Maximum power point tracking under partial shading conditions using an embedded system

The effects of global warming are deteriorating the planet and have enforced strict legıslatıons for carbon footprint reductıons. One of the main causes of global warming is the use of fossil fuels for power generatıon. Renewable energy is the solution to this problem as it produces electricity in a clean way. One of the promising forms of renewable energy is photovoltaic. However, solar is intermittent source of energy and dependent upon a number of factors including solar intensity and shadowing effects. This work aims to develop an effective and inexpensive microcontroller based control scheme to track the maximum power point in standalone solar photovoltaıc power systems. In conventional photovoltaic systems, the power curve has a single peak of power. There are many algorithms to track maximum power to maximise the efficiency of the photovoltaic system. However, when the photovoltaic is partially shaded, the output power can have multiple power peaks. A unique algorithm is derived to find the largest peak out of the many peaks. The entire power curve is scanned to find the maximum peak with respect to voltage, using a microcontroller. The largest peak is known as the global peak then presented to the output. The most commonly used algorithms; “perturb and observe” and “incremental conductance” were used. The scanning process is then repeated after a certain amount of time to maintain the global peak. The algorithm has achieved this with minimal loss of power. The algorithm scans and finds the global peak in 15 minutes of intervals, this process takes one second. Therefore, one second duration of power loss occurs from the photovoltaic in every 15 minutes. The algorithms are embedded in parallax microcontroller. Compare to the numerical Simulink model of photovoltaic systems experimental tracking efficiencies are slower. Nevertheless, in principle of the algorithms, perturb and observe works better than incremental conductance technique in terms of accuracy. The concentrated photovoltaic is required to move 11 times on an average day by using 0.7 W of power each time it moves, that of which the current photovoltaic modules can provide

Synthesis of 2-{[5-(aralkyl/aryl)-1,3,4-oxadiazol-2- yl]sulfanyl}-N-(4-methyl-1,3-thiazol-2-yl)acetamides: Novel bi-heterocycles as potential therapeutic agents

Purpose: To evaluate the therapeutic potential of new bi-heterocycles  containing a 1,3-thiazole and 1,3,4-oxadiazole in the skeleton against Alzheimer's disease and diabetes, supported by in-silico study. Methods: The synthesis was initiated by the reaction of 4-methyl- 1,3-thiazol-2-amine (1) with bromoacetyl bromide (2) in aqueous basic medium to obtain an electrophile,2-bromo-N-(4-methyl-1,3- thiazol- 2-yl)acetamide (3). In parallel reactions, a series of carboxylic acids, 4a-r, were converted through a sequence of three steps, into respective 1,3,4-oxadiazole heterocyclic cores, 7a-r, to utilize as nucleophiles. Finally, the designed molecules, 8a-r, were synthesized by coupling 7a-r individually with 3 in an aprotic polar solvent. The structures of these bi-heterocycles were elucidated by infrared (IR), electron ionization-mass spectrometry (EI-MS), proton nuclear magnetic resonance (1H-NMR) and carbon nuclear magnetic resonance (13C-NMR). To evaluate their enzyme inhibitory potential, 8a-r were screened against acetylcholinesterase (AChE), but brine shrimp lethality bioassay.Results: The most active compound against AChE was 8l with half-maximal inhibitory concentration (IC50) of 17.25 ± 0.07 μM. Against BChE, the highest inhibitory effect was shown by 8k (56.23 ± 0.09 μM). Compound 8f (161.26 ± 0.23μM) was recognized as a fairly good inhibitor of urease. In view of its inhibition of α-glucosidase, 8o (57.35 ± 0.17μM) was considered a potential therapeutic agent.Conclusion: The results indicate that some of the synthesized products with low toxicity exhibit notable enzyme inhibitory activity against selected enzymes compared with the reference drug, and therefore, are of potential therapeutic interestKeywords: 4-Methyl-1,3-thiazol-2-amine,1,3,4-Oxadiazole,  Cholinesterases, α-Glucosidase, Urease, Brine shrim

First Comprehensive In Silico

GalNAc-T1, a key candidate of GalNac-transferases genes family that is involved in mucin-type O-linked glycosylation pathway, is expressed in most biological tissues and cell types. Despite the reported association of GalNAc-T1 gene mutations with human disease susceptibility, the comprehensive computational analysis of coding, noncoding and regulatory SNPs, and their functional impacts on protein level, still remains unknown. Therefore, sequence- and structure-based computational tools were employed to screen the entire listed coding SNPs of GalNAc-T1 gene in order to identify and characterize them. Our concordant in silico analysis by SIFT, PolyPhen-2, PANTHER-cSNP, and SNPeffect tools, identified the potential nsSNPs (S143P, G258V, and Y414D variants) from 18 nsSNPs of GalNAc-T1. Additionally, 2 regulatory SNPs (rs72964406 and #x26; rs34304568) were also identified in GalNAc-T1 by using FastSNP tool. Using multiple computational approaches, we have systematically classified the functional mutations in regulatory and coding regions that can modify expression and function of GalNAc-T1 enzyme. These genetic variants can further assist in better understanding the wide range of disease susceptibility associated with the mucin-based cell signalling and pathogenic binding, and may help to develop novel therapeutic elements for associated diseases

