Evolution Of Patches Research Articles

Evolution of materials, geometries, and fabrication of sweat patches and their use in high-throughput point-of-care/onsite sensing

Sweat is a non-invasive fluid used to monitor various medically relevant analytes for disease diagnosis and healthcare monitoring. Sweat patches are used to collect contaminant-free sweat from individuals in any setting. In the past 50 years, sweat patches have evolved on various fronts, like fabrication methods, materials, and microfluidic channel designs. The primary goal of this study is to explore the evolution of sweat patches over the last 50 years in terms of materials such as polydimethylsiloxane (PDMS), adhesives, and other polymers, as well as microfluidic channel geometries and fabrication approaches. In addition, modern sweat patches are integrated with electrodes and electronic systems that enable sweat collection and in-situ analysis. The sweat patches are classified into two classes: early and modern sweat patches. Further, applications of these sweat patches in monitoring hydration, performance, metabolites, and disease diagnosis have been elaborately discussed. In the end, the conclusion and future outlook are discussed to give insight into further research.

Dynamic simulation and projection of land use change using system dynamics model in the Chinese Tianshan mountainous region, central Asia

A critical step in alleviating the contradiction between human activities and land systems is to project and analyze land use change traits in various scenarios to furnish a basis for formulating economic development and ecological conservation strategies. However, few studies have examined land use change using the system dynamics (SD) model and patch-generating land use simulation (PLUS) model in the Chinese Tianshan mountainous region (CTMR) affected by different economic growth patterns and climate change contexts. Therefore, based on the Shared Socioeconomic Pathways and Representative Concentration Pathways (SSPs-RCPs) scenarios, we attempted to construct a regional SD model (RSDM) including population, economic, land, and climate subsystems. Then, the coupled model by combining RSDM and PLUS was employed to simulate and project land use/cover changes (LUCC) in the CTMR at the regional level to explore the spatial distribution of land and its pattern of change in different climate contexts. The SD model is an effective method that can simulate the nonlinear behavior of a complex system and predict its evolution through the interactions and feedback relationships between different influencing factors. The PLUS model is an effective tool that can be used to simulate the evolution of land patches and capture the extent to which the driving factors contribute to LUCC. The relative errors were less than 5%, and the total accuracy of PLUS model was 91.77%. The above results demonstrated the effectiveness of RSDM and PLUS model in modeling LUCC across the CTMR. From 2005 to 2020, there was an expansion trend in the area of forest and construction land as well as in the area of cultivated land, while the grassland area displayed a significant decline. By 2040, the area of unused land, grassland, and water is expected to demonstrate a decreasing trend while other land types increase, with construction land showing the most significant increase of 101.37% under the SSP585 scenario. It is anticipated to expand mainly to cultivated land and grassland around cities. The cultivated land is expected to primarily encroach on the regions of unused land and grassland under the three scenarios, reaching the expansion demand. As opposed to the scenarios of SSP126 and SSP245, the SSP585 scenario distribution of the cultivated land patches will be more compact and denser. The SSP126 and SSP245 scenarios will exhibit similar patterns of future spatial distribution of land. The SSP585 scenario is anticipated to display marked differences. According to the three scenarios, grassland degradation will be severe and require increased grassland protection. The findings can offer novel perspective concepts with regard to future ecological and environmental management, judicious distribution of land resources, and sustainable progression in the CTMR.

Mass-balance and ablation processes of a perennial polar ice patch on the northern coast of Ellesmere Island

AbstractIce patches have implications for landscape and ecosystem dynamics in polar deserts, however, the understanding of the driving factors that control their spatio-temporal variability is limited. This study aims to assess the seasonal and long-term evolution of ice patches on Ward Hunt Island (WHI; 83°N, Canadian High Arctic) based on field measurements of surface mass and energy balance. Results show that mass gains of the ice patch systems occur mostly through drifting snow, making them highly linked to the topography as well as the frequency and magnitude of wind events. Summer ablation is primarily driven by net radiation, but the short-term variability in melt rate is driven by sensible heat fluxes. The highest ablation rates occur during the passage of warm fronts that combine strong winds and mild temperatures. Conversely, foggy days reduce fluxes of solar radiation and sensible heat to the snow/ice surface, thereby suppressing ablation. Ice patches are less climate-sensitive than other cryospheric elements due to a feedback between snow accumulation and topography, however, summer ablation is strongly influenced by micrometeorology. Model projections of these factors suggest that conditions will become critical for preserving ice patches at WHI and along the northern coast of Ellesmere Island as early as in the next decades.

