Global Peak Research Articles

A new meta-heuristic optimization-based MPPT control technique for green energy harvesting from photovoltaic systems under different atmospheric conditions.

At present, a photovoltaic (PV) system takes responsibility to reduce the risk of global warming and generate electricity. However, the PV system faces numerous problems to track global maximum peak power (GMPP) owing to the nonlinear nature of the environment especially due to partial shading conditions (PSC). To solve these difficulties, previous researchers have utilized various conventional methods for investigations. Nevertheless, these methods have oscillations around the GMPP. Hence, a new metaheuristic method such as an opposition-based equilibrium optimizer (OBEO) algorithm is used in this work for mitigating the oscillations around GMPP. To find the effectiveness of the proposed method, it can be evaluated with other methods such as SSA, GWO, and P&O. As per the simulation outcome, the proposed OBEO method provides maximum efficiency against all other methods. The efficiency for the proposed method under dynamic PSC is 95.09% in 0.16s, similarly, 96.17% for uniform PSC and 86.25% for complex PSC.

STrain Analysis and Mapping of the Plantar Surface (STAMPS): A novel technique of plantar load analysis during gait.

Diabetic foot ulceration is driven by peripheral neuropathy, resulting in abnormal foot biomechanics and elevated plantar load. Plantar load comprises normal pressure and tangential shear stress. Currently, there are no in-shoe devices measuring both components of plantar load. The STAMPS (STrain Analysis and Mapping of the Plantar Surface) system was developed to address this and utilises digital image correlation (DIC) to determine the strain sustained by a plastically deformable insole, providing an assessment of plantar load at the foot-surface interface during gait. STAMPS was developed as a multi-layered insole, comprising a deformable mid-layer, onto which a stochastic speckle pattern film is applied. A custom-built imaging platform is used to obtain high resolution pre- and post-walking images. Images are imported into commercially available DIC software (GOM Correlate, 2020) to obtain pointwise strain data. The strain and displacement data are exported and post-processed with custom analysis routines (MATLAB, Mathworks Inc.), to obtain the resultant global and regional peak strain (SMAG), antero-posterior strain (SAP) and medio-lateral strain (SML). To validate the core technique an experimental test process used a Universal Mechanical Tester (UMT) system (UMT TriboLab, Bruker) to apply controlled vertical and tangential load regimes to the proposed multi-layer insole. A pilot study was then conducted to assess the efficacy of using the STAMPS system to measure in-shoe plantar strain in three healthy participants. Each participant walked 10 steps on the STAMPS insole using a standardised shoe. They also walked 10 m in the same shoe using a plantar pressure measurement insole (Novel Pedar®) to record peak plantar pressure (PPP) as a gold-standard comparator. The results of the experimental validation tests show that with increased normal force, at a constant shear distance, SMAG increased in a linear fashion. Furthermore, they showed that with increased shear distance, at a constant force, SMAG increased. The results of the pilot study found participant 1 demonstrated greatest SMAG in the region toes 3-5 (15.31%). The highest mean SMAG for participant 2 was at the hallux (29.31%). Participant 3 exhibited highest strain in the regions of the first and second metatarsal heads (58.85% and 41.62% respectively). Increased PPP was strongly associated with increased SMAG with a Spearman's correlation coefficient 0.673 (p < 0.0001). This study has demonstrated the efficacy of a novel method to assess plantar load across the plantar surface of the foot. Experimental testing validated the sensitivity of the method to both normal pressure and tangential shear stress. This technique was successfully incorporated into the STAMPS insole to reliably measure and quantify the cumulative degree of strain sustained by a plastically deformable insole during a period of gait, which can be used to infer plantar loading patterns. Future work will explore how these measures relate to different pathologies, such as regions at risk of diabetic foot ulceration.

Inter-center reproducibility of standard and advanced echocardiographic parameters in the EACVI-AFib echo registry.

