Maximum Power Point Tracking Algorithm for Advanced Photovoltaic Systems

Photovoltaic (PV) systems are the major nonconventional sources for power generation for present power strategy. The power of PV system has rapid increase because of its unpolluted, less noise and limited maintenance. But whole PV system has two main disadvantages drawbacks, that is, the power generation of it is quite low and the output power is nonlinear, which is influenced by climatic conditions, namely environmental temperature and the solar irradiation. The natural limiting factor is that PV potential in respect of temperature and irradiation has nonlinear output behavior. An automated power tracking method, for example, maximum power point tracking (MPPT), is necessarily applied to improve the power generation of PV systems. The MPPT methods undergo serious challenges when the PV system is under partial shade condition because PV shows several peaks in power. Hence, the exploration method might easily be misguided and might trapped to the local maxima. Therefore, a reasonable exploratory method must be constructed, which has to determine the global maxima for PV of shaded partially. The traditional approaches namely constant voltage tracking (CVT), perturb and observe (P&O), hill climbing (HC), Incremental Conductance (INC), and fractional open circuit voltage (FOCV) methods, indeed some of their improved types, are quite incompetent in tracking the global MPP (GMPP). Traditional techniques and soft computing-based bio-inspired and nature-inspired algorithms applied to MPPT were reviewed to explore the possibility for research while optimizing the PV system with global maximum output power under partially shading conditions. This paper is aimed to review, compare, and analyze almost all the techniques that implemented so far. Further this paper provides adequate details about algorithms that focuses to derive improved MPPT under non-uniform irradiation. Each algorithm got merits and demerits of its own with respect to the converging speed, computing time, complexity of coding, hardware suitability, stability and so on

Mahanine restores RASSF1A expression by down-regulating DNMT1 and DNMT3B in prostate cancer cells

BACKGROUND: Hypermethylation of the promoter of the tumor suppressor gene RASSF1A silences its expression and has been found to be associated with advanced grade prostatic tumors. The DNA methyltransferase (DNMT) family of enzymes are known to be involved in the epigenetic silencing of gene expression, including RASSF1A, and are often overexpressed in prostate cancer. The present study demonstrates how mahanine, a plant-derived carbazole alkaloid, restores RASSF1A expression by down-regulating specific members of the DNMT family of proteins in prostate cancer cells. RESULTS: Using methylation-specific PCR we establish that mahanine restores the expression of RASSF1A by inducing the demethylation of its promoter in prostate cancer cells. Furthermore, we show that mahanine treatment induces the degradation of DNMT1 and DNMT3B, but not DNMT3A, via the ubiquitin-proteasome pathway; an effect which is rescued in the presence of a proteasome inhibitor, MG132. The inactivation of Akt by wortmannin, a PI3K inhibitor, results in a similar down-regulation in the levels DNMT1 and DNMT3B. Mahanine treatment results in a decline in phospho-Akt levels and a disruption in the interaction of Akt with DNMT1 and DNMT3B. Conversely, the exogenous expression of constitutively active Akt inhibits the ability of mahanine to down-regulate these DNMTs, suggesting that the degradation of DNMT1 and DNMT3B by mahanine occurs via Akt inactivation. CONCLUSIONS: Taken together, we show that mahanine treatment induces the proteasomal degradation of DNMT1 and DNMT3B via the inactivation of Akt, which facilitates the demethylation of the RASSF1A promoter and restores its expression in prostate cancer cells. Therefore, mahanine could be a potential therapeutic agent for advanced prostate cancer in men when RASSF1A expression is silenced

The clinical behavior of mixed ductal/lobular carcinoma of the breast: a clinicopathologic analysis

<p>Abstract</p> <p>Background</p> <p>To date, the clinical presentation and prognosis of mixed ductal/lobular mammary carcinomas has not been well studied, and little is known about the outcome of this entity. Thus, best management practices remain undetermined due to a dearth of knowledge on this topic.</p> <p>Methods</p> <p>In this paper, we present a clinicopathologic analysis of patients at our institution with this entity and compare them to age-matched controls with purely invasive ductal carcinoma (IDC) and historical data from patients with purely lobular carcinoma and also stain-available tumor specimens for E-cadherin. We have obtained 100 cases of ductal and 50 cases of mixed ductal/lobular breast carcinoma.</p> <p>Results</p> <p>Clinically, the behavior of mixed ductal/lobular tumors seemed to demonstrate some important differences from their ductal counterparts, particularly a lower rate of metastatic spread but with a much higher rate of second primary breast cancers.</p> <p>Conclusions</p> <p>Our data suggests that mixed ductal/lobular carcinomas are a distinct clinicopathologic entity incorporating some features of both lobular and ductal carcinomas and representing a pleomorphic variant of IDC.</p

