A biotechnological perspective on the application of iron oxide nanoparticles

In recent decades,magnetic iron nanoparticles (NPs) have attracted much attention due to properties such as superparamagnetism,high surface area,large surface-to-volume ratio,and easy separation under external magnetic fields.Therefore,magnetic iron oxides have potential for use in numerous applications,including magnetic resonance imaging contrast enhancement,tissue repair,immunoassay,detoxification of biological fluids,drug delivery,hyperthermia,and cell separation.This review provides an updated and integrated focus on the fabrication and characterization of suitable magnetic iron NPs for biotechnological applications.The possible perspective and some challenges in the further development of these NPs are also discussed.     

Processable Thermally Conductive Polyurethane Composite Fibers

The demand for wearable electronics has resulted in an increasing interest in the development of functional fibers, with a specific focus upon the development of electrically conductive fibers incorporable into garments. However, the production of thermally conductive fibers for heat dissipation has been largely neglected. Owing to the very rapid development of miniaturized wearable electronics, there is an increasing need for the development of thermally conductive fibers as heat sinks and thermal management processes. In this study, thermally conductive but electrically insulating boron nitride nanopowder (BNNP) fillers are used to effectively enhance the thermal conductivity and mechanical properties of elastomeric polyurethane fibers. Thermal conductivity enhancement of more than 160% is achieved at very low loadings of BNNP (less than 5 wt%) with an improvement in the mechanical properties of the unmodified fiber. These thermally conductive fibers are also incorporated into 3D textile structures as a proof of processability.     

Sex and age distribution in transport-related injuries in Tehran

Intercountry or regional differences in patterns of injury by the road user type have significant implication for prevention policies. In order to have an estimate from the existing conditions of transport-related injuries (TRIs) and especially to evaluate sex and age distribution of traffic accident victims, we analyzed information of 8426 hospitalized trauma patients during 13 months of data gathering process. Forty-five percent of the injuries were related to car accidents and men/women ratio in these patients was 4.2/1. The highest men/women ratio was (16/1) for motorcyclists, while the lowest ratio (1/1), was for rear seat car passengers. Mean (+/-S.D.) age of the patients was 31 (+/-18), and men were nearly 2 years younger than women (33 versus 31). Sixty-seven percent of the females' and 44% of the males' injuries were related to pedestrian crashes. Motorcycle-related injuries in men and car passenger related injuries in women were the second most common type of crash (42 and 22%, respectively). The use of protective devices in our population was worrisome. In only 6% of the male motorcyclists helmet use was reported, and 3% of the male car occupants had used seatbelts at the time of the accident. The condition in the female population was much worse and no use of the protective devices was reported in this group of the patients. Crude mortality rate in men was nearly two times that of women (6.2% versus 3.8%). After adjustment for age, injury severity score (ISS) and category of the road users, men and women had similar mortality rate.     

Adsorptive separation of meta-xylene from C8 aromatics

Industrial adsorptive separation process for liquids is most successful when the involved species have very close boiling points, making distillation expensive or are thermally sensitive at convenient distillation temperatures. The adsorption process was studied for separating meta-xylene from a feed mixture containing all C₈ aromatics on binder-free X and Y zeolites in the liquid phase. Zeolitic adsorbents with different SiO₂/Al₂O₃ were synthesized by the hydrothermal method and ion-exchanged with alkaline metal cations like lithium, sodium and potassium. The adsorption process was carried out in a breakthrough system at temperature of 110–160 °C and pressure of 6–8 atm. The influence of adsorbent moisture content on the separation process was studied. The optimization of adsorption process was also investigated by the changing operation conditions. The isotherms for each isomer of C₈ aromatics and the desorbent possess the adsorption characteristics of Langmuir type. The selectivity factor of meta-xylene and the saturation adsorption capacities of adsorbates were determined. It was observed that the selectivity of meta-xylene increased by sodium ion-exchanging of cationic sites in Y zeolite and the selectivity factor of meta-xylene/para-xylene, meta-xylene/ortho-xylene and meta-xylene/ethylbenzene in the optimum conditions was determined to be 2.62, 2.83 and 5.93, respectively.     

