The paper focuses on CMSX-4 and two experimental alloys, LDSX-5 and LDSX-6, developed to provide alternative performance attributes. The specific objective in this work was an exploration of the low cycle fatigue (LCF) characteristics of these three alloy variants and the assessment of methods for predicting the observed lives. A comparison of the alloys is presented in relation to their strain control fatigue response and notch fatigue behaviour. Predictions of notch lives are made from the plain specimen data but found to be extremely pessimistic at the lower temperature studied, 650 °C. The inaccuracies are attributed to the presence of casting pores. Using measured crack growth data and pore sizes, it is shown that fracture mechanics calculations of residual lives are more appropriate. At 800 °C, the higher temperature studied, Walker strain predictions of notch lives are more meaningful. This is explained in terms of the relaxation of stresses at the defects.

Introduction Dementia Platform UK (DPUK) brings together over 50 different dementia-related cohorts. Most studies have restricted follow-up times and all are based on information from people who volunteer time and data for research. Participants are therefore often not representative of the 'wider population' and generalization of results is complicated. The Secure Anonymised Information Linkage databank (SAIL) holds long-time information on every person in Wales registered with the national health service, so generalization of study results is easier; however, data management and analysis of SAIL data is not trivial. We used data from SAIL to construct an easily accessible, well described dementia e-cohort. Methods With some age restrictions, all Welsh residents for whom primary care data were available were included. Within SAIL, a table was created holding demographic information for every participant including follow-up times and several dementia indicators. Using valida...

The clues to life and death of mummified animals can remain hidden beneath their wrappings. Developments in non-invasive imaging have enabled detailed study of their internal structures. Laboratory-based X-ray microcomputed tomography (microCT) and focussed imaging protocols permit smaller mummified remains, such as animals, to be studied at higher resolution. In this study, we use microCT to image three different animal mummies. Revealing the internal structures provides insights into their biography, the conditions in which they were kept, complex mummification practices, possible causes of death, and subsequent handling damage. Thousands of years after the production of these mummified animals, the X-ray microCT technique facilitates new investigations, revealing ‘harder’ skeletal structures, mummification materials, and even desiccated soft tissues. Potential evidence for an ‘opening of the mouth’ procedure was found in a snake, along with indicators of the poor conditions in wh...

Building energy consumption accounts for 30%–45% of the global energy demand. With an ever-increasing world population, it has now become essential to minimize the energy consumption for the future of the environment. One of the most crucial aspects in this regard is the utilization of sensing and environmental monitoring technologies in buildings as these technologies provide stakeholders, such as owners, designers, managers, and occupants, with important information regarding the energy performance, safety and cost-effectiveness of the building. With the global sensors market value predicted to exceed $190 billion by 2021 and the number of sensors deployed worldwide forecasted to reach the ‘1 Trillion’ mark by 2025, a state-of-the-art review of various commercially-viable sensor devices and the wide range of communication technologies that complement them is highly desirable. This paper provides an insight into various sensing and environmental monitoring technologies commonly dep...

Zn-4.8 wt% Al coated steels exhibited a polynomial increase in Zn loss from the cut edge with increasing steel gauge for weight loss and SVET Zn loss in 0.1% NaCl in contrast to a linear increase observed for hot dipped galvanised (HDG) steels. Increasing steel gauge decreased nucleation and increased growth of Zn dendrites for Zn-4.8 wt% Al coated steels. SVET data showed larger Zn dendrites associated with thicker gauges produced more damaging anodes than small dendrites on thinner samples. A polynomial relationship was observed between dendrite size and Zn loss suggesting that microstructure influenced Zn loss in unison with the increased cathodic activity on thicker steels.

