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Energy demand has been overgrowing in developing countries. Moreover, the fluctuation of fuel prices is a primary concern faced by many countries that highly rely on conventional power generation to meet the load demand. Hence, the need to use alternative resources, such as renewable energy, is crucial in order to mitigate fossil fuel dependency, while ensuring reductions in carbon dioxide emissions. Algeria—being the largest county in Africa—has experienced a rapid growth in energy demand over the past decade due to the significant increase in residential, commercial, and industry sectors. Currently, the hydrocarbon-rich nation is highly dependent on fossil fuels for electricity generation, with renewable energy only having a small contribution to the country’s energy mix. However, the country has massive potential for renewable energy generation, such as solar, wind, biomass, geothermal, and hydropower. Therefore, the government aims to diversify away from fossil fuels and promote renewable energy generation through policies and renewable energy-related programs. The country’s Renewable Energy and Energy Efficiency Development Plan focuses on large scale solar, wind generation as well as geothermal and biomass technologies. This paper provides an update on the current energy position and renewable energy status in Algeria. Moreover, this paper discusses renewable energy (RE) policies and programs that aim to increase the country’s renewable energy generation and its implementation status.

This paper presents theoretical analysis and experimental implementation of a classical controller with intelligent properties. The controller has constant parameters, but it performs as an intelligent controller. The controller design mimics the fuzzy logic controller in a classical form and combines the advantages of classical controllers and properties of intelligent controllers. The designed controller parameters force the controlled variable to behave such as a first order system with a desired time constant. DC motor practical system is used to demonstrate the effectiveness of the presented controller. Root locus and frequency response using Bode diagram are used to help the design of the controller parameters. Simulation and experimental results verify the high performance of the presented controller. Keywords: Classical controller, DC motor, Root locus, Frequency response, Arduino microcontroller

This paper proposes a new method to calculate switching angles in selective harmonic elimination technique. It is introduced as a substitute for Newton–Raphson method and similar iteration methods. By utilizing classical control such as the proportional-integral (PI) control, the proposed method can perform a real-time calculation for multilevel inverter’s (MLI) switching angles over a wide range of modulation indexes. Therefore, it is able to respond to system dynamics without the need to store precalculated large lookup tables. The proposed method is applied to seven levels cascaded full H-bridge to eliminate its third- and fifth-harmonic contents from the modulation index 0.1 to 1.04. The same procedure can be extended to the vast majority of MLI topologies. A Simulink model is built to simulate and validate the accuracy, dynamics, and continuity of the solution generated by the proposed method. An experimental prototype is also built and its results are discussed to confirm the theory and simulation of the proposed method.

This paper proposes a new three-phase modular multilevel inverter ( MMLI ). The proposed inverter consists of repeated modular primary cells that are connected in series configuration. Therefore, the proposed topology can be extended to get more output voltage levels by adding additional cells without increasing voltage stresses across power switches. Both sinusoidal pulsewidth modulation ( SPWM ) and staircase modulation are successfully applied to the proposed inverter. The proposed inverter features many advantages such as reduced number of semiconductor power switches, driver circuits, dc-voltage sources, simplified control algorithm, and reduced voltage stresses across the switches independent of output voltage level. Furthermore, the performance of the proposed inverter is studied under both open-loop and closed-loop operations for highly inductive load. Beside the obtained simulation results, a laboratory prototype has been carried out and tested to verify the control techniques and performances of the topology. Simulation and experimental results are compared together to highlight the similarity and consistence of them.

