bluuebunny/crossref_metadata_2025 huggingface dataset:
Exercise-Based Dysphagia Treatment: A Proposed Checklist
Authors: Yee Joanne , Smaoui Sana , Rogus-Pulia Nicole ,   on behalf of the FRONTIERS Collaborative
Published: August 2024

Purpose:

Oropharyngeal swallowing exercise-based interventions are frequently utilized to target physiologic mechanisms with the goal of improving swallowing function. However, study replicability and evidence synthesis regarding effects of interventions are limited due to inconsistent reporting on factors known to influence treatment delivery. In order to promote consistency of reporting factors associated with replicability, the authors constructed a set of preferred parameters focused on dysphagia as part of the initial version of the larger tool (Framework for RigOr aNd Transparency In REseaRch on Swallowing or FRONTIERS).

Method:

Thirty-eight initial questions were assembled by the authors as part of the treatment subsection. Questions were then reviewed by individuals in the FRONTIERS collaborative who have expertise in research, clinical practice, or both.

Result:

Twenty-four questions were removed following review, reducing the final set of treatment-focused questions to 14 questions.

Conclusions:

The revised set of questions provides users of the exercise-based treatment section of the FRONTIERS checklist with an initial checklist to promote transparency and rigor to improve study replicability and evidence synthesis. We intend for this treatment section of FRONTIERS to undergo further refinement following commentary and feedback.
Participant Characteristics for Dysphagia Research: A Proposed Checklist
Authors: Werden Abrams Sophia , Kurosu Atsuko , Namasivayam-Macdonald Ashwini ,   on behalf of the FRONTIERS Collaborative
Published: August 2024

Purpose:

Participant characteristics are underreported; however, they impact swallowing impairments and subsequent access to assessment and intervention. Standards for rigorous and transparent reporting of dysphagia research are required. The Framework for RigOr aNd Transparency In REseaRch on Swallowing (FRONTIERS) offers a critical appraisal tool for dysphagia research. This article outlines questions for participant characteristics in dysphagia research as part of the larger FRONTIERS tool.

Method:

An exploratory literature review was conducted to determine how participant characteristics, eligibility criteria, and definitions of health and dysphagia are reported in the literature. Findings were cross-referenced with other relevant critical appraisal tools. A list of questions was generated and refined iteratively with the entire FRONTIERS collaborative until consensus was met.

Results:

The participant characteristics portion of the FRONTIERS tool includes eight questions and 16 possible subquestions. Examples for how the tool might be used, as well as rationales for inclusion of all questions, are included.

Conclusions:

Including detailed characteristics of research participants may support understanding of how best to serve marginalized and underrepresented populations more effectively. Critical appraisal tools, such as FRONTIERS, may help to improve the rigor and transparency in dysphagia research, ultimately improving patient care.
A Proposed Framework for Rigor and Transparency in Dysphagia Research: Prologue
Authors: Rogus-Pulia Nicole , Affoo Rebecca , Namasivayam-MacDonald Ashwini , Noad Brandon , Steele Catriona M. ,   on behalf of FRONTIERS Collaborative
Published: August 2024

Purpose:

Scientific transparency and rigor are essential for the successful translation of knowledge in clinical research. However, the field of oropharyngeal dysphagia research lacks guidelines for methodological design and reporting, hindering accurate interpretation and replication. This article introduces the Framework for RigOr aNd Transparency In REseaRch on Swallowing (FRONTIERS), a new critical appraisal tool intended to support optimal study design and results reporting. The purpose of introducing FRONTIERS at this early phase is to invite pilot use of the tool and open commentary.

Methods:

FRONTIERS was developed by collaborating researchers and trainees from six international dysphagia research labs. Eight domains were identified, related to study design, swallowing assessment methods, and oropharyngeal dysphagia intervention reporting. Small groups generated questions capturing rigor and transparency for each domain, based on examples from the literature. An iterative consensus process informed the refinement and organization of primary and subquestions, culminating in the current initial version of FRONTIERS.

Results:

FRONTIERS is a novel tool, intended for use by oropharyngeal dysphagia researchers and research consumers across disciplines. A web application enables provisional use of the tool, and an accompanying survey solicits feedback regarding the framework.

Conclusion:

FRONTIERS seeks to foster rigor and transparency in the design and reporting of oropharyngeal dysphagia research. We encourage provisional use and invite user feedback. A future expert consensus review is planned to incorporate feedback. By promoting scientific rigor and transparency, we hope that FRONTIERS will support evidence-based practice and contribute to improved health outcomes for individuals with oropharyngeal dysphagia.
Experiences of Acquired Brain Injury as Expressed Through Mask-Making: A Qualitative Analysis
Authors: Gregory Sarah Kaytlyn , Kemp Amy M.
Published: August 2024

Purpose:

Acquired brain injury (ABI) extends beyond the immediate aftermath, and understanding individual experience of ABI is paramount to providing effective support mechanisms. This study examined how people with ABI used mask-making to engage in self-expression.