Time-evolving dry patches in a flowing film around a horizontal tube

Dry patches could occur on the heat exchanger wall even if the initial liquid film covers the tube surface entirely. Here, we propose a simple three-dimensional model to predict the formation and evolution of dry patches in a water film coating on a horizontal tube, considering thermocapillary and evaporation of the liquid film. Results indicate that the film thickness distribution along the axis is not uniform, convex at ends and concaves at the center. Under the action of axial thermocapillary force, the growth rate of the dry patch in the circumferential direction is more significant than that in the axial direction and finally forms an elliptical shape. Comparative analysis reveals that the appearance of dry patches is delayed as the spray temperature decreases or Re increases. Tube radius has little influence on the drying of liquid film, which is not recommended to control dry patch formation by reducing the tube radius. This work could be beneficial to assist the feasibility design of falling film heat exchangers.

Rapid Evolution of Bald Patches in a Major Solar Eruption

Abstract A bald patch (BP) is a magnetic topological feature where U-shaped field lines turn tangent to the photosphere. Field lines threading the BP trace a separatrix surface where reconnection preferentially occurs. Here we study the evolution of multiple, strong-field BPs in AR 12673 during the most intense, X9.3 flare of solar cycle 24. The central BP, located between the initial flare ribbons, largely “disintegrated” within 35 minutes. The more remote, southern BP survived. The disintegration manifested as a 9° rotation of the median shear angle; the perpendicular component of the horizontal field (with respect to the polarity inversion line) changed sign. The parallel component exhibited a step-wise, permanent increase of 1 kG, consistent with previous observations of the flare-related “magnetic imprint.” The observations suggest that magnetic reconnection during a major eruption may involve entire BP separatrices, leading to a change of magnetic topology from BPs to sheared arcades.

The Role of Discrete Capillary Rings in Mass Transfer From the Surface of a Drying Capillary Porous Medium

The mass exchange between the surface of a model capillary porous medium and the adjacent gas-side boundary layer is studied in the limiting condition of isothermal, slow drying. In order to quantify the role and significance of liquid films in the mass exchange process, three-dimensional pore network Monte Carlo simulations are carried out systematically in the presence and absence of discrete capillary rings. The pore network simulations performed with capillary rings show a noticeable delay in transition from the capillary-supported regime to the diffusion-controlled regime. These simulation results differ significantly from the predictions of classical pore network models without liquid films, and they appear to be more consistent with the experiments conducted with real porous systems. As compared to classical pore network models, the pore network model with rings seems to predict favorably the spatiotemporal evolution of wet and dry patches at the medium surface as well as of their relative contributions to the net mass exchange rate. This is apparent when the analytical solution of the commonly used Schlünder’s model is examined against the numerical simulations conducted using classical and ring pore network models.

Growth of dry patches in an evaporating film flowing around a horizontal circular tube

The falling film flows over solid surfaces have been exploited extensively, but the modeling of film dry-out and the dry patches' formation poses a considerable challenge. Here, we presented a simple mathematical model that accounts for the evaporation to predict the evolution of dry patches in a falling film. Besides, we also analyzed the effect of flow rate, spray temperature, and tube diameter on the growth of dry patches. The distribution of liquid film thickness is asymmetrical, and the film thickness decreases firstly and then increases after a central angle of 90°. The liquid film covered the tube initially under the action of gravity, then evaporation thinned liquid film and induced small dry patches. With the increasing flow rate, decreasing spray temperature, or decreasing tube diameter, the dry-out time increases, and the dry patche area decreases. It is more effective to suppress dry patches' appearance by controlling both flow rate and spray temperature rather than tube diameter.

