Temperature-dependent R-curve behavior of Pb(Zr1−xTix)O3

The crack growth resistance behavior of polycrystalline Pb(Zr_1?xTi_x)O₃ has been characterized in a novel experimental arrangement between 24 and 140 °C. Experimental measurements were carried out on compact tension specimens submerged in a temperature-controlled silicone oil bath. The results show a decrease in the observed shielding toughness, leading to an overall reduction in the maximum toughness. The temperature-dependent stress–strain behavior and elastic properties were characterized, providing an insight into the effect of the changing ferroelastic properties on the temperature-dependent fracture behavior.     

Human resources in advanced environmental approaches–a case analysis

A weak organizational culture creates an environment that leads to inefficiencies in human resources. Both a weak organizational culture and inefficiencies in human resources are major barriers to the implementation of environmental action processes. However, very few studies have been published in this area. The objective of this study, therefore, is to conduct an exploratory case analysis and develop some proposals based on the conclusions arrived at. We have analyzed a total of 8 factories to ensure a sufficient number of sources of information. Some factors linked to organizational culture and the human resource management in a factory that favour environmental performance were found.     

On-chip electric field driven electrochemical detection using a poly(dimethylsiloxane) microchannel with gold microband electrodes

An external electric field driven in-channel detection technique for on-chip electrochemical detection in micro fabricated devices is described based on a microfluidic system containing an array of 20 microband electrodes. It is shown that an external electric field induces a potential difference between two gold microband electrodes in a poly(dimethylsiloxane) (PDMS) microchannel, and that this enables the electrochemical detection of electroactive species such as ascorbic acid and Fe(CN) 6 (4-). The results, which are supported by simulations of the behavior of the microband electrodes in the microfluidic system, show that the induced potential difference between the electrodes can be controlled by altering the external electric field or by using different microbands in the microband array. As the obtained currents depend on the concentrations of electroactive species in the flowing solution and the detection can be carried out anywhere within the channel without interference of the external electric field, the present approach significantly facilitates electrochemical detection in capillary electrophoresis. This approach consequently holds great promise for application in inexpensive portable chip-based capillary electrophoresis (CE) devices.     

Surgical Resection of Brain Metastases—Impact on Neurological Outcome

Brain metastases (BM) develop in about 30% of all cancer patients. Surgery plays an important role in confirming neuropathological diagnosis, relieving mass effects and improving the neurological status. To select patients with the highest benefit from surgical resection, prognostic indices (RPA, GPA) have been formulated which are solely focused on survival without considering neurological improvement. In this study we analyzed the impact of surgical resection on the neurological status in addition to overall survival in 206 BM patients. Surgical mortality and morbidity was 0.0% and 10.3% respectively. New neurologic deficits occurred in 6.3% of all patients. The median overall survival was 6.3 months. Poor RPA class and short time interval between diagnosis of cancer and the occurrence of BM were independent factors predictive for poor survival. Improvement of neurological performance was achieved in 56.8% of all patients, with the highest improvement rate seen in patients presenting with increased intracranial pressure and hemiparesis. Notably, the neurological benefits were independent from RPA class. In conclusion, surgical resection leads to significant neurological improvement despite poor RPA class and short overall survival. Considering the low mortality and morbidity rates, resection should be considered as a valid option to increase neurological function and quality of life for patients with BM.     

Boosting electrical conductivity in a gel-derived material by nanostructuring with trace carbon nanotubes

An organogelator with two distinct π-functional units is able to incorporate carbon nanotubes into its mesh of fibres in the gel state. The morphology of the material derived from this nanocomposite after evaporation of the solvent is a complex mesh of fibres which is clearly different from the pure gelator. This feature indicates a role of the nanotubes in assisting the formation of a fibre structure in the gel thanks to their interaction with the pyrene units in the organogelator. The nanocomposite conducts electricity once the p-type gelator is doped with iodine vapour. The change in morphology caused by the carbon material increases the conductivity of the material compared with the purely organic conducting system. It is remarkable that this improvement in the physical property is caused by an extremely small proportion of the carbon material (only present at a ratio of 0.1% w/w). The practically unique properties of TTF unit allow measurements with both doped and undoped materials with conducting atomic force microscopy which have demonstrated that the carbon nanotubes are not directly responsible for the increased conductivity.     