Supplemental Digital Content is available in the text., Background: Primary percutaneous coronary intervention is frequently successful at restoring coronary artery blood flow in patients with acute ST-segment–elevation myocardial infarction; however, failed myocardial reperfusion commonly passes undetected in up to half of these patients. The index of microvascular resistance (IMR) is a novel invasive measure of coronary microvascular function. We aimed to investigate the pathological and prognostic significance of an IMR>40, alone or in combination with a coronary flow reserve (CFR≤2.0), in the culprit artery after emergency percutaneous coronary intervention for acute ST-segment–elevation myocardial infarction. Methods: Patients with acute ST-segment–elevation myocardial infarction were prospectively enrolled during emergency percutaneous coronary intervention and categorized according to IMR (≤40 or >40) and CFR (≤2.0 or >2.0). Cardiac magnetic resonance imaging was acquired 2 days and 6 months after myocardial infarction. All-cause death or first heart failure hospitalization was a prespecified outcome (median follow-up, 845 days). Results: IMR and CFR were measured in the culprit artery at the end of percutaneous coronary intervention in 283 patients with ST-segment–elevation myocardial infarction (mean±SD age, 60±12 years; 73% male). The median IMR and CFR were 25 (interquartile range, 15–48) and 1.6 (interquartile range, 1.1–2.1), respectively. An IMR>40 was a multivariable associate of myocardial hemorrhage (odds ratio, 2.10; 95% confidence interval, 1.03–4.27; P=0.042). An IMR>40 was closely associated with microvascular obstruction. Symptom-to-reperfusion time, TIMI (Thrombolysis in Myocardial Infarction) blush grade, and no (≤30%) ST-segment resolution were not associated with these pathologies. An IMR>40 was a multivariable associate of the changes in left ventricular ejection fraction (coefficient, −2.12; 95% confidence interval, −4.02 to −0.23; P=0.028) and left ventricular end-diastolic volume (coefficient, 7.85; 95% confidence interval, 0.41–15.29; P=0.039) at 6 months independently of infarct size. An IMR>40 (odds ratio, 4.36; 95% confidence interval, 2.10–9.06; P40, the combination of IMR>40 and CFR≤2.0 did not have incremental prognostic value. Conclusions: An IMR>40 is a multivariable associate of left ventricular and clinical outcomes after ST-segment–elevation myocardial infarction independently of the infarction size. Compared with standard clinical measures of the efficacy of myocardial reperfusion, including the ischemic time, ST-segment elevation, angiographic blush grade, and CFR, IMR has superior clinical value for risk stratification and may be considered a reference test for failed myocardial reperfusion. Clinical Trial Registration: URL: https//www.clinicaltrials.gov. Unique identifier: NCT02072850.

This paper presents a three-phase hybrid multilevel converter (MLC) topology for photovoltaic (PV) grid-connected system with a new current control scheme. Deadbeat current controller in α-β reference frame is designed in S-domain using derivative feedback to make the actual current to track exactly the reference current. The controller generates α-β reference voltage for inverter with lower power electronic components. The inverter has high quality output voltage which leads to a high quality injected grid current thus eliminates the using of custom and more expensive power filter for the high power rating systems. Besides, MLC switching losses is very low due to most of the power cell switches are operating at nearly fundamental frequency. Some selected simulation results are presented to validate the proposed system and the proposed control scheme.

OBJECTIVE: To assess European Association of Urology guideline adherence on the surgical management of patients with T1 renal tumours and the effects of centralisation of care. PATIENTS AND METHODS: Retrospective data from all kidney tumours that underwent radical nephrectomy (RN) or partial nephrectomy (PN) in the period 2012-2016 from the British Association of Urological Surgeons Nephrectomy Audit were retrieved and analysed. We assessed total surgical hospital volume (HV; RN and PN performed) per centre, PN rates, complication rates, and completeness of data. Descriptive analyses were performed, and confidence intervals were used to illustrate the association between hospital volume and proportion of PN. Chi- squared and Cochran-Armitage trend tests were used to evaluate differences and trends. RESULTS: In total, 13 045 surgically treated T1 tumours were included in the analyses. Over time, there was an increase in PN use (39.7% in 2012 to 44.9% in 2016). Registration of the Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) complexity score was included in March 2016 and documented in 39% of cases. Missing information on postoperative complications appeared constant over the years (8.5-9%). A clear association was found between annual HV and the proportion of T1 tumours treated with PN rather than RN (from 18.1% in centres performing