we sought to test the inter-center reproducibility of 16 echo laboratories involved in the EACVI-Afib Echo Europe. This was done on a dedicated setting of 10 patients with sinus rhythm (SR) and 10 with persistent atrial fibrillation (AF), collected by the Principal Investigator. Images and loops of echo-exams were stored and made available for labs. The tested measurements included main echo-Doppler parameters, global longitudinal strain (GLS) and peak atrial longitudinal strain (PALS). Single measures interclass correlation coefficients (ICCs) of left ventricular mass and ejection fraction were suboptimal in both patients with SR and AF. Among diastolic parameters, ICCs of deceleration time were poor, in particular in AF (=.50). ICCs of left atrial size and function, besides optimal in AF, showed an acceptable despite moderate concordance in SR. ICC of GLS was .81 and .78 in SR and AF respectively. ICCs of PALS were suitable but lower in 4-chamber than in 2-chamber view. By depicting the boxplot of the 16 laboratories, GLS distribution was completely homogeneous in SR, whereas GLS of AF and PALS of both SR and AF presented a limited number of outliers. GLS mean±SE of the 16 labs was 19.7±.36 (95% CI: 18.8-20.4) in SR and 16.5±.29 (95% CI: 15.9-17.1) in AF, whereas PALS mean±SE was 43.8±.70 (95% CI: 42.3-45.3) and 10.2±.32 (95% CI: 9.5-10.9) respectively. While the utilization of some standard-echo variables should be discouraged in registries, the application of GLS and PALS could be largely promoted because their superior reproducibility, even in AF.

Is increased myocardial triglyceride content associated with early changes in left ventricular function? A 1H-MRS and MRI strain study.

Type 2 diabetes (T2D) and obesity induce left ventricular (LV) dysfunction. The underlying pathophysiological mechanisms remain unclear, but myocardial triglyceride content (MTGC) could be involved. This study aimed to determine which clinical and biological factors are associated with increased MTGC and to establish whether MTGC is associated with early changes in LV function. A retrospective study was conducted using five previous prospective cohorts, leading to 338 subjects studied, including 208 well-phenotyped healthy volunteers and 130 subjects living with T2D and/or obesity. All the subjects underwent proton magnetic resonance spectroscopy and feature tracking cardiac magnetic resonance imaging to measure myocardial strain. MTGC content increased with age, body mass index (BMI), waist circumference, T2D, obesity, hypertension, and dyslipidemia, but the only independent correlate found in multivariate analysis was BMI (p=0.01; R²=0.20). MTGC was correlated to LV diastolic dysfunction, notably with the global peak early diastolic circumferential strain rate (r=-0.17, p=0.003), the global peak late diastolic circumferential strain rate (r=0.40, p<0.0001) and global peak late diastolic longitudinal strain rate (r=0.24, p<0.0001). MTGC was also correlated to systolic dysfunction via end-systolic volume index (r=-0.34, p<0.0001) and stroke volume index (r=-0.31, p<0.0001), but not with longitudinal strain (r=0.009, p=0.88). Interestingly, the associations between MTGC and strain measures did not persist in multivariate analysis. Furthermore, MTGC was independently associated with LV end-systolic volume index (p=0.01, R²=0.29), LV end-diastolic volume index (p=0.04, R²=0.46), and LV mass (p=0.002, R²=0.58). Predicting MTGC remains a challenge in routine clinical practice, as only BMI independently correlates with increased MTGC. MTGC may play a role in LV dysfunction but does not appear to be involved in the development of subclinical strain abnormalities.

Heterogeneity or illusion? Track the carbon Kuznets curve of global residential building operations

Residential buildings, the “last mile” sector in the global decarbonization, have become the most significant uncertain factor hindering carbon neutrality with increasing household energy demand. To track the operational carbon in buildings, this study investigates the carbon Kuznets curve (CKC) and the corresponding decoupling status of residential building operations at four emission scales by using the data of 30 countries from 2000 to 2019. The results show that (1) the CKC model can fit more than half of the samples. Most curves have an inverted U-shape, with 76% of emission per household and 82% of total emissions. (2) In the presence of the CKC, over four-fifths of global residential buildings peak regardless of any emission scale. The analysis denotes that the carbon emissions of developed countries reach their peaks earlier. In the total emissions, the samples’ peaking proportion is 20% and 25% with income per capita < 20,000 United States dollars (USD) and 20,000–40,000 USD, respectively. (3) The Tapio decoupling analysis and the threshold regression effectively verify the robustness and the heterogeneity of CKCs, respectively. Strong decoupling effects of CKCs in most countries are demonstrated at the scales of emission per floor space and the total emissions, and the heterogeneity proves the classic inverted U-shaped relationship between economy and emissions doesn’t exist in all emitters. Overall, this study tracks the historical carbon emission trajectories of residential building operations at a global scale, providing reference for different economies to simulate the dynamic of building carbon emissions along with the economic booming.

