Flexible Dye-Sensitized Solar Cells: a Study of Photoanode and Counter Electrode Materials

Compare to flat devices based on rigid substrates, fiber-shaped dye sensitized solar cells hold advantages of smaller size, light weight, facile fabrication, flexibility, and low cost, thus a promising direction for applications such as wearable electronic devices. Due to their unique photovoltaic properties, nanostructured morphologies of TiO2 on flexible substrate have been studied extensively in the recent years for applications in dye sensitized solar cells (DSSCs). Micro-structured electrode materials with high surface area can facilitate rapid charge transport and thus improve the light-to-current conversion efficiency. In the first part of this work the nano-tree morphology of the TiO2 photoanode material on Ti wire has been investigated. To utilize the surface plasmon resonance (SPR) and hence increase the photon conversion efficiency, a plasmonic nanoparticle Ag has also been deposited using a very feasible photoreduction method. In the second part the micro-flower morphology of TiO2 on Ti wire has been synthesized and structural and photoelectric performance has been evaluated. In the third part, a non-platinum catalyst for the counter electrode has been synthesized and a detailed study of the performance has been conducted

FORMULATION AND STATISTICAL OPTIMIZATION OF BILAYER SUBLINGUAL TABLETS OF LEVOCETIRIZINE HYDROCHLORIDE AND AMBROXOL HYDROCHLORIDE

Objective: The aim of the present study is to formulate and optimize bilayer sublingual tablets of Levocetrizine hydrochloride and Ambroxolhydrochloride using a 23 response surface methodology employing design expert-10.0. Sodium starch glycolate and Camphor were selected asindependent variables while disintegration time (sec) and water absorption ratio (%) were considered as responses.Methods: The bilayer sublingual tablets were prepared by direct compression and evaluated for various evaluation parameters including hardness,thickness, friability, drug content uniformity, wetting time, water absorption ratio and disintegration time. The prepared optimized bilayer sublingualtablets of Levocetrizine hydrochloride and Ambroxol hydrochloride having above 2 responses-disintegration time (sec) and water absorption ratio.Results: The optimized batch having concentration of sodium starch glycolate and camphor was found within the standard limit of parametersdisintegrationtime (sec) and water absorption ratio (%) as 61 sec and 69.67%.Conclusion: The direct compression method in this study is relatively simple and safe and a stable, effective and pleasant tasting bilayer sublingualtablet, which has a good balance over disintegration time and water absorption ratio, was formulated.Keywords: Levocetirizine hydrochloride, Ambroxol hydrochloride, Croscarmellose sodium, Sodium starch glycolate, Camphor, Statistical optimization

Pharmacological screening of Alsotonia scholaris

A large number of medicinal plants are claimed to possess anthelmintic property in traditional systems of medicine and are also utilize by ethnic groups worldwide. The development of anthelmintic resistance and the high cost of conventional anthelmintic drugs led to the evaluation of medicinal plant as an alternative source of anthelmintice. In the current study were conducted to determine the possible anthelmintic and antibacterial effects of leaves of Alstonia scholaris. The plant Alstonia scholaris has been used in different system of traditional medication for the treatment of diseases and ailments of human beings including anthelmintic activity

Microbial contamination of cosmetics and the pharmaceutical products, and their preservation strategies: A comprehensive review

A brief discussion of the numerous types of microbial contamination of the pharmaceutical and cosmetic items and their corresponding effects is attempted in this study. The pharmaceutical and cosmetic products are particularly vulnerable to microbial contamination, because they contain chemical compounds that encourage the microbial development. Contamination can potentially happen during production; storage, and/ or usage. These contaminants can cause a variety of unfavorable effects, including alteration of the consistency and appearance; phase separation, alteration or loss of activity, and even the emergence of toxicity in the contaminated items. Organizations such as the United States Food and Drug Administration (FDA) actively regulate the consumer safety by frequently recalling the potentially dangerous or contaminated products from the market. Therefore, to prevent microbial contamination and increase the shelf life of a product, a variety of preservatives are added to the final formulation. However, some of these preservatives may be toxic to the consumer as well. In this context, we have also reviewed the mechanisms of action of some of the most commonly used antimicrobial preservatives, including the organic acids; parabens, phenol, organomercurials, ethanol, chlorobutanol, benzalkonium chloride, chlorocresol, sodium benzoate, isothiazolinones, sodium sulfite, and sodium metabisulfite, in addition to the potential toxicity caused by them to the consumers

Synthesis of mesogen-nanoparticle composites by doping 4-decyloxybenzoic acid with substrate-functionalized ZnO nanoparticle