Geomorphic Classification and Assessment of Mangrove Degradation in the Henry’s and Patibania Island, South Western Sundarban

The coast of Henry's island, extending from Saptamukhi River in the east to Bakkhali River in the West. In the hot and humid climate of the Sundarban, a negligible input of fresh water through tidal creeks, high evaporation rate at the surface area are the probable reasons behind the evolution of Hypersaline patches of Henry's and Patibunia Island. The dense salt patches develop in the abandoned portion of the surface then sinks and move out of the tidal estuaries as subterranean flow or a bottom current to make the environment more saline. Development of Saltpan is one of the major hindrances for the growth of mangroves and hampers the ecological balance of Sundarban. Present paper attempts to highlight- I) To study and identification of Geomorphological settings of both island. ii) Analysis of Physico-chemical properties of hyper saline soil. iii) Identification of hyper-saline patches and their impact on mangrove degradation. Application of remote sensing technique and GIS analysis help to find out the relationship between mangrove degradation and salinity within the islands area in the last few decades. Development of hyper saline patches and changing environmental parameters are how much responsible for the mangrove degeneration process are major issues of this paper. The Forest Department has attempted to restore the growth of mangrove and improve fragile ecosystem but without understanding the geomorphology and environmental condition, it is not possible to implement proper managemental strategies for wetland restoration process.

Geographic Atrophy and micronutritional supplements: A complex relationship

In 2019, the Age-Related Eye Disease Study (AREDS) remains the basis for micronutritional supplement guidelines aiming to slow the progression of Age-Related Macular Degeneration (AMD) and reduce the risk of neovascularization. However, for Geographic Atrophy (GA) patients specifically, there seem to be more arguments for prescribing micronutritional supplements for the prevention of neovascular complications than to slow the progression of the atrophy. The AREDS report 8 showed a significant decrease in AMD progression over a five-year follow-up associated with a formulation containing antioxidants and zinc. It is noteworthy that the protective effect that was demonstrated was mainly related to the risk of a neovascularization and that the AREDS did not really demonstrate a protective effect that would slow the progression of GA. The 2013 AREDS II results have led to a change in the AREDS formulation. Nevertheless, the replacement of beta-carotene by lutein and zeaxanthine and the addition of Omega-3 did not add any further evidence for a protective effect on GA. Furthermore, the AREDS study used color photographs rather than fundus autofluorescence or OCT to assess the presence or the evolution of patches of atrophy. Over the last 10 years, it has been shown that OCT is far more accurate than color photographs to measure the size of the atrophic areas and to evaluate the extent of alterations in the chorioretinal layers. While lack of evidence of a protective effect of the AREDS formulation for GA is not a proof of the absence of effect, many publications seem to have taken the results of the AREDS in such a global way that the lack of evidence concerning GA seems to have been ignored. Micronutrition supplements are well prescribed for AMD patients, and the key factor for adherence is explanation to the patient. So far, it appears worth explaining to GA patients that prescription of the AREDS formulation is mainly aimed at reducing the risk of neovascularization.

Coincident Observations of Dye and Drifter Relative Dispersion over the Inner Shelf

AbstractCoincident Lagrangian observations of coastal circulation with surface drifters and dye tracer were collected to better understand small-scale physical processes controlling transport and dispersion over the inner shelf in the Gulf of Mexico. Patches of rhodamine dye and clusters of surface drifters at scales of O(100) m were deployed in a cross-shelf array within 12 km from the coast and tracked for up to 5 h with airborne and in situ observations. The airborne remote sensing system includes a hyperspectral sensor to track the evolution of dye patches and a lidar to measure directional wavenumber spectra of surface waves. Supporting in situ measurements include a CTD with a fluorometer to inform on the stratification and vertical extent of the dye and a real-time towed fluorometer for calibration of the dye concentration from hyperspectral imagery. Experiments were conducted over a wide range of conditions with surface wind speed between 3 and 10 m s−1 and varying sea states. Cross-shelf density gradients due to freshwater runoff resulted in active submesoscale flows. The airborne data allow characterization of the dominant physical processes controlling the dispersion of passive tracers such as freshwater fronts and Langmuir circulation. Langmuir circulation was identified in dye concentration maps on most sampling days except when the near surface stratification was strong. The observed relative dispersion is anisotropic with eddy diffusivities O(1) m2 s−1. Near-surface horizontal dispersion is largest along fronts and in conditions dominated by Langmuir circulation is larger in the crosswind direction. Surface convergence at fronts resulted in strong vertical velocities of up to −66 m day−1.