A molecular approach to ascertain the success of "in situ" AM fungi inoculation in the revegetation of a semiarid, degraded land

The positive effect of arbuscular mycorrhizal fungi inoculation on plant establishment under field conditions has been shown. However, whether this effect is related to the survival of the AMF and how the AMF inoculum affects the colonisation of plant roots by the native AMF remain uncertain.In this study, we assessed the AMF community composition in O. europaea roots inoculated “in situ” with three types of AMF inoculum: Glomus sp., G. intraradices and a mixture of Glomus sp. and G. intraradices. All the AMF isolates inoculated showed a good percentage of persistence. Mycorrhizal inoculation with the mixture of Glomus sp. and G. intraradices was the most effective treatment for increasing the AMF diversity in roots 14 months after plantation. Plant growth was increased significantly by all the inocula tested, although plant biomass was not correlated with variation in the AMF diversity or with the AMF inoculum persistence. Thus, it seems that this positive effect was mediated by the interaction between the AMF inoculum and the natural colonisation. Therefore, the application of native AMF isolates in the planting hole may be considered a good strategy for the revegetation of semiarid, degraded soils, in order to reactivate the indigenous AMF populations and improve the performance of O. europaea seedlings, particularly when mixtures of native isolates are used.     

Thermal pre-treatment of aerobic granular sludge: impact on anaerobic biodegradability

The aerobic granular systems are a good alternative to the conventional activated sludge (AS) ones to reduce the production of sludge generated in wastewater treatment plants (WWTP). Although the quantity of produced sludge is low its post-treatment is still necessary. In the present work the application of the anaerobic digestion combined with a thermal pre-treatment was studied to treat two different aerobic granular biomasses: one from a reactor fed with pig manure (G1) and another from a reactor fed with a synthetic medium to simulate an urban wastewater (G2). The results obtained with the untreated aerobic granular biomasses showed that their anaerobic biodegradability (BD) (33% for G1 and 49% for G2) was similar to that obtained for an activated sludge (30-50%) and demonstrate the feasibility of their anaerobic digestion. The thermal pre-treatment before the anaerobic digestion was proposed as a good option to enhance the BD when this was initially low (33% G1) with an enhancement between 20% at 60 °C and 88% at 170 °C with respect to the untreated sludge. However when the initial BD was higher (49% G2) the thermal pre-treatment produced a slight improvement in the methane production (14% and 18%) and at high temperatures (190 and 210 °C) which did not justify the application of such a treatment.     

Photocatalytic properties of PMMA‐TiO2 class I and class II hybrid nanofibers obtained by electrospinning

The preparation, characterization, and photocatalytic activity evaluation of three hybrid fibrous materials composed mainly by poly(methyl methacrylate) (PMMA), methyl methacrylate (MMA): 3‐(trimethoxysilyl) propyl methacrylate (TMSPM): titanium butoxide (TBT), TiO₂ nanoparticles (NPTiO₂), and TiO₂ nanowires (NWTiO₂) is studied. Two types of fibe?s structures were prepared, single and core‐shell structures. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed both structures, single and core‐shell, as well as the inorganic phase were dispersed in the hybrid fibers. Infrared spectroscopic analysis (FT‐IR) and thermal analysis showed the organic and inorganic components, as well as the weight percentage of the inorganic phase present in hybrid fibers. The photocatalytic activity of the hybrid fibers class I and II showed that the best photodegradative efficiency for methylene blue in aqueous solution (2.9 × 10^?5 M) was 95%, provided by PMMA—10 wt % NPTiO₂. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44334.     

Temperature‐Dependent Deformation and Dislocation Density in SrTiO3 (001) Single Crystals

This study evaluates the change of flow stress as related to dislocation density in SrTiO₃ single crystals in order to provide guidance for later electrical studies. The key parameters varied are temperature and loading rate during the deformation. It is found that in <100>‐oriented SrTiO₃ single crystals, the dislocation density is enhanced by plastic deformation, more so at higher temperature as compared to room temperature. The experimental approach of quantifying the dislocation density through a determination of ex situ X‐ray diffraction rocking curves was successfully applied over the upper temperatures region of the lower temperature ductility zone for strontium titanate, i.e., in the so‐called “A‐regime”. For 1.0% deformed samples deformed at 300°C, a fourfold increase in dislocation density to 1.4 × 10¹³ m^?1 was found as compared to the nondeformed state (3.7 × 10¹² m^?1). Cross‐section techniques confirmed that the observed dislocation densities measured at the surfaces were identical to those seen in the core of the crystals. The use of rapid changes in loading rate provided an estimate for activation volume of the dislocation core for both 25°C and 300°C.