bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uranium speciation and its site occupancy in alkaline‐earth borophosphates
Authors: Rout Annapurna , Panigrahi Bhabani Shankar , Nayak Chandrani , Bhattacharyya Dibeyndu , Jha Shambhu Nath 
Published: April 2017

AbstractAlkaline‐earth (calcium, strontium, and barium) borophosphates doped with uranium (U) are prepared through conventional solid‐state reaction route. The form of stabilized uranium in these solid matrices was characterized and investigated using X‐ray diffraction (XRD), photo luminescence (PL) and extended X‐ray absorption fine structure (EXAFS). XRD measurements confirmed the single phase formation of uranium‐doped alkaline‐earth borophosphate samples. The PL characteristics of uranium in calcium and barium borophosphate are studied for the first time. Photoluminescence studies indicated presence of uranium as Uranyl in SrBPO5 and CaBPO5 matrices whereas in case of BaBPO5 the indication was for uranate species. The life time data corroborated the presence of a different uranium species in SrBPO5, CaBPO5, and BaBPO5. The site occupancy of uranium was further probed using EXAFS which confirmed that in case of BaBPO5, uranium enters the host as uranate whereas in case of SrBPO5 and CaBPO5, uranium enters as Uranyl.
Relationship between surface μ‐roughness and interface slurry particle spatial distribution during glass polishing
Authors: Suratwala Tayyab , Steele William , Feit Michael , Shen Nan , Wong Lana , Dylla‐Spears Rebecca , Desjardin Richard , Elhadj Selim , Miller Phil 
Published: April 2017

AbstractDuring optical glass polishing, a number of interactions between the workpiece (i.e., glass), polishing slurry, and pad can influence the resulting workpiece roughness at different spatial scale lengths. In our previous studies, the particle size distribution of the slurry, the pad topography, and the amount of material removed by a single particle on the workpiece were shown to strongly correlate with roughness at AFM scale lengths (nm‐μm) and weakly at μ‐roughness scale lengths (μm‐mm). In this study, the polishing slurry pH and the generation of glass removal products are shown to influence the slurry particle spatial and height distribution at the polishing interface and the resulting μ‐roughness of the glass workpiece. A series of fused silica and phosphate glass samples were polished with various ceria and colloidal silica slurries over a range of slurry pH, and the resulting AFM roughness and μ‐roughness were measured. The AFM roughness was largely invariant with pH, suggesting that the removal function of a single particle is unchanged with pH. However, the μ‐roughness changed significantly, increasing linearly with pH for phosphate glass and having a maximum at an intermediate pH for fused silica. In addition, the spatial and height distribution of slurry particles on the pad (as measured by laser confocal microscopy) was determined to be distinctly different at low and high pH during phosphate glass polishing. Also, the zeta potential as a function of pH was measured for the workpiece, slurry, and pad with and without surrogate glass products (K3PO4 for phosphate glass and Si(OH)4 for silica) to assess the role of interfacial charge during polishing. The addition of K3PO4 significantly raised the zeta potential, whereas addition of Si(OH)4 had little effect on the zeta potential. An electrostatic DLVO three‐body force model, using the measured zeta potentials, was used to calculate the particle–particle, particle–workpiece, and particle–pad attractive and repulsive forces as a function of pH and the incorporation of glass products at the interface. The model predicted an increase in particle–pad attraction with an increase in pH and phosphate glass products consistent with the measured slurry distribution on the pads during phosphate glass polishing. Finally, a slurry “island” distribution gap (IDG) model has been formulated which utilizes the measured interface slurry distributions and a load balance to determine the interface gap, the contact area fraction, and the load on each slurry “island”. The IDG model was then used to simulate the workpiece surface topography and μ‐roughness; the results show an increase in roughness with pH similar to that observed experimentally.
Strength improvement and purification of Yb2Si2O7‐SiC nanocomposites by surface oxidation treatment
Authors: Nguyen Son T. , Nakayama Tadachika , Suematsu Hisayuki , Suzuki Tsuneo , He Lingfeng , Cho Hong‐Baek , Niihara Koichi 
Published: April 2017

