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Performance Dependence of (I-V) and (C-V) for Solar Cells on Environmental Conditions
Get PDFThe present paper is a trial to shed further light on the dependence performance of mono-crystalline silicon solar cell (photovoltaic cell) on the environmental conditions. In this concern, the static (I-V) and dynamic (C-V) characteristics measurement were studied in details under the effect of illumination type, intensity and wavelength, as well temperature on the physical and electrical parameters of solar cell. The dependence of cell parameters- extracted from (I-V) characteristic curves- open-circuit voltage (Voc), short-circuit current (Isc), fill-factor (FF), conversion efficiency (η) as well the series -and shunt-resistances (Rs and Rsh), on the intensity has been investigated for a wide illumination intensity range 1.0 - 70 mW/cm2. It was observed that, for illumination levels higher than 10 klux, the values of Voc, Rsh, FF and efficiency were shown to be saturated. Isc was shown to be increased linearly, while Rs decreased exponentially as a function of illumination level. On the other hand, considering the dynamic characteristics (C-V), a detailed study was carried out for solar cells biased on both the forward - and reverse modes at frequency range of 20 kHz - 140 kHz and different illumination - levels. From which, the barrier potential (Vbi) and doping (charge carrier) concentration (Na) were determined. Besides, the influence of temperature within the range from 30 up to 110 oC on both the static and dynamic characteristics was tested. From which, it is clear that Voc, maximum powers (Pmax), FF, η of the sample were shown to be temperature decreasing functions. Moreover, Isc has a feeble increasing temperature coefficient. Finally, the solar cell capacitance (C) and dissipation factor (D) rise with rising temperature in both bias voltage conditions, while, impedance (Z), quality factor (Q), and phase angle (φ) reduce with rising temperature
Surprising Attraction of Non-Magnetic Materials to Magnets
Get PDFWe explored the effects of static magnetic fields on materials commonly classified as non-ferromagnetic and non-paramagnetic. By floating pieces of paper, wood, Teflon, and Nafion on different liquids and placing those objects near a neodymium magnet, we found that the objects moved consistently towards the magnet. As the distance between object and magnet diminished, the attraction strengthened. The results imply that objects currently classified as non-magnetic may in fact be at least weakly magnetic
Characterization and Antimicrobial Characteristics of Chitosan Modified Hibiscus Sabdariffal.Extract
Get PDFSamples of Chitosan (Cs) natural polymer containing successive amount of Hibiscus sabdariffaLextract were sucssesfuly synthesized using traditional simple casting route. Prepared thin films were characterized using fourier transform infrared (FTIR). FT-IR of synthesized thin films reveals maintenance of the characteristic bands of chitosan in addition to the appearance of two new sharp intense bands at 1782 and 954 cm-1 intensified with increasing plant extract content and assigned to the interaction between NH2 of polymer skeleton with falvanoids present in the extract. Obtained data poit out to a formation of homogenous composite structure. X-ray diffraction data (XRD) reval no prounounced band indicating the amorphous structure of synthesized final polymeric product. In vitro antimicrobial studies were performed using both gram negative and positive bacteria in addition to Fungul and Yeast activity using simple minimum inhibition zone (MIZ) standeredroutain
Issues on Design of Piled Raft Foundation
Get PDFA piled raft foundation consists of a thick concrete slab reinforced with steel which covers the entire contact area of the structure, in which the raft is supported by a group of piles or a number of individual piles. Bending moment on raft, differential and average settlement, pile and raft geometries are the influencing parameters of the piled raft foundation system. In this paper, a detailed review has been carried out on the issues on the raft foundation design. Also, the existing design procedure was explained
Synthesis , Characterization and Biological activity of new derivatives of Chromen-2-one
No full textWe report the organic syntheses of new derivatives from Chromen-2-one and their antibacterial activity. Compounds 4-[Acetyl-(2-oxo-2H-chromen-4-yl)-amino]-
benzenesulfonyl chloride 1a, 4-[Acetyl-(2-oxo-3-phenylsulfamoyl-2H-chromen-4-yl)-amino]-benzenesulfonyl chloride 2a , 2-{4-[Acetyl-(4-chlorosulfonyl-phenyl)-amino]-2-oxo-3-phenylsulfamoyl-2H-chromen-7-ylamino}-benzoic acid 3a.
All Structures have been synthesized and characterized using melting points , IR spectra , 1H-NMR, 13C-NMR spectra , and elemental analyses . The purified synthesized compounds (1a,2a,3a), at contcentrations 2,3,5 mg/ml was tested for their antibacterial activity against three bacterial cultures ;Staphylococcus aureus, Escherchia coli and Bacillus cereus. The antibacterial activity of synthesized compounds are compared with antibacterial activity of standard antibiotics cephalexine and streptomycine.
The compounds (1a,2a,3a) shows different bacteriostatic and bacteriocidal activity
Direct Spectrophotometric Determination of Glimepiride in Pure Form And Pharmaceutical Formulations Using Bromocresol Purple
Get PDFA simple, direct and accurate spectrophotometric method has been developed for the determination of Glimepiride (GLM) in pure and pharmaceutical formulations by complex formation with bromocresol purple (BCP). The method involves the formation of a yellow ion-pair complex between BCP with glimepiride at pH<3,8; after reacting GLM with Na2CO3 to give C24H33N4H+O5NaS which is extracted by chloroform. The formed complex [GLM]:[ BCP] was measured at lmax 418 nm against the reagent blank prepared in the same manner. Variables were studied in order to optimize the reaction conditions. Molar absorptivity (e) for complex was 20600 L.mol-1.cm-1. Beer’s law was obeyed in the concentration range of 1.226 – 46.608 mg.mL-1 in present of 5.0x10-4 mol/l of BCP with good correlation coefficient (R2= 0.9997). The relative standard deviation did not exceed 3.6%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.15 and 0.46 mg.mL-1, respectively. The proposed method was validated for specificity, linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ) and robustness. The developed method is applicable for the determination of GLM in pure and different dosage forms with average assay of 98.8 to 102.0% and the results are in good agreement with those obtained by the RP-HPLC reference method.  
NEAR RINGS ADMITTING CERTAIN DECOMPOSITION THEOREMS
Get PDFIn the present paper we shall investigate some decomposition theorems for near rings satisfying any one of the conditions; (1) (2)whereare integers
Functional moments estimators analysis by the Monte-Carlo method for model of mixture with varying concentrations
Get PDFThe functional moments estimation by the sample from the mixture with varying concentrations is studied. The problem of efficiency the simple linear estimator with fixed weight against the adaptive or improved estimators with random weight is considered. By the Monte-Carlo method it is shown that simple linear estimator is better for small sample sizes, but for large samples the adaptive and improved estimators are more efficient
Inverse System in The Category of Intuitionistic Fuzzy Soft Modules
Get PDFThis paper begins with the basic concepts of soft module. Later, we introduce inverse system in the category of intutionistic fuzzy soft modules and prove that its limit exists in this category. Generally, limit of inverse system of exact sequences of intutionistic fuzzy soft modules is not exact. Then we define the notion which is first derived functor of the inverse limit functor. Finally, using methods of homology algebra, we prove that the inverse system limit of exact sequence of intutionistic fuzzy soft modules is exact
The Neutrosophic Soft Modules
No full textMolodtsov initiated the concept of soft sets in [17]. Maji et al. defined some operations on soft sets in [13]. Aktas et al. generalized soft sets by defining the concept of soft groups in [2]. After then, Qiu-Mei Sun et al. gave soft modules in [20]. In this paper, the concept of neutrosophic soft module is introduced and some of its basic properties are studied