Synchronous Occurrence Research Articles

Landscapes of synchronous multiple primary cancers detected by next-generation sequencing.

An increase in the detection rate of multiple primary cancers has been accompanied with declining cancer death rates over the past few decades. However, synchronous multiple primary tumors have gradually increased, and the molecular mechanisms involved in the synchronous occurrence of multiple primary cancers of different origins are unclear. To investigate these mechanisms, we sequenced cancer tissues by FoundationOne CDx. Data were annotated with annovar, and we then performed pathway enrichment analysis. A total of 109 genes that were mutated in all samples were clustered into different diseases, biological processes, and molecular functions. GO and KEGG analyses indicated that the P53 and PKB signaling pathways may be relevant to the occurrence of synchronous multiple primary cancers. In summary, patients with a concordance of mutations in pathogenetic genes may have a higher risk of developing a second cancer. Our research may provide a basis for the development of individualized treatments for synchronous multiple primary cancers.

ABCL-260 Coexistence of Non-Hodgkin Lymphoma and Rectal and Stomach Adenocarcinomas: A Case Report

The exceptional case described by us involves several malignant neoplasms in one person at the same time and the patient's death from COVID-19 complications. Case Presentation: A 74-year-old woman had suffered from marginal zone B-cell lymphoma since 2007. She was under observation until 2013 when there was a progression of the disease. She received 6 non-complete courses of chemotherapy by the R-CVP program. The 6th course was completed in February 2014 because of neuropathy. As a result, clinical hematological remission was registered. Until 2018, the situation was stable and dynamic control continued. In 2018-2019, a tendency toward lower hemoglobin was observed, CT revealed a conglomerate up to 11 cm in the abdomen, a biopsy of the axillary lymph nodes was performed, and Grade I follicular lymphoma was found. The size of the conglomerate did not change during the year and iron deficiency anemia was expressed in the blood test, though other test indicators were within the norm. Significant weight loss of 10 kg was observed in 1.5 years. In February 2019, a colonoscopy was performed, revealing a tumor, and in March 2019, a hemicolectomy was performed. Immunohistochemical examination of the removed tumor confirmed invasive mucinous adenocarcinoma Low-Grade p73pN1b (2/12) pMxL1V0Pn0Rx. The patient continued with permanent diarrhea and anemia. After two years, in May 2021, the patient was admitted for chronic muscular pain. During hospitalization, an episode of melena occurred, following which she underwent both colonoscopy and gastroscopy; the latter disclosed an approximately 1.2-cm lesion in the greater curvature of the stomach. The patient underwent trepan biopsy, which revealed intestinal-type gastric adenocarcinoma. The patient received 3 courses of rituximab monotherapy and was discharged before surgery. However, COVID-19 changed the plans of the doctors and the patient died from its complications in the intensive care unit. Conclusions: The synchronous occurrence of non-Hodgkin lymphoma and rectal and stomach adenocarcinoma is rare but possible. Doctors must be alert to its existence. Treatment depends on the tumor stage of the adenocarcinomas but also the lymphoma and its grade, and any therapeutic decision should only be made in a multidisciplinary meeting.

Endometrioid Carcinomas of the Ovaries and Endometrium Involving Endocervical Polyps: Comprehensive Clinicopathological Analyses.

