan that is prepared to lead to the achievement of certain goals and targets, while the Coastal area is a transition area between land and sea ecosystems which is influenced by changes on land and sea. Research on strategies for implementing the Tiatiki concept in coastal resource conservation in Tabla Supa Depapre village, Jayapura Regency was carried out in August-October 2023 using survey and interview methods. Next, data analysis can be carried out using SWOT analysis. The results of data analysis show that there are 5 strategies for conserving coastal resources in Tabla Supa Village, Depapre District, Jayapura Regency: Developing tourism by involving the community and local wisdom, Increasing community capacity in managing coastal and marine resources in a sustainable manner based on local wisdom, Utilizing local wisdom through the Tabla Supa village community institution in minimizing the negative impacts of using coastal resources that are not environmentally friendly, managing coastal area resources with an integrated system based on community-based management and involving the community and increasing community understanding, especially the younger generation, about the values of local wisdom including Tiatiki by Village community organizations.

Human Trafficking- A Contemporary Form Of Slavery

Human trafficking is a growing menace which is ploughed into every country. The infection is so deeply rooted that it is an utter violation of sovereignty of any state by failure to observe the existing system of legal framework. Trafficking not only contravenes with the elemental human rights of an individual but is also a violation of ethics and morals a nation must hold in its essence. It is such a menace where the rights keep on violating throughout the vicious cycle and the misery never comes to an end. Trafficking here is compared with a ultra-modern form of slavery in the form of bonded labour, prostitution, domestic servitude and other kinds of toiling where thse victim has to act against his own will. No section of society or industry has remained untouched by trafficking. The victims are generally the people belonging to the economically disadvantaged section of society or those who lost their source of livelihood because of the natural calamities or armed conflicts. Some are even trapped by offering them a better standard of life. Human trafficking is on a boom in the entire world. It uses a variety of structures. The victims are pushed into organizations where they are unwillingly employed without any pecuniary benefit while the others are placed into such arrangements where they cannot seek help from anybody hence slamming the escape routes. The menace of human trafficking though spreading like a wildfire in the recent times but it was long established in the ancient India. It is nothing but a modern form of human subjugation. Earlier it was limited to the national boundaries but in the recent decades it has spread throughout the international borders. It does not only exert influence on the country of origin and destination but also leave its impact on the areas of transit. This paper deals with the offence of slavery in its modern sense which is human trafficking. It incorporates within itself a number of other offences that occur during the chain of transit.

Puttybot: A sensorized robot for autonomous putty plastering

AbstractPlastering is dominated manually, exhibiting low levels of automation and inconsistent finished quality. A comprehensive review of literature indicates that extant plastering robots demonstrate a subpar performance when tasked with rectifying defects in the transition area. The limitations encompass a lack of capacity to independently evaluate the quality of work or perform remedial plastering procedures. To address this issue, this research describes the system design of the Puttybot and a paradigm of plastering to solve the stated problems. The Puttybot consists of a mobile chassis, a lift platform, and a macro/micromanipulator. The force‐controlled scraper parameters have been calibrated to dynamically modify their rigidity in response to the applied putty. This strategy utilizes convolutional neural networks to identify plastering defects and executes the plastering operation with force feedback. This paradigm's effectiveness was validated during an autonomous plastering trial wherein a large‐scale wall was processed without human involvement.

Policy-making for peri-urban landscapes as arenas of human-wildlife interactions

Peri-urban landscapes are transitional areas between urban and rural areas that are constantly changing. They are characterised by land use mixes and land cover changes, leading to significant changes in wildlife habitats. These changes, combined with an increasing anthropogenic presence, turn peri-urban landscapes into arenas of intensified human-wildlife interactions. In many scientifically documented cases, scientists are focusing on negative interactions. Furthermore, research about appropriate policy instruments for managing human-wildlife interactions is rare. This study focused on case studies and their characteristics from around the world on positive, neutral, or negative interactions between humans and wildlife at local level. In addition, influencing factors of human-wildlife interactions and policy instruments for managing human-wildlife interactions in peri-urban landscapes were addressed. A survey was conducted with an international group of scientists and practitioners working in this field. The results showed that various species were involved in human-wildlife interactions in peri-urban landscapes worldwide, with mammals as being the most common taxon. Contemporary changes in land use and land cover could be identified as a significant factor for increasing human-wildlife interactions in peri-urban landscapes. It can be highlighted that a policy mix consisting mainly of social and cultural instruments in combination with legal and regulatory instruments could be most suitable to address this situation.