AbstractA two‐step processing was developed to prepare Yb2Si2O7‐SiC nanocomposites. Yb2Si2O7‐Yb2SiO5‐SiC composites were first fabricated by a solid‐state reaction/hot‐pressing method. The composites were then annealed at 1250°C in air for 2 hours to activate the oxidation of SiC, which effectively transformed the Yb2SiO5into Yb2Si2O7. The surface cracks purposely induced can be fully healed during the oxidation treatment. The treated composites have improved flexural strength compared to their pristine composites. The mechanism for crack healing and silicate transformation have been proposed and discussed in detail.
Improved thermal stability of the piezoelectric properties of (Li, Ag)‐co‐modified (K, Na) NbO3‐based ceramics prepared by spark plasma sintering
Authors: Li Mingyu , Chan Ngai Yui , Wang Danyang 
Published: April 2017

AbstractHigh‐performance lead‐free piezoelectric ceramics 0.94(K0.45Na0.55)1−xLix(Nb0.85Ta0.15)O3–0.06AgNbO3 (KNNLTAg‐x) were successfully prepared by spark plasma sintering technique. The doping effect of Li on the structural and electrical properties of KNNLTAg‐x (x=0, 0.02, 0.04, 0.06, 0.08 and 0.10) ceramics was studied. The lattice structure, ferroelectric and piezoelectric properties of the KNLNTAg‐x ceramics are highly dependent on the Li doping level. In particular, the Li dopant has a great impact on both Curie temperature Tc and orthorhombic‐tetragonal transition temperature TO‐T. The 4% Li‐doped sample exhibited relatively high TO‐T of 95°C, leading to a stable dynamic piezoelectric coefficient (d33*) of 220‐240 pm/V in a broad temperature range from 25°C to 105°C. Additionally, the 2% Li‐doped sample shows a high d33* of 320 pm/V at 135°C, suggesting its great potential for high‐temperature applications.
Microwave dielectric and nonlinear optical studies on radio‐frequency sputtered Dy2O3‐doped KNN thin films
Authors: Peddigari Mahesh , Patel Vivek , Bharti Gyan Prakash , Khare Alika , Pamu Dobbidi 
Published: April 2017

AbstractWe report the effect of oxygen mixing percentage (OMP) on structural, microstructural, dielectric, linear, and nonlinear optical properties of Dy2O3‐doped (K0.5Na0.5)NbO3 thin films. The (K0.5Na0.5)NbO3 + 0.5 wt%Dy2O3 (KNN05D) ferroelectric thin films were deposited on to quartz and Pt/Ti/SiO2/Si substrates by RF magnetron sputtering. An increase in the refractive index from 2.08 to 2.21 and a decrease in the optical bandgap from 4.30 to 4.28 eV indicate the improvement in crystallinity, which is also confirmed from Raman studies. A high relative permittivity (εr=281‐332) and low loss tangent (tanδ=1.2%‐1.9%) were obtained for the films deposited in 100% OMP, measured at microwave frequencies (5‐15 GHz). The leakage current of the films found to be as low as 9.90×10−9 A/cm2 at 150 kV/cm and Poole‐Frenkel emission is the dominant conduction mechanism in the films. The third order nonlinear optical properties of the KNN05D films were investigated using modified single beam z‐scan method. The third order nonlinear susceptibility (ǀχ(3)ǀ) values of KNN05D films increased from 0.69×10−3 esu to 1.40×10−3 esu with an increase in OMP. The larger and positive nonlinear refractive index n2=7.04×10−6 cm2/W, and nonlinear absorption coefficient β=1.70 cm/W were obtained for the 100% OMP film, indicating that KNN05D films are good candidates for the applications in nonlinear photonics and high‐frequency devices.
Structure and optical properties of Er‐doped CaO‐Al2O3 (Ga2O3) glasses fabricated by aerodynamic levitation
Authors: Xu Cheng , Wang Chaoyue , Yu Jianding , Zhang Ruili , Ren Jinjun , Liu Xiaofeng , Qiu Jianrong 
Published: April 2017

