Amine‐functionalized mesoporous silica: A material capable of CO2 adsorption and fast regeneration by microwave heating

The surface of ordered mesoporous (MCM‐48) silica has been subjected to covalent grafting with silane molecules containing one to three amino groups. The dielectric properties of the materials were studied in detail, and the functionalized materials were used for CO₂ adsorption at room temperature, followed by regeneration under either conventional heating or microwave irradiation. It has been found that, as the intensity of functionalization with amino groups increases (from mono‐ to tri‐amino silanes) both the CO₂ load and the dielectric response at microwave frequencies increase. In particular, functionalization with a tri‐amino silane derivative gave the highest CO₂ adsorption and the fastest microwave heating, resulting in a fourfold acceleration of adsorbent regeneration. The grafted material was fully stable for at least 20 adsorption‐regeneration cycles, making it an ideal candidate for microwave‐swing adsorption (MWSA) processes. © 2015 American Institute of Chemical Engineers AIChE J, 62: 547–555, 2016     

A Study on Hydrodynamics and Heat Transfer in a Bubble Column Reactor with Yeast and Bacterial Cell Suspensions

Hydrodynamics and heat transfer experiments were carried out in a slurry bubble column with air‐water‐yeast cells and air‐water‐bacteria cells systems to investigate gas hold‐up, bubble characteristics and heat transfer coefficients with cell concentrations of 0.1% w/w and 0.4% w/w and superficial gas velocity up to 0.20 m/s. The gas hold‐ups and heat transfer coefficients were found to increase with increasing gas velocity and cell concentration. The heat transfer coefficients were higher at the centre of the column as compared to the near wall region. The development of empirical correlations to predict the heat transfer coefficient in two‐ and three‐phase systems was carried out with ±15% confidence interval at most.     

Effect of the Incorporation of PVC on the Mechanical Properties of the Jute-Reinforced LLDPE Composite

Jute fabrics-reinforced linear low density polyethylene (LLDPE) matrix composites (50 wt% fiber) were prepared by compression molding and mechanical properties were studied. Polyvinyl chloride (PVC) matrix was incorporated instead of LLDPE in the jute based composites and their mechanical properties were investigated and compared with the control composites. It was found that with the increase of PVC in the LLDPE based composites, the mechanical properties were found to improve significantly. Degradation tests of the composites for upto 24 weeks were performed in soil medium. Water uptake and Thermo-mechanical properties of the composites were also studied.     

Assessment of permeability and injection depth at the Atasu dam site (Turkey) based on experimental and numerical analyses

This study was performed in order to evaluate the permeability of the basalts and pyroclastics and the maximum depth of grout injection at the Atasu dam site, Turkey, using the equations of Kiraly and Hoek and Bray based on values obtained from Lugeon tests. In order to evaluate maximum discharge values and depth of injection, seepage analyses were performed using the finite element technique for each 10 m up to 100 m. The results indicate that to establish an impermeable zone at the dam site, the depth of injection should be taken as 50 m for the left and right slopes and 40 m for the river bed.     

The morphological variants of papillary carcinoma of the thyroid: a clinico-pathological study--AFIP experience. Armed Forces Institute of Pathology

The article describes results of an anatomo-clinical investigation using video-endoscopy and contact microvascular dopplerography in surgery of cerebral aneurysms. The endoscopic anatomy of cisterns of the cerebral base was studied in 36 corpses of adult humans. More than 200 video-endoscopic operative interventions were performed on sectional material. Video-endoscopy in combination with contact microvascular dopplerography was conducted in the clinic on 20 patients with aneurysms of the brain. Main advantages of endoscopy used in combination with microvascular dopplerography during clipping the aneurysm are formulated. Complex using the two methods described gives less volume of the access and traumaticity of the intervention but not less radical effect. It is a valuable and highly informative method which optimizes performing the operation and has less amount of postoperative complications.     

Flutter of viscoelastic strips

Using linear model, the parametric sensitivity analysis of viscoelastic panel flutter with an arbitrary function of relaxation, is examined by the Laplace integral transform method. The critical values of free stream velocities and frequencies of vibrations are determined from the condition that the real parts of the poles of integrand must be zero, which correspond to harmonic motion. Approximate and exact values of critical speed and corresponding frequencies for a general isotropic viscoelastic constitutive relations are obtained. The solutions are analyzed for critical, subcritical and supercritical cases. It is shown that the viscoelastic flutter speed is smaller than the corresponding elastic one if elastic moduli of material is equal to the initial value of relaxation function. Influence of aerodynamical damper is studied assuming that the parameter of viscous property of material is small enough in comparison with the parameter of aerodynamical damper and vice versa. AMS subject classification: 74H10, 74H55, 74K20     

Type I and type II fractional Brownian motions: A reconsideration

The so-called type I and type II fractional Brownian motions are limit distributions associated with the fractional integration model in which pre-sample shocks are either included in the lag structure, or suppressed. There can be substantial differences between the distributions of these two processes and of functionals derived from them, so that it becomes an important issue to decide which model to use as a basis for inference. Alternative methods for simulating the type I case are contrasted, and for models close to the nonstationarity boundary, truncating infinite sums is shown to result in a significant distortion of the distribution. A simple simulation method that overcomes this problem is described and implemented. The approach also has implications for the estimation of type I ARFIMA models, and a new conditional ML estimator is proposed, using the annual Nile minima series for illustration.     

