Design and implementation of a new tuned hybrid intelligent model to predict the uniaxial compressive strength of the rock using SFS-ANFIS

This study proposes a novel design to systematically optimize the parameters for the adaptive neuro-fuzzy inference system (ANFIS) model using stochastic fractal search (SFS) algorithm. To affirm the efficiency of the proposed SFS-ANFIS model, the predicting results were compared with ANFIS and three hybrid methodologies based on ANFIS combined with genetic algorithm (GA), differential evolution (DE), and particle swarm optimization (PSO). Accurate prediction of uniaxial compressive strength (UCS) is of great significance for all geotechnical projects such as tunnels and dams. Hence, this study proposes the use of SFS-ANFIS, GA-ANFIS, DE-ANFIS, PSO-ANFIS, and ANFIS models to predict UCS. In this regard, the fresh water tunnel of Pahang–Selangor located in Malaysia was considered and the requirement data samples were collected. Different statistical metrics such as coefficient of determination (R²) and mean absolute error were used to evaluate the models. Referring to the efficiency results of SFS-ANFIS, it can be found that the SFS-ANFIS (with the R² of 0.981) has higher ability than PSO-ANFIS, DE-ANFIS, GA-ANFIS, and ANFIS models in predicting the UCS.

     

Predicting the blast-induced vibration velocity using a bagged support vector regression optimized with firefly algorithm

Ground vibration is the most detrimental effect induced by blasting in surface mines. This study presents an improved bagged support vector regression (BSVR) combined with the firefly algorithm (FA) to predict ground vibration. In other words, the FA was used to modify the weights of the SVR model. To verify the validity of the BSVR–FA, the back-propagation neural network (BPNN) and radial basis function network (RBFN) were also applied. The BSVR–FA, BPNN and RBFN models were constructed using a comprehensive database collected from Shur River dam region, in Iran. The proposed models were then evaluated by means of several statistical indicators such as root mean square error (RMSE) and symmetric mean absolute percentage error. Comparing the results, the BSVR–FA model was found to be the most accurate to predict ground vibration in comparison to the BPNN and RBFN models. This study indicates the successful application of the BSVR–FA model as a suitable and effective tool for the prediction of ground vibration.

     

Multiwall carbon-nanotube-doped ion conducting polymer electrolyte for electrochemical application

Electrical, structural and optical properties of a composite containing a polymer electrolyte (namely polyethylene oxide complexed with sodium iodide) and multiwall carbon nanotube (MWCNT) are reported. The films of these composites were ‘solution casted’ using the viscous solution of polyethylene oxide (PEO) complexed with sodium iodide (NaI) in desired ratios and characterised using various techniques. The conductivity versus composition plot in PEO:NaI shows conductivity maxima at 12?wt% NaI concentration while in MWCNTs doped polymer electrolyte it occurs at 40?wt% MWCNTs concentration. The surface morphology by scanning electron microscopy (SEM) shows the enhancement in amorphous reason by MWCNTs doping which is a well-known favourable condition for conductivity enhancement. The differential scanning calorimetry shows that dispersal of MWCNTs reduces the crystallinity of polymer electrolyte that is well-supported by our polarised optical micrographs and SEM measurements.     

Frequency and temperature dependence of electrical properties of barium and gadolinium substituted SrBi<Subscript>2</Subscript>Nb<Subscript>2</Subscript>O<Subscript>9</Subscript> ceramics

Barium strontium gadolinium bismuth niobate (Ba_0.1Sr_0.81Gd_0.06Bi₂Nb₂O₉, BSGBN) ceramics were prepared by using the conventional solid-state reaction method. The dielectric permittivity, modulus and impedance spectroscopy studies on BSGBN were investigated in the frequency range, 45 Hz–5 MHz and in the temperature range from room temperature (RT) to 570 °C. The dielectric anomaly with a broad peak was observed at 470 °C. Simultaneous substitution of Ba²⁺ and Gd³⁺ increases the transition temperature of SrBi₂Nb₂O₉ (SBN) from 392 to 470 °C. XRD studies in BSGBN revealed an orthorhombic structure with lattice parameters a = 5.4959 Å, b/a = 1.000, c = 25.0954 Å. Impedance and modulus plots were used as tools to analyse the sample behaviour as a function of frequency. Cole-Cole plots showed a non-Debye relaxation. Also, dc and ac conductivity measurements were performed on BSGBN. The electric impedance which describes the dielectric relaxation behaviour is fitted to the Kohlrausch exponential function. Near the phase transition temperature, a stretched exponential parameter β indicating the degree of distribution of the relaxation time has a small value.     

Controlled Delivery of Pan-PAD-Inhibitor Cl-Amidine Using Poly(3-Hydroxybutyrate) Microspheres

