Моделювання динамічних силових характеристик плунжерних токарних патронів з компенсаторами відцентрових сил

Efficient energy transfer was demonstrated in the SrF2:Eu2+, Pr3+ phosphor synthesized by the co-precipitation method. Results obtained with X-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray spectroscopy (XPS), photoluminescence (PL) and decay curves proposed the UV-Vis energy transfer process. The energy transfer process between the Eu2+ and Pr3+ ions in SrF2 was investigated to evaluate the potential of the Eu2+ ion as a sensitizer for the Pr3+ ion. The results proposed that Eu2+ could be a good sensitizer for absorbing the UV photons and efficiently enhancing the Pr3+ emission intensity. The energy transfer process was effective until concentration quenching for the Pr3+ ions occurred. The concentration quenching was attributed to cross-relaxation between the Pr3+ ions. (C) 2016 Author(s).Funding Agencies|South African Research Chairs Initiative of the Department of Science and Technology; National Research Foundation of South Africa; National Research Foundation (NRF); Cluster program of the University of the Free State</p

UV-Vis-NIR quantum cutting suitable for c-Si solar cell application

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.The possibility of using the broad band spectra of Eu2+ to improve the absorption of the Pr3+-Yb3+ quantum cutting couple was investigated. The energy transfer mechanisms between Eu2+ and Pr3+ in the SrF2 host are briefly discussed in order to evaluate the potential of Eu2+ as a sensitizer for the Pr3+-Yb3+ couple. The results showed that Eu2+ could be a good sensitizer for the absorption of UV photons and efficiently enhancing the Pr3+ emission, and hence improving the near infrared emission. The investigated system can therefore enable the c-Si solar cell to utilize the solar spectrum more efficiently in the broad wavelength region where c-Si shows a weak response.cf201

Biblical Theology of Life in the New Testament

This publication deals with A Biblical Theology of Life based on the New Testament. It forms the second of a two volume publication on A Biblical Theology of Life. These two volumes trace the concept of life throughout Protestant canon, working with the final form of the biblical books in Hebrew (vol. 5) and Greek (vol. 6) Scripture. This is done by providing the reader with a book-by-book overview of this concept. This book concludes with a final chapter synthesising the findings of the respective investigations of the Old and New Testament corpora in order to provide a summative theological perspective of the development of the concept through Scripture. It is clear that life forms a central and continuous theme throughout the Biblical text. The theme begins with the living God that creates life, but is shortly followed by death that threatens life. Despite this threat, God sustains life and awakens life from death. The text concludes with the consummation depicting eternal life in the new heaven and earth. The biblical theological approach that has been taken entails a thematic approach as it investigates the concept of life, with contextual foci on what individual books of Scripture teach about life, joined diachronically with an investigation of the progressive use of the concept of life in Scripture, while providing a theology of Scripture as a whole investigating the concept of life in all sixty-six books of the Protestant canon

Biblical Theology of Life in the New Testament

This publication deals with A Biblical Theology of Life based on the New Testament. It forms the second of a two volume publication on A Biblical Theology of Life. These two volumes trace the concept of life throughout Protestant canon, working with the final form of the biblical books in Hebrew (vol. 5) and Greek (vol. 6) Scripture. This is done by providing the reader with a book-by-book overview of this concept. This book concludes with a final chapter synthesising the findings of the respective investigations of the Old and New Testament corpora in order to provide a summative theological perspective of the development of the concept through Scripture. It is clear that life forms a central and continuous theme throughout the Biblical text. The theme begins with the living God that creates life, but is shortly followed by death that threatens life. Despite this threat, God sustains life and awakens life from death. The text concludes with the consummation depicting eternal life in the new heaven and earth. The biblical theological approach that has been taken entails a thematic approach as it investigates the concept of life, with contextual foci on what individual books of Scripture teach about life, joined diachronically with an investigation of the progressive use of the concept of life in Scripture, while providing a theology of Scripture as a whole investigating the concept of life in all sixty-six books of the Protestant canon