Some New Organometallic Polyamides based on Ferrocene

Three new polyamides containing ferrocene units in the main chain were synthesized via low temperature polycondensation route, reacting 1,1′-ferrocenedicarboxylic acid chloride with three different types of aromatic diamines. The products were characterized by their solubilities, elemental analysis, FTIR spectral analysis, differential scanning calorimetry, thermogravimetry and viscosity measurements. The glass transition temperatures of the polymers were found by DSC curves and the activation energies of pyrolysis were estimated from TG curves applying Horowitz and Metzger method. Among these, polyamide P-1 (prepared from 4-(4-aminophenyloxy)phenyl-4-aminobenzamide) was found soluble in some of the organic solvents at room temperature but has poor thermal stability. Polyamide P-2 (prepared from 1,2-di(para-aminophenyloxy)ethylene) was soluble on heating and is thermally stable. However, all of these were also miscible with concentrated H₂SO₄ forming red coloured solutions.

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Graphical Abstract Ferrocenedicarbonyl chloride was reacted with three different types of aromatic diamines via solution polycondensation to get three new polyamides. Two of which were soluble in some organic solvents. The resulting polymers were characterized by their solubilities, viscosity measurements, elemental analysis, FTIR spectroscopy, differential scanning calorimetric and thermogravimetric studies.

     

Evaluation of reproductive toxicity in male rats treated with novel synthesized ruthenium(II) and gold(I)-NHC complexes

In this study, we aimed to determine the reproductive toxicity in rat induced by ruthenium(II)-NHC (Ru(II)) and gold(I)-NHC (Au(I)) complexes that have anticarcinogenic effects. For this purpose, 35 Sprague-Dawley rats were randomly divided into 5 equal groups. In control group, rats treated with saline, Ru(II), and Au(I) complexes were intraperitoneally given high (10?mg/kg) and low (5?mg/kg) doses to rats via a one-time administration. The animals were sacrificed, and testis tissues were taken on Day 10 of the drug administration for the determination of the biochemical, histopathological, spermatological, and hormonal parameters. It was determined that treatment group that was subjected to treatment using both Ru(II) and Au(I) complexes significantly caused oxidative, histopathological, spermatological, and hormonal damage compared to control group. However, the sexual and accessory organ weight did not significantly change when compared to control. In addition, it was shown that Au(I) treatment generally caused more adverse effects than Ru(II) treatment in a dose-dependent manner. In conclusion, when these synthesized compounds are used for the treatment of cancer, they could cause toxic effects on male reproductive system and lead to infertility. However, Ru(II) complex is a more preferable option in cancer treatment, particularly in terms of user safety.     

Genetically modified Lactococcus lactis producing a green fluorescent protein–bovine lactoferrin fusion protein suppresses proinflammatory cytokine expression in lipopolysaccharide-stimulated RAW 264.7 cells

Lactoferrin (LF), an iron-binding glycoprotein distributed widely in the biological fluids of mammals, is believed to play an important role in host defenses against infection. Previous studies in animal models and humans demonstrated that combined administration of LF and probiotic lactic acid bacteria (LAB) can prevent sepsis. In this study, we genetically engineered a probiotic LAB strain, Lactococcus lactis, to produce recombinant bovine LF based on the green fluorescent protein (GFP)-fused expression system. Western blotting confirmed that the genetically modified L. lactis strain (designated NZ-GFP-bLF) produced a protein corresponding to a fusion of GFP and bLF in the presence of nisin, an inducer of target gene expression. The protein synthesized by NZ-GFP-bLF was fluorescent and thus we monitored the time-dependent change in the production level of the recombinant protein using fluorometric analysis. The utility of NZ-GFP-bLF in preventing sepsis was determined by investigating its anti-inflammatory property in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW 264.7 cells. Pretreatment of RAW 264.7 cells with NZ-GFP-bLF significantly attenuated the LPS-induced mRNA expression and protein production of 3 proinflammatory cytokines (IL-1α, IL-6, and tumor necrosis factor-α) compared with pretreatment with a vector control strain of L. lactis. Our results suggest that NZ-GFP-bLF holds promise for the development of a new prophylaxis for sepsis.