Pattern Map Research Articles

Mass transfer and modeling of deformed bubbles in square microchannel

Understanding of mass transfer in gas-liquid slug flow is imperative to design and optimize micro-reactors. There exist extensive studies on symmetric bubbles by the phase volume monitor technique, whereas deformed bubbles are rarely studied due to the limitation of volume calculation methods. In this work, CO2-water and N2-water two-phase flows were investigated in a square microchannel, obtaining annular flow, slug flow, and bubbly flow. A flow pattern map was then proposed and compared with the literature. A 3D slicing technique was developed to measure the volume and interfacial area of bubble, including symmetric bubbles and deformed bubbles, by slicing the bubble along the streamwise direction. Scaling laws of the important parameters that characterize the micro-reactors were proposed. Mass transfer coefficients kLa were quantified from the time-changing volume. The empirical correlation involving dimensionless numbers were fitted, which shows accurate predictive performance for mass transfer coefficients in this study and literatures. The bigger index of Reynolds number ReG indicated that gas flow condition is the main influencing factor during mass transfer process. To have a better universality, a new semi-theoretical model involving the ratio of the size of the liquid and gas phases LL/LG was developed based on the Pigford and Higbie penetration theory because experimental data confirms that the degree of bubble deformation is related to LL/LG. The semi-theoretical model shows a satisfactory agreement over the whole range of slug flow in this study.

Geophysical Evaluation of Agricultural Potential of Orlu and Environs Using Landsat Imagery

The scarcity of food afflicting third-world countries, particularly Nigeria, case study Orlu zone, Imo State, Nigeria, is intolerable, given the high rate of environmental degradation in the form of erosions, nation’s poor economic state, insecurity, and extremely low per capita income of citizens, motivated this research. This research is tailored to a possible approach to combating the threat of food insecurity via geophysical investigation of agricultural potential areas and as well help in managing food insecurity ravaging the area, particularly in this post-COVID lockdown era. In this research, a geophysical approach—Landsat imagery and interpretation—was used to identify areas with high agricultural yielding potentials and how to exploit them for bumper agricultural harvests to sustain livelihood and alleviate the food crisis and food inflation ravaging the zone. Within the study area, the following data were collected: Normalized Difference Vegetation Index (NDVI) map, lineament map and drainage pattern map. They were interpreted, and areas with high agricultural yield potentials were mapped. Band ratios (3/4, 4/2, 3/1, 5/4) were generated to reduce the effects of shadowing and as well improve the features present. The NDVI values that indicate soil viability, generated within the study area range from –0.22 to 0.51.

Distinct hemodynamic and functional connectivity features of fatigue in clinically isolated syndrome and multiple sclerosis: accounting for the confounding effect of concurrent depression symptoms

PurposeThis study aims to identify common and distinct hemodynamic and functional connectivity (FC) features for self-rated fatigue and depression symptoms in patients with clinically isolated syndrome (CIS) and relapsing–remitting multiple sclerosis (RR-MS).MethodsTwenty-four CIS, 29 RR-MS patients, and 39 healthy volunteers were examined using resting-state fMRI (rs-fMRI) to obtain whole-brain maps of (i) hemodynamic response patterns (through time shift analysis), (ii) FC (via intrinsic connectivity contrast maps), and (iii) coupling between hemodynamic response patterns and FC. Each regional map was correlated with fatigue scores, controlling for depression, and with depression scores, controlling for fatigue.ResultsIn CIS patients, the severity of fatigue was associated with accelerated hemodynamic response in the insula, hyperconnectivity of the superior frontal gyrus, and evidence of reduced hemodynamics–FC coupling in the left amygdala. In contrast, depression severity was associated with accelerated hemodynamic response in the right limbic temporal pole, hypoconnectivity of the anterior cingulate gyrus, and increased hemodynamics–FC coupling in the left amygdala. In RR-MS patients, fatigue was associated with accelerated hemodynamic response in the insula and medial superior frontal cortex, increased functional role of the left amygdala, and hypoconnectivity of the dorsal orbitofrontal cortex, while depression symptom severity was linked to delayed hemodynamic response in the medial superior frontal gyrus; hypoconnectivity of the insula, ventromedial thalamus, dorsolateral prefrontal cortex, and posterior cingulate; and decreased hemodynamics–FC coupling of the medial orbitofrontal cortex.ConclusionThere are distinct FC and hemodynamic responses, as well as different magnitude and topography of hemodynamic connectivity coupling, associated with fatigue and depression in early and later stages of MS.