Insights from 30 Years of Land Use/Land Cover Transitions in Jakarta, Indonesia, via Intensity Analysis

Here, we assess land use/land cover (LULC) transitions over the last 30 years in Jakarta, Indonesia. Land cover maps were prepared for 1990, 1995, 2000, 2005, 2010, 2015, and 2020 using seven categories of Landsat satellite image: bare land, built-up, cropland, green area, mangrove, water body, and pond. LULC changes were assessed through intensity analyses at the interval and transition levels. LULC changes were initially rapid (1990–1995) and then more gradual (1995–2000, 2000–2005, and 2005–2010). Unlike in previous intervals, annual changes were uniformly distributed over time in 2010–2015 and 2015–2020. Driven by high population and economic growth, built-up land was identified as an active gainer in all intervals except 2010–2015. Alongside built-up areas, cropland was the main supplier of other categories, including bare land, pond, built-up, and green areas. The largest transition area occurred in pond and green areas during 2005–2010 and in built-up land during 2015–2020. High demand for built-up land was observed in land changes driven by high population growth triggered by economic necessity. Economic and population growth exhibited a positive correlation (R2 = 0.78, t = 9.996). This study elucidates spatiotemporal LULC transition patterns over 30 years in a rapidly growing city.

Butterfly community (Lepidoptera: Papilionoidea) in a transition area of Atlantic Forest and Cerrado in Minas Gerais, Brazil

Butterfly community (Lepidoptera: Papilionoidea) in a transition area of Atlantic Forest and Cerrado in Minas Gerais, Brazil

Comparison and Evaluation of Five Global Land Cover Products on the Tibetan Plateau

The Tibetan Plateau (TP) region contains maximal alpine grassland ecology at the mid-latitudes. This region is also recognized as an ecologically fragile and sensitive area under the effects of global warming. Regional climate modeling and ecosystem research depend on accurate land cover (LC) information. In order to obtain accurate LC information over the TP, the reliability and precision of five moderate/high-resolution LC products (MCD12Q1, C3S-LC, GlobeLand30, GLC_FCS30, and ESA2020 in 2020) were analyzed and evaluated in this study. The different LC products were compared with each other in terms of areal/spatial consistency and assessed with four reference sample datasets (Geo-Wiki, GLCVSS, GOFC-GOLD, and USGS) using the confusion matrix method for accuracy evaluation over the TP. Based on the paired comparison of these five LC datasets, all five LC products show that grass is the major land cover type on the TP, but the range of grass coverage identified by the different products varies noticeably, from 43.35% to 65.49%. The fully consistent spatial regions account for 43.72% of the entire region of the TP, while, in the transition area between grass and bare soil, there is still a large area of medium-to-low consistency. In addition, a comparison of LC datasets using integrated reference datasets shows that the overall accuracies of MCD12Q1, C3S-LC, GlobeLand30, GLC_FCS30, and ESA2020 are 54.29%, 49.32%, 53.03%, 53.73%, and 60.11%, respectively. The producer accuracy of the five products is highest for grass, while glaciers have the most reliable and accurate characteristics among all LC products for users. These findings provide valuable insights for the selection of rational and appropriate LC datasets for studying land-atmosphere interactions and promoting ecological preservation in the TP.

