Crystal and Molecular Structure of Tosyl Pyrrolidine-2-Methanol (C12H17SO3N)

C₁₂H₁₇SO₃N, M_r = 255.33, Orthorhombic, P2₁2₁2₁, a = 11.703(1) Å, b = 14.797(3) Å, c = 14.971(2) Å, V = 2592.52 ų, Z = 8, D_m = 1.309 Mgm⁻³, D_c = 1.308 Mgm⁻³, mμ = 21.57 cm⁻¹, F(000) = 1088, T = 290 K, final R = 0.080 for 2416 unique reflections. There are two crystallographically independent molecules in the unit cell of the title compound.     

A variational principle for fully developed laminar heat transfer in uniform channels I

Summary A variational principle for forced convection in laminar flow in uniform channels is formulated. The concepts of thermal potential, dissipation function and thermal force have been introduced and a Lagrangian formulation of the thermal flow field using generalized coordinates is given. Special consideration is given to heat transfer in plug flow when the thermal field is a linear function of the generalized coordinates. The concept of normal and ignorable coordinates is introduced. An example showing the use of Lagrangian equations is worked out.     

The order parameter model for structural relaxation in glass

The order parameter model assumes that the state of a glass or liquid depends on T, P and a number of order parameters Z_i. Structural relaxation is due to the kinetically impeded evolution of the order parameters following a rapid change in T or P. The linear relaxation function for the evolution of property Q (V or H) in response to a change in X (T or P) is of the form φ_QX = Σ_igⁱ_QX exp(?tτ_i). Expressions are derived for the qeighting coefficients gⁱ_QX in terms of the dependences of V and H on the various order parameters. It is shown that gⁱ_VT = gⁱ_HP and that gⁱ_VTgⁱ_HP/gⁱ_VPgⁱ_HT = II, where II is the Prigogine-Defay ratio. The corresponding relations among the relaxation functions are φ_VT = φ_HP and φ_VTφ_HP/φ_VPφ_HT ? II. The predictions of the order parameter model for structural relaxation are compared with and found generally to agree with existing literature data. A number of suggestions for future investigations to test this model are made.     

Scattering losses in binary borate glasses

The purpose of this paper is to examine the potential of three binary borate glasses; namely PbOB₂O₃, K₂OB₂O₃ and Li₂OB₂O₃ as candidates for fabrication of low optical loss and low cost fiber-glass wave-guides.The importance of ultrasonic measurements as the first step in a systematic search for a glass with low optical loss, is discussed. Results of ultrasonic measurements of PbOB₂O₃ system are then presented. Using these results and the published results for the K₂OB₂O₃ and Li₂OB₂O₃ systems, estimates of the magnitude of density fluctuations as a function of composition have been made for each system. Comparison with the previously published results on the K₂OSiO₂ system suggests that out of the three systems chosen, only 50 mole % Li₂O50 mole % B₂O₃ glass is a likely candidate for the production of low optical loss glass fibers.     

Annealing of electron irradiated GaP studied by positron lifetime technique

GaP single crystals were irradiated by 3 MeV electrons at 20 K to a dose of 4 × 10¹⁸ e/cm². An isochronal annealing in temperature region 77 ÷ 650 K followed the irradiation. Positron lifetime measurement indicated the presence of irradiation-induced vacancies in Ga sublattice. The vacancies disappeared at two stages observed at temperatures 200 ÷ 300 K and 450 ÷ 550 K.     

A multiplicative Gauss-Newton minimization algorithm:Theory and application to exponential functions

Multiplicative calculus(MUC) measures the rate of change of function in terms of ratios, which makes the exponential functions significantly linear in the framework of MUC.Therefore, a generally non-linear optimization problem containing exponential functions becomes a linear problem in MUC. Taking this as motivation, this paper lays mathematical foundation of well-known classical Gauss-Newton minimization(CGNM) algorithm in the framework of MUC. This paper formulates the mathematical derivation of proposed method named as multiplicative Gauss-Newton minimization(MGNM) method along with its convergence properties.The proposed method is generalized for n number of variables, and all its theoretical concepts are authenticated by simulation results. Two case studies have been conducted incorporating multiplicatively-linear and non-linear exponential functions. From simulation results, it has been observed that proposed MGNM method converges for 12972 points, out of 19600 points considered while optimizing multiplicatively-linear exponential function, whereas CGNM and multiplicative Newton minimization methods converge for only 2111 and 9922 points, respectively. Furthermore, for a given set of initial value, the proposed MGNM converges only after 2 iterations as compared to 5 iterations taken by other methods. A similar pattern is observed for multiplicatively-non-linear exponential function. Therefore, it can be said that proposed method converges faster and for large range of initial values as compared to conventional methods.     

The facile and efficient organocatalytic platform for accessing 1,2,4-selenadiazoles and thiadiazoles under aerobic conditions

The first organocatalytic approach towards synthesis of rarely explored 1,2,4-selenadiazole and thiadiazole scaffolds have been devised using corresponding carboxamides as substrates. The transformations were realized using two distinct conditions in the presence of catalytic vitamin B₃ or thiourea under aerobic conditions. Developed methods overcome the associated limitations of previous reported approaches and the desired products were obtained in high yields and selectivity without the formation of toxic side-products.     

Wireless Coupling of Conducting Polymer Actuators with Light Emission

Combining the actuation of conducting polymers with additional functionalities is an interesting fundamental scientific challenge and increases their application potential. Herein we demonstrate the possibility of direct integration of a miniaturized light emitting diode (LED) in a polypyrrole (PPy) matrix in order to achieve simultaneous wireless actuation and light emission. A light emitting diode is used as a part of an electroactive surface on which electrochemical polymerization allows direct incorporation of the electronic device into the polymer. The resulting free-standing polymer/LED hybrid can be addressed by bipolar electrochemistry to trigger simultaneously oxidation and reduction reactions at its opposite extremities, leading to a controlled deformation and an electron flow through the integrated LED. Such a dual response in the form of actuation and light emission opens up interesting perspectives in the field of microrobotics.     

Electrophoretically Deposited Bismuth Iron Oxide Nanoparticles Film for Supercapacitor Application

Russian Journal of Electrochemistry - Bismuth iron oxide (BFO) nanoparticles film prepared by electrophoretic deposition (EPD) process has been explored for supercapacitor application. EPD process...