Method:

Publicly available data from the Unmasking Brain Injury Project website, an advocacy group for people with ABI, were analyzed. A qualitative approach with hybrid inductive/deductive analysis was used to explore how people with ABI use art to express their emotional experiences of ABI.

Results:

In total, 1,049 masks had narratives describing the visual components and meaning in the associated masks. Three major themes emerged: the multiplicity of experiences after ABI, including positive, negative, and mixed outcomes; the expression of emotional pain and living with loss through art; and the importance of positivity, purpose, and faith in the experience with ABI.
Multiplicity
was the central expression represented in the masks. The most commonly represented emotional experiences were:
emotional pain and living with loss
and
positivity, purpose,
and
faith
. The masks incorporated literal depictions of the ABI, visual metaphors, and intentional use of colors and shapes for self-expression.

Conclusions:

These results support previous findings that emotional experiences after ABI are complex and often interlaced with several emotions. The most prominent feelings include emotional pain and living with loss, and positivity, purpose, and faith. Mask-making may be a particularly appropriate method for people with ABI to process or express emotional experiences, as well as to provide clinicians with visual records of sense of self, coping, or progress.
Patient-Reported Outcome Measures for Swallowing: A Proposed Checklist
Authors: Shapira-Galitz Yael , Anderson Amber , Balou Matina ,   on behalf of the FRONTIERS Collaborative
Published: August 2024

Purpose:

Patient-reported outcome measures (PROMs) are an important tool both in clinical practice and research involving patients with swallowing disorders. There are several challenges to be overcome and methodological details to be adequately reported to ensure rigor and transparency in studies utilizing PROMs in dysphagia research. For this reason, the Framework for RigOr aNd Transparency In REseaRch on Swallowing (FRONTIERS), a critical appraisal tool developed to ensure rigor and transparency in dysphagia research, has devoted a domain to PROMs. The aim of this current article, as part of a larger forum of articles, is to present the PROM section of FRONTIERS and describe its development.

Method:

A literature review was carried out on PROMs in the field of dysphagia by three members of the FRONTIERS collaborative to identify items that were necessary for the rigorous application and transparent reporting of PROMs utilized in research of swallowing disorders in human subjects. Framework items were then subjected to an iterative process of feedback and consensus among the three members of the working group as well as all members of the FRONTIERS collaborative. Items were flagged for review and revised as needed until consensus was achieved on the final list. The final item list was compared to existing critical appraisal tools for PROMs.

Results:

The final checklist for the PROMs domain included 20 “Yes/No” questions that can be broadly divided into three categories: (a) development and validation, (b) patient population, and (c) PROM administration method. Each item is presented with a rationale for its inclusion.

Conclusions:

The use of the FRONTIERS Framework will serve researchers and those appraising quality of research involving PROMs. More broadly, the FRONTIERS Framework will facilitate improved rigor and transparency across dysphagia research. Special considerations and future goals are discussed.
Dimmable constant weight polar‐coded non‐orthogonal multiple access with orthogonal space‐time block coding visible light communication systems
Authors: Babalola Oluwaseyi Paul , Balyan Vipin
Published: August 2024

This study investigates the integration of dimmable constant weight polar‐coded non‐orthogonal multiple access (NOMA) with orthogonal space‐time block coding (OSTBC) in visible light communication (VLC) systems over Nakagami‐ fading environments. The proposed scheme aims to enhance the reliability of VLC systems by reducing the outage probability while accommodating dimming requirements. By allowing multiple users to utilize the same time‐frequency resources and adjust power levels based on individual channel conditions, the system optimizes resource utilization. Additionally, the OSTBC method provides effective communication among multiple users by leveraging transmit diversity to improve system performance. The efficacy of the proposed approach is demonstrated through analytical analysis and Monte Carlo simulations, showcasing superior outage probability performance compared to conventional Alamouti‐STBC schemes.
Improve conservation voltage regulation effects by integrating more distributed renewable generations
Authors: Li Ang , Zhong Jin
Published: August 2024

Due to intermittent renewable energy and fluctuating load demand, distribution networks with renewable distributed generation (DG) installations are more likely to suffer voltage issues and significant power losses. The performance of conservation voltage regulation (CVR) schemes may be adversely affected by the undesirable voltage profile at specific nodes. This paper aims to reduce power losses in CVR‐implemented networks by optimally planning new renewable DGs without changing the existing ones. A scenario‐based optimal renewable DG planning model is proposed with a novel scenario formation method. The uncertainties of load demand and renewables are captured jointly and formed into a finite number of scenarios based on a multivariate Gaussian mixture model (MultiGMM). The locations and capacities of different types of new renewable DGs are optimally planned for CVR performance improvements on power loss saving by aggregating the operation status and probabilities of the scenarios using mixed‐integer non‐linear programming (MINLP). A time‐series simulation is formulated for accuracy verification. The results of case studies show that the proposed model can significantly reduce power losses, active load demand, and reactive load demand. The accuracy of the planning results can be guaranteed with fewer scenarios compared to a widely used classical scenario‐based planning method.
Analysis of hybrid AC/DC transmission system: A Turkey case study
Authors: Karaca Eda , Nuroğlu Fatih Mehmet
Published: August 2024

