Inverted organic solar cells comprising low-temperature-processed ZnO films

Inverted organic solar cells are fabricated using low-temperature-annealed ZnO film as an electron transport layer. Uniform ZnO films were prepared by spin coating a diethylzinc (DEZ) precursor solution in air, followed by annealing at 100 °C. Organic solar cells prepared on these ZnO films with a 1:1 P3HT:PCBM blend as the active layer show a high power conversion efficiency of 4.03 %, which is more than 10 % higher than the PCE of solar cells comprising ZnO prepared via a high-temperature sol–gel route.     

Complexation study of Schiff base ligand: pyridin-2-ylimino methyl naphthanol with Co+2, Mn+2 and Ni+2 ions in solid and solution phase

Schiff base pyridin-2-ylimino methyl naphthanol (HL) was synthesized and characterized by spectroscopic (FTIR, ESIMS, and NMR) techniques. The ligand was reacted with perchlorate salts of Mn⁺², Co⁺², and Ni⁺². ESIMS mass spectra indicate the formation of mononuclear complex ML₂ for all three complexes. CoL₂ crystallizes in P₂1/n space group, adopting a distorted tetrahedral geometry where Co is in a N₂O₂ donor environment. Structure of the Co complex was optimized by DFT calculation. Solution-phase complexation between the ligand and the three metals ions: Mn⁺², Co⁺², and Ni⁺² (pH 7.2 in tris buffer), in CH₃CN–H₂O was performed spectrophotometrically by UV–vis spectral study. Job’s plot from each titration suggests a 1 : 2 metal to ligand combination. The association constants for the formation of ML₂ are as follows: Mn (19.80 × 10³ M^?1), Co (14.54 × 10³ M^?1) and Ni (19.04 × 10³ M^?1).     

A concise synthesis of 2-benzoyl-1-indanones and 1-indanones from 2-aryl-1-tetralones

Abstract

Methyl-2-(3-oxo-3-aryl) benzoates derived from acid catalyzed air oxidative fragmentation of 2-aryl-1-tetralones were efficiently undergone intramolecular-Claisen condensation in the presence of potassium tertiary butoxide. The resulting 2-benzoyl-1-indanones formed in two-step ring contractions were further subjected to indium triflate mediated retro-Claisen condensation to get 1-indanones.     

Coupled tapering/uptapering of soliton pairs in nonlinear media

Phenomenon of coupled tapering/uptapring of two mutually incoherent beams coaxially co-propagating in a nonlinear medium with small gain or loss has been investigated in this paper using standard parabolic equation approach (PEA) and the results are compared with the results obtained by Beam Propagation Method (BPM), i.e., by direct simulations of the underlying Nonlinear Schrödinger Equation (NLSE). The PEA results are shown to be in excellent agreement with the BPM results. It is seen that both beams of the pair induce uptapering in each other in presence of losses and tapering in presence of gain. When the medium offers gain to the first beam and losses to the other, both beams taper. When the medium offers gain/absorption to only one of the two beams, the beam undergoes self-tapering/self-uptapering and induces a taperd/uptaperd waveguide. The other beam (for which the medium is lossless) uptapers/tapers due to the taperd/uptaperd waveguide created by the first beam.     

Water extract of red mud: an efficient and renewable medium for environmentally benign synthesis of 2-amino-4H-chromenes

Molecular Diversity - In this study, an efficient and convenient domino Michael addition/intramolecular cyclization protocol is presented for the synthesis of biologically relevant...     

