[en] In this work, effect of processing temperature in electrochemical capacitors was investigated for g-C₃N₄. The g-C₃N₄ materials (CN) were synthesized by thermal condensation of melamine precursor at different temperature (450, 550 and 650 °C). Then, the g-C₃N₄ materials were deposited on electrochemically reduced TiO₂ nanowires/nanotubes arrays (rTWTA)/Ti substrate. The g-C₃N₄/rTWTA/Ti electrodes were used as supercapacitor electrodes. Morphology, crystal structure and chemical composition of the g-C₃N₄/rTWTA/Ti electrodes were studied by FESEM, XRD, FTIR and elemental analysis. Based on galvanostatic charge/discharge measurements, the CN(450)/rTWTA/Ti electrode exhibited the highest specific capacitance up to 22 mF/cm² at 0.3 mA/cm² with long cyclic durability at 96.8% capacitance retention after 500 cycle. This effect was attributed to the existence of higher nitrogen content, more active sites, the improved hydrophilicity and three-dimensional morphology of the CN(450)/rTWTA/Ti electrode as compared to the other electrodes. This research introduces the optimum thermal condensation temperature of the melamine for synthesis of the g-C₃N₄ with great potentials in supercapacitors.

[en] The Multi-walled carbon nanotube (MWCNT)/WO₃ nanocomposite thin films with different MWCNT’s weight percentages were prepared by sol–gel method as visible light induced photoanode in water splitting reaction. Weight percentage of MWCNT in the all nanocomposite thin films was confirmed by TGA/DSC analysis. According to XPS analysis, oxygenated groups at the surface of the MWCNT and stoichiometric formation of WO₃ thin films were determined, while the crystalline structure of the nanocomposite samples was studied by XRD indicating (0 0 2) peak of MWCNT in the monoclinic phase of WO₃. The influence of different weight percentage (wt%) of MWCNT on WO₃ photoactivity showed that the electron conductivity, charge transfer and electron life time had improved as compared with the pure WO₃. Based on linear sweep voltammetry and chronoamperometry measurements, the (1 wt%) MWCNT/WO₃ nanocomposite thin films photoanode has a maximum photocurrent density of ∼4.5 A/m² and electron life time of about 57 s. - Graphical abstract: Photocurrent density versus time at constant potential (0.7 V) for the WO₃ films containing different MWCNT weight percentages annealed at 400 °C under 1000 Wm⁻² visible photo-illumination. Display Omitted - Highlights: • MWCNT/ WO₃ nanocomposite thin films were synthesized using sol–gel derived method. • TGA/DSC confirmed the weight percentage of MWCNT in the all nanocomposite thin films. • XPS analysis revealed that WO₃ was attached on the oxygenated group of MWCNT surface. • The Highest Photoelectrochemical activity is achieved for (1 wt%)MWCNT/WO₃ thin film

[en] 

Purpose

Genotoxic wastes are one type of hospital wastes that are extremely dangerous and may cause cell mutation or cancer and their disposal should be taken seriously. Cytotoxic drugs are main component of these wastes. The purpose of this study was to determine the types and quantities of genotoxic wastes in hospitals of Tehran University of Medical Sciences and evaluation of genotoxic waste management index.

Methods

For this purpose, a questionnaire was used to collect data. Each question was scored according to compliance or non-compliance with the law, and genotoxic hospital waste management index was calculated for each hospital.

Results

Various parameters including waste generation rate, segregation, collection, transportation, storage, disposal and the hygiene of personnel were evaluated. The results showed that 60% of hospitals ranked medium, 27% ranked poor and 13% ranked as very poor according to this index.

Conclusions

Since the condition of genotoxic waste management in this study was ranked as medium, therefore some steps of hospital waste management system require improvement.

[en] 

Background

Edible coatings are useful method that applied to preserve postharvest quality of production. The coatings can extend the shelf life of products and inhibit microbial growth. Chitosan based coatings are one of the best methods to prolong fruit and vegetable shelf life. The antimicrobial and other properties of chitosan are developed when it is combined with other functional ingredients.

Methods

The effectiveness of chitosan, ethanolic extract of liquorice (LE) and complex of chitosan-liquorice extract (CHLE) was evaluated for controlling blue mold and extending shelf life in apples. The fruits were coated with chitosan(1.0%), LE (62.5 mg/ml) and CHLE coating, and stored at 25 °C. Quality properties of fruit (such as weight loss, firmness, total soluble solid content(TSS), titrable acidity and pH) and decay incidence were assessed on 0,1,4,7 and 14 days of incubation, respectively.

Results

The results of experiments indicated that minimum of water loss(3.8%), TSS(14.53) and firmness(5.6 kg/cm² ) were in CHLE coated apples. In addition, this coating significantly inhibited penicillium expansum during the storage and the lowest decay incidence was for apples coated with CHLE(29 mm). Chitosan and LE coating retarded undesirable changes during postharvest storage and inhibited decay incidence compared with uncoated samples. There was no significant difference (p ≤ 0/05) between treatments and control overtime in terms of titrable acidity and pH levels.

Conclusions

The results reported here indicate importance and efficacy of CHLE coating in extending shelflife and reduction of postharvest losses of apple in storage time.