An experimental development programme has been carried out for the production of resistive heated panels to be used in raised access flooring. Screen printing was used as the means of depositing the heating element and the paper examines the means by which the process is optimised from assessment of material formulations through to a pilot production run of 300 tiles. A material with a sheet resistance of 35 /sq, when printed through a 77-48 polyester mesh was selected by examining its rheological and drying behaviour. Higher film thickness with coarser screens was not possible as this incurred topological variations in the printed film and required excessive drying times. During a pilot manufacturing run of 300 panels, process drift was observed and this was attributed to squeegee softening due to solvent absorption. The generic findings of the study are applicable to many applications where screen printing is used for the continuous deposition of materials where the characteristics of the deposit and its subsequent curing is paramount such as sensor, third generation PV and circuit boards.

The synthesis of a pendant donor emissive macrocyclic ligand Py 2 N 4 S 2 with up to four naphthylmethylene arms (L) has been achieved. Their derivative solid metal complexes (Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ , Hg 2+ and Ag + ) have been isolated and characterized. The photophysical properties of the free ligand L and their complexation behaviour have been investigated in solution. In dichloromethane, the free ligand presents two emission bands which are related to the monomer naphthalene emission and a red-shifted band attributable to ground state dimers (interaction between two naphthalene chromophores), which was further validated from timeresolved data, with bi-exponential decay with absence of dynamic components. UV-Vis spectroscopy has revealed a 2:1 binding stoichiometry for Co 2+ , Cu 2+ , Zn 2+ , Hg 2+ and Ag + .

Two novel fluorescent probes bearing a single (P) and two (a podand-like structure, L) pyrene units derived from 1,5-bis(2-aminophenoxy)-3-oxopentane have been synthesized and investigated in dioxane using UV−vis absorption, and steady-state and time-resolved (in a picosecond time scale) emission spectroscopy; in the gas phase, matrix-assisted laser desorption ionization mass spectrometry was employed. In dioxane, the absorption and emission spectra of P present a unique band with maxima at 361 and 392 nm, which have been associated with the monomer absorption and emission bands, respectively. In dioxane, for compound L, an additional band with a maximum at ∼525 nm is observed; upon the addition of water, an emissive band (with maxima varying from 405 to 490 nm) appears in both P and L spectra; this is discussed in terms of the emission of a species with charge character. Upon metal addition (Cu 2+ , Zn 2+ , and Ag + ) to P, a gradual quenching effect of the monomer emission is observed and found to be more pronounced with Cu 2+ . In the case of L, upon the addition of metal cations, the long emission band (∼550 nm) decreases and the monomer emission band increases (with an isoemissive point at ∼450 nm) and no evidence for the intermediate band (at ∼405−490 nm) now exists. Time-resolved data in dioxane/water mixtures showed that for P and L these two fit double-and triple-exponential decay laws, respectively. With P, this has been attributed to a two-state system, which involves the monomer and a charged species, with its emission maxima varying with the polarity of the media (here mirrored by its dielectric constant), which can potentially be addressed to an exciplex-like species, whereas with L, it has been attributed to a three-state system involving, in addition to these two species, an excimer. From absorption and fluorescence excitation and time-resolved data, evidence is given for the presence of intramolecular dimer formation in the ground state.

A new simple and multifunctional fluorescent probe based on pyrene linked through an imine bond to a hydroxyphenol unit was synthesised, fully characterized and investigated in solution. Additionally, its behaviour in the presence of several ions (H þ , Zn 2þ , Cd 2þ , Cu 2þ , Ni 2þ , Pb 2þ , Fe 2þ , Hg 2þ and Al 3þ ) was investigated in CH 2 Cl 2 . It was found that the absorption spectra of probe 1 shows no differences for all ions titrations except in the presence of H þ and Hg 2þ where a new longer wavelength band becomes visible (inducing a colour change from yellow to orange and pink, respectively). In the emission, a blueshift and an enhancement of the fluorescence of the probe for all metal ions was observed with the exception of Al 3þ where no detectable changes could be observed. The probe was found to be selective for Hg 2þ ion at low concentrations (till one equivalent).

To celebrate the centenary of Science Progress we offer a short survey of the progress made over the past one hundred years in the research and application of photoinduced charge transfer. After a brief historical overview and introduction to photoinduced charge transfer, we discuss developments in the theory and practice of photography, photovoltaics, photocatalysis, fluorescent probes and chemosensing.