Structural Changes of Seagrass Seascapes Driven by Natural and Anthropogenic Factors: A Multidisciplinary Approach

Seascape ecology has been widely applied to marine habitats, including seagrass meadows, through various approaches all over the world for the past 30 years. However, these methods mainly study seagrass meadows on a single spatial scale and monitor a single driver of heterogeneity. In addition, few assess the seascape’s structural evolution. This creates gaps between the scientific data provided and those required by environmental managers and stakeholders in charge of seagrass meadow conservation. To meet their expectations, we developed in this paper a new multidisciplinary approach based on the coupling of mapping techniques, particle flux and biometric investigations in a Mediterranean Bay, the Calvi Bay (Corsica, France), to assess the structural evolution of Posidonia oceanica (L.) Delile meadows subject to disturbances. We focused our investigations on the structural characteristics, the spatial dynamics and the particle fluxes of natural sand areas generated by bottom currents and dead matte patches ensued from anchoring damages at 10, 15 and 20 m depth. Natural sand patches and anchoring patches differed in size, the first the largest. They also displayed different erosion-colonization dynamics. Natural sand patches were eroded at a mean speed of 12 cm.a-1 and colonized at a rate of 7 cm.a-1. Anchoring patches showed a mean erosion speed of 3.5 cm.a-1 and a colonization rate of 6.5 cm.a-1. Regarding particle fluxes, continuous meadow and natural patch sedimentation and resuspension rates were 3.7 gDW.m-2.d-1 and 4.1 gDW.m-2.d-1 in average, respectively. In contrast, anchoring patches at 20 m depth acted as sediment traps (112.60 gDW.m-2.d-1 in winter) and showed a higher particle resuspension rate. Our results highlighted the dichotomous dynamics of seagrass seascapes influenced by natural and anthropogenic factors (here anchoring). With an upscaling approach, together with the newest mapping tools of marine habitats, we suggest a new method to study the evolution of seagrass meadows at a large spatial scale. Due to the slow growth of P. oceanica and the centimetric annual evolution of patches revealed in the present study, it is obvious that a metric positioning accuracy is not sufficient to properly investigate the spatial evolution of P. oceanica seascapes.

From patch to channel scale: The evolution of emergent vegetation in a channel

Computational fluid dynamics was used to study the evolution of small patches of vegetation into a vegetated landscape in a channel. The growth of new vegetation occurred in regions where the flow velocity was reduced below a threshold value defined as a fraction of the channel-average velocity (U0). Two threshold values, or limiting velocity values (LV), were used: LV = 0.5 and 0.7. Two initial blockage factors (percentage vegetation coverage of the channel) were considered, 3% and 0.3%, chosen to represent cases with and without, respectively, hydrodynamic interaction between the initial patches. The simulation illustrated both positive feedbacks between flow and vegetation, which enhanced vegetation expansion, and negative feedbacks, which led to patch erosion and limited patch growth. The most rapid expansion of the vegetated area occurred during the initial simulation steps, when the flow blockage due to vegetation was small. A higher velocity threshold (higher LV) produced more rapid initial growth and a higher final coverage of vegetation. The patches evolved to one or a few elongated islands extending along the channel.

Resisting the perpetual update: Struggles against protocological power in video games

This article explores the evolution of video game updates and patches from a mechanism of customer support to a tool of control over the way games are played in the ecosystem of digital gaming platforms. It charts a historical trajectory across various cultural industries, including literary publishing, screen industries, and music, to show a shift from multiplicity of editions to one perpetually updated contingent commodity. Focusing on the issues of power and control enabled by the always-online platforms, the analysis shows that previously updating was often voluntary. However, now players must actively resist patches if they wish to play the game on their own terms. As illustrated by three case studies of update resistance, developers, publishers, and platform holders wield protocological power, which can be successfully opposed—although the outcome often remains localized and tends to alter a specific iteration of protocol and not the underlying infrastructure.