دراسة الصـوت والـدلالــة

The Phonetics deals with the production of speech sounds by humans, often without prior knowledge of the language being spoken. Phonology is about patterns of sounds, especially different patterns of sounds in different languages, or within each language, different patterns of sounds in different positions in words etc. This study dealing with phonemic and phonology, phonology have main role for sounds construction and word plays showing the meaning within the scope of composing. The total sounds of the singular word, whether these sounds are consonants or vowels. Phonetic connotation depends on the change of phonemes by using substitutionary matches between words and sentence, because every phoneme is a substitute for another, so changing it or replacing it with another must be followed by a difference in the meaning. This type of semantics is great importance among other semantics, and because of its importance, the Arabs treated this kind of semantics before Western linguists, therefore I have selected this topic for study for discovering something new in this filed

Tapping states: Effect of pump phase fluctuations in micromaser

We presented the exact solution for the photon statistics of one-mode $\Lambda -$type micromaser, including the effect of finite natural linewidth of microwave pump field. It is shown that trapping states exist in a $\Lambda -$type micromaser even for finite temperature limit and finite value of natural linewidth of the microwave pump field. A periodic dependence on interaction times is shown to arise as we move from zero to finite linewidth values

An exact solution of the Fokker-Planck equation for a cascade micromaser

We have developed the quantum theory of a three-level two-photon cascade micromaser by considering the atoms initially prepared in a partial coherent superposition of upper and lower states and then injected into the cavity. The master equation for the maser field is derived and converted into a Fokker-Planck equation. An exact steady state solution of the Fokker-Planck equation is presented. It has been seen that the symmetry of the field in the cavity is not ``broken'' in contradiction to the one-photon case

Structural Properties and Nonlinear Optical Responses of Halogenated Compounds: A DFT Investigation on Molecular Modelling

Computational chemistry is used to evaluate structures of different compounds by using principles of theoretical and quantum chemistry integrated into useful computer programs. It is used to determine energies, dipole moments and thermodynamic properties of different compounds. The present work reports the computational study of six donor-acceptor dyes. The computational method CAM-B3LYP with 6-31G(d,p) was used in this research to determine the effect of halogens on non-linear optical compounds. HOMO-LUMO energy gaps, dipole polarizabilities, first hyperpolarizabilities, and absorption spectra of six studied compounds (dye 1: 4-(2-(4-fluorophenyl)ethynyl)benzenamine; dye 2: 4-(2-(4-chlorophenyl)ethynyl)benzenamine; dye 3: 4-(2-(4-bromophenyl)ethynyl)benzenamine; dye 4: 5-(2-(4-fluorophenyl)ethynyl)benzene-1,2,3-triamine; dye 5: 5-(2-(4-chlorophenyl)ethynyl)benzene-1,2,3-triamine; dye 6: 5-(2-(4-bromophenyl)ethynyl)benzene-1,2,3-triamine) with aniline and halo phenyl segments were computed by using density functional theory (DFT) and time-dependent density functional theory (TDDFT). Results indicate that all dyes showed wavelengths of maximum absorbance in the visible region. Small HOMO-LUMO energy gaps were observed in all investigated dyes. The present calculations on these dyes (1-6) offer an understanding of the direction of charge transfer (CT) and how NLO behavior can be explained. The aniline-to-halo phenyl CT, caused by the combination of the donor amino group and the acceptor halo group, could be a reason for NLO behavior of these sorts of compounds. These compounds exhibit significant molecular second-order NLO responses, especially dyes (6) and (5), with second-order polarizability determined to be approximately 4600 a.u

Computational Study on Non-linear Optical and Absorption Properties of Benzothiazole based Dyes: Tunable Electron-Withdrawing Strength and Reverse Polarity

Various organic dyes possessing characteristic D-π-A-A configuration have been designed in this article. The analysis of the relation between polarity of charge transfer and the unsymmetrical nature of the benzothiazole group has been studied. The absorption spectra, electronic characteristic properties and non-linear optical responses were simulated using a quantum chemical approach. The results have indicated that the systems show higher polarizability (α) and hyperpolarizability (β) with commonly used polarity in comparison to the reverse polarity. A red-shifted absorption spectra were observed with systems having common polarities. This study illustrates the rule to design non-linear optical material with low energy charge transfer excited states and high value of oscillation

Evacuation of Difficulties and Challenges for Academic Writing in ESL Learning

This study explores the challenges encountered by 60 ESL undergraduate students across four universities in Lahore in their written compositions. Through a comprehensive analysis, the study identifies prominent issues hindering effective academic writing. The investigation reveals notable concerns, including coherence deficits between sentences and paragraphs, limited lexical choices, Subject-Verb Agreement and Pronoun-Antecedent Agreement errors, and punctuation inconsistencies. Aligning with prior research, these findings underline the significance of these linguistic aspects in shaping the quality and clarity of written work. The study underscores the importance of a multifaceted approach in addressing these challenges. It emphasizes the need for instructional interventions that integrate strategies for enhancing coherence, expanding vocabulary, reinforcing grammar rules, and refining punctuation accuracy. By recognizing the interconnectedness of these writing facets, educators can foster a more holistic development of writing skills among ESL undergraduates. The implications of this study resonate beyond the academic realm, equipping students with enhanced communication abilities that transcend educational boundaries and prepare them for effective engagement in a broader societal context