Noise decomposition of dual synchronized propellers in hover

Paper no. AIAA 2024-3045, Session: Propeller‚ Rotorcraft and V/STOL Noise IIIThis experimental study investigates the acoustic characteristics of dual propellers in the side-by-side configuration, and addresses the impact of blade tip-to-tip separation distances and relative blade-to-blade phase angles on the tonal noise generation with a specially designed propeller rig. The parametric study of co-rotating and counter-rotating configurations is performed to emphasize the effect and importance of phase synchronization in producing the tonal components, such as the first Blade Pass Frequency (BPF). The linearity of acoustic interference for the side-by-side propellers is investigated through the principle of superimposition. A unique noise decomposition algorithm for various rotation angles is developed to understand the directional behavior of the synchronized propellers. The responses of the first BPF noise radiation as a function of the rotation angle under different combinations of rotating direction and blade-to-blade phase angle have been established

Powder Compaction: Compression Properties of Cellulose Ethers

Effective development of matrix tablets requires a comprehensive understanding of different raw material attributes and their impact on process parameters. Cellulose ethers (CE) are the most commonly used pharmaceutical excipients in the fabrication of hydrophilic matrices. The innate good compression and binding properties of CE enable matrices to be prepared using economical direct compression (DC) techniques. However, DC is sensitive to raw material attributes, thus, impacting the compaction process. This article critically reviews prior knowledge on the mechanism of powder compaction and the compression properties of cellulose ethers, giving timely insight into new developments in this field

Pressure shielding mechanism of canopies for trailing edge noise reduction in aerofoils

Session: Airframe / High-Lift Noise IView Video Presentation: https://doi.org/10.2514/6.2023-3204.vidThe pressure shielding mechanism of bio-inspired surface treatment, called canopies, has been investigated experimentally and applied to reduce trailing edge noise generated by aero- foils. Surface pressure experiments beneath the boundary layer on a flat and aerofoil section show that canopies can attenuate surface pressure in two frequency ranges, ∆ f 1 = 0.1 to 1.0 kHz and ∆f2 = 2 to 12 kHz, at some critical canopies’ height from the wall. Canopies with an Open-Area-Ratio (OAR or σ) of 50 % placed closer (h/δ=0.08) to the surface tend to in- crease attenuation with frequency, without any low-frequency peak attenuation. This high- frequency attenuation is mainly due to the mechanism of dissipation, of small-scale structures in the boundary-layer, provided by the canopies, which have relatively higher wall shear stress compared to flat plate or thicker canopy designs. As h/δ increases, the low-frequency atten- uation in the surface pressure becomes noticeable, with a peak value of 5 dB for a critical height of h/δ∗ ∼ 1, indicating the mechanism of blockage or shielding of large structures in the boundary-layer is responsible for the low-frequency attenuation. For h/δ ≥ 0.16, both the low- and high-frequency attenuation reduces and becomes almost zero for h/δ = 0.5. Furthermore, the mechanism of pressure shielding provided by the canopy treatment is shown to be a local phenomenon, for 70% <OAR < 90 % and very sensitive to the location of the canopy itself. The maximum attenuation in surface pressure is seen for the canopy geometries with small rod diameters with less spacing. The optimum canopy geometry, based on the surface pres- sure studies, was applied near the trailing edge of the NACA0012 aerofoil. The far-field noise study demonstrates, for the first time, that canopies can reduce broadband noise levels up to 12-14 dB in the frequency range between 2 and 12 kHz, provided they are scaled appropriately based on the incoming turbulent boundary-layer flow.EPSRC under grant No. EP/V038273/1

Diuretics in pregnancy:Data from the ESC Registry of Pregnancy and Cardiac disease (ROPAC)

