Circular groove shaped resonator for millimeter waves

In millimeter wave lengths region semiconductor generators, amplifiers, mixers and other solid state UHF devices find a wide application. In our work, we suggested to use aCircular Through-Shaped Resonator for obtaining power combination using active elements at frequency region f20–40 GHz.The resonator is formed by two plane aluminum reflectors. The first reflector has a circular groove. The second reflector has coupling elements. The first and the second reflectors are considered as a ring groove shaped waveguide.A resonator spectrum was calculated and analyzed in the frequency range f 20–40 GHz. It is showed that, in the given frequency range the resonator spectrum has a complicated structure and is formed by a series of spectrum lines; a frequency range between the series increases with the frequency increasing.We studied on transmission coefficient of the resonator, frequency shifts of spectrum lines when inserting a thin (t/0.003) dielectric substrates into the resonator, and also attenuation constants of waves propagating in circular groove (due to losses in metal).     

Pure uterine lipoma

Lipomatous tumors of the uterus are unusual, benign neoplasms seen in postmenopausal women. Although many of the mixed-type cases such as lipoleiomyoma and fibrolipoma have been reported, pure uterine lipomas are extremely rare. In the literature, a few cases with pure uterine lipoma have been reported. We first present the advanced magnetic resonance findings of pure uterine lipoma, followed by those of ultrasonography (US) and computed tomography (CT). We markedly detected lipid peaks on the magnetic resonance spectroscopy (MRS) and the apparent diffusion coefficient value to be 0.00 due to chemical-shift effects with diffusion-weighted imaging (DWI). Although pelvic lipomatous tumors can be diagnosed with US and CT, in some cases, further workup may be required to localize the lesion. MRI may yield more valuable data for differential diagnosis. MRS and DWI findings provide additional clues on the nature of the lesion.     

Dynamic phase transitions in the kinetic spin-1 Blume-Capel model on the Bethe lattice

The stationary states of the kinetic spin-1 Blume-Capel (BC) model on the Bethe lattice are analyzed in detail in terms of recursion relations. The model is described using a Glauber-type stochastic dynamics in the presence of a time-dependent oscillating external magnetic field (h) and crystal field (D) interactions. The dynamic order parameter, the hysteresis loop area and the dynamic correlation are calculated. It is found that the magnetization oscillates around nonzero values at low temperatures (T) for the ferromagnetic (F) phase while it only oscillates around zero values at high temperatures for the paramagnetic (P) phase. There are regions of the phase space where the two solutions coexist. The dynamic phase diagrams are obtained on the (kT/J,h/J) and (kT/J,D/J) planes for the coordination number q=4. In addition to second-order and first-order phase transitions, dynamical tricritical points and triple points are also observed.     

Installation of multiple aryl ether crosslinks onto non-native substrate peptides by the vancomycin OxyB

The biosynthesis of glycopeptide antibiotics (GPAs) has been an active area of research for decades. But, insights into the activity of the cytochrome P450 enzymes required for installing the aromatic crosslinks, which form their cup-shaped topologies and render GPAs bioactive, have only recently emerged. Presently, little is known about the substrate scope and promiscuity of the P450 enzymes. Herein, we report that OxyB_van, the P450 enzyme that installs the first crosslink in vancomycin biosynthesis, is capable of catalyzing the formation of its conventional C-O-D bis-aryl ether bond in non-natural substrates and, furthermore, the formation of a second, novel linkage when D-Trp is incorporated at position 6. HR-MS/MS and isotope labeling studies indicate the second crosslink is formed between rings A and B, resulting in a novel GPA-type scaffold. OxyB is also capable of installing two crosslinks in kistamicin- and complestatin-like substrate peptides. These findings highlight the utility of OxyB_van in creating crosslinked GPA derivatives and provide clues regarding the unusual biosynthesis of kistamicin.     

The statistical mechanics of spin-1 Ising model with AFM/AFM interactions on a bilayer Bethe lattice

The spin-1 Ising model is studied for the case of antiferromagnetic (AFM)/AFM interactions on the bilayer Bethe lattice by using the pairwise approach for several values of the coordination numbers q=3, 4 and 6 when the layers are linked with the external magnetic fields. The ground state (GS) phase diagrams, thermal variations of the order-parameters and the response functions are studied in detail to obtain the phase diagrams of the model. It was found that the system gives only one Néel temperature, T_N, for q=3. Two T_N's and first-order phase transition temperature, T_t, thus tricritical point, are found and the existence of two T_N's leads to the reentrant behavior when q=4 and 6 for some given system parameters.     

An experimental study on optimization of $${\mathbf{SiO}}_{2}$$ SiO 2 /water nanofluid flows in circular minichannels

Journal of Thermal Analysis and Calorimetry - An experimental research was performed to examine the effect of hydrodynamically and thermally developing distilled water-based SiO $$_2$$ nanofluid...     

New soliton solutions of Davey–Stewartson equation with power-law nonlinearity

This study is related to new soliton solutions of Davey–Stewartson equation (DSE) with power-law nonlinearity. The generalized Kudryashov method which is one of the analytical methods has been used for finding exact solutions of this equation. By using this method, dark soliton solutions of DSE have been found. Also, by using Mathematica Release 9, some graphical representations have been done to analyze the motion of these solutions.     

New Electroactive Hybridization Indicators 2‐Phthalimido‐N‐Substitutedphenylethanesulfonamide Derivatives for Biosensor Applications: Ring Substituent Effect on Interaction between Compound and DNA

In this work, an electrochemical DNA‐based sensor was developed for the detection of the interaction between the anticonvulsant compounds 2‐phthalimido‐N‐substituted phenylethanesulfonamides (PMPES‐derivatives) and 24‐mer short DNA sequences by using differential pulse voltammetry (DPV) based on both compound and guanine oxidation signals at the renewable carbon graphite electrode (CGE) surface. The influence of compounds on DNA showed differences depending on the nature and position of the substituent on the N‐phenyl ring. Compounds bearing 3‐methoxy, 4‐chloro and 2,6‐dimethyl substituents bind to single stranded probe DNA more strongly than the other derivatives of PMPES. Thus, these compounds were evaluated for use as an electrochemical hybridization label (indicator).     

Reactions of (1E)‐Buta‐1,3‐dien‐1‐yl Acetate with Diazocarbonyl Compounds

Carbene transfer to appropriate substrates is a highly versatile tool for the construction of carbon frameworks with increased functional and structural complexity. In this study, some novel cyclopropane derivatives were synthesized via carbenoid reactions and their further reactivities were investigated. (1E)‐Buta‐1,3‐dien‐1‐yl acetate was reacted with four different diazocarbonyl compounds, ethyl diazoacetate, dimethyl diazomalonate, 1‐diazo‐1‐phenylpropan‐2‐one, and methyl (3E)‐2‐diazo‐4‐phenylbut‐3‐enoate, in the presence of two catalysts. All synthesized substituted cyclopropanes were obtained chemoselectively with respect to less‐hindered C?C bonds. Under the applied conditions, while cyclopropanes 7a and 7d underwent further reactions, cyclopropanes 7b and 7c were stable enough. Cyclopropanes 7a and an additional equivalent of ethyl diazoacetate yielded polyfunctionalized cyclohexenes. Cyclopropanes from methyl (3E)‐2‐diazo‐4‐phenylbut‐3‐enoate yielded polyfunctionalyzed cycloheptadiene isomers by Cope rearrangement.