Prognostic value of CMR regional longitudinal strain beyond global function and tissue characteristics in patients with suspected myocarditis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiovascular magnetic resonance imaging (CMR) feature tracking (FT) regional longitudinal peak strain (RLS) is a novel method to assess regional myocardial deformation. The aim of this study was to investigate the prognostic value of CMR-FT RLS in patients with suspected myocarditis. Purpose Risk-stratification in patients with myocarditis is challenging. While left ventricular ejection fraction (LVEF) and global longitudinal peak strain (GLS) have shown predictive power in patients with myocarditis, the role of RLS is unknown. Methods Patients meeting clinical criteria for suspected myocarditis who were referred for CMR were included. Global/regional functional and CMR tissue characteristics were analyzed and associated with first major adverse cardiac event (MACE, i.e. heart failure hospitalization, sustained ventricular tachycardia, recurrent myocarditis and all-cause death). RLS was defined as following: anterior-/septal-(inferoseptal-/anteroseptal-))/inferior-/lateral-(anterolateral-/inferolateral). Patients with normal versus impaired function (i.e. according to LVEF and GLS) were selected for further sub-analysis. Results 773 consecutive patients met the inclusion criteria and were included in the final analysis. Mean age was 48.3±16 years, 286 (37%) were female, and at a median follow up of 3.5 years, MACE was present in 131 (17%) of all patients. RLS of all regions were associated with outcome in the univaribale analysis. Lateral-, inferolateral- and anterolateral- RLS remained independent, significant outcome predictors after correcting for cardiovascular risk factors and CMR tissue characteristics/function (HR 1.05–1.08, c-statistics 0.711–0.721). In the 394 (51%) patients with normal LVEF and GLS, septal-, inferoseptal- and inferolateral-RLS were all significant independent predictors for MACE after adjustment for cardiovascular risk factors (HR between 1.11 and 1.13 (95%CI: 1.07–1.17, a c-statistics 0.707–0.721 ). In patients with impaired LVEF/GLS only all but anterior and anterolateral-RLS wereas independently associated with outcome. Conclusion Regional longitudinal strain was independently associated with outcome beyond clinical and CMR tissue characteristsics and might therefore represent a more granular marker to refine risk stratification in suspected myocarditis with impaired- or normal left ventricular function.

Left atrial deformation discloses atrial amyloid infiltration among patients with increased myocardial thickness

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Swedish research council Swedish heart and lung foundation Background Transthyretin cardiac amyloidosis (ATTR-CA) is an infiltrative disease with thickening and stiffening of the heart walls as a result. Amyloid deposits are found not only in the ventricular walls, but in the atriums as well. Atrial function is known to play an integral part in the overall function of the heart. Purpose We aimed to evaluate left atrial deformation including left ventricular-atrial strain loop (LV-LA loop). The latter to test LA deformation and its dependence of LV deformation in ATTR CA and compare it to left ventricular hypertrophy (LVH). Methods Retrospective analysis was performed on available echocardiographic data, obtained between years 2004–2022. The study population was divided into three groups: healthy controls with no identified cardiac disease; ATTR-CA patients with verified ATTR-CA diagnosis and interventricular septal thickness end diastole (IVSd) of ≥14mm; LVH including IVSd ≥14mm and no CA diagnosis. Left heart strain measurements, including LV global longitudinal strain (LV GLS) and LA peak atrial longitudinal strain (LA PALS), were acquired from apical 4-chamber view during same single heart cycle. Strain coordinates throughout the heart cycle were plotted using MATHLAB, combining LV GLS and LA PALS to compute a strain-strain loop. A slope was determined using regression line to index relative function of the left ventricle to left atrium (GLS-PALS-slope). Results Data was gathered in total of 90 patients (67.8±1.2 years, 55,6% male) divided into three groups containing 30 patients each: ATTR-CA including 24 hereditary ATTR (including mutations; 19 Val30Met, one The60Ala, one Val122Ile, one Ala45Glys, one Ala97Ser and one His88Arg) and six wild type ATTR, LVH with increased myocardial thickness believed caused by aortic stenosis (n=13; one grade I, three grade II-III and eight grade III), essential hypertension (n=10) and hypertrophic cardiomyopathy (n=7, four of which had outflow obstruction). The lowest PALS and PALS-GLS slope was detected in ATTR-CA (p-value 0.005 respectively 0.003 between ATTR-CA compared to LVH). No significant statistical difference could be verified in GLS between ATTR-CA and LVH (p-value 0.114). A ROC curve of ATTR-CA demonstrated similar results between PALS and GLS-PALS slope (AUC 0.79 resp. 0.78) which was slightly higher than GLS (AUC 0.69). Slightly higher AUC was generated when slope was indexed with LAVI (AUC 0.80). Conclusions LA deformation demonstrates a strong ability to differentiate ATTR-CA from LV hypertrophy. Adding LV strain in relation to LA deformation showcases the mechanical dissociation of LA to LV in ATTR-CA, potentially unmasking atrial infiltration. Its use in prognostic evaluation needs further studies.