The need to transmit energy in the most effective way arises in parallel with the demand for energy in developing countries. As the amount of transmitted power increases, transmission lines can become overloaded, causing a blackout. This study aims to increase the transmission capacity without experiencing right‐of‐way problems by converting Turkey's existing high voltage AC systems to hybrid AC/DC systems. With such a design, it is aimed at providing more efficient and continuous transmission by using the high‐voltage DC system's low‐loss feature at long distances. Using the 400 kV double circuit line structure, the existing electricity transmission system is modelled using real data in the DigSILENT PowerFactory. The electromagnetic fields that will occur due to the use of AC and DC circuits on the same tower in such a transformation situation are analysed with FEMM 4.2, based on the finite element method. The compliance of the electromagnetic fields that will occur with the use of hybrid 400 kV AC and 500 kV DC was determined in the study. In addition, according to the simulation results, it is predicted that in the case of hybrid AC/DC transmission, the current transmission capacity would increase and the losses would decrease.
Research on the optimal operation of a prosumer micro energy network centred on data centres
Authors: Zhang Yuanshi , Ge Yiwu , Wang Shunjiang , Pan Weiqi , Feng Yiwen , Qiu Peng
Published: August 2024

As the share of intermittent and fluctuating renewable energy sources in the power system continues to increase, demand‐side resources must be utilized to enhance the real‐time balance of power generation and supply. Data centres, as typical energy‐intensive loads with bidirectional supply and demand characteristics, are crucial demand‐side resources. However, their operation is complex, making reliable regulation difficult. This paper establishes a refined process‐level load model for data centres by considering the temporal and spatial shifting characteristics of computational loads, effectively reflecting the intricate interactions between these loads and servers. Based on this model, a micro‐energy network is constructed that integrates renewable energy access and waste heat recovery from the data centre. This network also participates in carbon emission trading and green electricity certificate trading markets, applying an interaction mechanism. By considering data interaction and power sharing among multiple micro‐energy networks, the alternating direction method of multipliers algorithm is used to solve the system‐distributed optimization problem in two stages. This approach results in an optimal energy management scheme that simultaneously reduces total operation costs and carbon emissions.
Ergodic properties of subcritical multitype Galton–Watson processes with immigration
Authors: Szűcs Gábor
Published: August 2024

In the paper ergodic properties of multitype Galton–Watson processes are investigated in the subcritical case without further regularity assumptions. Sufficient and necessary conditions for the existence of the stationary distribution and its moments are provided. Under moment conditions geometric ergodicity and rate of converge for the moments of the process are proved. Geometric properties of the Markovian class structure are also studied.
Preferred input-output analysis using inverse DEA: an application to retailer performance assessment
Authors: Ghiyasi Mojtaba , Soltanifar Mehdi , Sharafi Hamid
Published: August 2024

Inverse data envelopment analysis (DEA) approach deals with the input or output estimation preserving relative efficiency score. In many real-world applications, there is more prior information like price information or managerial preferences, etc. that should be considered in the efficiency analysis. Corporation of this sort of information is not dealt with in the inverse DEA literature, not in the input estimation process nor in the output estimation. Thus, the current paper develops a new inverse DEA model capable of dealing with prior information via weight restrictions. Proposed models are applied in the efficiency and inverse efficiency analysis of a real-world retailer application.
On multiobjective fractional programs with vanishing constraints
Authors: Laha Vivek , Singh Harsh Narayan , Mohapatra Ram
Published: August 2024

The aim of this article is to combine the study of fractional programming and mathematical programs with vanishing constraints for the first time in literature. This paper deals with multiobjective fractional programs with vanishing constraints (MFPVC) involving continuously differentiable functions. Necessary and sufficient optimality conditions are derived for a feasible point to be an efficient (or local efficient) solution of the (MFPVC). A parametric dual model has been formulated and duality results are established with the primal (MFPVC).
Intraoperative Germinoma Staining: A Technical Note
Authors: Naydenov Emanuil , Karazapryanov Petar , Pavlov Velislav , Metodiev Dimitar , Minkin Krasimir
Published: August 2024

As the main treatment modality of central neural system germinomas is radiotherapy and/or chemotherapy, the exact initial diagnosis of the disease is crucial. Depending on the different national protocols, histologic verification can be obligatory in some instances. This is a serious challenge, taking into account the usual location and nonspecific macroscopic appearance of these lesions. Here, we propose a safe and effective method of intraoperative tumor enhancement that can increase the confidence of the surgeon during the intervention.
Vertebral Endplate Cavities with Titanium Cages in Posterior Lumbar Interbody Fusion
Authors: Elfiky Tarek , El Mansy Yaser , Stienen Martin N. , Alabsi Abdelrahman Sa'ed , Nafady Mahmoud
Published: August 2024

Background Vertebral endplate cavities (VECs) have been reported with the use of titanium (Ti) cages. Only few articles have recently demonstrated unfavorable radiographic changes in the form of cysts or cavities, which may predispose to nonunion.