Outdoor thermal comfort in open transitional spaces with limited greenery in hot summer/cold winter climates

Regarding the constant use of transitional spaces, there is an intense interest in studies on the outdoor thermal comfort in transitional spaces, especially in regions with hot summers. This study aims to analyze the outdoor thermal comfort conditions of a transitional space focusing on vegetation cover change to distill findings into a set of design guidelines for landscape architects and urban planners to enhance the thermal comfort in open transitional spaces, especially in airport terminals with hot summer, and cold winter climate. The case study for this research is an open transitional area at the Mehr-Abad airport. Mehr-Abad airport experiences blistering summers and freezing winters. The environmental situation is analyzed using ENVI-met software. Subsequently, without-grass and without-tree scenarios were simulated to study the impact of greenery on transitional thermal comfort. The results were validated using the on-site collected data. In this study, results demonstrate that the average PET in the current situation is 39.81 ℃ in summer (hot sensation) and 5 ℃ in winter (cold sensation). Based on the results, removing the grass cover is the most suitable scenario for both summer with 35.80 ℃, and winter with 6.68 ℃. The best scenario consists of adding more deciduous trees to open transitional spaces to reduce solar shading in winter. This study provided a better understanding of the effects of vegetation in transient-oriented limited spaces on outdoor thermal comfort and looked deeper into vegetation characteristics concerning the transitional space requirements in hot summer/cold winter climates.

A two-point fatigue strength assessment for surface-hardened notched components under consideration of residual stresses based on the local strain approach

The “Guideline non-linear” of the German Research Association for Mechanical Engineering provides a fatigue strength assessment for machine components based on the local strain approach. Currently, this assessment is limited to homogeneous components and without the possibility to consider residual stresses. The methods are thus inadequate for surface-hardened components, where the presence of material inhomogeneity and the introduced residual stresses significantly impacts fatigue life and the potential failure origin. In the following paper, an adaptation of the proof of structural durability of the guideline is shown, that firstly includes a two-point assessment and the estimation of load cycles to crack initiation at two failure-relevant points simultaneously. This enables the consideration of inhomogeneous material states, since the failure of surface-hardened components may initiate from the notch root as well as from the transition area between the low-strength core material and the high-strength surface layer. Secondly, the consideration of the residual stress state for both failure-relevant points is also introduced as part of the adapted fatigue strength assessment.

Structural characteristics of amygdala subregions in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) patients often suffer from depressive symptoms, which seriously affect cooperation in treatment and nursing. The amygdala plays a significant role in depression. This study aims to explore the microstructural alterations of the amygdala in T2DM and to investigate the relationship between the alterations and depressive symptoms. Fifty T2DM and 50 healthy controls were included. Firstly, the volumes of subcortical regions and subregions of amygdala were calculated by FreeSurfer. Covariance analysis (ANCOVA) was conducted between the two groups with covariates of age, sex, and estimated total intracranial volume to explore the differences in volume of subcortical regions and subregions of amygdala. Furthermore, the structural covariance within the amygdala subregions was performed. Moreover, we investigate the correlation between depressive symptoms and the volume of subcortical regions and amygdala subregions in T2DM. We observed a reduction in the volume of the bilateral cortico-amygdaloid transition area, left basal nucleus, bilateral accessory basal nucleus, left anterior amygdaloid area of amygdala, the left thalamus and left hippocampus in T2DM. T2DM patients showed decreased structural covariance connectivity between left paralaminar nucleus and the right central nucleus. Moreover, there was a negative correlation between self-rating depression scale scores and the volume of the bilateral cortico-amygdaloid transition area in T2DM. This study reveals extensive structural alterations in the amygdala subregions of T2DM patients. The reduction in the volume of the bilateral cortico-amygdaloid transition area may be a promising imaging marker for early recognition of depressive symptoms in T2DM.