Prognostic role of feature tracking strain in stress cardiac magnetic eesonance (the PROGRESS study)

Abstract Funding Acknowledgements Type of funding sources: None. Objectives This study aims to assess the role of feature-tracking (FT) strain in the long-term risk stratification of a large population of patients with known or suspected coronary artery disease (CAD) undergoing stress cardiac magnetic resonance (S-CMR) with dipyridamole. Background Recently, FT strain has been applied to S-CMR to improve risk stratification of patients with known or suspected CAD. However, no data are available on the prognostication role of FT strain in patients undergoing a S-CMR with dipyridamole. Methods 729 consecutive patients (age: 63±10 y, male 84%) with stable symptoms suggesting possible cardiac ischemia underwent dipyridamole S-CMR and followed up for 5.8±1.2 years. CMR-FT analysis was performed in each patient to obtain 2D global peak systolic rest and stress longitudinal (GLS), circumferential (GCS), and radial strain (GRS). Major adverse cardiac events (MACE) were defined as non-fatal myocardial infarction and cardiac death. Results MACE occurred in 70 (9.6%) patients. At multivariate analysis, the presence of late gadolinium enhancement (LGE) (HR 2.737 [95% CI 1.534–4.884]), p &amp;lt;0.001, and stress GCS (HR 1.064 [95% CI 1.011–1.119]), p = 0.0164 were independently associated with MACE. By Kaplan-Meier analysis, patients with stress GCS &amp;gt;-15% had significantly reduced event-free survival compared with those with stress GCS ≤-15 (log-rank p = 0.007). The best predictive model of MACE included left ventricular ejection fraction (LVEF) + positive S-CMR for inducible ischemia (positive S-CMR) + LGE. A model based on LVEF + stress GCS (contrast free) showed higher performance in predicting MACE compared to LVEF alone and a similar performance compared to LVEF + positive S-CMR (p =0.05). Conclusions In patients with known or suspected CAD undergoing S-CMR with dipyridamole, stress GCS and LGE presence are independent predictors of MACE. Adding strain analysis of stress GCS can help define patients' risk after S-CMR on top of LVEF without needing contrast agents.

Left atrial dynamics and the pulmonary circulatory-right ventricular uncoupling in patients with severe degenerative mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background The uncoupling of right ventricular (RV) function to pulmonary circulation (Pc) represents a prognostic index in patients affected by degenerative mitral regurgitation (DMR) undergoing surgical or percutaneous repair. In this context, the deterioration of Left Atrial (LA) dynamics favors the development of pulmonary venous congestion and vascular remodeling, triggering pulmonary hypertension (PH) and right ventricular (RV) dysfunction. However, the relationship between LA function and RV-to-Pc coupling is not well defined in this population. Purpose The aim of the study was to investigate the association between RV-to-Pc uncoupling, assessed by the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PAPS), and LA dynamics, evaluated with Speckle Tracking Echocardiography (STE), in patients with DMR. Methods 351 consecutive patients with hemodynamically-significant DMR who were evaluated for cardiac surgery at San Raffaele Hospital and underwent a complete transthoracic and transesophageal echocardiography were retrospectively enrolled (mean age 59±14 years, 65% males). Patients were then stratified in two groups according to TAPSE/PAPS ratio (group I: TAPSE/PAPS &amp;gt;0.4 mm/mmHg; group II: TAPSE/PAPS ≤0.4 mm/mmHg). LA function was evaluated analyzing LA strain at peak relaxation (Global peak atrial longitudinal strain) and STE analysis was performed offline. All the patients enrolled were in sinus rhythm. Results At baseline, patients exhibited normal LV dimensions and function (EDVi 70±20 ml/m2, LVEF 63±6%), increased LA size (48±20 ml/m2) and a mean GPALS of 26±13%. Additionally, a preserved RV function and coupling with PC was found in the population in study (average TAPSE/PASP at admission: 0.84±0.2 mm/mmHg), with only 10% of the cohort exhibiting a reduced TAPSE/PAPS ratio. When stratified according to RV-to-PC coupling, patients with higher TAPSE/PAPS (&amp;gt;0.4 mm/mmHg) exhibited significantly higher values of LA reservoir strain (group I: GPALS 27.8±12.7% vs group II GPALS 22.7±11.3%; p = 0.04) (Figure 1, 2). Additionally, a direct correlation between LA-Strain values and TAPSE/PAPS ratio was noticed (r=0.3, CI 95% 0.21–0.5; p&amp;lt;0.001). Conclusions In DMR, there is a strong association between echo-derived measures of LA mechanics and RV to Pc uncoupling, with higher values of LA strain correlating with a better RV functioning and coupling. These results, although preliminary, suggest the importance of a multiparametric approach in the risk-stratification of these patients, potentially improving the long-term outcome.