Guidance in botulinum neurotoxin injection for lower extremity spasticity: Sihler's staining technique.

Spasticity is a motor disease characterized by a velocity-dependent acceleration in muscle tone or tonic stretch reflexes linked to hypertonia. Lower limb spasticity has been successfully treated with botulinum neurotoxin; however, the injection sites have not been generalized. Sihler's stain has been used to visualize intramuscular nerve distribution to guide botulinum neurotoxin injection. Sihler staining is a whole-mount nerve staining technique that allows visualization of nerve distribution and mapping of entire nerve supply patterns in skeletal muscle with hematoxylin-stained myelinated nerve fibers. This study reviewed and summarized previous lower extremity spasticity studies to determine the ideal injection site for botulinum neurotoxin.

Effect of high pressure on severe slugging and multiphase flow pattern transition in a long pipeline-riser system

Severe slugging poses an enormous threat to the safe operation of high-pressure long petroleum pipelines. However, most published studies are conducted in short pipelines under atmospheric pressure. In this work, the gas–liquid two-phase flow experiment is conducted in the pipeline-riser system of 380 m long and 75 mm inner diameter under the separator pressure from atmospheric pressure to high pressure (10 MPa), and flow pattern maps are established. Under high-pressure conditions, liquid fallback and second blowout of severe slugging disappear. In the flow pattern maps, flow pattern types reduce, and severe slugging region shrinks. The boundary between stable flow and severe slugging appears on the left side of the flow pattern map and moves in the direction of higher superficial gas velocity. Increasing separator pressure leads to the increase in the severe slugging period. A correlation equation applicable to predicting the severe slugging period for different pressures (0, 1 and 5 MPa) is proposed, and the average error is less than ± 7.9%. Due to the inhibition of high pressure, the amplitude of the riser differential pressure decreases at most working points and increases only at a few working points where flow pattern transition occurs.

Cortico–subcortical spatiotemporal dynamics in Parkinson’s disease can be modulated by transcranial alternating current stimulation

Objective: We investigated changes in cortico–subcortical spatiotemporal dynamics to explore the treatment mechanisms of transcranial alternating current stimulation (tACS) in patients with Parkinson’s disease (PD). Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) data were collected from 20 patients with PD and 20 normal controls (NC). Each patient with PD received successive multidisciplinary intensive rehabilitation treatment and tACS treatment over a one-year interval. Individual functional brain network mapping and co-activation pattern (CAP) analysis were performed to characterize cortico–subcortical dynamics. Results: The same tACS electrode placement stimulated different proportions of functional brain networks across the participants. CAP analysis revealed that the visual network, attentional network, and default mode network co-activated with the thalamus, accumbens, and amygdala, respectively. The pattern characterized by the de-activation of the visual network and the activation of the thalamus showed a significantly low amplitude in the patients with PD than in NCs, and this amplitude increased after tACS treatment. Furthermore, the co-occurrence of cortico–subcortical CAPs was significantly higher in patients with PD than in NCs and decreased after tACS treatment. Conclusions: This study investigated cortico–subcortical spatiotemporal dynamics in patients with PD and further revealed the tACS treatment mechanism. These findings contribute to understanding cortico– subcortical dynamics and exploring noninvasive neuromodulation targets of cortico–subcortical circuits in brain diseases, such as PD, Alzheimer’s disease, and depression.

FRI-317 - Characterization of the imaging signature of hepatocellular carcinoma with enhancement pattern mapping

FRI-317 - Characterization of the imaging signature of hepatocellular carcinoma with enhancement pattern mapping

An assessment of vegetation mapping scale for reserve management: does scale of assessment dominate assessment outcomes?

