The impact of fat tailed returns on asset allocation

This paper analyzes the asset allocation problem of an investor who can invest in equity and cash when there is time variation in expected returns on the equity. The solution methodology is multistage stochastic asset allocation problem with decision rules. The uncertainty is modeled using economic scenarios with Gaussian and stable Paretian non-Gaussian innovations. The optimal allocations under these alternative hypothesis are compared. Our computational results suggest that asset allocation may be up to 20% different depending on the utility function and the risk aversion level of the investor. Certainty equivalent return can be increased up to .13% and utility can be improved up to .72% by switching to the stable Paretian model.     

Novel reversible ionic-to-covalent transition in a highly conducting TTF derivative

TTF produces two completely different phenomena with the different isomers of chloranil; with the para isomer it produces an insulating, alternating stack, ambient temperature neutral solid. While with the ortho isomer, it produces a more interesting system consisting of interconvertible conducting ionic and covalent components.     

Polymeric electrochromics

Conducting polymers are excellent candidates for applications in displays, mirrors, windows, light-emitting diodes, photovoltaics, near-infrared devices and electrochromic devices. From these potential applications, in this article, we will focus on the electrochromic polymers and devices. Although several objective studies have been conducted in the last decade, bringing to light many advantages over other types of electrochromics, polymeric electrochromics have not yet received the industrial attention that they deserve. One of the most important and dazzling advantages of polymers over the other types of electrochromics is the ease of modification of a polymer's backbone, that changes almost the entire properties of the material and switches many disadvantages into advantages. Our recent completion of the deficient third leg of additive primary colour space was a very good example of tailoring the polymer backbone. This discovery could be considered as one of the milestones of commercialization of polymeric electrochromics. In this article, we will also discuss the completion of the additive primary colours, red, green and blue (RGB), in polymeric electrochromics and their ways of commercialization.     

Photon transmission technique for studying swelling and drying kinetics of heterogeneous gels formed with various cross-linker contents

Bifunctional polytetrahydrofuran (PTHF) macromonomer was synthesized by the termination of living polymerization of tetrahydrofuran (THF) initiated by triflic anhydride and subsequent termination by sodium methacrylate. PTHF macromonomer thus prepared was copolymerized with methyl methacrylate (MMA) by free radical polymerization to yield networks in various cross-linker densities. These PTHF-PMMA gels were used for swelling experiments in chloroform vapor. Drying processes were monitored after removing the gels from the solvent vapor. Photon transmission from PTHF-PMMA gels was monitored during swelling and drying processes using UV-visible spectrophotometer. Transmitted light intensities, I_tr from these gels decreased when they are subjected to chloroform vapor. Decrease in I_tr was attributed to the heterogeneous lattice structure of PTHF-PMMA gels which appeared during swelling. Decrease in I_tr was modeled using Li-Tanaka equation from which time constants, τ₁ and τ^′₁ and cooperative diffusion coefficients, D₀ and D^′₀ were determined. Increase in I_tr after removing of vapor from the cell was observed and attributed to the decrease in heterogenity of lattice structures during drying of the corresponding gels. Time constants, τ₂ for drying processes were also determined.     

Experimental Study into Droplet Formation in Steam Flows

Progress in the development of the steam turbines bring about a renewal of interest in wetness associated problems. Consequently, the present study investigates the droplet formation in low pressure steam flows. An experiment is conducted to measure the pressure ratio and size of the droplets developing in the divergent section of the convergent-divergent nozzle. The results obtained from the present study are compared with the existing data in the literature. It is found that the high rate of expansion results in large droplet size, which increases slightly as the stagnation pressure increases. In addition, the results obtained from the present analysis are in good agreement with the results of the previous study.     

Comparative study of liquid-crystalline ordering in a monomer,linear polymer,and graft copolymer by the photon transmission technique

The photon transmission technique was used to study the phase transitions of a liquid crystalline acrylate monomer, 6-(4-cyanobiphenyl-4′oxy)hexyl acrylate (LC6), its homopolymer (PLC6) and its graft copolymer (GLC6) with polytetrahydrofuran grafts. The phase transitions were also confirmed by DSC and polarizing microscopy. We observed the phase transition sequence isotropic–nematic–smectic A–smectic C in the LC6 monomer. In PLC6 and GLC6 polymers, the nematic and smectic A phases appear dominant. The apparent nematic–smectic A transition is of first order in PLC6 and of second order in GLC6, with the transition temperature remaining the same. The effects of quenched random constraints introduced in GLC6 are consistent with the theory of quenched random interactions. The critical exponents were also evaluated.     