Chemical and electrical characteristics of annealed Ni/Au and Ni/Ir/Au contacts on AlGaN

The evolution of Ni/Au and Ni/Ir/Au metal contacts deposited on AlGaN was investigated at different annealing temperatures. The samples were studied with electrical and chemical composition techniques. I-V characteristics of the Schottky diodes were optimum after 500 and 600 ºC annealing for Ni/Au and Ni/Ir/Au based diodes, respectively. The depth profiles of the contacts were measured by x-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy. These chemical composition techniques were used to examine the evolution of the metal contacts in order to verify the influence the metals have on the electrical properties of the diodes. The insertion of Ir as a diffusion barrier between Ni and Au effected the electrical properties, improving the stability of the contacts at high temperatures. Gold diffuses into the AlGaN film, degrading the electrical properties of the Ni/Au diode. At 500 ºC, the insertion of Ir, however, prevented the in-diffusion of Au into the AlGaN substrate.The National Research Foundation of South Africa (Grant specific unique reference number (UID) 87352).http://www.journals.elsevier.com/physica-b-condensed-matterhb2017Physic

Decadal changes in fire frequencies shift tree communities and functional traits

Global change has resulted in chronic shifts in fire regimes. Variability in the sensitivity of tree communities to multi-decadal changes in fire regimes is critical to anticipating shifts in ecosystem structure and function, yet remains poorly understood. Here, we address the overall effects of fire on tree communities and the factors controlling their sensitivity in 29 sites that experienced multi-decadal alterations in fire frequencies in savanna and forest ecosystems across tropical and temperate regions. Fire had a strong overall effect on tree communities, with an average fire frequency (one fire every three years) reducing stem density by 48% and basal area by 53% after 50 years, relative to unburned plots. The largest changes occurred in savanna ecosystems and in sites with strong wet seasons or strong dry seasons, pointing to fire characteristics and species composition as important. Analyses of functional traits highlighted the impact of fire-driven changes in soil nutrients because frequent burning favoured trees with low biomass nitrogen and phosphorus content, and with more efficient nitrogen acquisition through ectomycorrhizal symbioses. Taken together, the response of trees to altered fire frequencies depends both on climatic and vegetation determinants of fire behaviour and tree growth, and the coupling between fire-driven nutrient losses and plant traits

Towards Room Temperature Thermochromic Coatings with controllable NIR-IR modulation for solar heat management & smart windows applications

Solar heat management & green air-conditioning are among the major technologies that could mitigate heat islands phenomenon while minimizing significantly the CO2 global foot-print within the building & automotive sectors. Chromogenic materials in general, and thermochromic smart coatings especially are promising candidates that consent a noteworthy dynamic solar radiation Infrared (NIR-IR) regulation and hence an efficient solar heat management especially with the expected increase of the global seasonal temperature. Within this contribution, two major challenging bottlenecks in vanadium oxide based smart coatings were addressed. It is validated for the first time that the NIR-IR modulation of the optical transmission (∆TTRANS = T(T〈TMIT) − T(T〉TMIT) of Vanadium oxide based smart coatings can be controlled & tuned. This upmost challenging bottle-neck controllability/tunability is confirmed via a genuine approach alongside to a simultaneous drastic reduction of the phase transition temperature TMIT from 68.8 °C to nearly room temperature. More precisely, a substantial thermochromism in multilayered V2O5/V/V2O5 stacks equivalent to that of standard pure VO2 thin films but with a far lower transition temperature, is reported. Such a multilayered V2O5/V/V2O5 thermochromic system exhibited a net control & tunability of the optical transmission modulation in the NIR-IR (∆TTRANS) via the nano-scaled thickness’ control of the intermediate Vanadium layer. In addition, the control of ∆TTRANS is accompanied by a tremendous diminution of the thermochromic transition temperature from the elevated bulk value of 68.8 °C to the range of 27.5–37.5 ºC. The observed remarkable and reversible thermochromism in such multilayered nano-scaled system of V2O5/V/V2O5 is likely to be ascribed to a noteworthy interfacial diffusion, and an indirect doping by alkaline ions diffusing from the borosilicate substrate. It is hoped that the current findings would contribute in advancing thermochromic smart window technology and their applications for solar heat management in glass windows in general, skyscraper especially & in the automotive industry. If so, this would open a path to a sustainable green air-conditioning with zero-energy input