Scale is a critical factor in biodiversity assessments; assessments at inappropriate scales can compromise assessments and drive poor management outcomes. A key dataset for many conservation reserves is a map of vegetation patterns. However, the appropriateness, scale and accuracy of mapped vegetation values is rarely assessed. This study assessed vegetation mapping undertaken at differing scales using two common competing methods. The aim was to assess map utility for management planning within an important conservation reserve (Mugii Murum-ban State Conservation Area—MSCA) integral to the globally significant Greater Blue Mountains World Heritage Area in eastern Australia. Mapping typical of a common modelling approach failed to detect six of 21 vegetation types within MSCA. These vegetation types are part of four rare and/or endangered ecosystems. Overall accuracy (66%) was lower than sub-regional scale mapping based on air photo interpretation (77%) backed by higher levels of field data and local knowledge. Thus higher levels of spatial attribution applied to the modelling was not associated with increased map accuracy, although accuracy varied largely among vegetation types. The modelled map product has a consistent methodology across the state of New South Wales and provides important context for sub-regional mapping, but proved inappropriate for reserve management planning.

Combining atrial activation maps for the big picture of simulated atrial fibrillation mechanisms

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by PersonalizeAF project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860974. Background Pulmonary vein isolation (PVI) alone is not sufficient for all persistent atrial fibrillation (AF) patients. Ablation of localized AF drivers might be a promising adjunctive ablation strategy but detecting such drivers is limited by the small field of view of current mapping catheters. Purpose We propose a technique to detect localized AF drivers that combines sequential mapping of repetitive activation patterns into a larger composite map. The performance of this technique was evaluated in several simulated scenarios of known mechanisms during AF. Methods Representative repetitive conduction patterns that may occur in AF were simulated in a detailed volumetric 3D model of the atria: a large peripheral wave, stable and meandering re-entries, and single and multiple ectopic foci. Endocardial electrograms were sequentially generated from overlapping regions in the left posterior wall (4x4 grid, 3mm spacing, 0.5-1.5 seconds), and repetitive activation patterns were detected. Overlapping areas between sequential maps were used to align the repetitive patterns. Local patterns were then combined into larger composite maps (Fig. 1A). Reconstruction performance was quantified by the average local activation time (LAT) difference between original and reconstructed activation patterns. The relation between electrode overlaps and the quality of reconstructions were assessed at different degrees of spatial overlap (approximately 10% to 25% of the grid area, corresponding to 1.6 ± 0.6 and 4.1 ± 1.2 overlapping electrodes, respectively). Results All simulated patterns could be reconstructed from sequential recordings (Fig. 1B). LAT errors in recordings with 25% overlap were low in all cases: 5±2 msec for the peripheral wave, 5±2 and 3±1 msec for focal and multifocal activities and 6±2 and 11±2 & 17±3 msec for stable, meandering and highly meandering re-entries respectively (Fig. 2). Composite maps of meandering and highly meandering re-entries presented significantly higher reconstruction errors than other more stable patterns (p<0.01). Reducing spatial overlap to 10% did not significantly increase the errors, except for the highly meandering re-entrant activity (p<0.05). Conclusion We developed a novel methodology to combine high-density sequential recordings with limited coverage into larger composite activation maps. Using this method, we reconstructed highly accurate activation maps for multiple simulated AF mechanism scenarios. Results were promising even with a small overlap between sequential recording sites and relatively unstable patterns, providing a proof of principle to apply this approach in clinical recordings of human AF.

Analyzing the role of ICT in bridging the digital divide: a transitional analytical framework for ICT access to impact

PurposeIn light of the shift in focus from information communication technology (ICT) access (access divide) and skills (skills divide) to the tangible impacts of ICT use (impact divide), a growing number of scholars have called for further investigation into the inter-territorial and multi-dimensional aspects of the digital divide in China. This study aims to address these gaps by examining the disparities across 31 provinces, particularly emphasizing the transition from the traditional access and skills divides to the impact divide.Design/methodology/approachMultivariate regression analysis extensively investigates the transition from the access and skills divides to the impact divide across 31 provinces. Additionally, ArcGIS software is used to analyze spatial agglomeration and the auto-correlation (Moran-i) and predict mapping patterns in the data corresponding to all three levels of the digital divide.FindingsAccording to the study's findings, poverty is a significant factor in the digital divide between different regions in China. The research shows that provinces with advanced administrative systems, such as Guangdong, Shanghai, Beijing, Jiangsu, Shandon and Zhejiang, have high scores on the digital development index (DDI). However, regions with poverty-ridden and rural areas, primarily located in southwest, central and western China, tend to have lower DDI scores.Originality/valueThis study offers a novel contribution to the literature by presenting an innovative conceptual framework that explores the impact divide within China's provinces. The authors also address this lacuna in the literature by developing and testing two dimensions to examine the relationships statistically under a wide range of socioeconomic and ICT indicators.