Preparation of Curcumin Nanodispersions Using Subcritical Water – Screening of Different Emulsifiers

Nanodispersions can help to increase solubility and stability of bioactive components and food additives. Curcumin nanodispersions were prepared by a novel subcritical water method using eleven emulsifiers, namely, polyethylene glycol, Tween 20, Tween 80, casein, sodium caseinate, lecithin, guar gam, Arabic gum, inulin, β-cyclodextrin, and maltodextrin. Influences of the emulsifiers on the rheological, physicochemical, antioxidant, and antibacterial properties of the nanodispersion were evaluated. Results revealed that the nanodispersion prepared with Tween 20 showed the smallest particle size and lowest polydispersity index values as well as the highest antioxidant and antibacterial activities. Nanodispersions prepared with lecithin exhibited the highest zeta potential and lowest conductivity values.     

Fabrication of anodic aluminum oxide nanotemplate and investigation of their anodization parameters

Anodic Aluminum Oxide (AAO) nanotemplate, is a kind of layer made by anodizing a thin film of aluminum on a substrate. It contains alternate arrays and pores in the dimension of nanometer scale, which is currently being used to fabricate nano devices, magnetic nanostructures, polymeric nanowires, super conductors and nanofibers. This structure contains orderly columnar hexagonal porous cells. In this research, we have fabricated AAO nanotemplates on glass and pure aluminum substrate. In our research we have kept the temperature, concentration and voltage constant but the time was a variable. We observed that the dimensions of hexagonal pores increased with a linear speed of 100 nm per hour. Also the effect of annealing on the nanostructure is investigated. After analyzing annealed structure, it was observed that it is homogenous.     

Nutritional quality of important food legumes

The proximate composition, mineral constituents and amino acid profile of four important legumes (chickpea, lentil, cowpea and green pea) were studied in order to evaluate their nutritional performance. Significant (P < 0.05) variations existed among the legumes with respect to their proximate composition, mineral constituent and amino acid profile. Lentil was found to be a good source of protein, while cowpea was good in ash among the grain legumes tested. All four types of legumes were also better suppliers of mineral matter, particularly potassium, phosphorus, calcium, copper, iron, and zinc. However, the concentrations of various mineral constituents was not in good nutritional balance. It was concluded that the four legumes tested were rich in lysine, leucine and arginine and can fulfil the essential amino acid requirement of human diet except for S-containing amino acids and tryptophan. In order to make good, the deficiency of certain essential amino acids in legume protein, they must be supplemented with other vegetables, meat and dairy products (e.g., Whey, yogurt).     

A CFD-PBM coupled model under entire turbulent spectrum for simulating a bubble column with highly viscous media

To account for the effect of liquid viscosity, the bubble breakup model considering turbulent eddy collision based on the inertial subrange turbulent spectrum was extended to the entire turbulent spectrum that included the energy-containing, inertial, and energy-dissipation subranges. The computational fluid dynamics-population balance model coupled model was modified to include this extended bubble breakup model for simulations of a bubble column. The effect of turbulent energy spectrum on the bubble breakup and hydrodynamic behaviors was studied in a bubble column under different liquid viscosities. The results showed that when the liquid viscosity was <80 mPa s, the bubble breakup and hydrodynamics were almost independent on the turbulent spectrum. At liquid viscosity >80 mPa s, the bubble breakup rate and gas holdup were significantly under-predicted when the inertial turbulent spectrum was used, and when using the entire turbulent spectrum the predictions were more consistent with experimental data.     

Comparing two new routes for benzene hydroxylation

The vapour phase hydroxylation of benzene to phenol by two different methods has been investigated. In the first, a mixture of oxygen and hydrogen using a Pd membrane tubular reactor with and without second catalyst was used. Hydrogen dissociated on the palladium layer and reacted with oxygen to give active oxygen species, which reacted with benzene to produce phenol. The slow step in the overall reaction is the formation of usable hydrogen peroxide. Using a second catalyst changed the productivity, and conversion of benzene was increased by changing the length and diameter of porous reactor tubes. Low phenol productivity and selectivity was observed and showed that hydroxylation of benzene using a Pd membrane reactor is a far from economic method. In the second, selective oxidation of benzene with N₂O on iron zeolite of different SiO₂/Al₂O₃ composition, with concentration of iron rating from 50 to 2000 ppm was investigated. The effects of temperature, reactant mole ratio, and contact time were investigated. Phenol was formed with near 97% selectivity and average productivity of 5 mmol g⁻¹ h⁻¹.