Methods The aim was to assess the prevalence of VEC in posterior lumbar interbody fusion (PLIF) using Ti cages and to estimate their impact on fusion. The term “cavity” was used to describe the endplate changes. Computed tomography (CT) analysis of the VECs and fusion status following PLIFs with Ti cages was conducted by two observers. VECs were assessed according to the size, multiplicity, location, and presence of sclerosis.

Results Forty-two consecutive patients with surgeries conducted on 52 levels were enrolled. There were 20 males and 22 females. The mean age was 43.6 ± 10.89 years. The mean follow-up was 20.85 ± 8.49 months. Definite union was seen in 48 levels (92.3%) by observer 1 and in 40 levels (76.9%) by observer 2. The strength of agreement was moderate. The presence of VEC was observed in 9 levels (17.3%) by observer 1 and in 12 levels (23.1%) by observer 2. The strength of agreement was moderate. The majority of VECs in the endplates were less than 5 mm. The strength of agreement was high. The strength of agreement for location and multiplicity were moderate. The VEC was significantly correlated with the fusion status.

Conclusions Our study confirmed that VECs were observed following Ti cage placement after PLIF procedures. They tend to be small and might be associated with nonunion. Furthermore, it reflected the limited inter-rater reliability of the assessment of both the fusion status and VEC morphology after Ti PLIF cage placement.
Standard Operating Procedures Ex Utero Intrapartum Therapy (EXIT)
Authors: Dadhwal Vatsla , Sahay Neha , Sharma K. Aparna
Published: August 2024

EXIT, or Ex Utero Intrapartum Treatment, is a sophisticated technique designed to ensure a safe and effective transition for a fetus from the womb to the outside world while maintaining essential placental support. The applications of the EXIT approach are continually expanding and encompass various scenarios like facilitating airway access, conducting surgical resections, implementing extracorporeal membrane oxygenation (ECMO), and aiding in the separation of conjoined twins.

The method involves carefully planned delivery of fetus through hysterotomy, all the while keeping the uterus relaxed and ensuring placental assistance. This approach allows for the gradual establishment of neonatal cardiopulmonary stability in a controlled manner. The range of fetal interventions during the EXIT procedure is diverse, including tasks such as endotracheal intubation, tracheostomy, mass excision, removal of temporary tracheal devices, and ECMO.

A pivotal factor in the success of an EXIT procedure is the formation of a highly skilled and collaborative multidisciplinary team. This team, equipped with broad expertise in fetal intervention, works seamlessly across the stages of pre-, intra-, and postpartum care, ensuring the best possible outcomes for the mother and the newborn.
The Effectiveness of Botulinum Toxin Injections to the Extremities in the Pediatric Population with Severe Cerebral Palsy: A Systematic Review
Authors: Sala Debra A. , del Rosario Eduardo
Published: August 2024

The purpose of this review was to examine the effectiveness of botulinum toxin injections to the upper and lower extremities reported in studies of pediatric participants with severe cerebral palsy on improving ease of care, pain, and motor function. PubMed, CINAHL, and Web of Science were searched using combinations of cerebral palsy and various types and abbreviations of botulinum toxin. Additionally, reference lists and citations of reviewed studies were searched. The results of 25 studies were reviewed: three randomized controlled trials (RCTs) and 22 nonrandomized studies of interventions involving only a botulinum toxin-treated group. Seven studies focused solely on the targeted population while the remainder included participants of a wider range of severity. Ease of care was generally reported as improved. The effect on pain was variable: postoperative pain was significantly reduced in one RCT but not in another; nonspecific pain was improved in some cases; and joint specific pain was decreased in one study. Motor function changes were the most frequently evaluated in the studies without a comparison group; however, only a few used standardized assessment tools, e.g., Gross Motor Function Measure, and found pre- to postinjection improvement. The described findings need to be viewed cautiously due to the low level of rigorousness of most of the reviewed studies.
Incompatibility of Lacrimal Syringing Test with Dacryoscintigraphy in Patients Undergoing Successful Dacryocystorhinostomy Surgery
Authors: Yazicioglu Titap , Sarı Elif , Kesim Selin
Published: August 2024

Purpose The aim of our study was to evaluate the compatibility of lacrimal syringe test with dacryoscintigraphy (DSG) in the postoperative evaluation of external dacryocystorhinostomy (Ext-DCR) surgery.

Material and Methods Thirty eyes of 30 patients suffering from unilateral epiphora with discharge and showing complete obstruction on lacrimal irrigation test were included in the study. Patients with dysfunctional lacrimal pump function, revision surgery, partial obstruction, and ocular surface diseases were not included in the study.

