Leonid Plotnikov^*, Danil Davydov, Dmitry Krasilnikov, Vladislav Shurupov

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1309-1322, 2024, DOI:10.32604/fhmt.2024.056680 - 30 October 2024

Abstract Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world. The aim of the study was to evaluate the gas-dynamic, consumable and heat exchange characteristics of non-stationary air flows in a supply system with transverse profiling of valve channels based on experimental studies. Valve channels with cross sections in the form of a circle, square and triangle were used to control the consumable and heat exchange characteristics of the flows in the supply system of the reciprocating-engine model. The article presents data on changes in… More >

Xiao Sun¹, Huifan Huang¹, Yuliang Zhang², Lianghuai Tong^3,*, Xiaowei Xu², Xiaoqi Jia⁴, Litao Ou⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2251-2264, 2024, DOI:10.32604/fdmp.2024.050997 - 23 September 2024

Abstract In order to obtain the transient characteristics of a low-speed centrifugal pump during the start-up and shutdown stages, dedicated experimental tests were conducted with eight different valve opening conditions. The Pearson correlation coefficient was used to reveal the linear correlation between variables. According to the results, the stable rotational speed decreases with increasing valve opening (rotational speed decreases from approximately 1472 to 1453 r/min), while the stable shaft power exhibits an increasing trend (shaft power increases from approximately 0.242 to 0.390 kW). The stable time and zeroing time of each parameter during start-up and shutdown More >

Toshi Maeda^*, Hiroki Ito, Keiichi Hirose, Kisaburo Sakamoto

Congenital Heart Disease, Vol.19, No.2, pp. 177-183, 2024, DOI:10.32604/chd.2024.050945 - 16 May 2024

Abstract Congenital aortic stenosis (cAS) frequently requires intervention during the neonatal or infantile period. However, surgical repair is challenging because of the narrow surgical space. We performed bicuspidization using the open-sleeve technique for cAS with a unicuspid aortic valve in two patients. Postoperatively, the patients were doing well without reintervention for the aortic valve for 8 and 6 years, respectively. Their aortic annular diameter increased along with somatic growth. Bicuspidization for neonates or infancy can be performed safely using the open-sleeve technique as its midterm results have been satisfactory. More > Graphic Abstract

Long Chen¹, Ting Li¹, Liang Liu¹, Wenshuo Wang^2,*, Xiaoxiao Du³, Wei Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2773-2806, 2024, DOI:10.32604/cmes.2024.046641 - 11 March 2024

Abstract This study explores the implementation of computed tomography (CT) reconstruction and simulation techniques for patient-specific valves, aiming to dissect the mechanical attributes of calcified valves within transcatheter heart valve replacement (TAVR) procedures. In order to facilitate this exploration, it derives pertinent formulas for 3D multi-material isogeometric hyperelastic analysis based on Hounsfield unit (HU) values, thereby unlocking foundational capabilities for isogeometric analysis in calcified aortic valves. A series of uniaxial and biaxial tensile tests is executed to obtain an accurate constitutive model for calcified active valves. To mitigate discretization errors, methodologies for reconstructing volumetric parametric models, More > Graphic Abstract

Tianyu Zhou¹, Liang Hao¹, Xin Xu^2,3, Meng Si^2,3, Lian Zhang^2,3,*

Energy Engineering, Vol.121, No.1, pp. 145-168, 2024, DOI:10.32604/ee.2023.042798 - 27 December 2023

Abstract This paper discussed the experimental results of the performance of an organic Rankine cycle (ORC) system with an ultra-low temperature heat source. The low boiling point working medium R134a was adopted in the system. The simulated heat source temperature (SHST) in this work was set from 39.51°C to 48.60°C by the simulated heat source module. The influence of load percentage of simulated heat source (LPSHS) between 50% and 70%, the rotary valve opening (RVO) between 20% and 100%, the resistive load between 36 Ω and 180 Ω or the no-load of the generator, as well… More >

Jae Gun Kwak¹, Eung Re Kim², Taeyoung Yun¹, Sungkyu Cho¹, Chang-Ha Lee², Woong-Han Kim^1,*

Congenital Heart Disease, Vol.18, No.3, pp. 325-336, 2023, DOI:10.32604/chd.2023.027758 - 09 June 2023