Modeling of Human Prokineticin Receptors: Interactions with Novel Small-Molecule Binders and Potential Off-Target Drugs

The Prokineticin receptor (PKR) 1 and 2 subtypes are novel members of family A GPCRs, which exhibit an unusually high degree of sequence similarity. Prokineticins (PKs), their cognate ligands, are small secreted proteins of ∼80 amino acids; however, non-peptidic low-molecular weight antagonists have also been identified. PKs and their receptors play important roles under various physiological conditions such as maintaining circadian rhythm and pain perception, as well as regulating angiogenesis and modulating immunity. Identifying binding sites for known antagonists and for additional potential binders will facilitate studying and regulating these novel receptors. Blocking PKRs may serve as a therapeutic tool for various diseases, including acute pain, inflammation and cancer.Ligand-based pharmacophore models were derived from known antagonists, and virtual screening performed on the DrugBank dataset identified potential human PKR (hPKR) ligands with novel scaffolds. Interestingly, these included several HIV protease inhibitors for which endothelial cell dysfunction is a documented side effect. Our results suggest that the side effects might be due to inhibition of the PKR signaling pathway. Docking of known binders to a 3D homology model of hPKR1 is in agreement with the well-established canonical TM-bundle binding site of family A GPCRs. Furthermore, the docking results highlight residues that may form specific contacts with the ligands. These contacts provide structural explanation for the importance of several chemical features that were obtained from the structure-activity analysis of known binders. With the exception of a single loop residue that might be perused in the future for obtaining subtype-specific regulation, the results suggest an identical TM-bundle binding site for hPKR1 and hPKR2. In addition, analysis of the intracellular regions highlights variable regions that may provide subtype specificity

Nitrogen and Carbon Isotopic Dynamics of Subarctic Soils and Plants in Southern Yukon Territory and its Implications for Paleoecological and Paleodietary Studies

We examine here the carbon and nitrogen isotopic compositions of bulk soils (8 topsoil and 7 subsoils, including two soil profiles) and five different plant parts of 79 C3 plants from two main functional groups: herbs and shrubs/subshrubs, from 18 different locations in grasslands of southern Yukon Territory, Canada (eastern shoreline of Kluane Lake and Whitehorse area). The Kluane Lake region in particular has been identified previously as an analogue for Late Pleistocene eastern Beringia. All topsoils have higher average total nitrogen δ15N and organic carbon δ13C than plants from the same sites with a positive shift occurring with depth in two soil profiles analyzed. All plants analyzed have an average whole plant δ13C of −27.5 ± 1.2 ‰ and foliar δ13C of ±28.0 ± 1.3 ‰, and average whole plant δ15N of −0.3 ± 2.2 ‰ and foliar δ15N of ±0.6 ± 2.7 ‰. Plants analyzed here showed relatively smaller variability in δ13C than δ15N. Their average δ13C after suitable corrections for the Suess effect should be suitable as baseline for interpreting diets of Late Pleistocene herbivores that lived in eastern Beringia. Water availability, nitrogen availability, spacial differences and intra-plant variability are important controls on δ15N of herbaceous plants in the study area. The wider range of δ15N, the more numerous factors that affect nitrogen isotopic composition and their likely differences in the past, however, limit use of the modern N isotopic baseline for vegetation in paleodietary models for such ecosystems. That said, the positive correlation between foliar δ15N and N content shown for the modern plants could support use of plant δ15N as an index for plant N content and therefore forage quality. The modern N isotopic baseline cannot be applied directly to the past, but it is prerequisite to future efforts to detect shifts in N cycling and forage quality since the Late Pleistocene through comparison with fossil plants from the same region