AbstractWe fabricated a series of stable Er‐doped CaO‐Al2O3(Ga2O3) glasses by aerodynamic levitation (ADL) method. Using thermal analysis, we studied the influence of composition on the thermal stability of the glasses. The results unraveled the significance of composition on the stability of glasses. Magic angle spinning nuclear magnetic resonance (MAS‐NMR) and Raman spectra were used to analyze the glass microstructure. The optical and spectroscopic properties were examined by UV‐Vis absorption, steady‐state fluorescence spectroscopy, transient state fluorescence spectroscopy, and luminescence quantum yield measurements. The results unraveled a clear concentration‐dependent up‐conversion and NIR emissions of Er3+, with obvious spectral broadening and redshift. The related mechanisms of decrease in fluorescent lifetime (from about 9 ms to 2 ms) and quantum yield (from about 75% to 5%) are discussed.
Nanoscale mechanism of rare‐earth doping in Ga‐codoped glassy As‐Sb selenides
Authors: Shpotyuk Yaroslav 
Published: April 2017

AbstractThe method of annihilating positrons in positron annihilation lifetime measuring mode is applied to study mechanism of rare‐earth doping in Ga‐codoped arsenic selenide As2Se3 glass modified with Sb. The atomic‐deficient structure of parent As2Se3 glass is imagined as containing positron‐trapping sites in the form of free‐volume voids within cycle‐type arrangement of corner‐sharing trigonal AsSe3/2 pyramids, composed of atomic‐accessible geometrical holes arrested by surrounding atomic‐inaccessible Se‐based bond‐free solid angles. The Ga codoping in As2Se3 glass causes gradual decrease in trapping rate and fraction of trapped positrons due to agglomeration of free‐volume voids. Partial As‐to‐Sb replacement in Ga‐codoped As‐Se glasses leads to better stability against crystallization processes and possibility to further rare‐earth doping without principal changes in the type of positron‐trapping defects. Effect of 500 wppm of Pr3+ in Ga2(As0.28Sb0.12Se0.60)98 glass is explained in terms of competitive contribution of changed occupancy sites in Ga‐modified glassy network available for rare‐earth ions and annihilating positrons.
Application of Powers’ model to modern portland and portland limestone cement pastes
Authors: Nadelman Elizabeth I. , Kurtis Kimberly E. 
Published: April 2017

AbstractPowers’ model is a simple approach for estimating the relative volumes of hydration products, porosity, and chemical shrinkage present in portland cement paste as a function of its starting water‐to‐cement ratio (w/c) and current degree of hydration. It forms an important link between cement composition, microstructure, and performance, necessary for modeling cement‐based systems. Previous researchers have adapted Powers’ model for inert fillers to illustrate their effects on the hydration, porosity, and chemical shrinkage of blended cements; however, it is well‐documented that limestone is not, in fact, an inert filler, but rather participates in cement hydration through both chemical and physical processes. This research experimentally investigates the applicability of Powers’ model to modern portland cements containing up to 15% by mass finely divided limestone. The results demonstrate that the modified Powers’ model is insufficient for predicting the influence of finely divided limestone additions on the chemical shrinkage of both ordinary portland cement pastes and portland limestone cement pastes. Possible explanations for the discrepancy are discussed and a plausible source is proposed.
Li2MoO4‐based composite ceramics fabricated from temperature‐ and atmosphere‐sensitive MnZn ferrite at room temperature
Authors: Väätäjä Maria , Kähäri Hanna , Juuti Jari , Jantunen Heli 
Published: April 2017

AbstractThe first magnetic ceramic composites manufactured, using the room‐temperature densification method are reported. The samples were prepared at room temperature using Li2MoO4 as a matrix and MnZn ferrite with loading levels of 10‐30 vol‐% followed by postprocessing at 120°C. The method utilizes the water solubility of the dielectric Li2MoO4 and compression pressure instead of high temperatures typical of conventional solid‐state sintering. Hence, composite manufacturing using temperature‐ and atmosphere‐sensitive materials is possible without special conditions. This was demonstrated with MnZn ferrite, which is prone to oxidation when heat treated in air. Samples manufactured with room‐temperature densification showed no signs of reactivity during processing, whereas reference samples sintered at 685°C suffered from oxidation and formation of an additional reaction phase. The densities achieved with different loading levels of MnZn ferrite with both methods were very similar. Measurements up to 1 GHz showed relatively high values of relative permittivity (21.7 at 1 GHz) and permeability (2.6 at 1 GHz) with 30 vol‐% loading of MnZn ferrite in the samples manufactured by room‐temperature densification. In addition, pre‐granulation is proposed to improve the processability of the composite powders in room‐temperature densification.
On shrinkage and structure changes of pure and blended Portland concretes
Authors: Zhang Yao , Davy Catherine A. , Tricot Gregory , Albert‐Mercier Cyrille , Henry Natacha , Bertier Pieter , Cazaux Frédéric , Damidot Denis , Bourbon Xavier 
Published: April 2017