Verification of the nasolacrimal duct obstruction (NLDO) was achieved with dye disappearance test, Jones test 1 (JT 1), and JT 2. According to the type of obstruction seen on DSG, patients were classified into two groups: presac and postsac obstruction. Patients with complete obstruction detected in the lacrimal syringing and dynamic scintigraphy underwent Ext-DCR, and the results were evaluated.

Results Thirty patients, mean age 58.93 ± 12.11 years, all with unilateral NLDO were included in the study. All had grade 5 Munk score epiphora and discharge. The mean duration of obstruction was 24.57 ± 10.65 months. In the lacrimal irrigation test, all patients had complete obstruction in one eye, while the other eye was normal. According to preoperative DSG results, there were 20 (66.7%) patients with presac delay and 10 (33.3%) patients with postsac delay. All patients underwent Ext-DCR with silicone tube intubation and were followed for 1 year. Although there was symptomatic improvement in all patients and the lacrimal syringing test was patent, no change was seen in scintigraphy.

Conclusion Although DSG is a sensitive nuclear medicine method, it is not useful for predicting the functional success of the Ext-DSR.
Medial Sural Artery Islanded Pedicled Perforator Flap for Resurfacing Areas in the Popliteal Fossa Following Postburn Contracture Release Using Normal versus Scar Tissue
Authors: Giri Sanjay Kumar , Suba Santanu , Bandyopadhyay Ahana , Sahu R. K. , Kanungo Aparna , Minz Reena
Published: August 2024

Background The medial sural artery perforator (MSAP) flap is reliable in resurfacing defects of the popliteal fossa. There is possibility of resurfacing the popliteal fossa defects after postburn contracture release with scarred MSAP flaps with good overall long-term outcomes.

Materials and Methods A study was conducted from June 2017 to July 2023 to evaluate the functional and surgical scar aesthetic outcome in patients with soft-tissue defects in the popliteal fossa after postburn contracture release that were reconstructed using scarred and unscarred MSAP flap with 10 patients in each group.

Results The clinical outcome was assessed in terms of the perioperative and late postoperative complications, range of motion of the knee joint along with surgical scar outcome using the Patient and Observer Scar Assessment Scale (POSAS). The functional results in the scar tissue flap group were comparable with those in the normal tissue flap group, but the aesthetic outcome of surgical scar was found to be better in the normal tissue flap group.

Conclusion The MSAP flap provides ideal tissue for soft-tissue reconstruction with minimal donor site morbidity for popliteal fossa defects after postburn contracture release in both the scarred and unscarred flap groups.
Assessment and Prognostic Resources for Gross Motor Development in a Child with Cerebral Palsy Related to Congenital Zika Syndrome
Authors: Ventura Paloma A. , Carvalho Alessandra L. de , Nascimento-Carvalho Cristiana M.
Published: August 2024

This article describes how the Gross Motor Ability Estimator (GMAE) software can provide important information based on the Gross Motor Function Measure (GMFM)-66 score of a child with congenital Zika syndrome.

A child was assessed at 9, 17, and 25 months of age through the GMFM-66. At 2 years, the child's gross motor ability was estimated and classified according to the Gross Motor Function Classification System (GMFCS).

At 2 years of age, the child in this case required assistance to roll and was unable to maintain antigravity trunk posture in sitting position, typical abilities of GMFCS level V.

GMAE can be useful to guide health professionals that care for children with lifelong physical and developmental care needs. This is the first study that demonstrated how to use the GMAE in this specific population.
Pancreatic Arteriovenous Malformation Presenting with Upper Gastrointestinal Bleeding: Treatment with Transarterial Embolization—A Case Report
Authors: Vignesh S. , K.V Abdulla , K.P Haris , Vasudevan Satheesh , Balan Athulya
Published: August 2024

Pancreatic arteriovenous malformations (AVMs) are a rare entity among visceral AVMs and less common cause of gastrointestinal bleeding. We report a case of pancreatic AVM in a 45-year-old man who presented with upper gastrointestinal bleeding and duodenal ulcers, and was hemodynamically unstable. Ultrasound and computed tomography (CT) of the abdomen showed multiple dilated arterial channels in the head region of the pancreas, arising from the gastroduodenal artery, with early filling of the portal vein, suggestive of an AVM. Transarterial embolization was performed by selectively embolizing the arterial feeders using poly-vinyl alcohol (PVA) particles. Postembolization, obliteration of the AVM was seen. On follow-up 2 months later, the patient was clinically stable.
Past, present, and future of hybrid plasmonic waveguides for photonics integrated circuits
Authors: Sharma Tarun , Zhang Zunyue , Wang Jiaqi , Cheng Zhenzhou , Yu Kyoungsik
Published: August 2024