Objectives: \ud The aim of this study was to mechanistically investigate associations among cigarette smoking, microvascular pathology, and longer term health outcomes in patients with acute ST-segment elevation myocardial infarction (MI).\ud \ud Background: \ud The pathophysiology of myocardial reperfusion injury and prognosis in smokers with acute ST-segment elevation MI is incompletely understood.\ud \ud Methods: \ud Patients were prospectively enrolled during emergency percutaneous coronary intervention. Microvascular function in the culprit artery was measured invasively. Contrast-enhanced magnetic resonance imaging (1.5-T) was performed 2 days and 6 months post-MI. Infarct size and microvascular obstruction were assessed using late gadolinium enhancement imaging. Myocardial hemorrhage was assessed with T2* mapping. Pre-specified endpoints included: 1) all-cause death or first heart failure hospitalization; and 2) cardiac death, nonfatal MI, or urgent coronary revascularization (major adverse cardiovascular events). Binary logistic regression (odds ratio [OR] with 95% confidence interval [CI]) with smoking status was used.\ud \ud Results: \ud In total, 324 patients with ST-segment elevation MI were enrolled (mean age 59 years, 73% men, 60% current smokers). Current smokers were younger (55 ± 11 years vs. 65 ± 10 years, p < 0.001), with fewer patients with hypertension (52 ± 27% vs. 53 ± 41%, p = 0.007). Smokers had better TIMI (Thrombolysis In Myocardial Infarction) flow grade (≥2 vs. ≤1, p = 0.024) and ST-segment resolution (none vs. partial vs. complete, p = 0.010) post–percutaneous coronary intervention. On day 1, smokers had higher circulating C-reactive protein, neutrophil, and monocyte levels. Two days post-MI, smoking independently predicted infarct zone hemorrhage (OR: 2.76; 95% CI: 1.42 to 5.37; p = 0.003). After a median follow-up period of 4 years, smoking independently predicted all-cause death or heart failure events (OR: 2.20; 95% CI: 1.07 to 4.54) and major adverse cardiovascular events (OR: 2.79; 95% CI: 2.30 to 5.99).\ud \ud Conclusions: \ud Smoking is associated with enhanced inflammation acutely, infarct-zone hemorrhage subsequently, and longer term adverse cardiac outcomes. Inflammation and irreversible myocardial hemorrhage post-MI represent mechanistic drivers for adverse long-term prognosis in smokers. (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction. [BHF MR-MI]; NCT02072850).

This paper aims to study the multi-level inverter (MLI) fed the widely used doubly-fed induction generators (DFIG). The new DFIG generator connected to the electrical grid is evaluated during single-pole autoreclosure operation to continue the generator support to the system. The effect of using MLI on the performance of the DFIG system during the dynamic operation of the autoreclosure is studied for the first time and integrating a new MLI during the fault and clearing periods. A dynamic arc model is represented depending on Kizilcay model. Furthermore, the dynamics performance of the DFIG during integration with MLI to improve the performance is studied. The MLI is preferred because of processing high power with high resolution of the voltage waveforms and lower stresses on switches. The MLI enhances the performance of DFIG-based generating system associated with electrical grid system in case of single-pole autoreclosure. The proposed cases of studies are simulated using Matlab/Simulink to evaluate the proposed system performance during the autoreclosure operation for faults in double-circuit transmission systems.

