Existence and multiplicity of positive radial solutions for singular superlinear elliptic systems in the exterior of a ball

We prove the existence and multiplicity of positive radial solutions to the nonlinear system

$\{\begin{array}{c}\hfill ?\mathrm{\Delta }{u}_i=\lambda K_i(|x|)f_i(u_j)\text{ in }\mathrm{\Omega },\hfill \\ \hfill d_i\frac{?u_i}{?n}+{\stackrel{?}{c}}_i(u_i)u_i=0\text{ on }|x|=r_0,\hfill \\ \hfill u_i(x)\to 0\text{ as }|x|\to \infty ,\hfill \end{array}$

for a certain range of $\lambda >0$, where $i,j\in \{1,2\},i\ne j$, $\mathrm{\Omega }=\{x\in {\mathbb{R}}^N:|x|>r_0>0\}$, $N>2,d_i\ge 0$, $K_i:[r_0,\infty )\to (0,\infty )$, $\stackrel{?}{c}:[0,\infty )\to [0,\infty ),f_i:(0,\infty )\to \mathbb{R}$ are continuous with possible singularity ±∞ at 0 and satisfy a combined superlinear condition at ∞.     

Electromagnetic reflection, shielding and conductivity of polypyrrole thin film electropolymerized in P-Tulensulfonic acid

The electrosynthesis of polypyrrole (PPy) thin film on stainless steel electrode was performed in P- Tulensulfonic acid. The electromagnetic reflection, shielding effectiveness, permittivity and conductivity in the frequency range 8.2 to 18 GHz were studied. The effect of change in the acid concentration on the properties is reported. The microwave conductivity varies from 16 S/cm to 415 S/cm with frequency. The dielectric constant and dielectric loss factor decreases with increase in frequency.     

Microwave Promoted,Sodium Acetate Catalyzed One Pot Synthesis of Poly Functionalized 4H‐Pyrans

A clean and efficient one pot synthesis of 4H‐pyran derivatives through condensation of aromatic aldehydes, malononitrile and dicarbonyl compounds under microwave irradiation in presence of Sodium acetate as a catalyst is described.     

Fluorescent and Chromogenic Receptor Bearing Amine and Hydroxyl Functionality for Iron (III) Detection in Aqueous Solution

The noncyclic 2,2′-[ethane-1,2-diylbis (iminomethanediyl)]diphenol (4) fluorescent receptor bearing two amine and hydroxyl groups have been designed and investigated for their binding properties towards various cations. The fluorescent spectral measurements revealed that receptor 4 is a selective fluorescent sensor for Fe³⁺ ions but not for metal ions such as Cr³⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Pb²⁺ and Bi³⁺. The binding ability was confirmed with spectroscopic methods and density functional theory calculation (DFT). This straightforward and cost effective receptor provides rapid detection of Fe³⁺ ions at concentrations as low as 2.5 μM and expected to be useful to design efficient chemically and biological sensor.     

Diffusive logistic equation with constant yield harvesting and negative density dependent emigration on the boundary

The structure of positive steady state solutions of a diffusive logistic population model with constant yield harvesting and negative density dependent emigration on the boundary is examined. In particular, a class of nonlinear boundary conditions that depends both on the population density and the diffusion coefficient is used to model the effects of negative density dependent emigration on the boundary. Our existence results are established via the well-known sub-super solution method.     

Pictet‐spengler cyclization in room temperature ionic liquid: A convenient access to tetrahydro β‐carbolines

1,2,3,4‐Tetrahydro‐β‐carbolines have been synthesized in moderate to good yields in short reaction time using the ionic liquid [bbim] BF₄ as reaction medium and promoter. There was no need for the use of an additional catalyst normally employed in Pictet‐Spengler condensation.     

Gas sorption kinetics by differential closed-loop recycle method: Effect of heat of adsorption

An analytical mathematical model is used to investigate the influence of minute adsorbent temperature changes on the kinetics of sorption of a gaseous adsorbate from mixture with a carrier gas using a differential closed loop recycle method. Isothermal operation may not be achieved even when a very high gas circulation rate is used. Very small changes in the adsorbent temperature during the process can cause substantial departure from isothermal uptake behavior. It is shown that the kinetic process can be assumed to be isothermal only for trace adsorbate concentrations. A criterion for validity of isothermal data analysis is proposed.     

Ultrasound assisted,synthesis of N-(7-(R)-2-oxa-8-azabicyclo[4.2.0]octan-8-yl)isonicotinamide derivatives and their biological evaluation

In this study, new series of azetidine derivatives were synthesized ( 4a-n ) from isoniazide ( 1 ), Aromatic aldehydes ( 2a-n ), dihydropyran ( 3 ) using SnCl₂ catalyst, via one pot multicomponent reaction/cycloaddition reaction. The synthesized azetidine derivatives were characterized by IR, ¹H NMR and ¹³C NMR and have been screened for antimicrobial, antituberculosis and anti-inflammatory activities. In relation to Staphylococcus aureus (ATCC 25923) promising antibacterial activity was shown, compounds 4e and 4k , followed by compounds 4h , 4n , 4f , 4g and 4l . The synthesized azetidine derivatives, 4a , 4e , 4j and 4m (with zone 12 mm) displayed antituberculosis activity. But its lower potential than, the standard streptomycin (with zone 18 mm). Further 4d compound alone displayed similar activity.     

Phytochemical Screening on Mussaenda Philipica Sepals — Isolation of Iridoid Glycosides and Flavones

JPC – Journal of Planar Chromatography – Modern TLC - Three iridoid glycosides, 5-hydroxy davisioside (1), 4-acetoxy-7-methoxy secologanin (4) and 6-methoxy mussaenoside (5) as well as...     

Synthesis and Antimicrobial Activities of Novel Series of 1-((4-Methyl-2-Substituted Thiazol-5-yl)Methyleneam INO)-2-Substituted Isothiourea Derivatives

A novel series of 1-((4-methyl-2-substituted thiazol-5-yl)methyleneamino)-2-substituted isothiourea derivatives was synthesized by alkylation of (Z/E)-1-((4-methyl-2-substituted thiazol-5-yl)methylene)thiosemicarbazide with alkylhalide in acetone. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, and mass spectrometry) methods. The newly synthesized compounds were screened for in vitro antimicrobial activity. Most of the compounds show moderate to excellent antimicrobial activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.]