This article addresses the past, present, and future status of hybrid plasmonic waveguides (HPWs). It presents a comprehensive review of HPW-based photonic integrated circuits (PICs), covering both passive and active devices, as well as potential application of on-chip HPW-based devices. HPW-based integrated circuits (HPWICs) are compatible with complementary metal oxide semiconductor technology, and their matched refractive indices enables the adaptation of existing fabrication processes for silicon-on-insulator designs. HPWs combine plasmonic and photonic waveguide components to provide strong confinement with longer propagation length Lp of HP modes with nominal losses. These HPWs are able to make a trade-off between low loss and longer Lp, which is not possible with independent plasmonic and photonic waveguide components owing to their inability to simultaneously achieve low propagation loss with rapid and effective all-optical functionality. With HPWs, it is possible to overcome challenges such as high Ohmic losses and enhance the functional performance of PICs through the use of multiple discrete components. HPWs have been employed not only to guide transverse magnetic modes but also for optical beam manipulation, wireless optical communication, filtering, computation, sensing of bending, optical signal emission, and splitting. They also have the potential to play a pivotal role in optical communication systems for quantum computing and within data centers. At present, HPW-based PICs are poised to transform wireless chip-to-chip communication, a number of areas of biomedical science, machine learning, and artificial intelligence, as well as enabling the creation of densely integrated circuits and highly compact photonic devices.
Active chiral flows in the separating wall during cell division
Authors: Ganguly Vijit , Chatterjee Mainak , Sain Anirban
Published: August 2024

Material flow in the actomyosin cortex of a cell, during cell division, has been found to be chiral in nature. It has been attributed to active chiral torques generated in the actomyosin cortex. Here, we explore the possible signature of such chirality during the growth of the intra-cellular membrane partition, which physically divides the cell into two compartments. We use standard hydrodynamic theory of active gel to predict possible chiral flow structures in the growing partition. While the flows in the growing annular-shaped membrane partition is believed to be radial, it can also develop non-zero azimuthal velocity components (rotation) due to chirality. We show that the direction of rotation (clock or anti-clockwise) will not solely be decided by the sign of the active chiral torque but also by the relative strengths of rotational viscosity and flow coupling parameter.
Equation of state for boron nitride along the principal Hugoniot to 16 Mbar
Authors: Zhang Huan , Yang Yutong , Yang Weimin , Guan Zanyang , Duan Xiaoxi , Yang Mengsheng , Liu Yonggang , Shen Jingxiang , Batani Katarzyna , Singappuli Diluka , Lan Ke , Li Yongsheng , Huo Wenyi , Liu Hao , Li Yulong , Yang Dong , Li Sanwei , Wang Zhebin , Yang Jiamin , Zhao Zongqing , Zhang Weiyan , Sun Liang , Kang Wei , Batani Dimitri
Published: August 2024

The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics, but they are poorly understood owing to the challenges of performing experiments and realizing ab initio calculations. Here, we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar, using hohlraum-driven shock waves at the SGIII-p laser facility in China. Our density functional theory molecular dynamics calculations closely match experimental data, validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV temperatures. The results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion, hydrogen–boron fusion, and high-energy-density physics.
Linewidth narrowing in self-injection locked lasers: Effects of quantum confinement
Authors: Prokoshin Artem , Chow Weng W. , Dong Bozhang , Grillot Frederic , Bowers John , Wan Yating
Published: August 2024

This paper explores the impact of gain medium on linewidth narrowing in integrated self-injection locked III–V/SiN lasers, theoretically and experimentally. We focus on the effects of carrier densities of states in zero- and two-dimensional structures due to quantum-dot and quantum-well confinement. The theoretical approach includes (a) multimode laser interaction to treat mode competition and wave mixing, (b) quantum-optical contributions from spontaneous emission, and (c) composite laser/free-space eigenmodes to describe outcoupling and coupling among components within an extended cavity. For single-cavity lasers, such as distributed feedback lasers, the model reproduces the experimentally observed better linewidth performance of quantum-dot active regions over quantum-well ones. When applied to integrated III–V/SiN lasers, our analysis indicates Hz-level linewidth performance for both quantum-dot and quantum-well gain media due to overcoming the difference in carrier-induced refractive index by incorporating a high-Q SiN passive resonator. Trade-offs are also explored between linewidth, output power, and threshold current.
The interplay between gravity and centrifugal forces in the continuous circular hydraulic jump
Authors: Baayoun Abdelkader , Khayat Roger E.
Published: August 2024

The flow of a thin film over a rotating disk is crucial in many industrial applications, such as spin coating and jet cooling. Accurate prediction of hydrodynamic features is essential for optimizing these processes. In this study, we examine the vertical downward impingement of a circular Newtonian liquid jet on a horizontally rotating disk, focusing on two distinct regimes based on the rotation level. For a stationary disk and low rotation speed, a continuous hydraulic jump is formed, while increased rotation speed leads to the transformation of the jump into a hump. A composite mean-field thin-film approach is utilized to analyze the flow dynamics in different regions of the domain. The effects of gravity and rotation are considered by developing a model to capture the continuous jump and vortex structure. The influence of rotation on the laminar boundary layer near impingement is found to be negligible. Specific conditions for gravity and rotation are established to differentiate between the jump and hump regimes. The model is validated for both regimes against existing experiment. In the jump regime, the flow transitions from predominantly azimuthal near the disk to predominantly radial toward the free surface, while in the hump regime, the flow maintains an azimuthal character around the hump. The vortex associated with the jump diminishes with increasing rotation speed, indicating the occurrence of a type-0 jump on a rotating disk. For small gravity, the vortex does not form in conjunction with the jump at any rotation level. In the case of small rotation, large gravity, and large disk size, the film exhibits a hydraulic jump near impingement followed by a sharp rise in thickness near the edge of the disk.
Photo-thermoacoustic waves propagation flow of excited magneto-nonlocal semiconductors in stability region with varying thermal conductivity
Authors: Kamel Alwaleed , Yaseen Nesreen A. , El-Bary Alaa A. , Hassanin W. S. , Lotfy Kh.
Published: August 2024

