Microwave assisted synthesis of MCM-41 type mesoporous materials and diffusion of organic vapors in porous media: MCM-41 and carbon nanotubes

In this study a novel synthesis technique of MCM-41 has been successfully applied for the production of pure and metal incorporated MCM-41 type mesoporous molecular sieves under microwave radiation by using a household microwave oven operated at several different combinations of power and time. High quality MCM-41 hexagonal mesoporous materials of good thermal stability were obtained in 30 minutes at 120 Watt by microwave assisted hydrothermal autoclave heating with specific surface area value of 1438 m²/g and average pore diameter of 3.49 nm. The effect of metal incorporation into the MCM-41 mesoporous molecular sieves was studied in detail with transition metals such as copper, nickel, cobalt and iron. Impregnation and microwave assisted direct synthesis techniques were used in the production of MCM-41 type catalytic materials and the physical and structural properties of these were investigated. The incorporation of metal into MCM-41 structure was investigated using different Si/Metal mol ratios as 25, 50, 75 and 100. Development of the hexagonal mesoporous structure was confirmed by X-ray diffraction (XRD) and N₂ [Nitrogen] physisorption and Fourier transform infrared (FT-IR), while the metal dispersion were characterized by energy dispersion spectroscopy (EDS) and transmission electron microscopy (TEM). Thermal stabilities of the samples were characterized by thermal gravimetric analyzer (TGA). Diffusion of organic volatile chemicals in pure MCM-41, metal incorporated MCM-41 (Si/Metal mol ratio: 25) and carbon nanotubes were investigated. Diffusion coefficients, mode of transport and activation energies of diffusion of alcohols (methanol, ethanol, n-propanol, n-butanol) and aromatic solvents (benzene, toluene, ethylbenzene, propylbenzene, o-xylene, m-xylene, p-xylene) into the porous media were measured in 26-32 ºC [degrees Celsius] temperature range with a macroscopic measurement technique. As the molecular weight of the alcohols and aromatics increased, diffusion coefficients into MCM-41 and CNTs decreased, activation energy for diffusion increased, and the time necessary to reach equilibrium increased. The diffusion of alcohols and aromatics into MCM-41 and CNTs obeyed the anomalous transport mechanism. Diffusion rate constants slightly increased with increasing temperature. The diffusion coefficients of volatile molecules into the CNTs were at least 10 times higher than that of diffusion coefficients into MCM-41

On The Power of Subtle Expressive Cues in the Perception of Human Affects

In this study, we introduce a sketch-based method for testing how subtle expressive cues influence the perception of affect in illustrations of human figures. We specifically study the impact of human posture and gaze direction, implicitly specified through nose orientation, on perceived emotions and mood. Through a series of user studies using sketchy illustrations of a running figure, where a professional illustrator manipulated gaze direction through adjustments on the nose orientation, we found that this simple change resulted in a diverse range of perceived affects, spanning from fear to concern and wonder. These findings shed light on the importance of fine details in defining context for context-aware system designs and underscore the importance of recognizing and expressing affect. Understanding minor expressive cues is crucial to developing emotionally intelligent systems capable of expressing affect.Comment: 11 page

Synthesis of mesoporous MCM-41 materials with low power microwave heating

Crystalline, high surface area, hexagonal mesoporous MCM-41 having uniform pore sizes and good thermal stability was successfully synthesized at 90-120oC in 30 minutes using low power microwave irradiation. This appears to be the first comprehensive and quantitative investigation of the comparatively rapid synthesis of mesoporous MCM-41 using low power microwave heating of 80W (90oC) and 120W (120oC). The influence of reaction temperature and the duration of heating were carefully investigated and the calcined MCM-41 materials were characterized by XRD, SEM, TEM, nitrogen adsorption, TGA and FTIR. The mesoporous MCM-41 product synthesized in 30 minutes at 120W and calcined at 550oC had a very high surface area of 1438 m2/g and was highly ordered, contained uniform pores with diameters in the range of 3.5-4.5 nm. The wall thickness of the materials highly depended on the power of the microwave energy used during the synthesis. Synthesis of the mesoporous MCM-41 products at 120oC resulted with a structure having thinner walls. The mesoporous MCM-41 materials synthesized in the present work had good thermal stability

Cervical Priming Before Diagnostic Operative Hysteroscopy in Infertile Women: A Randomized, Double-Blind, Controlled Comparison of 2 Vaginal Misoprostol Doses