Purpose: \ud To investigate the prognostic value of circumferential left ventricular (LV) strain measured by using cardiac MRI for prediction of major adverse cardiac events (MACE) following an acute ST-segment–elevation myocardial infarction (STEMI).\ud \ud Materials and Methods: \ud Participants with acute STEMI were prospectively enrolled from May 11, 2011, to November 22, 2012. Cardiac MRI was performed at 1.5 T during the index hospitalization. Displacement encoding with stimulated echoes (DENSE) and feature tracking of cine cardiac MRI was used to assess circumferential LV strain. MACE that occurred after discharge were independently assessed by cardiologists blinded to the baseline observations.\ud \ud Results: \ud A total of 259 participants (mean age, 58 years ± 11 [standard deviation]; 198 men [mean age, 58 years ± 11] and 61 women [mean age, 58 years ± 12]) underwent cardiac MRI 2.2 days ± 1.9 after STEMI. Average infarct size was 18% ± 13 of LV mass and circumferential strain was −13% ± 3 (DENSE method) and −24% ± 7 (feature- tracking method). Fifty-one percent (131 of 259 participants) had presence of microvascular obstruction. During a median follow-up period of 4 years, 8% (21 of 259) experienced MACE. Area under the curve (AUC) for DENSE was different from that of feature tracking (AUC, 0.76 vs 0.62; P = .03). AUC for DENSE was similar to that of initial infarct size (P = .06) and extent of microvascular obstruction (P = .08). DENSE-derived strain provided incremental prognostic benefit over infarct size for prediction of MACE (hazard ratio, 1.3; P < .01).\ud \ud Conclusion: \ud Circumferential strain has independent prognostic importance in study participants with acute ST-segment–elevation myocardial infarction.

Objectives We aimed to assess for sex differences in invasive parameters of acute microvascular reperfusion injury and infarct characteristics on cardiac MRI after ST-segment elevation myocardial infarction (STEMI). Methods Patients with STEMI undergoing emergency percutaneous coronary intervention (PCI) were prospectively enrolled. Index of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were measured in the culprit artery post-PCI. Contrast-enhanced MRI was used to assess infarct characteristics, microvascular obstruction and myocardial haemorrhage, 2 days and 6 months post-STEMI. Prespecified outcomes were as follows: (i) all-cause death/first heart failure hospitalisation and (ii) cardiac death/non-fatal myocardial infarction/urgent coronary revascularisation (major adverse cardiovascular event, MACE) during 5- year median follow-up. Results In 324 patients with STEMI (87 women, mean age: 61 ± 12.19 years; 237 men, mean age: 59 ± 11.17 years), women had anterior STEMI less often, fewer prescriptions of beta-blockers at discharge and higher baseline N-terminal pro-B-type natriuretic peptide levels (all p < 0.05). Following emergency PCI, fewer women than men had Thrombolysis in Myocardial Infarction (TIMI) myocardial perfusion grades ≤ 1 (20% vs 32%, p = 0.027) and women had lower corrected TIMI frame counts (12.94 vs 17.65, p = 0.003). However, IMR, CFR, microvascular obstruction, myocardial haemorrhage, infarct size, myocardial salvage index, left ventricular remodelling and ejection fraction did not differ significantly between sexes. Female sex was not associated with MACE or all-cause death/first heart failure hospitalisation. Conclusion There were no sex differences in microvascular pathology in patients with acute STEMI. Women had less anterior infarcts than men, and beta-blocker therapy at discharge was prescribed less often in women. Trial registration number NCT02072850.

When a photovoltaic (PV) system is exposed to physical objects and cloud coverage and connected to bypass diodes, a partial shading condition (PSC) occurs, which causes a global maximum power point (GMPP) and numerous local maximum power points (LMPPs) on the power-voltage (P-V) curve. Unlike conventional MPPT techniques that search for multiple LMPPs on the P-V curve, it is possible to track GMPP straightaway by designing a simple but robust MPPT technique that results in faster tracking speed and low power oscillations. Hence, in this study, an improved proportional-integral (PI) coordinated Maximum Power Point Tracking (MPPT) algorithm is designed to enhance the conversion efficiency of a PV system under PSC with fast-tracking speed and reduced power oscillations. Here, PI controllers are used to mitigating the steady-state errors of output voltage and current of PV system that later on passed through an incremental conductance (INC) algorithm to regulate the duty cycle of a dc&ndash, dc boost converter in order to ensure fast MPPT process. The PV system is integrated with the grid through an H-bridge inverter, which is controlled by a synchronous reference frame (SRF) controller. Tracking speed and steady-state oscillations of the proposed MPPT are evaluated in the MATLAB/Simulink environment and validated via a laboratory experimental setup using Agilent solar simulator and dSPACE (DS1104) controller. Results show that the proposed MPPT technique reduces the power fluctuations of PV array significantly and the tracking speed of the proposed method is 13% and 11% faster than the conventional INC and perturb and observe (P&amp, O) methods respectively under PSCs.