While synchronous ovarian and endometrial endometrioid carcinomas (ECs) have long been described in the literature, ovarian or endometrial EC involving concomitant endocervical polyp (ECP) has not yet been reported. This study aimed to investigate the histological types and prevalence of gynecological tumors co-existing with ECP and to comprehensively analyze the clinicopathological characteristics of ovarian and endometrial ECs involving ECPs. We searched for ECP cases associated with premalignant lesions or malignancies of the female genital tract occurring between March 2019 and February 2022. We then investigated the histological types and prevalence of gynecological tumors co-existing with ECP. In addition, we reviewed electronic medical records and pathology slides to collect the clinicopathological features of four patients with ovarian or endometrial EC involving ECP. We found 429 ECPs over the three-year study period. Of these, 68 (15.9%) were associated with premalignant or malignant lesions occurring in the uterine cervix, endometrium, and ovaries. Four of these cases, including two (0.5%) ovarian grade 3 ECs and two (0.5%) endometrial grade 1 ECs, involved ECPs. In the former cases (cases 1 and 2), ECs involving ECPs exhibited similar morphology and immunohistochemical staining results to those of advanced-stage ovarian EC. In the latter cases (cases 3 and 4), the histological and immunophenotypical features of EC involving ECP were identical to those of primary endometrial EC, despite the lack of tumor involvement in the myometrium, lower uterine segment, and cervical stroma as well as the absence of lymphovascular invasion and lymph node metastasis. In all cases, no evidence of benign endometriosis, endometrial hyperplasia without atypia, or atypical hyperplasia/endometrial intraepithelial neoplasm within ECP or the adjacent endocervical tissue was noted. Considering our results, the involvement of ECP by EC may have been caused by an implantation metastasis from the ovarian (cases 1 and 2) or endometrial (cases 3 and 4) EC. To the best of our knowledge, this is the first exploration of the synchronous occurrence of endometrial or ovarian EC and ECP involvement. Implantation metastasis via transtubal and trans-endometrial cavity migration may have been the pathogenic mechanism of ECP involvement.

Identifying the spatiotemporal organization of high-traffic events in a mobile communication system using event synchronization and complex networks.

In mobile communication systems, congestion is related to high-traffic events (HTEs) that occur in the coverage areas of base stations. Understanding, recognizing, and predicting these HTEs and researching their occurrence rules provides theoretical and decision-making support for preventing system congestion. Communication sectors are regarded as nodes, and if HTEs occur synchronously among sectors, then the corresponding nodes are connected. The total number of synchronous HTEs determines the edge weights. The mobile-communication spatiotemporal data are mapped to a weighted network, with the occurrence locations of HTEs as the basic elements. Network analysis provides a structure for representing the interaction of HTEs. By analyzing the topological features of the event synchronization network, the associations among the occurrence times of HTEs can be mined. We find that the event synchronization network is a small-world network, the cumulative strength distribution is exponential, and the edge weight obeys a power law. Moreover, the node clustering coefficient is negatively correlated with the node degree. A congestion coefficient based on several topological parameters is proposed, and the system congestion is visualized. The congestion coefficient contains information about the synchronous occurrence of HTEs between a sector and its neighbors and information about the synchronous occurrence of HTEs among its neighbors. For the mobile communication system considered in this study, the congestion coefficient of a large number of sectors is small and the risk of system congestion is low.

SYNCHRONOUS DENTIGEROUS CYST AND ODONTOGENIC KERATOCYST IN MANDIBLE: CASE REPORT

Odontogenic keratocyst and dentigerous cyst are noninflammatory odontogenic cysts and account for 10% to 20% and 20% of all odontogenic cysts, respectively. We report an uncommon synchronous occurrence of both lesions in a 46-year-old White man. The patient presented with bilateral asymptomatic unilocular well-demarcated radiolucent lesions of the mandible. The right lesion measured 2.5 cm and involved the crown of the third molar. The left lesion measured 4.0 cm, had scalloped margins, and extended apically along the root to the lower margin of the jaw. The left second molar root was reabsorbed. Large-needle aspirations showed yellow liquid on the right side and white liquid on the left. Lesions were enucleated and tooth extraction was performed. A titanium plate was placed on the left side. Histopathologic examination confirmed the diagnosis of dentigerous cyst on the right side and odontogenic keratocyst on the left side. After 9 months of follow-up, there was complete bone regeneration with no recurrence.

Anticipating measure synchronization in coupled Hamiltonian systems with machine learning.

A model-free approach is proposed for anticipating the occurrence of measure synchronization in coupled Hamiltonian systems. Specifically, by the technique of parameter-aware reservoir computing in machine learning, we demonstrate that the machine trained by the time series of coupled Hamiltonian systems at a handful of coupling parameters is able to predict accurately not only the critical coupling for the occurrence of measure synchronization, but also the variation of the system order parameters around the transition point. The capability of the model-free technique in anticipating measure synchronization is exemplified in Hamiltonian systems of two coupled oscillators and also in a Hamiltonian system of three globally coupled oscillators where partial synchronization arises. The studies pave a way to the model-free, data-driven analysis of measure synchronization in large-size Hamiltonian systems.