Characterisation of dissimilar P91 and P92 steel welds joint

ABSTRACTIn the present study, dissimilar weld joint was prepared using the P91 and P92 steel plate of 8-mm thickness, using the multi-pass gas tungsten arc (GTA) welding with filler (weld 1) and autogenous tungsten inert gas welding (A-TIG) process (weld 2). Evolution of δ-ferrite patches was studied in weld zone and heat affected zone (HAZ) for both weld 1 and weld 2. Effect of varying post weld heat treatment (PWHT) duration was also studied on δ-ferrite patches and mechanical properties of the dissimilar weld joint. PWHT was carried out at 760°C. For weld 2, weld zone showed poor impact toughness and higher peak hardness as compared to weld 1. After the PWHT, a considerable reduction in hardness was obtained for both weld 1 and weld 2,while impact toughness of weld zone showed a continuous increment with PWHT duration. For weldments characterisation, optical microscope, scanning electron microscope (SEM) and microhardness tester were utilised.

Mycosis fungoides-clinical and histopathologic features, differential diagnosis, and treatment.

Mycosis fungoides (MF) is the most common type of cutaneous lymphoma. The term MF should be used only for the classical presentation of the disease characterized by the evolution of patches, plaques, and tumors or for variants showing a similar clinical course. MF is divided into 3 clinical phases: patch, plaque, and tumor stage, and the clinical course is usually protracted over years or decades. Histopathologically, MF is characterized by an epidermotropic infiltrate of T lymphocytes that displays in most cases a helper phenotype. Cytotoxic variants are well described and do not have specific clinical, histopathological, or prognostic features. MF should be differentiated from other cutaneous epidermotropic lymphomas and from many inflammatory dermatoses with some similar clinicopathological features. The therapy of MF is planned mainly according to the stage and extent of the disease. In early phases, nonaggressive options represent the first-line strategy (eg, local corticosteroids, psoralen, and ultraviolet A [UV-A] irradiation, etc.). In patients with advanced disease, good results with potential for cure have been obtained with allogeneic stem cell transplantation, but toxicity is a serious limiting factor for this treatment. Conventional systemic chemotherapy and single-agent chemotherapy (eg, gemcitabine) give usually good results in advanced MF, but recurrences are the rule. Monoclonal antibodies directed against cluster of differentiation (CD)52 (alemtuzumab), CD30 (brentuximab vedotin), and chemokine receptor 4 (CCR4; mogamulizumab), as well as several other experimental therapies, have shown promising results and represent a valid alternative.

Autogenous Tungsten Inert Gas and Gas Tungsten Arc With Filler Welding of Dissimilar P91 and P92 Steels

Creep strength ferritic/martensitic modified 9Cr-1Mo-V-Nb (P91) steel also designated as ASTM A335 and P92 steel are used for piping, cladding, ducts, wrappers, and the pressure vessel in Gen IV nuclear reactors. In the present investigation, a comparative study of the effect of autogenous tungsten inert gas welding (A-TIG) with double pass and multipass gas tungsten arc (GTA) welding with filler on microstructure evolution in the weld fusion zone and the mechanical properties of P91 and P92 steel welded joints was carried out. The microstructure evolution was studied in as-welded and postweld heat treatment (PWHT) condition. The study also focused on the evolution of δ-ferrite patches and their influence on the tensile properties of welded joints. PWHT was carried out at 760 °C with durations from 2 to 6 h. To study the effect of δ-ferrite evolution on mechanical properties, Charpy toughness, microhardness, and tensile tests were performed. The acceptable microstructure and mechanical properties were obtained after the 6 h of PWHT for A-TIG arc welding process while for GTA weld with filler wire, it was obtained after the 2 h of PWHT at 760 °C.