The aim of this study was to evaluate the efficacy of vaginal misoprostol for cervical priming at doses of 200 mcg and 400 mcg, 12 to 15 hours before diagnostic office hysteroscopy (OH) without anesthesia in patients with infertility. Sixty infertile patients requiring a diagnostic office hysteroscopy for investigation of infertility were included in the study. The patients were randomly allocated into 3 vaginally administered misoprostol groups: (1) control group, (2) 200-mcg dose group, and (3) 400-mcg dose group. Misoprostol significantly facilitated the procedure of OH: cervical entry was easier; procedural time was shorter; baseline cervical width was larger; and pain scoring was lower in the misoprostol groups compared with the control group. Increasing the dose of misoprostol from 200 mcg to 400 mcg did not improve the effect on cervical dilation. Misoprostol is a promising analog to use for cervical priming before OH. Since doses of 200 mcg and 400 mcg vaginal misoprostol 12 hours before the OH both have proven to be effective regimens, 200 mcg may be preferred. However, before routine clinical usage, further research is needed through large, randomized, controlled trials powered to detect a difference in complications to determine whether misoprostol reduces complications in OH.Scientific Research Projects Coordination Unit of Istanbul UniversityIstanbul University [26324]An earlier version of this research was presented at the 42nd Annual Meeting of American Society of Reproductive Medicine in San Diego, 2012. This was made possible by funding from the Scientific Research Projects Coordination Unit of Istanbul University (grant 26324)

Template synthesis of boron nitride nanotubes over iron impregnated mesoporous silica MCM-41 by chemical vapor deposition technique

BN nanotubes were successfully grown over iron impregnated MCM-41 at a relatively low temperature of 750oC for 1 hour by CVD technique. BN nanotubes were obtained after the purification procedure including HCl and HNO3 treatments to remove impurities. SEM image showed the formation of nano-fibrous network BN structures in the diameter range of 20 nm to 40 nm. Both XRD and FTIR characterization results supported the formation of h-BN and c-BN nanostructures. Oxidative TGA results indicated that the synthesized BN nanostructures were thermally stable at temperatures higher than 550oC. Hydrogen storage measurements via IGA showed that BNNTs could adsorb 0.85 wt% hydrogen which was two times larger than for commercial CNTs

Registration and Optimization in Fintropic Graphs Using Branch Skeleton Features

25th Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2017 -- Antalya, TURKEYWOS: 000413813100311In image registration process, it is necessary to find the similarity of the images and thetranslation, rotation and scaling transformation parameter values that maximize the similarity between the two images. When the similarity measure and related parameters are calculated, information theory based entropic graphs can be used. In this study, similarity and optimization measures are compared on different entropic graphs. It has been seen that skeleton branch feature points to build entropic graphs give successful results.Turk Telekom, Arcelik A S, Aselsan, ARGENIT, HAVELSAN, NETAS, Adresgezgini, IEEE Turkey Sect, AVCR Informat Technologies, Cisco, i2i Syst, Integrated Syst & Syst Design, ENOVAS, FiGES Engn, MS Spektral, Istanbul Teknik Uni

A saliency-weighted orthogonal regression-based similarity measure for entropic graphs

Unlu, Mehmet Zubeyir/0000-0003-1605-0160; Ergun, Asli/0000-0003-0476-0069WOS: 000490956300015Various measures are used to determine similarity ratios among images before and after image registration. Image registration methods are based on finding the translation, rotation, and scaling parameters that maximize the similarity between two images by taking advantage of the feature points and densities that are found. While the similarity criterion is calculated, it is possible and advantageous to use approximation methods on the graphs based on information theory. the current study proposes a new similarity measure based on saliency-weighted orthogonal regression derived from the weighted sums of the saliency map of the orthogonal regression residuals formed on the entropic graph. It is evaluated in terms of both quantitative and qualitative methods and compared with other graph-based similarity measures

Physical characteristics of ceramic/glass-polymer based CAD/CAM materials: Effect of finishing and polishing techniques.

The aim of this study was to compare the effect of different finishing and polishing techniques on water absorption, water solubility, and microhardness of ceramic or glass-polymer based computer-aided design and computer-aided manufacturing (CAD/CAM) materials following thermocycling

Theoretical study of projectile fragmentations in relativistic heavy-ion reactions

We have investigated and interpreted the production cross sections and isotopic distributions of projectile-like residues in the reactions 124Sn + 124Sn and 112Sn + 112Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. For the interpretation of the data, calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters. The possible modification of symmetry energy parameter, in the multifragmentation region at the low density and hot freeze-out environment, is studied. It is reconfirmed that a significant reduction of the symmetry energy term is found necessary to reproduce experimental results at these conditions. We have also found a decreasing trend of the symmetry energy for large neutron-rich fragments of low excitation energy which is interpreted as a nuclear-structure effect