AbstractThis research investigates the long‐term shrinkage and Relative Mass Loss (RML) of mature Portland concretes (pure CEMI and blended CEMV/A), at temperatures of 20°C and 80°C. When placed at 80°C and at relative humidities (RH) below 50‐60%, concrete shrinkage increases with very slow stabilization kinetics by several hundreds of μm/m, while RML remains of about 0.2%. The origins of this continued shrinkage, simultaneously with limited RML, are investigated through the changes in (i) the pore structure of the concretes (by Mercury Intrusion Porosimetry and nitrogen adsorption) and in (ii) their solid phases (by TGA/DTA, FTIR spectroscopy coupled to DVS, quantitative X‐Ray Diffraction by Rietveld analysis, and 29Si and 27Al MAS NMR). While the pore structure coarsens during continued shrinkage, several phase transformations occur, namely ettringite decomposition and changes in the silicate chain length of the C–A–S–H. While these structural changes are documented, their relationship with shrinkage/RML and to the pore structure is novel.
Effects of Bi0.5Na0.5HfO3 addition on the phase structure and piezoelectric properties of (K, Na)NbO3‐based ceramics
Authors: Chen Yi , Xue Dandan , Shi Meng , Jiang Xianquan , Chen Zhiqian , Liu Xiaokui , Liu Gang , Xu Zunping 
Published: April 2017

AbstractLead‐free perovskite (1‐x)(K0.48Na0.48Li0.04)Nb0.95Sb0.05O3‐x(Bi0.5Na0.5)HfO3 piezoelectric ceramics were prepared by a traditional ceramic fabrication method. An investigation was conducted to assess the effects of (Bi0.5Na0.5)HfO3 content on the crystal structure, microstructure, phase‐transition temperatures, and piezoelectric properties of the ceramics. The X‐ray diffraction results, combined with the temperature dependence of dielectric properties, revealed that the ceramics experienced a structural transition from an orthorhombic phase to a tetragonal phase with the addition of (Bi0.5Na0.5)HfO3, and a coexistence of orthorhombic and tetragonal phases was identified in the composition range of 0.005≤x≤0.015. An obviously improved piezoelectric activity was obtained for the ceramics with compositions near the orthorhombic‐tetragonal phase boundary, among which the composition x=0.005 exhibited the maximum values of piezoelectric constant d33, and planar and thickness electromechanical coupling coefficients (kp and kt) of 246 pC/N, 0.435, and 0.554, respectively. Furthermore, the Curie temperature of the ceramics was found decreasing with the increase in (Bi0.5Na0.5)HfO3 content, but still maintaining above 300°C for the phase boundary compositions. These results indicate that the ceramics are promising lead‐free candidate materials for piezoelectric applications.
The effectiveness of massage and touch on behavioural and psychological symptoms of dementia: A quantitative systematic review and meta‐analysis
Authors: Wu Jie , Wang Yi , Wang Zhiwen 
Published: April 2017

AbstractBackgroundMany original studies have explored the effectiveness of massage and touch on behavioural and psychological symptoms of dementia. However, the study design, interventions, measurements and outcomes varied among studies.AimTo systematically evaluate the effectiveness of massage and touch on the behavioural and psychological symptoms of older people with dementia.DesignA quantitative systematic review and meta‐analysis.Data sourcesCochrane Library, The Joanna Briggs Institute (JBI) Library, PubMed, CINAHL, ProQuest Health & Medical Complete, SinoMed, China National Knowledge Infrastructure (CNKI) and Wanfang were searched from the date the database established to January 2016.Review methodsRandomized, controlled trials or quasi‐experimental studies, involving massage and touch intervention for older people with dementia were considered to be included. Risk of bias assessment was performed using the Cochrane Collaboration's tool and meta‐analysis was performed using Revman 5.3.ResultsA total of 11 studies, involving 526 older people were included. The results of the meta‐analysis showed the total score of behavioural and psychological problems with older people with dementia and subgroup scores of physical aggressive behaviour, physical non‐aggressive behaviour, verbal aggressive behaviour and verbal non‐aggressive behaviour decreased significantly after receiving massage or touch, while the subgroups scores of anxiety, sadness and anger did not decreased significantly.ConclusionsDue to relatively small sample size and low quality of the included studies in this review, it is difficult to draw a conclusion on the effect of massage and touch on behavioural and psychological syndrome of dementia or implications for practice.
“I'm still here”: Exploring what matters to people with intellectual disability during advance care planning
Authors: McKenzie Nicola , Mirfin‐Veitch Brigit , Conder Jennifer , Brandford Sharon 
Published: April 2017