This study deals with the process of optimization and synthesis of Poly(3-hydroxybutyrate) microspheres with encapsulated Cl-amidine. Cl-amidine is an inhibitor of peptidylarginine deiminases (PADs), a group of calcium-dependent enzymes, which play critical roles in a number of pathologies, including autoimmune and neurodegenerative diseases, as well as cancer. While Cl-amidine application has been assessed in a number of in vitro and in vivo models; methods of controlled release delivery remain to be investigated. P(3HB) microspheres have proven to be an effective delivery system for several compounds applied in antimicrobial, wound healing, cancer, and cardiovascular and regenerative disease models. In the current study, P(3HB) microspheres with encapsulated Cl-amidine were produced in a size ranging from ~4–5 µm and characterized for surface morphology, porosity, hydrophobicity and protein adsorption, in comparison with empty P(3HB) microspheres. Cl-amidine encapsulation in P(3HB) microspheres was optimized, and these were found to be less hydrophobic, compared with the empty microspheres, and subsequently adsorbed a lower amount of protein on their surface. The release kinetics of Cl-amidine from the microspheres were assessed in vitro and expressed as a function of encapsulation efficiency. There was a burst release of ~50% Cl-amidine in the first 24 h and a zero order release from that point up to 16 days, at which time point ~93% of the drug had been released. As Cl-amidine has been associated with anti-cancer effects, the Cl-amidine encapsulated microspheres were assessed for the inhibition of vascular endothelial growth factor (VEGF) expression in the mammalian breast cancer cell line SK-BR-3, including in the presence of the anti-proliferative drug rapamycin. The cytotoxicity of the combinatorial effect of rapamycin with Cl-amidine encapsulated P(3HB) microspheres was found to be 3.5% more effective within a 24 h period. The cells treated with Cl-amidine encapsulated microspheres alone, were found to have 36.5% reduction in VEGF expression when compared with untreated SK-BR-3 cells. This indicates that controlled release of Cl-amidine from P(3HB) microspheres may be effective in anti-cancer treatment, including in synergy with chemotherapeutic agents. Using controlled drug-delivery of Cl-amidine encapsulated in Poly(3-hydroxybutyrate) microspheres may be a promising novel strategy for application in PAD-associated pathologies.     

The structural characterization of (NH4)2B10H10 and thermal decomposition studies of (NH4)2B10H10 and (NH4)2B12H12

The structure of (NH₄)₂B₁₀H₁₀ (1) was determined through powder XRD analysis. The thermal decomposition of 1 and (NH₄)₂B₁₂H₁₂ (2) was examined between 20 and 1000 °C using STMBMS methods. Between 200 and 400 °C a mixture of NH₃ and H₂ evolves from both compounds; above 400 °C only H₂ evolves. The dihydrogen bonding interaction in 1 is much stronger than that in 2. The stronger dihydrogen bond in 1 resulted in a significant reduction by up to 60 °C, but with a corresponding 25% decrease in the yield of H₂ in the lower temperature region and a doubling of the yield of NH₃. The decomposition of 1 follows a lower temperature exothermic reaction pathway that yields substantially more NH₃ than the higher temperature endothermic pathway of 2. Heating of 1 at 250 °C resulted in partial conversion of B₁₀H₁₀²⁻ to B₁₂H₁₂²⁻. Both 1 and 2 form an insoluble polymeric material after decomposition. The elements of the reaction network that control the release of H₂ from the B₁₀H₁₀²⁻ can be altered by conducting the experiment under conditions in which pressures of NH₃ and H₂ are either near, or away from, their equilibrium values.     

Effects of genotype and cultivation environment on lycopene content in red‐ripe tomatoes

Lycopene, a natural red pigment found in tomato, is correlated with reduced incidence of some cancers. Forty tomato varieties, including cluster F₁ hybrid tomatoes, round breeding line tomatoes (Lycopersicon esculentum Mill) and cherry tomato types (L esculentum var cerasiforme), grown under greenhouse and field conditions were evaluated for their lycopene content using high‐performance liquid chromatography (HPLC) and spectrophotometry. Lycopene content varied significantly among the tomato varieties, with cherry tomato types having the highest lycopene content. Greenhouse‐grown cluster and round tomatoes contained more lycopene (mean = 30.3 mg kg^?1) than field‐grown tomatoes (mean = 25.2 mg kg^?1), whereas cherry tomato types had a higher lycopene content in field‐grown (mean = 91.9 mg kg^?1) than in greenhouse‐grown (mean = 56.1 mg kg^?1) fruits. HPLC analysis of lycopene isomeric forms revealed a higher content of all‐trans isomers in all tomato genotypes examined. However, the cis isomeric form was exceptionally higher in the field‐ and greenhouse‐grown cherry tomato L esculentum var cerasiforme cv Gardener's Delight, which contained ～9.3 and 9.9 mg kg^?1 cis isomers respectively. Results indicate that genetics and choice of cultivation environment may have a strong influence on tomato lycopene content. Copyright © 2005 Society of Chemical Industry     

Numerical study of spontaneous ignition of pressurized hydrogen release into air

Numerical simulations have been carried out for spontaneous ignition in the sudden release of pressurized hydrogen into air. A mixture-averaged multi-component approach was used for accurate calculation of molecular transport. Spontaneous ignition and combustion chemistry were accounted for using a 21-step kinetic scheme. To reduce false numerical diffusion, extremely fine meshes were used along with the arbitrary Lagrangian–Eulerian (ALE) method in which convective terms are solved separately from the other terms.     

Co-based catalysts from Co/Fe/Al layered double hydroxides for preparation of carbon nanotubes

Carbon nanotubes have been prepared via catalytic chemical vapor deposition of acetylene on a series of catalysts derived from Co/Fe/Al layered double hydroxides (LDHs). The catalytically active cobalt particles were obtained by calcination of LDHs containing cobalt (II) ions followed by reduction. The obtained products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, high-resolution electron microscopy and Raman spectroscopy. The content of Co in the precursors had a distinct effect on the growth of carbon nanotubes. Increasing Co content enhanced the carbon yield, due to good dispersion of a large number of active Co species. This indicated that the agglomeration of metallic Co particles did not take place even at high Co content. Higher Co content led to the formation of carbon nanotubes with smaller diameters and less structural disorder.