This work examines the complex interaction between acoustic pressure, photothermal excitation, and magnetic fields in a nonlocal semiconductor material according to the dual phase lag thermoelastic model. An extensive theoretical framework is employed to investigate the dynamic behavior of the semiconductor system, encompassing a wide range of physical phenomena when the thermal conductivity is variable to modify the heat conduction equation. An investigation is carried out using theoretical analysis and numerical simulations to comprehend the complex interaction between these fundamental physical processes. By including the relevant equations in our simulations, we can examine the impact of the magnetic field on the thermal-mechanical characteristics of the medium. The magnetic field and acoustic pressure combine to generate complex variations in temperature, strain, and displacement. The harmonic wave approach is employed to get the analytical expression of the fundamental physical fields, including temperature, mechanical stress, displacement, carrier density, and acoustic pressure, by mathematical means. The theoretical findings are examined and visibly shown due to the powerful magnetic field of the nonlocal semiconductor medium according to changes in thermal conductivity.
A generalized density dissipation for weakly compressible smoothed particle hydrodynamics
Authors: Zheng B. X. , Cai Z. W. , Zhao P. D. , Xu X. Y. , Chan T. S. , Yu P.
Published: August 2024

Weakly compressible smoothed particle hydrodynamics (SPH) is known to suffer from numerical pressure noise, posing challenges to simulation stability and accuracy. To address this, the present study introduces a novel density dissipation scheme aimed at suppressing such unphysical noise. The proposed solution overcomes the limitation of traditional density dissipation schemes being ineffective at fluid interfaces in multiphase flow simulations. The novel scheme is generally applicable to the entire computational domain, encompassing both single-phase flow and multiphase flow. This advancement is achieved through two key components. First, the traditional density dissipation is replaced with a density increment dissipation approach that enables dissipation to cross interfaces separating different fluids. Second, based on dissipation volume conservation, a dissipation volume correction factor is employed to stabilize simulations characterized by large density ratios. The accuracy, stability, and robustness of our method are demonstrated through direct comparisons with experimental data or numerical results in four three-dimensional benchmarks: sloshing under external excitations, the rising of single and double bubbles, Rayleigh–Taylor instability, and Kelvin–Helmholtz instability. Additionally, our study reveals the relationship between SPH utilizing density dissipation and the approximate Riemann solver.
Solutocapillary convection and instability near the air–liquid interface
Authors: Wu Zuo-Bing
Published: August 2024

Steady solutocapillary convection and instability near the air–liquid interface are studied. First, under the assumption of the conically similar viscous flow, an exact axisymmetric solution of the steady solutocapillary convection near the air–liquid interface is determined due to a constant mass flux. It is shown that the constant mass flux and the radial surface tension cause the divergent motion at the interface and the Marangoni convection beneath the interface. Then, the linear stability of the steady solutocapillary convection in response to the azimuthal disturbance is analyzed. At a given Peclet number (or Schmidt number), the steady basic flow loses its stability when the Reynolds number is beyond its critical value. It is found that for the fixed Schmidt number, the critical Reynolds number increases monotonously as the harmonic wave number of the azimuthal disturbance increases. However, for the fixed Peclet number, a nonlinear relationship between the critical Reynolds number and the harmonic wave number of the azimuthal disturbance is found. The structures of iso-concentration lines and velocity fields in the three-dimensional flow system depend on the disturbance harmonic wave number, which is dominated by both the radial and the azimuthal surface tensions. This study provides a profound understanding of the soluble surfactant-driven instability of a divergent flow near the air–liquid interface, which is of great significance for practical applications in the micro-fluidics related to chemistry and biology.
Local randomized neural networks with hybridized discontinuous Petrov–Galerkin methods for Stokes–Darcy flows
Authors: Dang Haoning , Wang Fei
Published: August 2024

