Solving a full fuzzy linear programming using lexicography method and fuzzy approximate solution

This paper discusses full fuzzy linear programming (FFLP) problems of which all parameters and variable are triangular fuzzy numbers. We use the concept of the symmetric triangular fuzzy number and introduce an approach to defuzzify a general fuzzy quantity. For such a problem, first, the fuzzy triangular number is approximated to its nearest symmetric triangular number, with the assumption that all decision variables are symmetric triangular. An optimal solution to the above-mentioned problem is a symmetric fuzzy solution. Every FLP models turned into two crisp complex linear problems; first a problem is designed in which the center objective value will be calculated and since the center of a fuzzy number is preferred to (its) margin. With a special ranking on fuzzy numbers, the FFLP transform to multi objective linear programming (MOLP) where all variables and parameters are crisp.     

Production of natural fruity aroma by Geotrichum candidum

Based on its aromatic potential, Geotrichum candidum isolated from olive vegetation water was tested for the production of volatile compounds. When G. candidum was cultivated on media with glucose as the carbon source, flavor volatile compounds were produced and accumulated in the broth. Fruity flavoring compounds (pineapple-like) such as esters and alcohols were analyzed by gas chromatography coupled to mass spectrometry, including ethyl esters of acetic acid and butyric acid, methyl-3-butan-1-ol, and methyl-2-propan-1-ol. Their synthesis corresponded to the stationary growth phase of the strain. Production of the volatile compounds reached 9.5 g/L of 2-hexanoic acid ethyl ester and 1.6 g/L of benzaldehyde as the main concentrated molecules. Ethyl alcohol seems to be an intermediate metabolite in this pathway.     

Asymmetric Cycloaddition: An Efficient Synthesis of Enantiopure Isoxazolines Substituted with Carbohydrate Analogues

A simple and convenient method for the synthesis of heterocycles substituted with carbohydrate analogs is described. The chiral optically pure five‐membered glycoconjugates containing the isoxazoline unit were obtained by an aromatic nitrile oxides cycloaddition with 1‐phenyl‐1,2‐dihydro‐pyridazine‐3,6‐dionyl N‐glycoside derivatives.     

Fabrication and Characterization of 150-mm Silicon-on-Polycrystalline Silicon Carbide Substrates

Silicon-on-insulator (SOI) substrates can reduce radiofrequency (RF) substrate losses due to their buried oxide (BOX). On the other hand, the BOX causes problems since it acts as a thermal barrier. Oxide has low thermal conductivity and traps heat generated by devices on the SOI. This paper presents a hybrid substrate which uses a thin layer of polycrystalline silicon and polycrystalline silicon carbide (Si-on-poly-SiC) to replace the thermally unfavorable BOX and the silicon substrate. Substrates of 150 mm were fabricated by wafer bonding and shown to be stress and strain free. Various electronic devices and test structures were processed on the hybrid substrate as well as on a low-resistivity SOI reference wafer. The substrates were characterized electrically and thermally and compared with each other. Results showed that the Si-on-poly-SiC wafer had 2.5 times lower thermal resistance and exhibited equal or better electrical performance compared with the SOI reference wafer.     

Design of a highly PAE class-F power amplifier using front coupled tapered compact microstrip resonant cell

This article presents the design and implementation of a class-F power amplifier (PA) with a low voltage pHEMT, using a novel Front Coupled Tapered Compact Microstrip Resonant Cell (FCTCMRC) for obtaining a high-efficiency performance. The FCTCMRC is used as a harmonic control circuit, which is short and open circuit for the second and third harmonics, respectively. The required dc-supply voltage is low due to application of a low-voltage pHEMT in the circuit implementation. Therefore, the class-F power amplifier is designed with a high power added efficiency (PAE) and compact circuit size. To verify the method, the designed class-F PA is fabricated using a pHEMT at 1.1 GHz. The proposed class-F power amplifier using the FCTCMRC has obtained 86%PAE under 10 dBm input power, which achieves 16% improvement, also, the circuit size including the harmonic control circuit and output matching is decreased about 25%, all in comparison with the designed PA using the conventional CMRC. The measurement results of the fabricated power amplifier are in good agreement with the simulation results, which verifies the proposed design methodology.     

Localized proton spectroscopy without water suppression: removal of gradient induced frequency modulations by modulus signal selection

Most Magnetic Resonance Spectroscopy (MRS) localization methods can generate gradient vibrations at acoustic frequencies and/or magnetic field oscillation, which can cause a time-varying magnetic field superimposed onto the static one. This effect can produce frequency modulations of the spectral resonances. When localized MRS data are acquired without water suppression, the associated frequency modulations are manifested as a manifold of spurious peaks, called sidebands, which occur symmetrically around the water resonance. These sidebands can be larger than the small metabolite resonances and can present a problem for the quantitation of the spectra, especially at short echo times. Furthermore, the resonance lineshapes may be distorted if any low frequency modulations are present. A simple solution is presented which consists of selecting the modulus of the acquired Free Induction Decay (FID) signal. Since the frequency modulations affect only the phase of the FID signal, the obtained real spectrum of the modulus is free from the spurious peaks where quantitative results may be directly obtained. Using this method, the distortions caused by the sidebands are removed. This is demonstrated by processing proton MRS spectra acquired without water suppression collected from a phantom containing metabolites at concentrations comparable to those in human brain and from a human subject using two different localization methods (PRESS and Chemical Shift Imaging PRESS-(CSI)). The results obtained illustrate the ability of this approach to remove the spurious peaks. The corrected spectra can then be fit accurately. This is confirmed by the results obtained from both the relative and the absolute metabolites concentrations in phantoms and in vivo.     