Urbanization altered atmospheric humidity diurnally and seasonally through ecohydrological processes in five urban agglomerations in China

The large-scale conversion of vegetated land to urban use leads to a significant reduction in evapotranspiration (ET) due to the lack of vegetation, which may aggravate urban dry island (UDI) effect. Analysis of diurnal and seasonal (e.g. growing season) variations in UDI can help us to better identify the role of ET in processes of UDI. We compared six-hourly weather observation data (1980–2017) from 140 paired urban-rural stations across a large climatic gradient in China to explore how near-surface atmospheric dryness changed both diurnally and seasonally, and its relationship with urbanization-associated ecohydrological processes. We showed that the difference in atmospheric dryness (i.e. UDI intensity) between urban and rural areas, as measured by specific humidity (Δq < 0), is more pronounced during the daytime and growing seasons. The nighttime urban wet island (UWI, Δq > 0) effect partially offset daily UDI effect, which has made the latter underestimated. Intensified nighttime urban heat island (UHI) reduced the diurnal temperature range (DTR) in cities and thus enhanced nighttime UWI effect from 2000 to 2010. However, after 2010, nighttime UWI effect weakened or disappeared, whereas nighttime UDI intensified in humid cities, resulting in a significant increase in daily UDI. Intensified UHI and UDI are often closely coupled (synchronous occurrence) through latent heat (LE) or ET processes, especially after 2010. Our results indicate that the conversion of vegetated lands to urban impervious surface, especially in humid regions, leads to the reduction in transportation during daytime and evaporation at night in urban cores, which alters the relationships between near-surface air temperature, atmospheric moisture, and ET. The present diurnal and seasonal variations in UDI were delineated in detail to explicate the patterns and interconnections of local urban climate and surface ecohydrological processes, which are critical for ecosystem services in urban landscape design.

Origin of the Nordic Indo-European Group in the Light of the Latest Paleogenetics Data

The subject of the article is ethnogenesis of the Balto-Slavic-Germanic&#x0D; group of the Indo-European language family. The article analyzes data on the&#x0D; genetic composition of the population of the Corded Ware cultures in Central&#x0D; Europe and the Northern Circle cultures in Jutland and Southern Scandinavia.&#x0D; The study aims to determine the primary habitat of the Nordic Indo-Europeans in&#x0D; the period preceding the disintegration of dialectal unity and the beginning of&#x0D; their migrations to Central Europe. The methodology is based on comparative&#x0D; and cluster analysis of mitochondrial components in the studied populations and&#x0D; their synchronous or diachronic occurrence in other populations and areas. The&#x0D; analysis results are verified by the data of archeology, anthropology and glotto-&#x0D; chronology according to the principle of mutual convergence.&#x0D; In the course of the study, we have established that the substrate of Corded&#x0D; Ware cultures lived in the middle reaches of the Dnieper since the Neolithic pe-&#x0D; riod, at the same time, it is possible to localize the Nordic Indo-Europeans in the&#x0D; indicated region as a single and undivided dialect group not earlier than the&#x0D; emergence of the Middle Dnieper variant of the Yamnaya culture, for which the&#x0D; chronological framework is determined. It was also found that the influx of mito-&#x0D; chondrial genes from the eastern regions of the Yamnaya culture into the habitat&#x0D; of the Nordic Indo-Europeans was quantitatively insignificant and did not entail&#x0D; a qualitative change in culture and language.

An exceedingly rare simultaneous incidental occurrence of synchronous primary malignancies; Invasive Ductal Carcinoma and Renal Cell Carcinoma in a male - A Case Report.