Left atrial strain is associated with the burden of symptoms in cardiac amyloidosis: a speckle tracking study

Abstract Funding Acknowledgements Type of funding sources: None. Background cardiac amyloidosis (CA) is characterized by an impairment of cardiac diastolic and, in the severe state of the disease, systolic function, with increasing worsening of functional capacity and quality of life (QoL). Six minute walking test (6MWT) and Kansas City Cardiomyopathy Questionnaire (KCCQ) are two well-known and validated methods to assess the impact of heart failure (HF) symptoms and functional capacity. Left atrial strain by speckle tracking echocardiography has emerged as an index of left ventricular (LV) diastolic function and filing pressure, and is also associated with symptoms in HF. However, its possible association with functional capacity and QoL in CA has not yet been investigated. Objectives in this observational pilot study, our aim was to evaluate the relationship of left atrial strain with 6MWT and KCCQ in patients with CA (both AL and ATTR). Methods we enrolled consecutive patients with CA during routine follow up visits. Patients underwent clinical and echocardiographic evaluation. On the same day, 6MWT was performed and KCCQ was administered. Speckle tracking analysis was performed offline by an experienced operator blinded to the other data. Correlation analysis was conducted using Pearsons’ coefficient and linear regression analysis Results overall, 43 patients with CA (25 ATTR, 18 AL) were enrolled. Mean age was 74 ±11, 16% (n=7) were female. Most patients showed normal left ventricular (LV) ejection fraction (55±9) and reduced LV global longitudinal strain (GLS =−12 ± 7%), 32 of them with apical sparing pattern (Table 1). Mean global peak atrial longitudinal strain (PALS) was 14 (median[IQR]=6.5;23.5), mean 6MWT score = 382 ± 104 and mean KCCQ score= 67 ± 24. Global PALS showed a strong direct correlation with 6MWT (Fig 1, P= 0.4, R2=0.2, p-value=0.032) and a trend towards correlation with KCCQ (R2=0.3, p-value=0.06), although not reaching statistical significance, probably due to the low sample size. The correlation between PALS and 6MWT was even stronger in patients with ATTR (p = 0.7, R2 0.4; p-value&amp;lt;0.0001). Conclusions our preliminary results show that, global PALS is associated with functional capacity and the burden of HF symptoms in ATTR and AL, suggesting its role as a more objective marker of disease severity in CA.

A Novel MPPT Technique based on Hybrid Radial Movement Optimization with Teaching Learning Based Optimization for PV system

Because of its pure and plentiful accessibility, solar power is a remarkable resource of energy for the generation of electrical power. The solar photovoltaic mechanism transforms sunlight striking the photovoltaic solar panel or array of photovoltaic panels directly into non-linear DC power. Due to the nonlinear characteristics of solar photovoltaic panels, power must be tracked for their effective usage. When the photovoltaic arrays are shaded, the problem of nonlinearity becomes more pronounced, resulting in large power loss and intensive heating in a few areas of the photovoltaic arrangement. The tracking challenge is made more difficult by the fact that bypass diodes, which are used to completely eradicate the shading effect, generate numerous power peak levels on the power vs. voltage (P-V) curve. Traditional methods for tracing the global peak point are unable to examine the entire P-V curve as they frequently get stuck at the local peak point. Recently, machine learning or optimization algorithms have been used to determine the global peak point. Because these algorithms are random, they search the entire search area, reducing the possibility of being caught in the local maximum value. This article proposes a hybrid of two optimization approaches: radial movement optimization and teaching-learning optimization (HRMOTLBO). The proposed MPPT method was thoroughly investigated and tested in a wide range of photovoltaic partial shading combinations. The recommended HRMOTLBO MPPT approach outperforms and is more reliable than a recent Jaya-based MPPT approach in terms of tracing time and power variation under dynamic and static partial shading conditions. Experimental as well as simulation outcomes demonstrate that the proposed MPPT successfully traces the global peak point in less time and with fewer fluctuations during various partial shading conditions.

