Efficiency evaluation of the photocatalytic degradation of zinc oxide nanoparticles immobilized on modified zeolites in the removal of styrene vapor from air

Styrene monomer is a volatile organic compound that has many applications in plastics, rubber, and paint manufacturing industries. Exposure to styrene vapor has certain effects, including suppression of the central nervous system, loss of concentration, weakness and fatigue, and nausea and there is a possibility of carcinogenesis in long-term exposure. Therefore, it is necessary to control and eliminate this vapor. The aim of this study was to investigate the performance of zinc oxide nanoparticles on modified natural zeolites in removing styrene vapor from the air. Natural zeolites of clinoptilolite were modified using hydrochloric acid and diphenyldichlorosilane. Next, zinc oxide nanoparticles with different ratios of 3, 5, and 10 wt% were stabilized on the zeolites. To determine their characteristics, samples were used from BET, SEM and XRD analyses. The input styrene concentration and the ratio of nanoparticles stabilized on zeolites were studied as effective functional parameters on the removal process. The efficiency results of natural zeolites (Ze) and modified zeolites (Mze) in styrene adsorption from the air show that the styrene breakthrough in the bed of MZe compared to that of Ze increases approximately two times. Also, the results showed that the removal by the process of UV/MZe-ZnO 3%, UV/MZe-ZnO 5%, and UV/MZe-ZnO 10%, was 36.5%, 40%, and 26%, respectively. From the results it can be concluded that MZe can increase the efficiency of photocatalytic degradation. Clinoptilolites of Iran can be used as an adsorbent to remove polluted air in industries that have low concentrations and flow rates.     

Recent Advances in CNT-based FET Transistor Biosensors to Detect Biomarkers of Clinical Significance

Silicon - The development of advanced materials has attracted interest for promising novel applications in biosensing and realm of nanophotonics. This interest in nanoelectronics, and...     

Spectral analysis methods for vehicle interior vibro-acoustics identification

Noise has various effects on comfort, performance and health of human. Sound are analysed by human brain based on the frequencies and amplitudes. In a dynamic system, transmission of sound and vibrations depend on frequency and direction of the input motion and characteristics of the output. It is imperative that automotive manufacturers invest a lot of effort and money to improve and enhance the vibro-acoustics performance of their products. The enhancement effort may be very difficult and time-consuming if one relies only on ‘trial and error’ method without prior knowledge about the sources itself. Complex noise inside a vehicle cabin originated from various sources and travel through many pathways. First stage of sound quality refinement is to find the source. It is vital for automotive engineers to identify the dominant noise sources such as engine noise, exhaust noise and noise due to vibration transmission inside of vehicle. The purpose of this paper is to find the vibro-acoustical sources of noise in a passenger vehicle compartment. The implementation of spectral analysis method is much faster than the ‘trial and error’ methods in which, parts should be separated to measure the transfer functions. Also by using spectral analysis method, signals can be recorded in real operational conditions which conduce to more consistent results. A multi-channel analyser is utilised to measure and record the vibro-acoustical signals. Computational algorithms are also employed to identify contribution of various sources towards the measured interior signal. These achievements can be utilised to detect, control and optimise interior noise performance of road transport vehicles.     

A comprehensive experimental evaluation of asphaltene dispersants for injection under reservoir conditions

As the efficiency of dispersants with different origins is questionable for each typical oil sample, the present study provides a reproducible and reliable method for screening asphaltene dispersants for a typical asphaltenic crude oil. Four different asphaltene dispersants (polyisobutylene succinimide, polyisobutylene succinic ester, nonylphenol-formaldehyde resin modified by polyamines, and rapeseed oil amide) were prepared and their performance on two oils from an Iranian field under laboratory and reservoir conditions was studied. A thorough analysis including ash content and SARA tests was performed on the solid asphaltene particles to characterize the nature of deposits. Then a highly efficient carrier fluid, which is crucial when injecting dispersant into the wells, was selected from a variety of chemicals by comparing their solubility. In the next step, using an optical microscope, a viscometer, and a Turbiscan, the screening of dispersants under laboratory conditions was done on a mixture of dead oil and dispersant to evaluate the onset of asphaltene precipitation and its stability when titrating by a precipitant. Finally, two different mixtures of the efficient dispersants, live oil, and carrier fluid were used with the solid detection system (SDS) and the filtration method to examine their effects on the onset pressure of asphaltene precipitation and the asphaltene content of the crude oil under reservoir conditions. The results show that the combination of experimental methods used in this work could be consistently applied to screening asphaltene dispersants. Among the four different dispersants applied here, the dispersant based on nonylphenol-formaldehyde resin modified by polyamines showed the best performance on the available live oils. This chemical modified the onset pressure of asphaltene precipitation of light oil from 4300 psi to about 3600 psi and decreased the precipitated asphaltene of heavy oil by about 30 %.     