In this paper, a single phase cascaded semi-Z-source inverter is proposed for photovoltaic (PV) applications. The proposed semi-Z-source inverter utilizes a nonlinear Sinusoidal Pulse Width Modulation (SPWM) to produce sinusoidal voltage at the output as microinverter. The proposed system is able to produce an AC voltage at its output terminals by utilizing only four switches for each PV cell. Moreover, the proposed system overcomes the shading problem of PV systems as the maximum power point tracking can be independently achieved. One of the main advantages of the proposed topology is its modularity, which leads directly to increase the installed power. In addition, the proposed topology reduces the Total Harmonic Distortion (THD) and DC current components at the output during DC-AC conversion.

Background—The incidence and clinical significance of persistent T2 hyperintensity after acute ST-segment–elevation myocardial infarction (STEMI) is uncertain.\ud \ud Methods and Results—Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI: NCT02072850). Two hundred eighty-three STEMI patients (mean age, 59±12 years; 75% male) had cardiac magnetic resonance with T2 mapping performed at 2 days and 6 months post-STEMI. Persisting T2 hyperintensity was defined as infarct T2 >2 SDs from remote T2 at 6 months. Infarct zone T2 was higher than remote zone T2 at 2 days (66.3±6.1 versus 49.7±2.1 ms; P20% change in left ventricular end-diastolic volume; 21.91 [2.75–174.29]; P=0.004). Persistent T2 hyperintensity was associated with all-cause death and heart failure, but the result was not significant (P=0.051). ΔT2 was associated with all-cause death and heart failure (P=0.004) and major adverse cardiac events (P=0.013).\ud \ud Conclusions—Persistent T2 hyperintensity occurs in two thirds of STEMI patients. Persistent T2 hyperintensity was associated with the initial STEMI severity, adverse remodeling, and long-term health outcome.\ud \ud Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT02072850.

This paper presents a new design and implementation of a three-phase multilevel inverter $(MLI)$ for distributed power generation system using low frequency modulation and sinusoidal pulse width modulation $(SPWM)$ as well. It is a modular type and it can be extended for extra number of output voltage levels by adding additional modular stages. The impact of the proposed topology is its proficiency to maximize the number of voltage levels using a reduced number of isolated dc voltage sources and electronic switches. Moreover, this paper proposes a significant factor $(F_{C/L})$ , which is developed to define the number of the required components per pole voltage level. A detailed comparison based on $F_{C/L}$ is provided in order to categorize the different topologies of the $MLI$ s addressed in the literature. In addition, a prototype has been developed and tested for various modulation indexes to verify the control technique and performance of the topology. Experimental results show a well-matching and good similarity with the simulation results.

Background: This study was aimed to evaluate complete mandibular overdentures retained by a symphyseal single implant using ball and magnet attachments in both clinical and radiographic evaluation. Materials and Methods: Ten dental press fit titanium implants were installed in the lower jaws of completely edentulous patients according to two-stage surgical protocol. For each patient, one implant was installed in the symphyseal midline region, and left submerged and unloaded for 4 months. The patients were then divided into two equal groups. The first group received mandibular overdentures retained by ball and socket attachment. The second group received mandibular overdentures retained by magnet attachment. Both groups were supplied with conventional maxillary complete dentures. All patients were evaluated immediately after denture insertion, 6 months, and 12 months and after 24 months of overdenture insertion. Results: The study showed insignificant difference regarding the clinical condition and the marginal bone height changes in both groups during the follow-up period. Conclusion: Single implant retained overdenture with ball and socket or magnetic attachments was easy in construction, required less home care to maintain gingival health and give satisfactory clinical results.