Unveiling intra-rural divides: investigating decline and prosperity in rural areas. The case study of southern Italy

ABSTRACT Strategies to address the decline and marginalization of rural areas are emerging as a central issue of European and national policies. Yet, the conceptualization of decline and the recognition of forms of decline specific to distinct rural areas, resulting in conditions of intra-rural divide, are fundamental aspects for developing place-based and targeted strategies. The article thus focuses on the concept of intra-rural divide. It introduces the categories of declining, adapting, stabilizing, and developing regions as spatial clusters that present specific population trends and require specific place-based policies. These policies are defined as adaptation, mitigation, and development strategies. The aim of the study is to develop a procedure, based on a set of indicators of population trends and population structure, to investigate the impact of active decline resulting from out-migration and legacy decline resulting from demographic imbalances produced by past migration. The objective is to understand the intra-rural divide and identify clusters of declining transition and prosperous rural areas. Six Italian regions were selected as study areas, including Abruzzo, Basilicata, Calabria, Campania, Molise, and Puglia. The Municipalities are selected as the unit of analysis. The study’s findings provide relevant information for defining targeted policies and balancing adaptation, mitigation, and development strategies.

Artificial neural network-substituted transition model for crossflow instability: Modeling strategy and application prospect

Data-driven approaches have made preliminary inroads into the area of transition–turbulence modeling, but are still in their infancy with regard to widespread industrial adoption. This paper establishes an artificial neural network (ANN)-based transition model to enhance the capacity of capturing the crossflow (CF) transition phenomena, which are frequently identified over a wide range of aerodynamic problems. By taking a new CF-extended shear stress transport (SST) transition-predictive (SST-γ) model as the baseline, a mapping from mean flow variables to transition intermittency factor (γ) is constructed by ANN algorithm at various Mach and Reynolds numbers of an infinite swept wing. Generalizability of the resulting ANN-based (SST-γANN) model is fully validated in the same infinite swept wing, an inclined 6:1 prolate spheroid, and a finite swept wing in extensive experiment regimes, together with two effective a priori analysis strategies. Furthermore, the calculation efficiency, grid dependence, and performance of the present model in non-typical transitional flow are also assessed to inspect its industrial feasibility, followed by the elucidation of rationality behind the preliminary success and transferability of present framework. The results manifest that the SST-γANN model aligns well with the benchmark SST-γ model, and both can capture the CF transition accurately compared with their experiment counterpart, completely breaking through the disability of original SST-γ model without CF correction. In addition, good properties of efficiency, robustness, and generalizability are achieved for the ANN-alternative transition model, together with the usability of present framework across various transitional flows.

Wave-gravity-induced sediment transport on steep shoreface

ABSTRACT This research is dedicated to examining downslope sediment transport on steep shorefaces. We present a model that incorporates nonlinear surface wave profiles, sediment movement thresholds, and slope effects, utilizing a set of semi-empirical formulas. The model quantitatively assesses the disparity between wave-augmented upslope transport and gravity-augmented downslope transport, and computes sediment transport rates using a single calibration coefficient. Validation of the model is carried out in the Fuji coast of Japan, where offshore wave conditions and seabed topography with a uniform grain size distribution serve as inputs. The computational outcomes reveal that sediment transport primarily occurs under high wave conditions, and downslope transport dominates on steep slopes. The calibration coefficient is determined through a comparison with observed data, demonstrating a strong agreement in the average annual sediment loss in the target area. Moreover, the model offers insights into the possible mechanism behind the existence of a transition area between the upper and lower shoreface, marked by an abrupt change in seabed slope.

Technological guiding principles for manufacturing full-contour zirconia prosthetic restoration using the CAD/CAM method

The introduction of CAD/CAM technology in dentistry opened the way for the use of numerous materials for prosthetic restorations: dental alloys, ceramic masses, zirconia, PMMA, etc. One of the materials suitable for CAD/CAM technology is zirconia, used either ceramic-plated or full-contour, through its mechanical and optical properties. Zirconia, proves to be a real competitor for dental alloys used in porcelain fused to metal technology, with great results on posterior and frontal areas of dental arches. Prosthetic restorations made of zirconia in transit areas (including canines and premolars) exemplify the perfect combination between mechanical resistance and aesthetics of this material.