Temperature dependence of the ohmic conductivity and activation energy of Pb1+y(Zr0.3Ti0.7)O3 thin films

The ohmic conductivity of the sol-gel derived Pb1+y(Zr0.3Ti0.7)O3 thin films (with the excess lead y=0.0 to 0.4) are investigated using low frequency small signal alternate current (AC) and direct current (DC) methods. Its temperature dependence shows two activation energies of 0.26 and 0.12 eV depending on temperature range and excess Pb levels. The former is associated with Pb3+ acceptor centers, while the latter could be due to a different defect level yet to be identified.Comment: 13 pages, 3 figures, PostScript. Submitted to Applied Physics Letter

Effects of canine-assisted intervention on the mental health of higher education students: a systematic review

The aim of this systematic review was to evaluate existing literature exploring the effects of canine assisted intervention (CAI) on the mental health of Higher Education (HE) students. A literature search was performed on 14th January 2021 for studies that investigated the effects of CAI on HE students. Thirty three papers (6093 participants) encompassing 37 studies were included in this review. Study design varied in research objective, intervention type, timing, procedure, and measures. The Effective Public Health Practice Project Quality Assessment Tool found studies ranged in quality from moderate (n=7) to weak (n=30). The review identified CAI has a positive effect on levels of anxiety and stress in HE students. Key limitations of the studies include confounding influences during the intervention as well as a lack of control groups and standardized measures. Furthermore, intervention and procedures ranged substantially in design and application making direct comparisons difficult. The authors conclude two main outcomes from the review. Firstly, CAI improves mental health in HE students, in particular anxiety and stress. Secondly, CAI has a social benefit, encouraging communication and a shared experience. However, a number of methodological limitations of the studies are identified and reviewed. To conclude, this systematic review reveals strong support for the use of CAI in HE students as a form of therapy

Porous SnO2-Cu x O nanocomposite thin film on carbon nanotubes as electrodes for high performance supercapacitors.

Metal oxides are promising materials for supercapacitors due to their high theoretical capacitance. However, their poor electrical conductivity is a major challenge. Hybridization with conductive nanostructured carbon-based materials such as carbon nanotubes (CNTs) has been proposed to improve the conductivity and increase the surface area. In this work, CNTs are used as a template for synthesizing porous thin films of SnO2-CuO-Cu2O (SnO2-Cu x O) via an electroless deposition technique. Tin, with its high wettability and electrical conductivity, acts as an intermediate layer between copper and the CNTs and provides a strong interaction between them. We also observed that by controlling the interfacial characteristics of CNTs and varying the composition of the electroless bath, the SnO2-Cu x O thin film morphology can be easily manipulated. Electrochemical characterizations show that CNT/SnO2-Cu x O nanocomposite possesses pseudocapacitive behavior that reaches a specific capacitance of 662 F g-1 and the retention is 94% after 5000 cycles, which outperforms any known copper and tin-based supercapacitors in the literature. This excellent performance is mainly attributed to high specific surface area, small particle size, the synergistic effect of Sn, and conductivity improvement by using CNTs. The combination of CNTs and metal oxides holds promise for supercapacitors with improved performance.Lloyds Register Foundation Londo

Flexible free-standing Ni-Mn oxide antenna decorated CNT/nanofiber membrane for high-volumetric capacitance supercapacitors

There is growing demand for lightweight flexible supercapacitors with high electrochemical performance for wearable and portable electronics. Here, we spun nanoparticles of nickel-manganese oxides along with carbon nanotubes into carbon nanofibers and engineered a 3D networked Ni-Mn oxides/CNT@CNF free-standing membrane for flexible supercapacitor applications. The electrospinning process controlled the nanoparticle aggregation while subsequent heat treatment generates nanochannels in the fibres, resulting in a very porous tubular nanocomposite structure. The preparation process also enabled good interfacial contact between the nanoparticles and the conductive carbon network. The resulting Ni-Mn oxides/CNT@CNF membrane displays high mass loading (Ni-Mn oxides) of 855 mg cm-3 and low CNT incorporation of ∼0.4%. The outstanding porous structure, synergy of the carbon with Ni-Mn oxides, and fast and facile faradaic reactions on the electrode were responsible for the superior volumetric capacitance of 250 F cm-3 at 1 A cm-3, energy density as high as 22 mW h cm-3 and an excellent power density of 12 W cm-3. Despite the low CNT loading, the hybrid electrode exhibits excellent cycling performance with capacitance retention of 96.4% after 10 000 cycles evidencing a well-preserved Ni-manganese oxide nanostructure throughout the cycling. The resulting outstanding electrochemical performances of the Ni-Mn oxides/CNT@CNF synergic system offer new insights into effective utilization of transition metal oxides for establishing high-performance flexible supercapacitors within a confined volume

The Aerodynamic Design and Use of Multi-Sensor Pressure Probes for MEMS Applications

ABSTRACT A family of novel planar geometries suitable for the construction of a MEMS (Micro-Electro-Mechanical-System)-based 5-hole flow sensor is introduced. The desired directional sensitivity is achieved by placing fences on the planar frontal surface of a cylindrical probe. The flow over such probes with and without fences has been investigated in a low speed wind tunnel at Reynolds numbers between 15,000 and 40,000 based on probe diameter. The potential of each design for use as a 5-sensor probe has been determined from pressure measurements and flow visualisations. It was found that fences could significantly increase the directional sensitivity of cylindrical probes. The best design tested had at least equivalent angular sensitivity compared to traditional 5-hole probes, while displaying no significant Reynolds number effects in the range tested