Introduction and importanceSynchronous malignancies are defined as the emergence of one or more tumors which either occur simultaneously or within 6 months of each other. Populations older than 50 years of age are the most vulnerable. Documented prevalence rates of synchronous neoplasia are 4.5–11.7 %. To the best of our knowledge, ours is the first documented case of synchronous primary incidental occurrence of Invasive Ductal Carcinoma (IDC) and Renal Cell Carcinoma (RCC) in a Middle Eastern male. This type of co-occurrence must be borne in mind because such neoplastic occurrence is potentially fatal. Documentation is essential to raise awareness and to decrease the resultant morbidity and mortality.Case presentationWe present a case of a 61-year-old male who presented to our clinic with a 22-day-history of gradual, painless, and disproportionate hypertrophy of his left breast. CT scan revealed incidental breast and right kidney masses. Therapeutic intervention included a modified radical mastectomy with Sentinel lymph node excision along with right radical nephrectomy.Clinical discussionTreatment of our patient was multimodal. Accurate radiological studying together with clinical examination helped us in making a diagnosis. Treatment options for this pathology consist of a combination of surgery and/or adjuvant therapy.ConclusionSynchronous IDC and RCC are an extremely rare co-occurrence, especially in males, particularly Middle Eastern males, and more specifically, those presenting asymptomatically as incidental findings. It is vital to further document and study such cases to establish innovative surgical techniques, screening modalities for males, and to overcome the consequential morbidity and mortality.

Synchronous occurrence of different polyp types during colonoscopy.

The general probabilities of finding different types of hyperplastic or neoplastic colon lesions clustering in the same patient are unknown. We hypothesised that a systematic analysis of polyp clustering would reveal a high frequency of different concurrent types and that such clustering would be influenced by the underlying histopathology of the individual polyps. Using an electronic database of histopathologic records, a cross-sectional study of 2,910,174 colonoscopies evaluated the concordant occurrence of hyperplastic and neoplastic mucosal lesions. Amongst patients harbouring any colon polyp, one can expect to find another histopathologic type in about 22%. Being the most prevalent type of polyp, tubular adenoma was the most common type of colonic polyp to be associated with other lesions. For instance, 31% of all colonoscopies with sessile serrated adenomas or hyperplastic polyps also revealed tubular adenomas. Hyperplastic polyp, the second most prevalent type of colonic polyp, was also the second most common type of polyp to be found associated with other types of neoplasia. For instance, 25% of all colonoscopies with sessile serrated adenomas and 31% of those with tubular adenomas also revealed hyperplastic polyps. Different types of colon polyps commonly coincide in individual patients. The present set of data from a large nationwide database may provide guidance for the endoscopist of what variety in colon polyps to expect during colonoscopy.

Synchronous occurrence of intrahepatic, intraductal cholangiocarcinoma and rectal cancer

Liver metastasis from colorectal cancer is a common finding, but synchronous occurrence of intrahepatic cholangiocarcinoma (ICC) and colorectal cancer is extremely rare. We report a case of a 68-year-old man, diagnosed with rectal cancer and in whom, the staging CT scan showed a hepatic metastasis with intra-ductal hilar lesion. Biopsy of the hepatic lesion revealed an infiltrating cholangiocarcinoma. And the final diagnosis was a klatskin tumor coinciding with a rectal carcinoma. The possibility of multiple primary cancers should always be suspected in every oncologic patient even if the cancer is known to have metastatic lesions.

Climate-driven dinoflagellate cyst stratigraphy of the Oligocene-lower Miocene turbidite succession of the Lower Congo Basin (offshore NW Angola)