Optimization of Image Processing Based MPPT Algorithm Using FSO Algorithm

An image processing-based Firebug Swarm Optimization (FSO) algorithm is developed in this article to detect maximum power point tracking (MPPT) under shadowing conditions on PV arrays. After capturing an image and applying image processing techniques, the proposed method can detect the shading portion of photovoltaic array (PV). The image processing results can then be used to modify the current rating in power equations. The Firebug swarm optimization (FSO) algorithm is metaheuristic algorithm that identifies and controls switching configurations under partial shading patterns by detecting the maximum global peak point (GPP) of output power generated by multiple configurations. This research is proposed with an image processing edge detection algorithm called the Otsu-Canny algorithm for detecting the partial shade on PV array. The FSO algorithm is used to rearrange the shaded photovoltaic array to significantly reduce the power and efficiency losses. MATLAB simulations were carried out using a 280 W PV panel to verify the efficiency of the proposed FSO MPPT technique with an image processing-based algorithm. The proposed FSO MPPT scheme’s performance is compared to current cutting-edge MPPT methods. Under partial shading conditions, the proposed algorithm successfully detected the maximum peak point of a photovoltaic array, increasing power output and efficiency.

Transmural fibre orientations based on Laplace–Dirichlet-Rule-Based-Methods and their influence on human heart simulations

It is well known that the orthotropic tissue structure decisively influences the mechanical and electrical properties of the heart. Numerous approaches to compute the orthotropic tissue structure in computational heart models have been developed in the past decades. In this study, we investigate to what extent different Laplace–Dirichlet-Rule-Based-Methods (LDRBMs) influence the local orthotropic tissue structure and thus the electromechanical behaviour of the subsequent cardiac simulation. In detail, we are utilising three Laplace-Dirichlet-Rule-Based-Methods and compare: (i) the local myofibre orientation; (ii) important global characteristics (ejection fraction, peak pressure, apex shortening, myocardial volume reduction, fractional wall thickening); (iii) local characteristics (active fibre stress, fibre strain). We observe that the orthotropic tissue structures for the three LDRBMs show significant differences in the local myofibre orientation. The global characteristics myocardial volume reduction and peak pressure are rather insensitive to a change in local myofibre orientation, while the ejection fraction is moderately influenced by the different LDRBMs. Moreover, the apical shortening and fractional wall thickening exhibit a sensitive behaviour to a change in the local myofibre orientation. The highest sensitivity can be observed for the local characteristics.

Analysis on the Use of Fluid Mechanics and Thermodynamics in Future Vehicles

Petroleum is mainly used in the transportation industry and it is now becoming rarer in the world. Petroleum Geologists and analysts have predicted an imminent global peak of petroleum consumption, at which the maximum rate of petroleum extraction will be reached, and then followed by an irreversible decline. To date, 50 countries have passed the point of no return. Therefore, there is no time to delay the saving of petroleum. Since petroleum is mostly used by various means of transport, vehicles that are more efficient with less use of petroleum are needed. Under this context, this paper introduces three types of vehicles making full use of energy. Through case studies, the development tendency of future vehicles is illustrated, and a conclusion can be drawn that clean energy hybrids and hydrogen-powered fuels have become a future development trend for vehicles.

Implementation of PSO algorithm on MPPT PV System using Arduino Uno under PSC

The availability of fossil energy sources decreases as consumers' demand for electrical energy increases rapidly. Currently, the utilization of renewable energy sources is crucial. PV is a renewable energy source that converts photon energy into DC current. Maximum power point tracker (MPPT) control technology for photovoltaics has advanced significantly. PV is unique in that its P-V characteristic curve is non-linear. Conditions of partial shading can cause the P-V curve to have multiple peaks. This research will design MPPT PV using the Particle Swarm Optimization (PSO) algorithm in partially shaded conditions with an Arduino Uno and boost converter. Conventional algorithms, incremental conductance (IC), and Perturb and Observe (P&amp;O) are implemented as a comparison. The purpose of implementing the PSO algorithm is to find the global peak of power to minimize power losses of PV. It leads to optimal power in case of partial shading conditions. Two PV modules are arranged in series for MPPT in a partially shaded environment. The examination was conducted in a darkened room with spotlights. The mean absolute percentage error of the current sensor, INA219, and the voltage sensor, voltage divider, was less than 1% during testing. The MPPT PV system test results indicate that the PSO algorithm can extract approximately 1.64 Watts of average power. In contrast, the IC and P&amp;O algorithms can extract about 1.25 Watts and 1.41 Watts, respectively. When no algorithm exists in the control system, the extracted power is approximately 1.13 watts. Thus, the PSO algorithm tracks global or optimal power under partial shading conditions.