Chameleon masculinity: developing the British ‘population-centred’ soldier

In this article I develop what I term chameleon masculinity as a specific form of gendered adaptation of military agency opened up by the post-9/11 shift towards ‘population-centred’ counterinsurgency and stabilisation. A gendered analysis of this carefully cultivated form of military agency is central to revealing some of the concealed embodied dynamics that challenge the hegemony of the traditional combat soldier, and in practice enables this form of war. Drawing on 18 months of anthropological fieldwork, for the most part alongside the UK’s Military Stabilisation Support Group, this research incorporates my auto-ethnography as an officer in the Royal Naval Reserves. Rather than focusing at the level of policy, strategy, and doctrine, I examine how the specialized and masculinized agency of ‘the chameleon’ translates tactically into the body of the British military stabilisation operative, showing how this is developed though intensive pre-deployment training in the UK, and embodied and practised through operational deployment in Afghanistan. This reveals the specific agency of chameleon masculinity and how its potential for inherent violence becomes deceptively ‘hidden in plain sight’

A randomised comparison evaluating changes in bone mineral density in advanced prostate cancer: luteinising hormone-releasing hormone agonists versus transdermal oestradiol.

BACKGROUND: Luteinising hormone-releasing hormone agonists (LHRHa), used as androgen deprivation therapy (ADT) in prostate cancer (PCa) management, reduce serum oestradiol as well as testosterone, causing bone mineral density (BMD) loss. Transdermal oestradiol is a potential alternative to LHRHa. OBJECTIVE: To compare BMD change in men receiving either LHRHa or oestradiol patches (OP). DESIGN, SETTING, AND PARTICIPANTS: Men with locally advanced or metastatic PCa participating in the randomised UK Prostate Adenocarcinoma TransCutaneous Hormones (PATCH) trial (allocation ratio of 1:2 for LHRHa:OP, 2006-2011; 1:1, thereafter) were recruited into a BMD study (2006-2012). Dual-energy x-ray absorptiometry scans were performed at baseline, 1 yr, and 2 yr. INTERVENTIONS: LHRHa as per local practice, OP (FemSeven 100μg/24h patches). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was 1-yr change in lumbar spine (LS) BMD from baseline compared between randomised arms using analysis of covariance. RESULTS AND LIMITATIONS: A total of 74 eligible men (LHRHa 28, OP 46) participated from seven centres. Baseline clinical characteristics and 3-mo castration rates (testosterone ≤1.7 nmol/l, LHRHa 96% [26 of 27], OP 96% [43 of 45]) were similar between arms. Mean 1-yr change in LS BMD was -0.021g/cm(3) for patients randomised to the LHRHa arm (mean percentage change -1.4%) and +0.069g/cm(3) for the OP arm (+6.0%; p<0.001). Similar patterns were seen in hip and total body measurements. The largest difference between arms was at 2 yr for those remaining on allocated treatment only: LS BMD mean percentage change LHRHa -3.0% and OP +7.9% (p<0.001). CONCLUSIONS: Transdermal oestradiol as a single agent produces castration levels of testosterone while mitigating BMD loss. These early data provide further supporting evidence for the ongoing phase 3 trial. PATIENT SUMMARY: This study found that prostate cancer patients treated with transdermal oestradiol for hormonal therapy did not experience the loss in bone mineral density seen with luteinising hormone-releasing hormone agonists. Other clinical outcomes for this treatment approach are being evaluated in the ongoing PATCH trial. TRIAL REGISTRATION: ISRCTN70406718, PATCH trial (ClinicalTrials.gov NCT00303784)

Holder exponents of irregular signals and local fractional derivatives

It has been recognized recently that fractional calculus is useful for handling scaling structures and processes. We begin this survey by pointing out the relevance of the subject to physical situations. Then the essential definitions and formulae from fractional calculus are summarized and their immediate use in the study of scaling in physical systems is given. This is followed by a brief summary of classical results. The main theme of the review rests on the notion of local fractional derivatives. There is a direct connection between local fractional differentiability properties and the dimensions/ local Holder exponents of nowhere differentiable functions. It is argued that local fractional derivatives provide a powerful tool to analyse the pointwise behaviour of irregular signals and functions.Comment: 20 pages, Late

Temperature and pH-responsive nano-hydrogel drug delivery system based on lysine-modified poly (vinylcaprolactam).

BACKGROUND: Smart materials capable of responding to external stimuli are noteworthy candidates in designing drug delivery systems. In many of the recent research, temperature and pH have been recognized as the main stimulating factors in designing systems for anti-cancer drugs delivery systems. PURPOSE: In this study, thermo and pH-responsive character of a nano-carrier drug delivery platform based on lysine modified poly (vinylcaprolactam) hydrogel conjugated with doxorubicin was assessed. METHODS: Poly (vinylcaprolactam) cross-linked with poly (ethyleneglycol) diacrylate was prepared via RAFT polymerization, and the prepared structure was linked with lysine through ring-opening. The anti-cancer drug doxorubicin, was linked to lysine moiety of the prepared structure via Schiff-base reaction. The prepared platform was characterized by 1HNMR and FT-IR, while molecular weight characterization was performed by size exclusion chromatography. The temperature-responsive activity was evaluated using differential scanning calorimetry and dynamic light scattering. In vitro release pattern in simulated physiologic pH at 37°C was compared with acidic pH attributed to tumor site and elevated temperature. The anticancer efficiency of the drug-conjugated structure was evaluated in breast cancer cell line MCF-7 in 24 and 48 h, and cell uptake assay was performed on the same cell line. CONCLUSION: According to the results, well-structure defined smart pH and temperature responsive nano-hydrogel was prepared. The enhanced release rates are observed at acidic pH and elevated temperature. We have concluded that the doxorubicin-conjugated nanoparticle results in higher cellular uptakes and more cytotoxicity