BackgroundThis study sought to identify, from the perspective of people with intellectual disabilities and life limiting conditions, the factors that strengthened and inhibited their Advance Care Planning.MethodsThis in depth qualitative study explored the experiences of four people with intellectual disability and life limiting conditions, through interviews and documentation reviews.ResultsThere was strong agreement across all participants about what positively influenced Advance Care Planning, namely; going at my pace; supporting me to make my own choices; adapting the process to suit me, and, most importantly; continuing to support and plan the life I'm still living. With the exception of being comfortable/skilled in end‐of‐life support, the skills required of facilitators were similar to those required for all forms of person‐centred planning.ConclusionThe findings are encouraging and demonstrate that Advance Care Planning is a useful tool in ensuring that people with intellectual disability have control and choice over their lives, right to the end.
Contributions of feather microstructure to eider down insulation properties
Authors: D'alba Liliana , Carlsen Thomas Holm , Ásgeirsson Árni , Shawkey Matthew D. , Jónsson Jón Einar 
Published: April 2017

Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common eider Somateria mollissima nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined.Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild common eiders and compared them to properties of plumules of wild greylag goose Anser anser. We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that greylag goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to common eider down. These differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than greylag goose down feathers, likely increasing their air‐trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In greylag goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In common eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds.
GC‐MS metabolomics‐based approach for the identification of a potential VOC‐biomarker panel in the urine of renal cell carcinoma patients
Authors: Monteiro Márcia , Moreira Nathalie , Pinto Joana , Pires‐Luís Ana S. , Henrique Rui , Jerónimo Carmen , Bastos Maria de Lourdes , Gil Ana M. , Carvalho Márcia , Guedes de Pinho Paula 
Published: April 2017

AbstractThe analysis of volatile organic compounds (VOCs) emanating from biological samples appears as one of the most promising approaches in metabolomics for the study of diseases, namely cancer. In fact, it offers advantages, such as non‐invasiveness and robustness for high‐throughput applications. The purpose of this work was to study the urinary volatile metabolic profile of patients with renal cell carcinoma (RCC) (n = 30) and controls (n = 37) with the aim of identifying a potential specific urinary volatile pattern as a non‐invasive strategy to detect RCC. Moreover, the effect of some confounding factors such as age, gender, smoking habits and body mass index was evaluated as well as the ability of urinary VOCs to discriminate RCC subtypes and stages. A headspace solid‐phase microextraction/gas chromatography–mass spectrometry‐based method was performed, followed by multivariate data analysis. A variable selection method was applied to reduce the impact of potential redundant and noisy chromatographic variables, and all models were validated by Monte Carlo cross‐validation and permutation tests. Regarding the effect of RCC on the urine VOCs composition, a panel of 21 VOCs descriptive of RCC was defined, capable of discriminating RCC patients from controls in principal component analysis. Discriminant VOCs were further individually validated in two independent samples sets (nine RCC patients and 12 controls, seven RCC patients with diabetes mellitus type 2) by univariate statistical analysis. Two VOCs were found consistently and significantly altered between RCC and controls (2‐oxopropanal and, according to identification using NIST14, 2,5,8‐trimethyl‐1,2,3,4‐tetrahydronaphthalene‐1‐ol), strongly suggesting enhanced potential as RCC biomarkers. Gender, smoking habits and body mass index showed negligible and age‐only minimal effects on the urinary VOCs, compared to the deviations resultant from the disease. Moreover, in this cohort, the urinary volatilome did not show ability to discriminate RCC stages and histological subtypes. The results validated the value of urinary volatilome for the detection of RCC and advanced with the identification of potential RCC urinary biomarkers.