The photochemistry and stability of fullerene films is found to be strongly dependent upon film nanomorphology. In particular, PC61BM blend films, dispersed with polystyrene, are found to be more susceptible to photobleaching in air than the more aggregated neat films. This enhanced photobleaching correlated with increased oxygen quenching of PC61BM triplet states, and the appearance of a carbonyl FTIR absorption band indicative of fullerene oxidation. sug-gesting PC61BM photo-oxidation is primarily due to triplet-mediated singlet oxygen generation. PC61BM films were observed to undergo photo-oxidation in air for even modest (≤ 40 mins) irradiation times, degrading electron mobility substantially, indicative of electron trap formation. This conclusion is supported by observation of red shifts in photo- and electro-luminescence with photo-oxidation, shown to be in agreement with time-dependent density functional theory calculations of defect generation. These results provide importan...

Low dimensional semiconductor quantum dots (<10 nm) have received great attention for potential use in biomedical applications (diagnosis and therapy) for which larger nanoparticles (>10 nm) are not suitable. Here, we demonstrate a green, biogenic synthesis route for making CdS quantum dots (QDs) with 2-5 nm particle size using tea leaf extract (Camellia sinensis) as a toxic-free particle stabilizing agent. We have explored the biological activity of these CdS QDs in different applications, namely; a) antibacterial activity b) bioimaging and c) apoptosis of lung cancer cells. The antibacterial activity of the CdS QDs has been studied against different types of bacteria growth, showing that CdS QDs effectively inhibit the bacterial growth and exhibit cytotoxicity towards A549 cancer cells when compared to a control (no QD treatment). We have compared this cytotoxicity effect on A549 cancer cells with a standard drug, cisplatin, showing comparable results. Additionally, these CdS QDs produce high contrast fluorescence images of A549 cancer cells indicating a strong interaction with the cancer cell. To further understand the role of CdS QDs in bioimaging and cytotoxicity effect in A549 cells, fluorescence emission and flow cytometry analysis were carried out. The fluorescence emission of CdS QDs were recorded with λexc= 410 nm, showing concentration dependence fluorescence emission centered at 670 nm. From the flow cytometry analysis, it is confirmed that the CdS QDs are arresting the A549 cell growth at the S phase of cell cycle, inhibiting further growth of lung cancer cell. The multifunctional advantages of Camellia sinensis extract mediated green CdS QDs will be of widespread interest in implementing in-vivo based bioimaging and therapeutic cancer treatment applications.

Perovskite solar cells have attracted a great deal of attention thanks to their high efficiency, ease of manufacturing, and potential low cost. However, the stability of these devices is considered their main drawback and needs to be addressed. Mesoporous carbon perovskite solar cells (m-CPSC), consisting of three mesoporous layers (TiO 2 /ZrO 2 /C) infiltrated with CH 3 NH 3 PbI 3 (MAPI) perovskite, have presented excellent lifetimes of more than 10 000 h when the additive NH 2 (CH 2) 4 CO 2 HI (5-aminovaleric acid iodide; 5-AVAI) is used to modify the perovskite structure. Yet, the role of 5-AVAI in enhancing the stability has yet to be determined. Here, superoxide-mediated degradation of MAPI m-CPSC with and without the 5-AVAI additive is studied using the fluorescence probe dihydroethidium for superoxide detection. In situ X-ray diffractometry shows that amino valeric acid methylammonium lead iodide (AVA-MAPI) perovskite infiltrated in mesoporous layers presents higher stability in an ambient environment under illumination, evidenced by a slower decrease of the MAPI/PbI 2 peak ratio. Superoxide yield measurements demonstrate that AVA-MAPI generates more superoxide than regular MAPI when deposited on glass but generates significantly less when infiltrated in mesoporous layers. It is believed that superoxide formation in m-CPSC is dependent on a combination of competitive factors including oxygen diffusion, sample morphology, grain size, and defect concentration.