A new simple analytical and closed‐form solution for the harmonic content injected in the five‐level inverters at low switching control technique is proposed. The equations of the fundamental and the third harmonic are formulated and solved. The switching angles have been calculated to fix the fundamental voltage at a specified value and cancel the third‐order harmonic. Two approaches have been proposed based on the modulation index. The proposed method can be feasible for a wide range of modulation index.

Objectives This study sought to determine the incidence and prognostic significance of persistent iron in patients post–ST-segment elevation myocardial infarction (STEMI). Background The clinical significance of persistent iron within the infarct core after STEMI complicated by acute myocardial hemorrhage is poorly understood. Methods Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI [Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction]). Cardiac magnetic resonance imaging including T2* (observed time constant for the decay of transverse magnetization seen with gradient-echo sequences) mapping was performed at 2 days and 6 months post-STEMI. Myocardial hemorrhage or iron was defined as a hypointense infarct core with T2* signal, Graphical abstract

This study presents a new design and implementation of a three-phase hybrid multilevel inverter (MLI) using space vector modulation. The proposed MLI consists of a reduced number of dc sources and switches to minimise the control complexity. The developed topology consists of two stages: main stage and auxiliary stage. The main stage is a conventional three-phase inverter with one high-voltage input dc source and six switches. The auxiliary stages contain three individual cells. Each cell consists of two switches and one low-voltage input dc source. This topology is a modular type and without changing the previous connection it can be extended for more number of output voltage levels by adding certain number of auxiliary stages. A space vector modulation control technique has been utilised in order to generate different switching sequences. The special feature of the proposed system is its capability to maximise the number of voltage levels using a reduced number of isolated dc voltage sources and electronic switches. A prototype has been developed and tested for various modulation indexes to verify the control technique and performance of the topology. Experimental results validate the simulation results and the experimental results show a good similarity with the simulation results.

Differential mode Three-phase Micro inverter DTMI has many features in low voltage application such as module integrated PV architectures. It has the ability to increase the PV module voltage using single stage with low components count. Differential inverter is implemented using three DC-DC converters with their input terminals connected in parallel and their outputs terminals connected differentially to perform three-phase voltages. Isolated DC-DC converters such as Flyback, Cuk and SEPIC converters have imperative inherent features to be utilized in differential inverter such as high voltage gain and voltage isolation. Moreover, the wide voltage range provided by buck-boost feature and low Common Mode Voltage CMV is substantial for micro inverters. This paper introduces full performance analysis for the three candidate differential inverters. Basic features such as voltage gain, voltage stress, efficiency and number of components are compared and illustrated in details. Also, simulation results for the three candidates are demonstrated to conclude the principal features of each one.

This study proposes a new two-stage high voltage gain boost grid-connected inverter for AC-module photovoltaic (PV) system. The proposed system consists of a high-voltage gain switched inductor boost inverter cascaded with a current shaping (CS) circuit followed by an H -bridge inverter as a folded circuit and its switches operate at line frequency. The switched inductor boost converter (SIBC) has one switch operates like a continuous conduction mode. The maximum power of the PV module is achieved through the SIBC circuit whereas the grid connection requirements are accomplished using the CS circuit with the H -bridge inverter. The switch of the CS circuit is controlled with a sine wave modulation control scheme. The main advantages of the new proposed system are high boosting gain, lower switching losses and reduces the ground leakage current as all H -bridge switches operate at the line frequency. A 120 W prototype has been built and experimentally tested. It has been found that experimental results have a good matching with the proposed analysis and simulation results.