A Water Cycle Approach for Maximum Power Point Tracking through an Interleaved Boost Converter

In this work, an Interleaved Boost Converter (IBC) is developed for Sun Powered E-vehicles (SPEVs) to reduce input/output filters, improve dynamic characteristics, and minimize device stress compared to conventional designs. The IBC achieves these goals by utilizing current control loops and lowering the size of passive components, resulting in excellent efficiency and reduced input/output voltage variation. To ensure an uninterrupted power supply (UPS) and support vehicle movement under erratic conditions, an MPPT (Maximum Power Point Tracking) controller is essential in the PV battery system. However, under non-ideal conditions such as shading, irradiance, temperature, and inclination angle variations, PV systems may experience multiple power peaks, making it challenging to identify the global peak. To address this issue, a unique Water Cycle Optimized Perturb and Observe (WCO-PO) method is proposed in this work. The proposed technique demonstrates shorter computation time, rapid convergence rate, and minimal variations after reaching the MPP (Maximum PowerPoint) in various weather scenarios, as demonstrated using MATLAB/Simulink software. The test results are presented with a comparison of the proposed approach against other methods, showcasing the advantages of the Water Cycle approach in MPPT through an Interleaved Boost Converter.

CMR left ventricular strains beyond global longitudinal strain in differentiating light-chain cardiac amyloidosis from hypertrophic cardiomyopathy.

The clinical value of left ventricular (LV) global longitudinal strain (GLS) in the differential diagnosis of light-chain cardiac amyloidosis (AL-CA) and hypertrophic cardiomyopathy (HCM) has been previously reported. In this study, we analyzed the potential clinical value of the LV long-axis strain (LAS) to discriminate AL-CA from HCM. Furthermore, we analyzed the association between all the LV global strain parameters derived from cardiac magnetic resonance (CMR) feature tracking and LAS in both the AL-CA and HCM patients to assess the differential diagnostic efficacies of these global peak systolic strains. Thus, this study enrolled 89 participants who underwent cardiac MRI (CMRI), consisting of 30 AL-CA patients, 30 HCM patients, and 29 healthy controls. The intra- and inter-observer reproducibility of the LV strain parameters including GLS, global circumferential strain (GCS), global radial strain (GRS), and LAS were assessed in all the groups and compared. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic performances of the CMR strain parameters in discriminating AL-CA from HCM. The intra- and inter-observer reproducibility of the LV global strains and LAS were excellent (range of interclass correlation coefficients: 0.907-0.965). ROC curve analyses showed that the differential diagnostic performances of the global strains in discriminating AL-CA from HCM were good to excellent (GRS, AUC = 0.921; GCS, AUC = 0.914; GLS, AUC = 0.832). Furthermore, among all the strain parameters analyzed, LAS showed the highest diagnostic efficacy in differentiating between AL-CA and HCM (AUC = 0.962). CMRI-derived strain parameters such as GLS, LAS, GRS, and GCS are promising diagnostic indicators that distinguish AL-CA from HCM with high accuracy. LAS showed the highest diagnostic accuracy among all the strain parameters.

Predicting Left Ventricular Myocardial Fibrosis in Patients with Hypertrophic Cardiomyopathy by Speckle Tracking Automated Functional Imaging.

The study was performed to explore the predictive value of multiple strain parameters for myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) by using speckle tracking automated functional imaging (AFI). A total of 61 patients diagnosed with HCM were finally enrolled in this study. All patients completed transthoracic echocardiography and cardiac magnetic resonance late gadolinium enhancement (LGE) within 1 month. Twenty age- and sex-matched healthy participants were included as the control group. Multiple parameters, including segmental longitudinal strain (LS), global longitudinal strain (GLS), post-systolic index and peak strain dispersion, were automatically analyzed by AFI. A total of 1458 myocardial segments were analyzed according to the left ventricular 18-segment model. Among the 1098 segments from HCM patients, segments with LGE had a lower absolute value of segmental LS than those without LGE (p < 0.05). The cutoff values of segmental LS for predicting positive LGE in the basal, intermediate and apical regions were -12.5%, -11.5% and -14.5%, respectively. GLS could predict significant myocardial fibrosis (≥2 positive LGE segments) at a cutoff value of -16.5% with a sensitivity of 80.9% and specificity of 76.5%. As an independent predictor of significant myocardial fibrosis, GLS was substantially associated with the severity of myocardial fibrosis and 5 years sudden cardiac death risk score in HCM patients. Speckle tracking AFI could efficiently identify left ventricular myocardial fibrosis in patients with HCM by multiple parameters. GLS predicted significant myocardial fibrosis at a cutoff value of -16.5%, which may indicate the adverse clinical outcomes in HCM patients.