Human Serum Albumin−Gold Nanoparticle Based Impedimetric Sensor for Sensitive Detection of miRNA-200c

Here, human serum albumin conjugated gold nanoparticles (HSA−AuNPs) were synthesized by a simple route to develop an impedimetric sensor for miRNA-200c detection based on a selective oligo-hybridization process without any labeling. The synthetic DNA capture probe for miRNA-200c was decorated onto the HSA−AuNPs modified pencil graphite electrodes. Impedimetric signals were monitored after the hybridization process between the DNA probe and target miRNA-200c. HSA−AuNPs adsorption time, incubation time of the capture probe and hybridization time-temperature were optimized. The proposed miRNA-200c biosensor demonstrated proper sensitivity and selectivity, low detection limit (1.13 fM), good reproducibility and simple direct detection of miRNA-200c in serum.     

Synthesis of chalcone‐containing methacrylate‐based hydrogen bonded side chain liquid crystalline polymer and its dielectric properties

In this work, a new methacrylate‐based hydrogen bonded side chain liquid crystalline polymer having chalcone moieties (HBCP) was prepared from poly(4‐(3‐(pyridin‐4‐yl)acryloyl) phenyl methacrylate) and 11‐(4‐cyanobiphenyl‐4(‐oxy) undekan‐1‐ol (LC11)) by molecular self‐assembly processes via hydrogen bond formation between nitrogen of the HBCP and hydroxyl group of the LC11. The formation of H bond was confirmed by using Fourier transform infrared (FTIR) spectroscopy. The phase transition temperatures and liquid crystalline phases of the HBCP were examined by DSC and POM measurements. The dielectric properties of HBCP have been determined by impedance analyzer within the frequency interval of 100 Hz–15 MHz. According to Cole–Cole plot, the equivalent circuit of the LC system has been found as a capacitor in parallel with a resistor. The resonance frequency, f_r, of the R–C circuit has also been calculated as 1.59 MHz by phase angle versus frequency curve. The dielectric relaxation type of HBCP has been determined as nearly‐Debye type because the absorption coefficient, α, equals to 0.01655. From the conductivity point of view, HBCP displays dc conductivity at the low and high frequency regions that correspond to 100 Hz–12 kHz and 3.3 MHz–15 MHz, respectively. On the other hand, it has been revealed that the ac conductivity of the LC system investigated obeys Super Linear Power Law (SLPL) at the intermediate frequency domain. Copyright © 2015 John Wiley & Sons, Ltd.     

Poly(p-phenylenes) with well-defined side chain polymers

1,4-Dibromo-2,5-bis(bromomethyl)benzene and benzene-2,5-dibromomethyl-1,4-bis(boronic acid propanediol diester) were used as bifunctional initiators in Atom Transfer Radical Polymerization (ATRP) of styrene or in cationic ring opening polymerization (CROP) of tetrahydrofuran in conjunction with CuBr /2,2'-bipyridine or AgSbF₆, respectively. The resulting well-defined macromonomers with low polydispersities, bearing functional groups as bromine or boronic ester were used in Suzuki or Yamamoto type couplings, leading to poly(p-phenylene)s (PPPs) with polystyrene (PSt), polytetrahydrofuran (PTHF) or alternating PSt/PTHF side chains. The new polymers were characterized by GPC, ¹H-NMR, ¹³C-NMR, IR and UV analysis. Thermal behavior of the precursors PSt or PTHF macromonomers and the final polyphenylenes were investigated by TGA and DSC analyses and compared.     

Anodic stripping voltammetric determination of vardenafil hydrochloride at pencil graphite electrode

In this paper, we present a very popular and low-cost sensor material as disposable pencil graphite electrode (PGE) system for the trace-level determination of vardenafil hydrochloride (VRL). Electrochemical behavior and determination of VRL was carried out by cyclic and square-wave adsorptive anodic stripping (SW-AdAS) voltammetry. The proposed method was highly sensitive and had a linear calibration range from 3 × 10^?10 to 1 × 10^?7 M with a correlation coefficient of 0.997. The limit of detection and limit of quantitation values were calculated as 1 × 10^?10 and 3 × 10^?10 M, respectively. Developed method with disposable PGE shows high sensitivity, selectivity and stability in a wide concentration range for VRL determination without the necessity of any modification. Additionally, this system was successfully applied in Levitra^® tablets and spiked human serum in trace level of VRL. Some kinetic parameters of VRL’s were represented for the first time. The results showed that the proposed method is highly sensitive, easy and low cost for trace-level determination of VRL.