Nanotechnology in the public eye: the case of Iran,as a developing country

Using survey data, public awareness of and attitudes toward nanotechnology are examined in Iran (N = 759). Iran is a developing country with a national nanotechnology action plan for a ten year period starting from 2003 and has been active in the field of research and development of nanotechnology meanwhile. First, the results show that majority of people are still not familiar with nanotechnology and perceived risks posed by this technology are not considered to be a lot and most people feel its benefits outweigh the risks. The emotions toward this technology are of a hopeful and positive nature and this technology is looked upon favorably in Iran. In particular, our results reveals that although the level of trust is high specially in scientists to communicate the risks with the public, there are a great number who just have some trust not quite a lot of it. Knowing that it is a hard and time-consuming effort to manage a nation’s view on nanotechnology, extensive research as well as collaboration with other countries is needed to effectively communicate the risks in time.     

ZL-amenability and characters for the restricted direct products of finite groups

Let G   be a restricted direct product of finite groups _{Gi}i∈I${\{G_i\}}_{i\in I}$, and let Z?¹(G)${\mathrm{Z}?}^1(G)$ denote the centre of its group algebra. We show that Z?¹(G)${\mathrm{Z}?}^1(G)$ is amenable if and only if _Gi$G_i$ is abelian for all but finitely many i  , and characterize the maximal ideals of Z?¹(G)${\mathrm{Z}?}^1(G)$ which have bounded approximate identities. We also study when an algebra character of Z?¹(G)${\mathrm{Z}?}^1(G)$ belongs to _c0$c_0$ or ?^p${?}^p$ and provide a variety of examples.     

Synthesis of attapulgite-MnO2 nanocomposite from manganese complex by ultrasound for hydrogen storage

The research included the synthesis of a new complex of manganese with 3,4,5-tri-methoxybenzoic acid in the presence of triethylamine as a base to which gives the complex with formula [Mn (TMB)₂].2H₂O. This complex was characterized by FTIR, CHN, magnetic susceptibility and thermal analysis. Furthermore, this complex was used as a novel precursor of manganese in preparing the attapulgite-MnO₂ nanocomposite by one-pot addition method using ultrasound. The resulting nanocomposite was characterized by X-ray diffraction and TEM and the results prove that this composite was found as nanochannel of the diameter 45 nm decorated with 26–41 nm of MnO₂ nanoparticles. The attapulgite-MnO₂ nanocomposite was used in the application of hydrogen storage, and the results proved that attapulgite-MnO₂ nanocomposite has the ability to store 3.55 wt% of hydrogen under a pressure of 90 bar and a temperature of 77 K. Furthermore, the measurement demonstrated that increasing the pressure increased the stored hydrogen, implying that the stored gas will be liberated by altering the pressure, implying that the storage will be of the physical kind.     

Design,synthesis and antibacterial activity evaluation of novel 2-(4-((1-aryl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)2-(2-oxoazetidin-1-yl)acetamide derivatives

In this paper, a novel series of 2-(4-((1-aryl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)2-(2-oxoazetidin-1-yl)acetamide derivatives are synthesized in two steps. The first step involved Ugi multicomponent reaction of β-alanine, o-(propargyl)benzaldehyde and isocyanide derivatives. The product of this step, underwent a click 1,3-dipolar cycloaddition reaction with benzyl azide derivatives. The 2-(4-((1-aryl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)2-(2-oxoazetidin-1-yl)acetamide product was characterized and their antibacterial activities were evaluated against various G-positive (Staphylococcus aureus and Bacillus subtilis) and G-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria, using minimal inhibition concentration. The compounds showed very good antimicrobial activity and a number of products have been more active than ciprofloxacin.     

Squeezed flow and heat transfer over a porous surface for viscous fluid

Flow and heat transfer over a permeable sensor surface placed in a squeezing channel is analyzed. A constant transpiration through the sensor surface is assumed. Locally non-similar momentum and energy equations are solved by three different methods, against the transpiration parameter τ, for different values of the squeezing parameter b, and Prandtl number Pr. From the investigation, it is found that when the channel being squeezed, the skin-friction reduces but the heat transfer coefficient increases. Increase in the value of the squeezing parameter onsets reverse flow at the sensor surface when fluid is being injected and the affect is enhanced with the increase of injection through the surface. It is further observed that increase of suction of fluid through the sensor thins the thermal and the momentum boundary layer regions, whereas injection of fluid leads to thickening of both the thermal and the momentum boundary layer regions. Heat transfer from the surface of the sensor increases with the increase of the value of Pr for the entire range of surface mass-flux parameter τ. M. A. Hossain is on leave of absence from University of Dhaka.     

“Hot Potato Voice” in Peritonsillitis: A Misnomer

The "hot potato voice" is widely recognized as a symptom of peritonsillar cellulitis or abscess; yet there have been no studies assessing the resonance characteristics of the vocal tract in peritonsillitis. Analysis was undertaken of formant frequencies in the articulation of the vowels /i:/. /a:/ and /u:/ in six subjects with peritonsillitis and compared with articulation once the peritonsillitis had settled. Significant variation was found in F1 when articulating /i:/ and in F2 when articulating /a:/, which are explainable by dyskinesis of the peritonsillar musculature. These findings were compared with six subjects articulating the same vowels with and without a hot potato in their mouth. Variation was found in both F1 and F2 when articulating /i:/, which can be related to interference of the potato with movement of the anterior tongue. The changes in the vocal tract differ in these two cases and the title "hot potato voice" in peritonsillitis is a misnomer.     

Measurements of electron density, temperature and photoionization cross sections of the excited states of neon in a discharge plasma

In the present work emission and absorption spectroscopy have been used to determine the plasma parameters of neon in a hollow cathode discharge lamp. The excitation temperature is determined using the intensity ratio method and Boltzmann's plot method whereas the electron density is determined from the Stark broadening of the spectral lines. The behavior of the optogalvanic signal as a function of laser energy has been studied for three transitions from the 2p⁵3s [1/2]₂ metastable state following ΔJ=ΔK=0, ±1 dipole selection rules. The saturation technique has been used to measure the photoionization cross section from three intermediate states 2p⁵3p′ [1/2]_1, 2p⁵3p′ [3/2]₂ and 2p⁵3p [5/2]₃ up to the 2p^{5 2}P_1/2 ionization threshold.     

A study on melt grafting of maleic anhydride onto low‐density polyethylene and its blend with polyamide 6

Graft copolymerization of low‐density polyethylene (LDPE) with a maleic anhydride (MAH) was performed using intermeshing corotating twin‐screw extruder in the presence of benzoyl peroxide (BPO). The LDPE/polyamide 6 (PA6) and LDPE‐g‐MAH/PA6 blends were prepared in a corotating twin‐screw extruder. The melt viscosity of the grafted LDPE was measured by a capillary rheometer. The grafted copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microcopy (SEM). The influence of the variation in temperature, BPO and MAH concentration, and temperature on the grafting degree and on the melt viscosity was studied. The grafting degree increased appreciably up to about 0.45 phr and then decreased continuously with an increasing BPO concentration. According to the FTIR analysis, it was found that the amount of grafted MAH on the LDPE chains was ～5.1%. Thermal analysis showed that melting temperature of the graft copolymers decreases with increasing grafting degree. In addition to this, loss modulus (E″) of the copolymers first increased little with increasing grafting and then obviously decreased with increasing grafting degree. Furthermore, the results revealed that the tensile strength of the blends increased linearly with increasing PA6 content. The results of SEM and mechanical test showed that the blends have good interfacial adhesion and good stability of the phase structure, which is reflected in the mechanical properties. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 267–275, 2010