Magnetic exchange coupling in imido bimetallic uranium(V) complexes. A relativistic DFT study

Magnetic exchange coupling between uranium U(V) ions, in the case of the two para- and meta-imido diuranium complexes, respectively [(C₅H₅)₃U]₂(μ-1,4-N₂C₆H₄) and [(C₅H₅)₃U]₂(μ-1,3-N₂C₆H₄) exhibiting the 5f¹-5f¹ configuration, have been investigated using relativistic DFT calculations, combined with the broken symmetry (BS) approach. Using the B3LYP functional, the singlet BS state of the para complex has been found of lower energy than the high spin (HS) triplet one, in agreement with the observed antiferromagnetic character of the complex. On the contrary the BP86 functional fails to predict this magnetic property. The spin density distributions and MO analysis explain well the antiferromagnetic character of the para complex and clarify the failure of the BP86 functional. The effective participation of the 5f metal orbitals in bonding with the imido ligand plays a key role for electronic and magnetic communication between the two active U(V) 5f¹ electrons. The same technique led us to explain the ferromagnetic character of the meta isomer in agreement with experiment. For both isomers the spin polarization mechanism explains well their observed magnetic behaviour.     

A relativistic DFT study of magnetic exchange coupling in ketimide bimetallic uranium(IV) complexes

Magnetic exchange couplings in bis(ketimide) binuclear U^IV/U^IV complexes [Cp′₂UCl]₂(μ-ketimide) diuranium(IV) and [(C₅H₅)₂(Cl)An]₂(μ-ketimide) (Cp′ = C₅Me₄Et; ketimide = N=CMe-(C₆H₄)-MeC=N) have been investigated computationally using relativistic density functional theory (DFT) combined with the broken symmetry (BS) approach. Using the B3LYP hybrid functional, the BS ground state of these U^IV/U^IV 5f ²–5f ² complexes has been found of lower energy than the high spin (HS) quintet state, indicating an antiferromagnetic character (estimated coupling constant |J| < 5 cm⁻¹) which has not yet been evidenced unambiguously experimentally. On the contrary, the BP86 GGA functional overestimates greatly the antiferromagnetic character of the complexes (|J| > 100 cm⁻¹). As recently reported for para-bis(imido) [(C₅H₅)₃U]₂(μ-imido) uranium(V) complex, spin polarization is mainly responsible for the antiferromagnetic coupling through the π-network orbital pathway within the bis(ketimide) bridge. Furthermore, spin polarization is exalted by the combined roles of the 5f metal orbitals and of the π-conjugated ketimide bridging ligand which permit electronic communication between the two uranium atoms albeit separated by a distance of the order of 10 ?. The MO analysis clarifies which MOs contribute to the antiferromagnetic coupling in the binuclear complexes under consideration and brings to light the 5f orbitals driving contribution.     

AC conductivity and dielectric studies of (C5H10N)2BiCl5 compound

The bis (3-dimethylammonium-1-propyne) pentachlorobismuthate (III) exhibits a structural phase transition at T₁?=?(337?±?2?K), which has been characterized by differential scanning calorimetric, X-ray powder analysis, AC conductivity and dielectric measurements. The dielectric dispersion yielded the real and imaginary parts of impedance of (C₅H₁₀N)₂BiCl₅ in the form of a semicircle in a complex plane. Besides, a Cole?CCole plot was observed at frequencies ranging from 209?Hz to 5?MHz, whose result was found to fit the theoretical resistor?Ccapacitor parallel circuit model. The temperature dependence of the electrical conductivity in the different phases follows the Arrhenius law. The frequency-dependent conductivity data were fitted in the modified power law: $ \sigma = {\sigma_{dc}} + {B_1}(T){\omega^{{s_1}}} + {B_2}(T){\omega^{{s_2}}} $ . The imaginary part of the permittivity constant is analyzed with the Cole?CCole formalism. With regard to the modulus plot, it can be characterized by full width at half height or in terms of a non-exponential decay function $ \phi (t) = \exp {\left( {\frac{{ - t}}{{{\tau_\sigma }}}} \right)^\beta } $ . Besides, the activation energy responsible for relaxation has been evaluated and found to be close the DC conductivity.     

Advances in surface plasmon resonance-based high throughput biochips

This article reviews our recent advances in surface plasmon resonance (SPR) based biochips. It includes four issues, which are the preparation and characterization of high quality gold film, the preparation and characterization of self-assembled monolayer (SAM), dynamics of DNA adsorption on SAMs, and SPRbased microscopies. Numerous topics related to SPR, such as, the modeling of SPR by transmission matrix, effective medium theory, applications of SPR in biology, and SPR-based novel microscopies, are discussed. A novel electrochemical technique, which is extremely useful for the preparation and characterization of high quality SAMs, is also discussed.