Increasing the photocatalytic and fungicide activities of Ag3PO4 microcrystals under visible-light irradiation

The present study reports for the first time the performance of silver phosphate (Ag₃PO₄) microcrystals as photocatalyst (degradation of Rodamine B-RhB) and antifungal agent (against Candida albicans–C. albicans) under visible-light irradiation (455 nm). Ag₃PO₄ microcrystals were synthesized by a simple co-precipitation (CP) method at room temperature. The structural and electronic properties of the as-synthetized Ag₃PO₄ have been investigated before and after 4 cycles of RhB degradation under visible light using X-ray diffraction (XRD), micro-Raman spectroscopy, UV–Vis spectrophotometer and field emission scanning electron microscopy (FE-SEM) images. The antifungal activity was analyzed in planktonic cells and 48h-biofilm of C. albicans by colony forming units (CFU) counting, confocal laser and FE-SE microscopies. Statistical analysis was carried out using SPSS software. Morphological and structural modifications of Ag₃PO₄ were observed upon recycling. After 4 recycles, the material maintained its photodegradation property; an eightfold increase in the efficiency of Ag₃PO₄ was observed in planktonic cells and a two fold increase in biofilm when irradiated under visible light. Thus, higher antifungal effectiveness against C. albicans was obtained when associated with visible-light irradiation.     

Self-service — but is it good to talk?

Drives to increase the volume of customers who use self-service channels are a common strategic goal. The promise of significant cost reduction is a tempting carrot. Couple this with the vision of customers benefiting from quick, effective and usable contact channels, avoiding human error (except perhaps their own!) or potential frustration at being passed around to an ‘appropriate’ contact centre advisor is a very worthy vision … but is it as simple as this? In this discussion paper the authors speculate that self-service, while potentially being a revenue-saving opportunity, could also erode customer satisfaction and loyalty. Self-service doubtless appeals to some customers, but is it what all customers want? Do organisations understand enough about customer experience to enable them to build successful self-service channels, i.e. those that are useful, usable and used by customers? Do businesses really want to lose the opportunity to actually talk to customers and gain insight and knowledge about them? What impact will increased levels of self-service have on more traditional channels, such as customer contact centres? This paper also discusses evidence that self-service can actually serve to increase communication between organisations and customers across multiple channels. For many organisations, the Internet has actually resulted in more calls to the contact centre, not less. The seductive promise of self-service to cut costs through reducing call volumes may be an empty one.     

The Fe-Ni (iron-nickel) system

The online version of the original article can be found at     

Sintering-driven effects on the band gap of (Pb,La)(Ti,Ni)O3 photovoltaic ceramics

In this work, the influence of the sintering temperature on the physical properties of (Pb_0.8La_0.2)(Ti_0.9Ni_0.1)O₃ (PLT-Ni) ceramics is reported. The experimental data revealed that the energy band gap of PLT-Ni ceramics could be tailored from approximately 2.7 to 2.0 eV by changing the sintering temperature from 1100°C to 1250°C. It is demonstrated that the simple substitution of Ti⁴⁺ by Ni²⁺ cations is effective to decrease the intrinsic band gap while increasing the tetragonality factor and the spontaneous polarization. However, the additional red-shift observed in the absorption edge of the PLT-Ni with increasing the sintering temperature was associated with a continuous increase in the oxygen vacancies () amount. It is believed that the impact of the creation of these thermally induced is manifold. The presence of and Ni²⁺ ions generate the Ni²⁺- defect-pairs that promoted both a decrease in the intrinsic band gap and an additional increase of the tetragonality factor, consequently, increasing the spontaneous polarization. The creation of Ni²⁺- defects also changed the local symmetry of Ni²⁺ ions from octahedral to a square pyramid, thus lifting the degeneracy of the Ni²⁺ 3d orbitals. With the increase in the sintering temperature, lower-energy absorbing intraband states were also formed due to an excess of , being responsible for an add-on shoulder in the absorption edge, extending the light absorption curve to longer wavelengths and leading to an additional absorption in “all investigated” spectrum as well.     

Antistatic packaging based on PTT/PTT-g-MA/ABS/MWCNT nanocomposites: Effect of the chemical functionalization of MWCNTs

Polymer/carbon nanotube nanocomposites have attracted high interest for a wide spectrum of applications, including antistatic packaging used to protect electronic devices against electrostatic discharge. Polytrimethylene terephthalate (PTT)/maleic-anhydride-grafted PTT (PTT-g-MA)/acrylonitrile butadiene styrene (ABS) blend-based multiwall carbon nanotubes (MWCNTs) nanocomposites were prepared through extrusion. It was conducted chemical functionalization on the MWCNTs by oxidation using nitric acid to introduce functional groups. The effect of the amount (0.5 or 1.0 wt%) and functionalization of MWCNTs on the nanocomposites was investigated. Despite the poor barrier properties of PTT/PTT-g-MA/ABS/MWCNT nanocomposites due to the presence of voids confirmed by scanning electron microscopy (SEM), the nanocomposites with functionalized MWCNT (MWCNTf) showed excellent barrier properties, indicating that the functionalization process improved the interaction between the MWCNTs and the matrix. The addition of MWCNTs into PTT/PTT-g-MA/ABS blend decreased the electrical resistivity by eight orders of magnitude. The use of MWCNTf may still disrupt the electrical network pathway and slightly decreasing the electrical resistivity, but the nanocomposites present the desired properties required for antistatic packaging.     

Technical and economical assessment of energy-saving roof and wall construction in Thailand

This research assessed the economic impact and construction costs of buildings with solar chimneys in Thailand, called bioclimatic houses. A solar chimney uses a combination of air gaps between walls and roof, and effective ventilation to lower the indoor temperature and reduce the need for air conditioning. The study looked at small, medium, and large size houses and studied construction techniques, the materials used, and the time needed to build a residential structure. It also polled owners of bioclimatic houses about their satisfaction. The techniques employed in building bioclimatic houses take slightly longer and cost slightly more than those used in standard construction. However, the study found that bioclimatic houses use approximately 10–20% less electricity for air conditioning require less maintenance and have a payback period of 6–13 years, depending on the size. The lifespan of insulation material used in standard houses is about 20–25 years, while the lifespan of a solar chimney is about 40–50 years. The solar chimney concept can also be applied to standard houses with minimal renovation. The study found that this type of house was suitable for use in Thailand, and with increased consumer awareness, had a high probability for adoption.     

Information channel diagrams: an approach for modelling information flows

In this article, the ‘information channel diagram’ (ICD) approach is introduced as a diagrammatical tool for modelling information flow during the delivery phase of organisations in which goods are deployed or delivered to customers. An initial review and evaluation of current tools for modelling information flow will be conducted based on the characteristics of information flow during the delivery phases in organisations. Diagrammatic primitives and a prescribed modelling methodology for developing an ICD will be presented, and a case scenario of the delivery phase of an organisation within the health care sector will be applied to demonstrate the use of the ICD. The article concludes by discussing some applications, generalisation potential and limitations of the ICD approach.