Probing of complete and incomplete fusion dynamics in heavy-ion collision

Three different types of experiments have been performed to explore the complete and incomplete fusion dynamics in heavy-ion collisions. In this respect, first experiment for the measurement of excitation functions of the evaporation residues produced in the ²⁰Ne + ¹⁶⁵Ho system at projectile energy ranges ≈2–8 MeV /nucleon has been done. Measured cumulative and direct cross-sections have been compared with the theoretical model code PACE-2, which takes into account only the complete fusion process. It has been observed that, incomplete fusion fraction is sensitively dependent on projectile energy and mass asymmetry between the projectile and the target systems. Second experiment for measuring the forward recoil range distributions of the evaporation residues produced in the ²⁰Ne + ¹⁶⁵Ho system at projectile energy ≈8 MeV /nucleon has been done. It has been observed that, some evaporation residues have shown additional peaks in the measured forwardrecoil range distributions at cumulative thicknesses relatively smaller than the expected range of the residues produced via complete fusion. The results indicate the occurrence of incomplete fusion involving the breakup of ²⁰Ne into ⁴He + ¹⁶O and /or ⁸Be + ¹²C followed by one of the fragments with target nucleus ¹⁶⁵Ho. Third experiment for the measurement of spin distribution of the evaporation residues produced in the ¹⁶O + ¹²⁴Sn system at projectile energy ≈6 MeV /nucleon, showed that the residues produced as incomplete fusion products associated with fast α and 2 α-emission channels observed in the forward cone, are found to be distinctly different from those of the residues produced as complete fusion products. The spin distribution of the evaporation residues also inferred that in incomplete fusion reaction channels input angular momentum (J ₀) increases with fusion incompleteness when compared to complete fusion reaction channels. Present observation clearly shows that the production of fast forward α-particles arises from relatively larger angular momentum in the entrance channel leading to peripheral collision.     

Distribution of residues and primitive roots

Given an integer N?≥?3, we shall prove that for all primes p?≥?(N???2)²4 ^N , there exists x in (?/p?)^* such that x, x?+?1, ..., x?+?N???1 are all squares (respectively, non-squares) modulo p. Similarly, for an integer N?≥?2, we prove that for all primes $\displaystyle p \geq \exp(2^{5.54N})$ , there exists an element x?∈?(?/p?)^* such that x, x?+?1, ..., x?+?N???1 are all generators of (?/p?)^*.     

Assessment of pollution level in a Himalayan Lake,Kashmir, using geomatics approach

Pollution indices aggregate concentrations of several water quality parameters into a single quantity to indicate the general status of pollution in a region. In this study, a variant of the previous water quality index was used to evaluate the pollution status in the Wular Lake, Kashmir, which is a Ramsar site and wetland of international importance. The index termed as water quality status index (WQSI) is considered as a simple pollution indicator to support management actions in the Wular Lake, Kashmir. WQSI is a valuable and unique rating to depict the overall water quality status and pollution level of the waterbody in a spatial context and is also capable of dealing with those water quality parameters which do not have well-developed standard values. In this study, the water quality of the Wular Lake was investigated in June 2013 for 21 sample locations. The index used in this work is composed of 13 measurable physico-chemical parameters – pH, dissolved oxygen, chemical oxygen demand, biological oxygen demand, alkalinity, hardness, chloride, total dissolved solids, ammonia, iron, nitrite, nitrate and fluoride. The generation of WQSI is based on weighted overlay technique, in which interpolated raster maps were generated for all the 13 water quality parameters and weights are assigned to each and every parameter using analytic hierarchy process technique, considering their status as benefit or cost criteria. Based on the value of WQSI, the whole lake was divided into five zones, comprising least polluted zone (23%), moderately polluted zone (20%), high polluted zone (30%), very high polluted zone (22%) and extremely polluted zone (5%). From this study, it has been found that 60 km² (77%) of total lake area constitutes the moderate to extremely polluted zone and only 18 km² (23%) of the total lake area constitutes the least polluted zone, which is in the north-west region of the lake. The study reveals that the world-famous Wular Lake is undergoing the eutrophication process and as a result of which the lake is losing its water holding capacity to deal with the disastrous flood problem in Kashmir region.     

Propagation properties of strongly dispersion-managed soliton trains

We analyze the intra-channel interactions of strongly dispersion-managed soliton trains. We systematically study the transmission system in terms of a coalescence distance. The impact of third-order dispersion and the positions of the amplifiers are evaluated. We also study the effect produced on the interaction patterns by the modifications in the pulse timings and relative amplitudes. Based on the results obtained, we propose a channel encoding scheme which gives a noiseless capacity very close to that of the conventional binary soliton signaling and, yet, provides a significant improvement in the interaction limitations.