Biostratigraphic studies of cuttings from wells located in the Lower Congo Basin, offshore northwestern Angola, document with unprecedented wealth of data the organic-walled dinoflagellate cyst (dinocyst) assemblages of the Malembo Formation. The identification of a series of dinocyst events (highest and lowest occurrences, influxes and acmes) recurring in the same stratigraphic position in different wells and cross-calibrated by calcareous nannofossil data, provides a tool for age control and correlation of the Oligocene and lower Miocene in the equatorial and South Atlantic region.Proceeding downwards in the stratigraphy of the examined succession, the lowest occurrence of Pyxidinopsis pastilliformis, detected within the CN3 nannofossil Zone, approximates the Langhian-Burdigalian boundary, whereas the lowest occurrences of Sumatradinuim druggii and Sumatradinium hispidum occur at the base of the CN2 nannofossil Zone in the Burdigalian. The lowest occurrences of Sumatradinium soucouyantiae and Barssidinium taxandrianum fall within the Zone of acme of Hystrichokolpoma rigaudiae at the Burdigalian-Aquitanian transition, and immediately above the acmes of Cribroperidinium tenuitabulatum and Systematophora-Cleistosphaeridium group that are supposed to reflect climate cooling pulse Mi-1a. The presence of Chiropteridium spp. and Membranophoridium aspinatum is limited to the upper part of the Chattian. An influx of Tuberculodinium vancampoae, possibly related to a warmer interlude during a period of overall climate cooling, occurs in proximity of the Chattian-Rupelian boundary. The nearly synchronous highest occurrences of Gerdiocysta conopeum, Eocladopyxis peniculata and Heterosphaeridium sp. provide a robust infra-Rupelian biohorizon. Further down in the Rupelian, the influxes of Pentadinium laticinctutm and Distatodinium paradoxum are interpreted as responses to cooling pulses. The lowest occurrence of G. conopeum, detected in the basal part of the NP23 nannofossil Zone, corresponds to the global first appearance of this excellent Rupelian marker. Genera Deflandrea and Wetzeliella are noticeably missing in the studied material just as they lack in some coeval dinocyst assemblages reported in the literature from low paleolatitude Atlantic sections.The recorded alternation of influxes and acmes of Gonyaulacoid dinocyst taxa indicative of cooler and warmer water conditions was probably climate-driven, i.e. paced by cooling pulses and relatively warmer interludes characterizing the climate evolution during the Oligocene and early Miocene. Indeed, the lack of acmes of Peridinioid cysts suggests that climate, rather than constantly elevated nutrient levels ensured by the Congo River discharge, was the discriminant factor triggering the observed blooms of Gonyaulacoid cyst-forming taxa.The delivery of large volumes of sands into deepwater settings via gravity-driven fluxes was favored by sea-level drops and is ultimately associated with pulses of climate cooling and Antarctic ice-sheet growth, finally reflected by the composition of the dinocyst assemblages. In addition to paleoecological factors, hydraulic fractionation resulting from sedimentary processes that transported palynomorphs down the slope as part of turbidite fluxes, contributed to shape the palynological assemblages observed in this study.

Swarmalators under competitive time-varying phase interactions

Swarmalators are entities with the simultaneous presence of swarming and synchronization that reveal emergent collective behavior due to the fascinating bidirectional interplay between phase and spatial dynamics. Although different coupling topologies have already been considered, here we introduce time-varying competitive phase interaction among swarmalators where the underlying connectivity for attractive and repulsive coupling varies depending on the vision (sensing) radius. Apart from investigating some fundamental properties like conservation of center of position and collision avoidance, we also scrutinize the cases of extreme limits of vision radius. The concurrence of attractive–repulsive competitive phase coupling allows the exploration of diverse asymptotic states, like static π, and mixed phase wave states, and we explore the feasible routes of those states through a detailed numerical analysis. In sole presence of attractive local coupling, we reveal the occurrence of static cluster synchronization where the number of clusters depends crucially on the initial distribution of positions and phases of each swarmalator. In addition, we analytically calculate the sufficient condition for the emergence of the static synchronization state. We further report the appearance of the static ring phase wave state and evaluate its radius theoretically. Finally, we validate our findings using Stuart–Landau oscillators to describe the phase dynamics of swarmalators subject to attractive local coupling.

Temporal changes in the histology of microscopic colitis.