Comparing actual evapotranspiration estimations by METRIC to in-situ water balance measurements over an irrigated field in Turkey

ABSTRACT Estimating actual evapotranspiration (ETa) rates in large-scale irrigation schemes is of great importance to improve water use efficiency. Crop types can be determined by employing remote sensing techniques coupled with ground truth data. This study aimed to: (a) conduct a water balance study by making in-situ water balance measurements, (b) derive cropping pattern maps, (c) acquire crop evapotranspiration (ETc), (d) generate fully distributed ETa maps, and (e) compare ETa estimations with ETc and in-situ water balance. Landsat 7 and 8 satellite data, and meteorological data were used to estimate ETa in the Eastern Mediterranean Region of Turkey in the 2021 hydrological year. Crop types were classified using Sentinel 2A–2B satellite images. The change in catchment storage was +67.08 mm with a 3.34% water balance closure error. The correlation between ETa and ETc for irrigated wheat, potato, lettuce, corn-1, peanut-1, soybean-2, and citrus was significant in the growing season.

Prosodic location modulates listener’s perception of novel German sounds

Interaction of sounds on the melodic tier (segments) with prosodic and phonotactic structure (syllabic context) in cross-language perception is not explicitly addressed by models of second language phonology (e.g., Perceptual Assimilation Model: Best, 1995). At initial stages of foreign language exposure, learners rely on position-specific phonetic detail more than native speakers or advanced learners, thus mappings according to prosodic and phonotactic context are a crucial factor in early interlanguage phonological development. In a perceptual assimilation experiment, we manipulated syllable position (onset vs. coda) and phonotactic complexity (simple vs. complex codas) in phonotactically similar languages for auditory presentation of six German obstruents (i.e., familiar [h k ʃ] and novel [ç x p͡f]) to native speakers of American English who had no previous exposure to German. By means of weighted proportions (Park & de Jong, 2008) and overlap scores (Levy, 2009), we found that [h k ʃ p͡f] mapped categorically to English orthographic categories <h>, <k>, <sh>, and <f>, respectively, in all positions, whereas the novel fricatives [ç x] exhibited distinct mapping patterns from each other, from other sounds, and according to syllable position. These results demonstrate profound influences of both low-level prosodic and phonotactic contexts on perceptual assimilation of novel sounds

Mapping of stones and their deterioration forms: the Clock Tower, Venice (Italy)

The HYPERION EU project aims to develop a Decision Support System to improve resilience and sustainable reconstruction of historic areas faced with climate change and extreme events. In this context, Venice presents an outstanding example of urban and architectural complexity and richness. The mapping of the ornamental stones of the façade of the Venice Clock Tower (Torre dell’Orologio) and their deterioration patterns acts as a milestone on which to build the knowledge-acquisition process of the system as regards stone artefacts and their decay products. The Clock Tower is an early Renaissance building (1499) in Lombardesque style and stands over the entrance to the Mercerie on the northern side of St. Mark’s Square. Detailed surveys and mapping of both building materials (mainly stones) and deterioration patterns were carried out, the latter following the glossary of weathering forms, coupled with an easy-to-use scale of evaluation of their intensity. The data output consists of several monothematic maps which can be handled separately, each one focusing on precise lithological or specific deterioration aspects. This study also proposes a simple approach to summarizing the total state of deterioration of the building in the form of a Total Deterioration Rank (TDR) and its representation. The stones used in the façade are regional (Ammonitico Rosso and Scaglia Rossa) and extra-regional limestones (Istrian Stone), as well as Mediterranean white and coloured marbles and stones already used in antiquity (i.e., Fior di Pesco or marmor chalcidicum, lapis porphyrites, a volcanic rock from the Egyptian Eastern Desert, Proconnesian marble from the Island of Marmara, Pavonazzetto toscano and white Carrara marble from the Italian Apuan Alps). The most frequent forms of deterioration detected are black crusts, patinas, discoloration and patterns linked to erosion processes. The interrelation of different mappings led to a number of useful considerations concerning differences in the effectiveness of maintenance procedures between public and private management of the monument.

