Optical spacers based on metal oxide layers have been intensively studied in poly(3‐hexylthiophene) (P3HT) based polymer solar cells for optimizing light distribution inside the device, but to date, the potential of such a metal oxide spacer to improve the electronic performance of the polymer solar cells simultaneously has not yet be investigated. Here, a detailed study of performance improvement in high efficient polymer solar cells by insertion of solution‐processed ZnO optical spacer using ethanolamine surface modification is reported. Insertion of the modified ZnO optical spacer strongly improves the performance of polymer solar cells even in the absence of an increase in light absorption. The electric improvements of the device are related to improved electron extraction, reduced contact barrier, and reduced recombination at the cathode. Importantly, it is shown for the first time that the morphology of optical spacer layer is a crucial parameter to obtain highly efficient solar cells in normal device structures. By optimizing optical spacer effects, contact resistance, and morphology of ZnO optical spacers, poly[[4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6diyl] [3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl] thieno[3,4‐b]thiophenediyl]] (PTB7):[6,6]‐phenyl‐C71‐butyric acid (PC70BM) bulk heterojunction solar cells with conversion efficiency of 7.6% are obtained in normal device structures with all‐solution‐processed interlayers.

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Atomistic simulations and experimental investigations are combined to study heterojunction interfaces of hybrid polymer solar cells, with the aim to better understand and precisely predict their photovoltaic properties. The focus is on a hybrid ternary model system based on a poly(3-hexylthiophene) (P3HT)/zinc phthalocyanine (ZnPc)/ZnO interface, in which a ZnPc interlayer is applied to improve the performance of the hybrid interface. Theoretical predictions of the ternary system are validated against the properties of a concrete P3HT/ZnPc/ZnO planar heterojunction device. The theoretical predictions closely agree with the photovoltaic properties obtained in P3HT/ZnPc/ZnO solar cells, indicating the strength of the method for modeling hybrid heterojunction interfaces. The theoretical and experimental results reveal that: i) ZnPc molecules in direct contact with a ZnO surface insert new energy levels due to a strong ZnPc/ZnO coupling, ii) electron injection from these new energy levels of ZnPc into ZnO is highly efficient, iii) the ZnPc/ZnO coupling strongly influences the energy levels of the ZnO and P3HT leading to a reduction of the open circuit voltage, and iv) charge carrier recombination at the P3HT/ZnO interface is reduced by the ZnPc interlayer. The intercalation of ZnPc leads to an increase in photocurrent as well as to an overall increase in power conversion

Geopolymer belongs to a new class of emerging materials for a number of applications owing to the advantages such as low cost; higher compressive strength; improved fire & acid resistance as well as reduced greenhouse gas emission. In this work, we explore the effective utilization of marble waste as a reactive filler and binder for the development of fly ash based geopolymer hybrid composite materials using extrusion process. The effect of marble waste content on the physicochemical and mechanical characteristics of prepared hybrid materials was studied through various characterization techniques. The geopolymerization was conducted at two different molarities of

The nature of charge injection has been investigated across the Au-poly͑3-hexylthiophene-2,5-diyl͒ ͑P3HT͒ interface of two kinds: P3HT on Au ͑bottom contact͒ and Au on P3HT ͑top contact͒. The J-V characteristics of a Au͑bottom͒/P3HT/Au͑top͒ sandwich cell are analyzed by using the Fowler-Nordheim model and the hole barrier height at the top and bottom contacts has been estimated. The top contact showed a higher barrier height in comparison to the bottom contact. The quenching of photoluminescence spectra and the disappearance of characteristic P3HT peaks from the absorption spectra for the top contact supports that the ionically sputtered gold atoms on the polymer give rise to greater density of interfacial trap sites than those at bottom interface.

Background:Clonidine is added to intrathecal local anesthetics to improve intraoperative analgesia and to increase the duration of sensory and motor block. Aim of this study was to evaluate and compare the effects of addition of two different doses of clonidine (15 and 30 mcg) to 11 mg hyperbaric bupivacaine in patients undergoing inguinal herniorrhaphy surgery under spinal anesthesia.Materials and Methods:Seventy-five patients enrolled in the study were randomly divided into three groups of 25 each. Group I patients received 11 mg hyperbaric bupivacaine, whereas groups II and III received 15 mcg and 30 mcg clonidine, respectively, as an adjuvant to 11 mg hyperbaric bupivacaine. The volume of solution was kept constant to 2.4 ml by adding saline wherever needed.Results:Highest level of sensory block, time to achieve this level, and highest Bromage scale recorded were comparable among the groups. The mean time to two-segment regression, regression of sensory block to L3 dermatome, and mean duration of motor block were the greatest in group III followed by group II and group I. There was significant fall in mean arterial pressure (MAP) in groups II and III as compared to group I (P = 0.04). Episodes of hypotension were more in group III than in group II.Conclusion:30 mcg clonidine was associated with more incidence and duration of hypotension than 15 μg of clonidine. 15 mcg clonidine added to 11 mg hyperbaric bupivacaine provides better sensory and motor blockade for inguinal herniorrhaphy.

India is one of the biggest marble producing country in the world (~10%). State of Rajasthan has nearly 85% of marble production capacity. Recently, the massive quantity of marble waste fine particulates generated in marble industry has become a major environmental hazard issue. Major minerals present in marble waste are calcite (CaCO 3) and dolomite (CaMg (CO 3) 2). The particle sizes of marble waste particulates has been found to be 200 µm (D 90). The chemical composition of marble wastes reveals oxides of calcium (CaO), silica (SiO 2), alumina (Al 2 O 3) and alkaline oxides (Na 2 O, K 2 O). Apart from that, iron oxide, mica, fluorine, chlorite and organic matter have also been noticed. Marble waste has been explored for possible utilization in industries, thereby it helps in preventing the environmental problems such as dumping and pollution. This article addresses the efficiency of marble wastes for materials development, leading to create some sustainable green composite materials for construction applications.

The technique of surface doping is used to reduce the contact resistance between Au and poly(3-hexylthiophen-2,5-diyl) (P3HT) in Au(bottom)/P3HT/Au(top) sandwich type cells. To implement this technique, dodecyl benzene sulfonic acid (DBSA) is found to be an effective bulky dopant of P3HT as confirmed by four probe conductivity measurements, absorption and photoluminescence spectra. Sandwich cells treated with DBSA showed electrical short due to diffusion of DBSA across the P3HT film in Au(bottom)/DBSA/P3HT/DBSA/Au(top) sandwich cells, which confirms that DBSA is not immobilized at the surface. To restrict DBSA primarily at the surface, an aqueous solution of poly(ethylenedioxy thiophene) stabilized in poly(styrene sulfonic acid) (PEDOT : PSS) is utilized to make an emulsion with DBSA. The application of this emulsion at the top and bottom Au/P3HT interface has resulted in a decrease of contact resistance by nearly four orders of magnitude.