In a subgroup of patients with microscopic colitis [MC], its histopathology changed from lymphocytic [LC] to collagenous colitis [CC] and vice versa. Previous studies have also observed histopathological transitions between MC and inflammatory bowel disease [IBD]. The aim of the present study was to analyse the prevalence of such transitions in a large population of MC patients. The Inform Diagnostics database is an electronic repository of histopathology records of patients distributed throughout the USA. In a cross-sectional study, we analysed the prevalence of changes in MC histology. Each prevalence was expressed as the rate per 100 MC patients with its 95% Poisson confidence interval. In a total population of 29 307 MC patients, our cross-sectional study focused on a subgroup of 4363 patients who underwent two or more consecutive colonoscopies between December 2008 and March 2020. Overall, 1.6% [95% CI 1.2-2.0%] of patients changed their MC phenotype from LC to CC, and 0.5% [0.3-0.7%] from CC to LC. Of 4363 MC patients, 414 [9.5%] were also diagnosed with IBD. In 2.9% [2.4-3.5%], MC and IBD were diagnosed as synchronous mucosal lesions. In 2.1% [1.7-2.6%], MC changed to IBD, and in 4.5% [3.9-5.2%] IBD changed to MC. The analysis confirmed the synchronous occurrence of MC and IBD and transitions between the two diagnoses. In patients who fail therapy for either one of the two diseases, the gastroenterologist should search for changes in the underlying phenotype as a possible explanation.

Formation conditions and geological structure of the Yenisei-Khatanga regional through

A comprehensive analysis of geophysical data was carried out and a model of the deep structure of the Yenisei–Khatanga regional trough was constructed. A distinct platform appearance of the Neoproterozoic-Paleozoic sediments, the synchronous occurrence of ancient and Mesozoic sedimentary complexes in the axial most submerged part of the Yenisei–Khatanga linear depression. A wide territorial distribution of trap magmatism was revealed, which is not localized in the linear structure of the trough. It is concluded that the formation of the Yenisei-Khatanga regional trough is not associated with the Late Permian–Early Triassic rifting.

Synchronous occurrence of papillary thyroid microcarcinoma, medullary thyroid carcinoma and Hashimoto thyroiditis in a single thyroid: A case report with literature review.

IntroductionThe synchronous development of a medullary and papillary carcinoma as two different tumors has only been reported very rarely. The aim of the current report is to describe an extremely rare occurrence of medullary carcinoma, papillary microcarcinoma, and Hashimoto thyroiditis.Case reportA 53-year-old man presented with a right-sided neck mass. Ultrasound showed a well-defined nodule in the right mid third with microcalcification and increased nodular vascularity associated with multiple right-sided cervical lymphadenopathy. The histopathological examination showed multifocal medullary carcinoma with incidental finding of unifocal papillary microcarcinoma conventional type on the left side. Additional pathology of Hashimoto thyroiditis with a small intra-thyroidal parathyroid gland in the left thyroid gland. The procedure went perfectly and the patient was discharged home without any difficulties.DiscussionSynchronous existence of these two neoplasms can occur in two forms: distinct medullary carcinoma and papillary carcinoma isolated by normal thyroid tissue, or mixed medullary and follicular-derived thyroid carcinoma, in which single or multiple lesions show morphology and immunoreactivity for both medullary carcinoma and follicular-derived carcinoma.ConclusionThe synchronous coexistence of papillary microcarcinoma, medullary carcinoma, and Hashimoto's thyroiditis is an uncommon thyroid condition.

A synchronous medullary and papillary thyroid carcinoma

&lt;p&gt;The synchronous occurrence of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) is rare (&amp;lt;1%). The medullary component determines the prognosis. A 31-year-old female with no relevant personal or family cancer history presented with swelling on the right side of the neck. A fine-needle aspiration biopsy was positive for MTC and PTC. Mass sequencing of 322 genes associated with cancer came back negative. The histopathological examination revealed synchronous MTC and PTC with thymic and bilateral lymph node metastasis. The patient underwent total thyroidectomy with bilateral radical neck dissection (II-V), central dissection, and mediastinal dissection including the thymus. The extent of surgery is determined by MTC and the analysis of RET and BRAF mutations. Post-operative treatment must include monitoring for specific markers (calcitonin and thyroglobulin, respectively, for MTC and PTC). Based on histopathological results and recurrent PTC, TSH suppression and iodine-131 therapy should be considered. Recurrent MTC must be treated with new targeted therapies.&lt;/p&gt;