Study on flow characteristics and interfacial interaction of two immiscible liquid phases on vertical wall

Water and silicone oil were used as an immiscible mixture, whose flow characteristics and liquid–liquid interfacial interaction on the vertical wall were analyzed by a combination of experiments and numerical simulations. The results indicated that the oil phase of the immiscible mixture flows on the wall as a liquid film, whereas the water phase flows on the oil film as droplets or rivulets. The immiscible mixture flow patterns can be divided into film-drop (FD), film-drop and rivulet (FD-RV), and rivulet (RV) flow according to the different flow behaviors of the water phase. A flow pattern map for the immiscible mixture of oil–water on the vertical wall was determined. In addition, the oil and water two phases influence the spreadability and fluidity of the liquid film, respectively. The water phaseflow can improve the oil film flow velocity, increase the oil–water interface shear stress, and change the oil film thickness.

Direct nano-imaging of light-matter interactions in nanoscale excitonic emitters

Strong light-matter interactions in localized nano-emitters placed near metallic mirrors have been widely reported via spectroscopic studies in the optical far-field. Here, we report a near-field nano-spectroscopic study of localized nanoscale emitters on a flat Au substrate. Using quasi 2-dimensional CdSe/CdxZn1-xS nanoplatelets, we observe directional propagation on the Au substrate of surface plasmon polaritons launched from the excitons of the nanoplatelets as wave-like fringe patterns in the near-field photoluminescence maps. These fringe patterns were confirmed via extensive electromagnetic wave simulations to be standing-waves formed between the tip and the edge-up assembled nano-emitters on the substrate plane. We further report that both light confinement and in-plane emission can be engineered by tuning the surrounding dielectric environment of the nanoplatelets. Our results lead to renewed understanding of in-plane, near-field electromagnetic signal transduction from the localized nano-emitters with profound implications in nano and quantum photonics as well as resonant optoelectronics.

Systematic evidence mapping of thyroid hormone patterns after exposure to endocrine disrupting chemicals in adult rodents

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Semi-Supervised Learning for Simultaneous Location Detection and Classification of Mixed-Type Defect Patterns in Wafer Bin Maps

Identifying the patterns of defective chips in wafer bin maps (WBMs) in semiconductor manufacturing processes is crucial because different defect patterns correspond to different root causes of process failures. Recently, mixed-type defect patterns (i.e., multiple defect patterns in a single wafer) have become increasingly common owing to the increased complexity of semiconductor manufacturing processes. Previous methods for classifying mixed-type defect patterns in WBMs focused on outputting only the class labels of the defect patterns and not their locations, although location information of the defect patterns is useful for tracking the root causes of failure and improving processes. Moreover, most previous methods used only labeled WBM data, although a larger quantity of unlabeled WBM data are more accessible because of the costly process of label annotation. Therefore, in this paper, we propose a semi-supervised learning method for classifying mixed-type defect patterns and detecting their locations simultaneously using both labeled and unlabeled WBM data. The proposed method extends a recent unsupervised object detection method called Attend-Infer-Repeat in a semi-supervised manner to perform object detection and classification simultaneously. The performance of the proposed method is verified using WBM datasets of different sizes. The results demonstrate the effectiveness of the proposed method for classification and location detection.