This paper introduces a new numerical approach that integrates local randomized neural networks (LRNNs) and the hybridized discontinuous Petrov–Galerkin (HDPG) method for solving coupled fluid flow problems. The proposed method partitions the domain of interest into several subdomains and constructs an LRNN on each subdomain. Then, the HDPG scheme is used to couple the LRNNs to approximate the unknown functions. We develop local randomized neural networks with hybridized discontinuous Petrov–Galerkin (LRNN-HDPG) methods based on velocity-stress formulation to solve two types of problems: Stokes–Darcy problems and Brinkman equations, which model the flow in porous media and free flow. We devise a simple and effective way to deal with the interface conditions in the Stokes–Darcy problems without adding extra terms to the numerical scheme. We conduct extensive numerical experiments to demonstrate the stability, efficiency, and robustness of the proposed method. The numerical results show that the LRNN-HDPG method can achieve high accuracy with a small number of degrees of freedom.
Modeling considerations about a microchannel heat sink
Authors: Chej L. G. , Monastra A. G. , Carusela M. F.
Published: August 2024

Many computational studies on hotspot microfluidic cooling devices found in the literature rely on simplified assumptions and conventions that do not capture the full complexity of the conjugate thermal problem, such as constant thermophysical fluid properties, radiation, and free air convection on the external walls. These assumptions are generally applied to typical microfluidic devices with a large number of microchannels and operating at Reynolds numbers between 100 and 1000. A one microchannel chip is a suitable starting point to analyze more systematically the implications of these assumptions, in particular at lower Reynolds numbers. Although it is a simpler system, it has been studied experimentally and numerically as a basic block of a thermal microfluidic device. In this work, we analyze the modeling of the overall heat transfer from a hotspot to a microfluidic heat sink, focusing on the effect of the different thermal transfer mechanisms (conduction, convection, and radiation), and temperature-dependent thermophysical properties of the fluid and the chip material. The study is developed as a function of the pressure difference applied to the system based on simulations performed using a finite volume method. Analyzing and comparing the different contributions to the energy losses, this work provides a critical discussion of the usually considered approximations, to make a reliable modeling of the overall thermal performance of a single rectangular straight channel embedded in a polydimethylsiloxane microfluidic chip.
Experimental investigations of aero-engine pre-swirl system performance improvement with consideration of inner seal flow effect
Authors: Zhang Yue , Liu Gaowen , Wu Yuyue , Duan Yu , Ma Jiale , Chen Yan , Lin Aqiang
Published: August 2024

The pre-swirl system is essential for delivering cooling air to turbine blades within aviation engines. To explore the impact of the inner seal on the pre-swirl system, a high pressure ratio and high rotational speed experimental platform was constructed. The impact of inner seal inflow and outflow on the pre-swirl system's performance was evaluated. In response to the adverse effects of inner seal inflow on the system, a bypass structure was proposed to divert the inner seal flow, and the optimization effects and underlying mechanisms of the bypass structure were analyzed through a combination of experimental and numerical simulation approaches. The results indicate that the impact of inner seal outflow on the system is minimal, with the maximum variation in the temperature drop efficiency remaining below 1.9% under experimental conditions. Inner seal inflow, on the other hand, can have a significant negative impact on the system's performance. At a pressure ratio of 1.6, increasing inner seal inflow ratio leads to a decline in temperature drop efficiency from 0.55 to 0.43, representing a reduction of 21.8%. The bypass structure for inner seal can effectively prevent the mixing of inner seal flow with the mainstream within the pre-swirl cavity, reducing the pressure and temperature within the pre-swirl cavity. At a pressure ratio of 1.6 and inner seal inflow ratio of 15%, the specific work done by the airflow increased from 9.23 to 12.72 kW/(kg/s), increased by 37.8%, and the system temperature drop efficiency increased from 0.426 to 0.546, representing a 28.0% increase.
Resistance-driven low power H2S sensors based on MWCNT@CuO heterojunction
Authors: Kumar Sumit , Mitra Rahul , Barala Suraj , Kumar Ashok , Kwoka Monika , Biswas Krishnau , Kumar Mahesh
Published: August 2024

Low power, high sensitivity, and selectivity chemiresistive gas sensors are in urgent demand for hydrogen sulfide (H2S) detection to protect human health and the world's ecosystem. In this study, multiwalled carbon nanotubes (MWCNTs) and copper oxide (CuO) submicrometer size particles’ compositions were utilized to fabricate low-temperature H2S gas sensors, which were prepared using a screen-printing technique on inter-digited patterned SiO2/Si substrates. The heterostructure of MWCNT@CuO was confirmed through high-resolution transmission electron microscopy analysis and x-ray diffraction patterns. The x-ray photoelectron spectroscopy analysis reveals the chemical states, binding energies, and oxygen vacancy (Ov). Brunauer–Emmett–Teller analysis of nitrogen physisorption analysis was conducted on the samples to analyze sensor surface areas and pore size distribution. The as-fabricated MWCNT@CuO sensor shows a relative response (ΔR/R%) of 73% toward 10 ppm H2S at 50 °C temperature in a selective manner, which is 1.6 times higher than that of devices based on bare CuO. The MWCNT@CuO interface modifies the morphology and also constructs a p–p heterojunction. This leads to the reforming of the band structure and results in a low resistance of the matrix, as well as a high chemisorbed oxygen content. The use of metal oxide semiconductors with MWCNTs offers a promising approach for the development of high-performance gas sensors that are energy-efficient.