Experimental–numerical study on strain and stress partitioning in bainitic steels with martensite–austenite constituents

To achieve safety and reliability in pipelines installed in seismic and permafrost regions, it is necessary to use linepipe materials with high strength and ductility. The introduction of dual-phase steels, e.g., with a bainite and dispersed martensite–austenite (MA) constituent, would provide the necessary ingredients for the improvement of the strain capacity (as required by a new strain-based linepipe design approach) and toughness. To fine-tune the alloy design and ensure these dual-phase steels have the required mechanical properties, an understanding of the governing deformation micromechanisms is essential. For this purpose, a recently developed joint numerical–experimental approach that involves the integrated use of microscopic digital image correlation analysis, electron backscatter diffraction, and multiphysics crystal plasticity simulations with a spectral solver was employed in this study. The local strain and stress evolution and microstructure maps of representative microstructural patches were captured with a high spatial resolution using this approach. A comparison of these maps provides new insights into the deformation mechanism in dual-phase microstructures, especially regarding the influence of the bainite and MA grain size and the MA distribution on the strain localization behavior.

Simulating urban growth in a megalopolitan area using a patch‐based cellular automata

AbstractAlthough traditional cellular automata (CA)‐based models can effectively simulate urban land‐use changes, they typically ignore the spatial evolution of urban patches, due to their use of cell‐based simulation strategies. This research proposes a new patch‐based CA model to incorporate a spatial constraint based on the growth patterns of urban patches into the conventional CA model for reducing the uncertainty of the distribution of simulated new urban patches. In this model, the growth pattern of urban patches is first estimated using a developed indicator that is based on the local variations in existing urban patches. The urban growth is then simulated by integrating the estimated growth pattern and land suitability using a pattern‐calibrated method. In this method, the pattern of new urban patches is gradually calibrated toward the dominant growth pattern through the steps of the CA model. The proposed model is applied to simulate urban growth in the Tehran megalopolitan area during 2000–2006–2012. The results from this model were compared with two common models: cell‐based CA and logistic‐patch CA. The proposed model yields a degree of patch‐level agreement that is 23.4 and 7.5% higher than those of these pre‐existing models, respectively. This reveals that the patch‐based CA model simulates actual development patterns much better than the two other models.

Effect of welding process and PWHT on δ-ferrite evolution in dissimilar P91 and P92 steel joint

Ferritic/martensitic 9Cr-1Mo-V-Nb (P91) and 9Cr-0.5Mo-1.8W-V-Nb (P92) steel are used for high temperature (600-650°C) operating components in nuclear and thermal power plants. The present research work deals with the dissimilar joining of P91 and P92 steel using autogenous tungsten inert gas (TIG) welding and multi-pass gas tungsten arc welding (GTAW) with filler. The evolution of δ-ferrite patches in weld fusion zone and heat affected zones (HAZs) were characterized in as-welded and post weld heat treatment (PWHT) condition. PWHT was carried out at 760 °C for 2 h and 6 h, for both autogenous-TIG and GTA weld joints. Charpy toughness and microhardness tests were performed for autogenous-TIG welding and GTA welding process under as-welded and PWHT condition.

A brief study on δ-ferrite evolution in dissimilar P91 and P92 steel weld joint and their effect on mechanical properties

Ferritic/martensitic 9Cr-1Mo-V-Nb steel also designated as ASTM A335 used in construction of several components of power plants operating in temperature range of 600–650°C. In present investigation, dissimilar weld joint of P91 and P92 steel were prepared using the autogenous tungsten inert gas (A-TIG) welding and multi-pass gas tungsten arc welding (GTAW) process. A comparative study was performed on evolution of δ-ferrite patches in weld fusion zone and heat affected zones (HAZs) of welded joints. The evolution of δ-ferrite patches was studied in as-welded and post-weld heat treatment (PWHT) condition. PWHT was carried out at 760°C for tempering time of 2h and 6h, for both A-TIG and GTA weld joints. It was observed that presence of higher content of ferrite stabilizer in P92 steel promote the formation of δ-ferrite patches in weld fusion zone as well as HAZs. To study the effect of welding process and PWHT, Charpy V impact energy and microhardness tests were performed. For microstructure characterization, field-emission scanning electron microscope (FESEM) and optical microscope were utilized.