Nanomaterials and Mesogenic materials are two important pillars of today’s science and technology, in the fields of both material and biological applications. Mesogens or liquid crystals (LC) are self-aggregated anisotropic fluids with long range order, and the nature of self-aggregation largely controls their physical and material properties. Doping of nanomaterials over liquid crystalline matrix can provide valuable tools for development of materials with new or improved properties. In the present work 4-decyloxybenzoic acid is taken as the mesogenic matrix. It is observed that, composite prepared by doping of 4-decyloxybenzoic acid mesogen matrix by ZnO nanoparticle pre-functionalized with the same mesogen, caused a marked alteration in the mesogenic behavior. With 3% doping of matrix pre-functionalized ZnO NP on 4- decyloxy benzoic acid, we could achieve a shift of about 31ºC in the N-Iso transition temperature and, a decrease of >10ºC for the onset of liquid crystallinity by this method without quenching any of the mesophases exhibited by the pure mesogen. The synthesized materials have been characterized by variable temperature Polarised optical microscopy (POM), DSC, FTIR, XRD, EDX, and TEM This process may be considered for preparation other nanoparticle-mesogen composites as well. It was observed that, the effect of doping on the transition temperature and enthalpy of 4-Decyloxybenzoic Acid can be significantly enhanced by pre-functionalizing the dopant (ZnO NP) with the substrate molecules and then mixing this substrate functionalized ZnO nanoparticle with the bulk substrate

A photoanode with hierarchical nanoforest TiO 2 structure and silver plasmonic nanoparticles for flexible dye sensitized solar cell

Due to unique photovoltaic properties, the nanostructured morphologies of TiO2 on flexible substrate have been studied extensively in the recent years for applications in dye sensitized solar cells (DSSCs). Microstructured electrode materials with high surface area can facilitate rapid charge transport and thus improve the light-to-current conversion efficiency. Herein we present an improved photoanode with forest like photoactive TiO2 hierarchical microstructure using a simple and facile hydrothermal route. To utilize the surface plasmon resonance (SPR) and hence increase the photon conversion efficiency, a plasmonic nanoparticle Ag has also been deposited using a very feasible photoreduction method. The branched structure of the photoanode increases the dye loading by filling the space between the nanowires, whereas Ag nanoparticles play the multiple roles of dye absorption and light scattering to increase the light-to-current conversion efficiency of the device. The branched structure provides a suitable matrix for the subsequent Ag deposition. They improve the charge collection efficiency by providing the preferential electron pathways. The high-density Ag nanoparticles deposited on the forest like structure also decrease the charge recombination and therefore improve the photovoltaic efficiency of the cells. As a result, the DSSC based on this novel photoanode shows remarkably higher photon conversion efficiency (ηmax = 4.0% and ηopt = 3.15%) compared to the device based on pristine nanowire or forest-like TiO2 structure. The flexibility of the device showed sustainable and efficient performance of the microcells

Carbon Fibers Coated with Ternary Ni-Co-Se Alloy Particles as Low-cost Counter Electrode for Flexible Dye Sensitized Solar Cell

Compared to flat devices based on rigid substrates, cable-shaped dye-sensitized solar cells hold advantages of smaller size, light weight, facile fabrication, flexibility, and low cost, thus a promising direction for applications such as wearable electronic devices. However, most reported fiber-shaped dye-sensitized solar cells use Pt wires as counter electrodes, which are high in cost. Herein, a flexible Pt-free counter electrode is fabricated via depositing ternary nickel cobalt selenide (Ni–Co–Se) particles on the surface of carbon fibers. Scanning electron microscopy and X-ray diffraction are used to characterize the counter electrode and alloy material. Results from bare and modified carbon fiber counter electrodes reveal that Ni–Co–Se alloy particles greatly enhance electrocatalytic activity, leading to significant improvement in power conversion efficiency, which is comparable with devices using carbon fiber coated with Pt as the counter electrode. The performance increase may be attributed to the improved catalytic property of CoSe2 due to its higher composition ratio and larger crystallite size. Bending and multiple irradiation cycling tests are also performed to show the superior flexibility and durability of the novel device

Quantitative analysis of bio-active phytochemical(s) in selected scented rice varieties (Oryza sativa) reveals its intake towards advantage against metabolic disorders

210-220Based on ancestral knowledge towards health beneficial effect, the current study led to investigate the content of bioactive phytochemical(s) in the scented rice (variety “joha”) grain indigenous to the NER-India and their effects on the enzyme involved in metabolic disorders and cellular glucose uptake efficacy. Results of both α-glucosidase inhibitory activity and the glucose uptake assay-guided fractionation based on column purification followed by spectral data analysis confirmed the presence of two major bioactive compounds as linoleic (ω-6-fatty-acid) and linolenic (ω-3-fatty-acid) acid. Quantitative analysis showed that linolenic acid content in scented rice verities was 2.1±0.3 mg/g, which is ~1.6 fold higher than its content in non-scented rice variety from the same region. The relative ratio (ω-6/ω-3) of these two essential unsaturated fatty acids content in the scented rice variety seeds was calculated as 23.5±0.6 while, in non-scented rice variety seeds, it was 31.6. Chemical fingerprinting by GCMS and HPLC of methanolic extract of selected rice samples revealed the presence of various fatty-acid along with other volatile and polar compounds. In conclusion, the scented rice seeds contain a better ratio of two essential unsaturated fatty acid compare to non-scented rice seed, which may be an effective choice as diet towards controlling metabolic disorder