PO-04-110 MAPPING TRENDS IN AVNRT ABLATION: AN INTERNATIONAL ANALYSIS

Electroanatomic mapping (EAM) in AVNRT procedures is an ongoing area of interest due to AVNRT prevalence and safety considerations, particularly in pediatric populations. The utility of voltage mapping to identify the slow pathway has been documented. However, use of mapping techniques differs widely across geographies, and trends in clinical practice of these techniques and the acute outcomes have not been quantified. To assess mapping patterns in AVNRT procedures by geography. Acute observational data from 484 AVNRT procedures were prospectively collected from 125 centers in 12 countries in North and South America, Europe, and Australia. Choice of mapping and ablation strategy was left to physician discretion. Procedure data (mapping approach, catheter choice, and number of Ablation lesions required Before Consolidation (ALBC)) were compared to analyze acute outcomes and regional use trends. There was a significant difference in EAM use in AVNRT cases in the US vs. OUS (89.5% vs. 64.5%, respectively, p<.05). Low voltage bridge (LVB) mapping was the most frequently used technique globally; 37.7% of US and 52.7% of OUS cases (p<.05). Wavefront collision mapping (WFC) and Local Activation Time (LAT) mapping applying isochronal late activation mapping concepts saw high use in the US (WFC: 28.2%, LAT: 22.3%) but infrequently OUS (7.5%, p<.05; 4.3%, p<.05). Fractionation mapping was uncommon in all regions (US 1.4%, OUS 0%; p>.05) (Figure 1). There was a significant decrease in ALBC between procedures that used EAM and those that did not (4.39±5.5 and 6.6±9.0 ablation lesions, respectively, p=.01). ALBC was also significantly different by mapping catheter choice, with cases that used HD Grid requiring fewer ablation lesions than cases that mapped with ablation or linear catheters (3.7±3.9, 5.4±7.1, and 6.0±6.8, respectively, p=.02). There was a significant difference in mapping catheter choice in the US vs. OUS (Table 1). In all regions analyzed, LVB mapping was the most common EAM technique and ablation catheters were the most commonly used mapping catheter. There were significant regional differences in the rate of EAM use and technique. Procedures that used EAM required fewer ALBC, an effect further amplified in the cases using HD Grid. Therefore, use of both EAM and HD Grid may help to minimize ALBC in AVNRT, an important safety and efficiency consideration. Further analysis exploring long-term efficacy by approach in a protocol-driven cohort may be warranted.Tabled 1Table 1.USOUSAblation Catheter54.0% (n=122)58.1% (n=111)HD Grid30.1% (n=68)34.6% (n=66)Linear Mapping Catheter16.0% (n=36)7.3% (n=14)Prevalence of mapping catheter choices compared between cases in the US and OUS. All differences were significant (p<.05) Open table in a new tab

Networking Based ISAC Hardware Testbed and Performance Evaluation

As one of the candidate technologies for 6G mobile system, integrated sensing and communication (ISAC) can support the mobile network evolving from the communicationonly network to the multi-functional network. The networking based ISAC can empower the effective multi-node cooperative perception and sensing data sharing among multiple sensing nodes. In this article, we explore different properties of signals available for radar sensing and aim to combine the ISAC technology with the cellular network by optimizing the multidimensional resource scheduling. In the developed simulation platform, different mapping patterns of reference signals are exploited to realize the performance trade-off between communication and sensing functions. Finally, the ISAC enabled cooperative perception hardware testbed has been designed and implemented, which can decrease the positioning error by 61% compared to a single ISAC system.

Convective condensation of R134a and R1234ze(E) inside microfin tube

Environmental concerns are forcing the replacement of the commonly used refrigerants and finding new fluids is a top priority. The hydro-fluoro-olefin (HFO) R1234ze(E), because of its smaller global warming potential (GWP) and shorter atmospheric lifetime, replaced R134a. Accordingly, for HVAC systems design, a detailed knowledge of the thermo-fluid-dynamic characteristics of the fluids and reliable predictive models are required. To improve the understanding, R134a and R1234ze(E) were employed in convective condensation experiments (saturation temperature Tsat = 35°C, mean quality xm = 0.1~0.9, quality changes Δx = 0.05~0.6, mass flux G = 43~444 kg·m−2s−1) inside a microfin tube (outer diameter D = 9.52 mm, fin number n = 60, fin height H = 0.2 mm). The results were used for two goals: the former is the comparison of the heat transfer features of the two fluids, while the latter aims at testing the performance of prediction models available in the open literature. At the saturation temperature T = 35°C, the two fluids show small differences in the thermal properties so that, as expected, the experiments highlighted a very similar behavior in the typical operating conditions of HVAC systems. In fact, for all the operating conditions marginal differences were observed in the pressure drop, the heat transfer coefficient and the flow pattern maps. The issue of prediction reliability, however, is still open. Actually, not all the models achieving good results for R134a show the same performance for R1234ze(E), especially for the pressure drop.