Aims: Data on diuretic use in pregnancy are limited and inconsistent, and consequently it remains unclear whether they can be used safely. Our study aims to evaluate the perinatal outcomes after in-utero diuretic exposure. Methods and results: The Registry Of Pregnancy And Cardiac disease (ROPAC) is a prospective, global registry of pregnancies in women with heart disease. Outcomes were compared between women who used diuretics during pregnancy versus those who did not. Multivariable regression analysis was used to assess the impact of diuretic use on the occurrence of congenital anomalies and foetal growth. Diuretics were used in 382 (6.7%) of the 5739 ROPAC pregnancies, most often furosemide (86%). Age &gt;35 years (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.2–2.0), other cardiac medication use (OR 5.4, 95% CI 4.2–6.9), signs of heart failure (OR 1.7, 95% CI 1.2–2.2), estimated left ventricular ejection fraction &lt;40% (OR 2.9, 95% CI 2.0–4.2), New York Heart Association class &gt;II (OR 3.4, 95% CI 2.3–5.1), valvular heart disease (OR 6.3, 95% CI 4.7–8.3) and cardiomyopathy (OR 3.9, 95% CI 2.6–5.7) were associated with diuretic use during pregnancy. In multivariable analysis, diuretic use during the first trimester was not significantly associated with foetal or neonatal congenital anomalies (OR 1.3, 95% CI 0.7–2.6), and diuretic use during pregnancy was also not significantly associated with small for gestational age (OR 1.4, 95% CI 1.0–1.9). Conclusions: Our study does not conclusively establish an association between diuretic use during pregnancy and adverse foetal outcomes. Given these findings, it is essential to assess the risk–benefit ratio on an individual basis to guide clinical decisions.</p

Diuretics in pregnancy: Data from the ESC Registry of Pregnancy and Cardiac disease (ROPAC)

AIMS Data on diuretic use in pregnancy are limited and inconsistent, and consequently it remains unclear whether they can be used safely. Our study aims to evaluate the perinatal outcomes after in-utero diuretic exposure. METHODS AND RESULTS The Registry Of Pregnancy And Cardiac disease (ROPAC) is a prospective, global registry of pregnancies in women with heart disease. Outcomes were compared between women who used diuretics during pregnancy versus those who did not. Multivariable regression analysis was used to assess the impact of diuretic use on the occurrence of congenital anomalies and foetal growth. Diuretics were used in 382 (6.7%) of the 5739 ROPAC pregnancies, most often furosemide (86%). Age >35 years (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.2-2.0), other cardiac medication use (OR 5.4, 95% CI 4.2-6.9), signs of heart failure (OR 1.7, 95% CI 1.2-2.2), estimated left ventricular ejection fraction II (OR 3.4, 95% CI 2.3-5.1), valvular heart disease (OR 6.3, 95% CI 4.7-8.3) and cardiomyopathy (OR 3.9, 95% CI 2.6-5.7) were associated with diuretic use during pregnancy. In multivariable analysis, diuretic use during the first trimester was not significantly associated with foetal or neonatal congenital anomalies (OR 1.3, 95% CI 0.7-2.6), and diuretic use during pregnancy was also not significantly associated with small for gestational age (OR 1.4, 95% CI 1.0-1.9). CONCLUSIONS Our study does not conclusively establish an association between diuretic use during pregnancy and adverse foetal outcomes. Given these findings, it is essential to assess the risk-benefit ratio on an individual basis to guide clinical decisions

Modified TNO-Blake model for aerofoil surface pressure prediction with canopies

Session: Airframe / High-Lift Noise IView Video Presentation: https://doi.org/10.2514/6.2023-3203.vidThe modelling of the surface pressure spectrum beneath a turbulent boundary layer near the trailing edge of an aerofoil with bio-inspired surface treatments, called canopies, is investigated. Canopies are simply a cylindrical rods uniformly spaced along the span of the aerofoil. The velocity measurements indicated that the flow at the trailing edge of an aerofoil treated with canopies is localised and shows periodic behaviour across the span with treatment spacing. As a result, the mean-flow velocity gradient along the span (@U1=@x3) cannot be assumed as zero for x2=h = 4, which is shown in this paper. Therefore, the original surface pressure solution of Poisson’s equation is modified by introducing an additional source term consisting of the mean-shear contribution, given as @U1=@x3 @u3=@x1. Furthermore, the surface pressure attenuation due to the canopies shows a periodic behaviour across the span for treatments with an Open-Area-Ratio (OAR) between 70% and 90 %. This observation is consistent with our previous experimental results; therefore, the primary motivation for proposing a 3D TNO-Blake model, accounting for the interaction between the gradient of the stream-wise mean velocity along the span and span-wise fluctuating component along the stream. The model is built based on the inputs from Large Eddy Simulation results and additional wind tunnel measurements.EPSRC under grant No EP/V038273/1