Abstract Objectives: To access the effectiveness of our modified right-ventricular overhauling procedure on tricuspid valve (TV) growth in patients with pulmonary atresia with intact ventricular septum (PAIVS). Methods: We retrospectively reviewed 21 patients with PAIVS who underwent modified right ventricular overhauling (mRVoh) between 2008 and 2019 at two institutions. Our mRVoh consisted of wide resection of hypertrophied infundibular and trabecular muscle, peeling off fibrotic endocardial tissue in the right ventricle (RV) cavity, surgical pulmonary valvotomy, and Blalock-Taussig shunt or banding of ductus arteriosus under cardiopulmonary bypass. The TV annulus sizes were measured and analyzed using echocardiography… More > Graphic Abstract

Norman Aiad^1,2,3,7, Mark V. Sherrid^1,7, Adam J. Small¹, Youssef Elnabawi^1,7, Jodi Feinberg¹, Leon Axel^1,4, Ralph Mosca⁵, T. K. Susheel Kumar⁵, Michael Argilla⁶, Dan G. Halpern^1,7,*

Congenital Heart Disease, Vol.18, No.3, pp. 267-277, 2023, DOI:10.32604/chd.2023.025853 - 09 June 2023

Abstract Introduction: We sought to investigate whether the development of sub-pulmonic systolic anterior motion (SAM) may be inherent to the anatomy of the the mitral valve (MV) or affected by external factors, such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation (d-TGA/AtS). Methods: Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS (age 42 ± 6 years old, 56% male) between 2015–2019. Echocardiography data included mitral apparatus anatomy, and CT/MRI data included biventricular dimensions, function, and Haller index… More >

Salah Alzghoul^1,*, Othman Smadi¹, Ali Al Bataineh², Mamon Hatmal³, Ahmad Alamm⁴

Intelligent Automation & Soft Computing, Vol.37, No.1, pp. 455-470, 2023, DOI:10.32604/iasc.2023.038338 - 29 April 2023

Abstract Currently, the decision of aortic valve replacement surgery time for asymptomatic patients with moderate-to-severe aortic stenosis (AS) is made by healthcare professionals based on the patient’s clinical biometric records. A delay in surgical aortic valve replacement (SAVR) can potentially affect patients’ quality of life. By using ML algorithms, this study aims to predict the optimal SAVR timing and determine the enhancement in moderate-to-severe AS patient survival following surgery. This study represents a novel approach that has the potential to improve decision-making and, ultimately, improve patient outcomes. We analyze data from 176 patients with moderate-to-severe aortic… More >

Jingnan Zhang¹, Junyi Wan¹, Yihang Li², Yu Han², Jiahua Pan³, Fang Fang¹, Shiliang Jiang⁴, Xiangbin Pan¹, Gejun Zhang^1,*

Congenital Heart Disease, Vol.18, No.2, pp. 219-234, 2023, DOI:10.32604/chd.2023.027562 - 15 March 2023

Abstract Background: The Venus-P valve was the first self-expanding valve used world-wide for transcatheter pulmonary valve replacement (TPVR) in patients with severe pulmonary regurgitation (PR). We intended to report the extended follow-up results from the prospective trial (No. NCT02590679). Methods: A total of 38 patients with severe PR (mean age 24.2 ± 13.2) were included. Follow-up data were obtained after implanted at 1, 6, and 12 months and yearly after. The frame geometry was assessed on post-implant computer tomography (CT) scanning by calculating the non-circularity [circularity ratio (minimum diameter/maximum diameter) < 0.9] and under-expansion [expansion ratio (derived external valve… More > Graphic Abstract

Cherith Somerville^1,2, Kelsey Kalbfleisch^1,2, Roozbeh Manshaei^1,2, Qiliang Ding^1,2, John B.A. Okello^1,2,3, Rachel Silver⁴, David Chitayat^2,4, Varsha Thakur⁵, Olivier Villemain^5,6,7, Rebekah Jobling^1,2,8,*

Congenital Heart Disease, Vol.18, No.2, pp. 213-218, 2023, DOI:10.32604/chd.2023.023042 - 15 March 2023

Abstract We report a three-year-old male child who presented with congenital valvular defects, right ventricular malformation, and initial developmental delay. Genome sequencing showed rare deleterious biallelic missense variants in PLD1. In his parents’ second pregnancy, echocardiogram at 13 weeks gestation revealed right-sided cardiac malformations resembling the clinical presentation of the family’s first child. Targeted DNA analysis showed that the fetus carried the same biallelic PLD1 variants as their older sibling. This case helps to further delineate the clinical spectrum of PLD1-related defects and highlights the value of both genome sequencing in congenital heart disease and early fetal echocardiography More >