Precambrian history of the Pacific Mantle Domain: New constraints from Woodsreef and Port Macquarie serpentinized spinel harzburgites of the New England Orogen, Australia

Abstract The present-day mantle is divided into the African and Pacific domains by the circum-Pacific subduction girdle. Very little is known about the mantle composition of the Pacific Domain before 120 Ma due to the scarcity of the oceanic record, having mostly been destroyed by subduction processes. Accreted oceanic lithosphere (ophiolites) in orogens along the Paleo-Pacific margins provide rare opportunities to partially fill this knowledge gap. The early Cambrian (530–505 Ma) Weraerai ophiolite mélange in the New England Orogen in Eastern Australia represents fragments of the now-consumed Paleo-Pacific oceanic plate, predecessor of the Panthalassa and Pacific oceanic plates, accreted to east Gondwana during ca. 410–277 Ma. Early work revealed the presence of an accreted volcanic island(s) of possible mantle plume origin. However, due to their heavy alteration and weathering, the geochemical signature of the mafic rocks in the Weraerai ophiolite cannot be used to certify their plume origin with confidence. Therefore, mantle rocks found in the ophiolitic belt offer an alternative way to decipher the origin of the oceanic lithospheric fragments in the Weraerai ophiolite mélange. Here we report the petrographic, major, and trace elements composition, including highly siderophile elements (HSE), and Re-Os isotope composition for 16 serpentinized spinel harzburgite samples from Woodsreef and Port Macquarie. The observed spinel-orthopyroxene symplectite intergrowth textures are interpreted as garnet-breakdown textures due to cooling from an initial high temperature of &amp;gt;1200°C. Silicon and Al contents and Mg# of serpentinized spinel harzburgite, as well as heavy rare earth element modelling results, suggest a high-degree of melt extraction of 20–30% in the garnet stability field and in an anhydrous environment, probably in ocean island or oceanic plateau environments. The samples in this study have HSE concentrations interpreted to have resulted from post-melting processes rather than a melt extraction feature, indicating that their Re-Os model ages need to be interpreted with caution. Nevertheless, the melt depletion ages obtained from the Woodsreef and Port Macquaries samples range between 1.4 and 1.1 Ga, consistent with previous studies on other Pacific-rim ophiolitic rocks. We argue that these ages might be related to a major depletion event during the transition between supercontinents Nuna and Rodinia. Such depletion events affected a large proportion of this section of the mantle before the incorporation of the peridotites into the oceanic lithosphere in the Paleo-Pacific associated with rapid ascent of mantle plumes. This interpretation is consistent with the occurrence of accreted volcanic islands in the Werearai ophiolite mélange, as shown by the OIB chemical signatures of some of the mafic rocks, and their association with shallow water limestones that formed in near-equatorial latitudes. The proposed ca. 530–510 Ma Paleo-Pacific Ocean mantle plume event coincides with a global peak of oceanic mantle plume events that may record the legacy of a circum-Rodinia subduction girdle driving antipodal mantle superplume episodes.

Application of two dimensional speckle tracking imaging in the follow up of patients with coronary heart disease treated with metalol

Purpose: To investigate the application of two-dimensional speckle tracking imaging (2D-STI) in the follow-up of patients with coronary heart disease (CHD) who were treated with metalol. Methods: A total of 100 patients with CHD (CHD group) who were treated with metalol and had undergone percutaneous coronary intervention (PCI) at Tangshan Works’ Hospital, Tangshan, China, and another 100 healthy people (control group) were enrolled in this study. Prior to and after 6 months of treatment, echocardiography was performed on patients in control and CHD groups, respectively, and the wall motion score was calculated. The 2D-STI was used to obtain systolic peak longitudinal strain value (SLs), global peak longitudinal strain (GSL) and early diastolic peak longitudinal strain rate (SrLe) in the early diastolic period of 6 wall basal segments, middle segments, and apical segments of the left ventricle. Results: The wall motion score index (WMSI) of CHD group was higher than that of the control group, while the WMSI of CHD group after treatment was significantly lower than the value before treatment, (p &lt; 0.05). In 2D-STI, the SLs, SrLe and GLS of patients after 6 months of treatment were significantly higher than those before treatment (p &lt; 0.05).Conclusion: Thus, 2D-STI can be used to quantify the motion of the chamber wall and the effect of PCI surgery, and it also provides a stable new index and technique for evaluating the effects of treatment of CHD.