Binding events through the mutual synchronization of spintronic nano-neurons

The brain naturally binds events from different sources in unique concepts. It is hypothesized that this process occurs through the transient mutual synchronization of neurons located in different regions of the brain when the stimulus is presented. This mechanism of ‘binding through synchronization’ can be directly implemented in neural networks composed of coupled oscillators. To do so, the oscillators must be able to mutually synchronize for the range of inputs corresponding to a single class, and otherwise remain desynchronized. Here we show that the outstanding ability of spintronic nano-oscillators to mutually synchronize and the possibility to precisely control the occurrence of mutual synchronization by tuning the oscillator frequencies over wide ranges allows pattern recognition. We demonstrate experimentally on a simple task that three spintronic nano-oscillators can bind consecutive events and thus recognize and distinguish temporal sequences. This work is a step forward in the construction of neural networks that exploit the non-linear dynamic properties of their components to perform brain-inspired computations.

Investigation on the by-pass line orifice plate assisted hydrodynamic cavitation (B-PLOPA HC) degradation of basic fuchsin (BF) in wastewater

HC technology has been widely used in the field of wastewater treatment due to its advantages of simple operation, low operating cost and large treatment capacity. However, the conventional HC devices that rely solely on the main line cavitator to treat organic pollutants show unsatisfactory degradation effect. Therefore, it is difficult to enhance the degradation effect of organic pollutants only by optimizing the cavitator geometry and experimental operation parameters. In fact, for traditional HC device the pressure in front of the throttle valve in the by-pass line is same as the inlet pressure of the main line cavitator. In this study, the orifice plate cavitator is firstly used to replace the throttle valve in the by-pass line of the traditional HC device to form a by-pass line orifice plate assisted hydrodynamic cavitation (B-PLOPA HC) device after optimizing the cavitator geometry and experimental operation parameters, realizing the synchronous occurrence of HC effects in the main and by-pass line cavitator and greatly enhancing the degradation effect of organic pollutants. A triphenylmethane dye, basic fuchsin, is used as the simulated pollutant to carry the degradation experiment by using an improved HC device. It was found that, under inlet pressures of 3.0, 4.0 and 5.0 bar within 90 min, the degradation ratios of basic fuchsin were increased from 59.72 %, 73.60 % and 65.23 % by using conventional HC device to 80.93 %, 81.15 % and 81.38 % by using B-PLOPA HC device, respectively. Correspondingly, the wastewater treatment costs were reduced by 41.82 %, 26.16 % and 29.87 %, respectively, compared with those before modification. Obviously, such modification not only enhances the degradation effect of organic pollutants, but also reduces the cost of wastewater treatment. Besides, the active substances generated in B-PLOPA HC system were explored by adding free radical trapping agent. According to the determined results from Liquid Chromatograph Mass Spectrometer (LC-MS) and Total Organic Carbon (TOC), the possible degradation path of basic fuchsin is proposed. In a word, the overall HC effect of system is effectively strengthened through the use of the by-pass line orifice plate. This study provides a solid theoretical basis for large-scale application of HC technology in the field of wastewater treatment.© 2021 Elsevier Ltd. All rights reserved.

An overset mesh approach for a vibrating cylinder in uniform flow

Abstract This paper has numerically investigated twodimensional laminar flow over a vibrating circular cylinder. Numerical simulation is performed using the dynamic overset mesh method available in commercial software ANSYS FLUENT 19.0. A simple harmonic motion is applied to simulate the cylinder vibration using the user-defined function (UDF) tool in FLUENT. To examine the accuracy and the capability of the present overset mesh approach, two test types of cylinder vibration are simulated: crossflow and inline vibrations. All simulations are performed at a constant Reynolds number (Re = 100) to predict the occurrence of synchronization or lock-in phenomenon. For the case of crossflow vibration, it is observed that lock-in occurs with cylinder oscillation frequency near the Strouhal frequency of the fixed cylinder. However, for the inline vibration, lockin occurs near twice the Strouhal frequency of the fixed cylinder. Furthermore, in the case of crossflow oscillation, the frequency content in the lift coefficients’ time history is successfully linked to the phase portraits’ shape and the vorticity field. The simulation results are consistent with the available published data in the literature. This indicates that the present numerical technique is valid and capable of modeling flows with moving structural systems.