The effects of depressed mood on smoking cessation: Mediation by postcessation self-efficacy.

This study evaluated the relationship between precessation depressed mood and smoking abstinence and assessed the mediation of this effect by postcessation self-efficacy, urges to smoke, nicotine withdrawal, and coping behavior. The sample included 121 smokers previously treated in a randomized controlled trial involving behavior therapy and the nicotine patch. The results showed that precessation depressed mood was inversely related to 6-month abstinence. This effect remained significant after controlling for treatment, possible depression history, baseline smoking rates, and several other demographic factors. Postcessation self-efficacy, at the 2-, 4-, and 8-week postquit assessments, was the strongest mediator of the effects of precessation depressed mood on abstinence, accounting for 32%, 38%, and 48% of the effect of mood on abstinence, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spin Transport Through a Poly(p-phenylene)-Like Molecular Wire with Multi-noncollinear Polarized Terminals

We numerically investigated the spin transport through a poly(p-phenylene)-like molecular wire connected to three noncollinear polarized terminals. Using the generalized Green’s function technique based on the tight-binding model and Landauer–Büttiker theory, we have calculated the transmission probability, currents, and tunnel magnetoresistance (TMR). It is found that the spin-dependent transport properties are significantly influenced by the relative directions of spin polarized leads, in which one can tune the magnitude of TMR by changing spin direction in the leads. We have also tested the effect of terminal positions as a source of quantum interference. Our results show that different terminal positions have profound effects on the current and TMR characteristics. Different TMR strength and threshold bias voltage V _t are also detected.     

Developing an ordering-based renumbering approach for triangular unstructured grids

The unstructured grid generation and employment have become very common in computational fluid dynamics applications since a few decades ago. Comparing with the structured grid data, the unstructured grid has a random data structure known as unstructured data structure (USDS). In this work, we develop a new method to convert the USDS of a triangular unstructured grid to a quasi-structured data structure (QSDS) using an ordering-based renumbering approach. In this method, the unstructured grid data is re-ordered in a manner to represent several bands in the original unstructured grid domain. Each band presents one element layer and two node lines. Then, the indices of elements and nodes are renumbered in a unified direction for the entire constructed element layers and node lines, respectively. These numbers eventually present ascending sets of element and node indices in each element layer and every node line of the resulting QSDS. This method alleviates the random USDS drawbacks because the scattered node and element numbers in the original USDS are reordered and renumbered properly. To show the robustness of the current method, we construct a few arbitrary unstructured grid distributions and convert their ordinary USDS to our innovated QSDS without requiring additional data storage.     

Use of adjuvant ICE chemotherapy in the treatment of anaplastic ependymomas

Despite the improved outcome for patients with ependymoma treated by surgery and radiotherapy, their prognosis remains relatively poor. To assess the impact of adjuvant chemotherapy, we reviewed the overall survival of consecutive patients with anaplastic ependymoma treated over a 10-year period with surgery and ICE (ifosfamide+ VP 16+carboplatin) chemotherapy with or without radiation at our institution. There were 11 patients (6 male, 5 female), with a median age of 3.4 years (range 1.2-1 1.1): 4 under 2 years and 7 were over 2 years old. Overall, 5 had gross total resections: 4 are alive, 2 in continuous complete remission and 2 in second complete remission. One patient who was less than 2 years old died. Among the 6 with subtotal resection, 2 achieved a complete remission after chemotherapy. However, 5 of the 6 patients have since died of progressive disease, with a median overall survival of 75 months. Overall survival was 24% and progression-free survival was 39%. In 2 of 6 patients with residual postoperative disease a temporary objective response was noted with adjuvant ICE chemotherapy. This regimen did not confer an overall survival advantage.