349,299 research outputs found
Recent Applications of the Simple Hydrocarbon Cyclooctatetrene as a Starting Material for Complex Molecule Synthesis
Cyclooctatetraene [COT], a simple non-aromatic cyclic polyene, is capable of undergoing a variety of oxidation and cycloaddition reactions to afford polycyclic structures. In addition, complexation of COT or the cycloaddition products with transition metals facilitates bond formation. Recent developments in the reactivity of COT and application to the synthesis of naturally occurring and non-naturally occurring compounds is reviewed
Middleware Technologies for Cloud of Things - a survey
The next wave of communication and applications rely on the new services
provided by Internet of Things which is becoming an important aspect in human
and machines future. The IoT services are a key solution for providing smart
environments in homes, buildings and cities. In the era of a massive number of
connected things and objects with a high grow rate, several challenges have
been raised such as management, aggregation and storage for big produced data.
In order to tackle some of these issues, cloud computing emerged to IoT as
Cloud of Things (CoT) which provides virtually unlimited cloud services to
enhance the large scale IoT platforms. There are several factors to be
considered in design and implementation of a CoT platform. One of the most
important and challenging problems is the heterogeneity of different objects.
This problem can be addressed by deploying suitable "Middleware". Middleware
sits between things and applications that make a reliable platform for
communication among things with different interfaces, operating systems, and
architectures. The main aim of this paper is to study the middleware
technologies for CoT. Toward this end, we first present the main features and
characteristics of middlewares. Next we study different architecture styles and
service domains. Then we presents several middlewares that are suitable for CoT
based platforms and lastly a list of current challenges and issues in design of
CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268,
Digital Communications and Networks, Elsevier (2017
Middleware Technologies for Cloud of Things - a survey
The next wave of communication and applications rely on the new services
provided by Internet of Things which is becoming an important aspect in human
and machines future. The IoT services are a key solution for providing smart
environments in homes, buildings and cities. In the era of a massive number of
connected things and objects with a high grow rate, several challenges have
been raised such as management, aggregation and storage for big produced data.
In order to tackle some of these issues, cloud computing emerged to IoT as
Cloud of Things (CoT) which provides virtually unlimited cloud services to
enhance the large scale IoT platforms. There are several factors to be
considered in design and implementation of a CoT platform. One of the most
important and challenging problems is the heterogeneity of different objects.
This problem can be addressed by deploying suitable "Middleware". Middleware
sits between things and applications that make a reliable platform for
communication among things with different interfaces, operating systems, and
architectures. The main aim of this paper is to study the middleware
technologies for CoT. Toward this end, we first present the main features and
characteristics of middlewares. Next we study different architecture styles and
service domains. Then we presents several middlewares that are suitable for CoT
based platforms and lastly a list of current challenges and issues in design of
CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268,
Digital Communications and Networks, Elsevier (2017
Recommended from our members
Metal-ligand pair anisotropy in a series of mononuclear Er-COT complexes.
Synthetic control of the crystal field has elevated lanthanides to the forefront of single-molecule magnet (SMM) research, yet the resultant strong, predictable single-ion anisotropy has thus far not translated into equally impressive molecule-based magnets of higher dimensionality. This roadblock arises from the dual demands made of the crystal field: generate anisotropy and facilitate magnetic coupling. Here we demonstrate that particular metal-ligand pairs can dominate the single-ion electronic structure so fully that the remaining coordination sphere plays a minimal role in the magnitude and orientation of the magnetic anisotropy. This Metal-Ligand Pair Anisotropy (MLPA) effectively separates the crystal field into discrete components dedicated to anisotropy and magnetic coupling. To demonstrate an MLPA building unit, we synthesized four new mononuclear complexes that challenge the electronic structure of the iconic lanthanocene ([Ln(COT)2]+; COT2- = cyclooctatetraene dianion) complex which is known to generate strong anisotropy with Ln = Er3+. Variation in symmetry and coordination strength for Er(COT)I(THF)2 (THF = tetrahydrofuran) (1), Er(COT)I(Py)2 (Py = pyridine) (2), Er(COT)I(MeCN)2 (MeCN = acetonitrile) (3), and Er(COT)(Tp*) (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate) (4) shows that the Er-COT unit stabilizes anisotropy despite deliberate de-optimization. All four half-sandwich complexes display SMM behavior with effective energy barriers of U eff = 95.6(9), 102.9(3.1), 107.1(1.3), and 133.6(2.2) cm-1 for 1-4 by a multi-relaxation-process fitting. More importantly, the basic state splittings remain intact and the anisotropy axes are within several degrees of normal to the COT2- ring according to complete active space self-consistent field (CASSCF) calculations. Further investigation of the MLPA conceptual framework is warranted as it can provide building units with well-defined magnetic orientation and strength. We envision that the through-barrier processes observed herein, such as quantum tunneling, can be mitigated by formation of larger clusters and molecule-based materials
Inclusive angular distribution of alpha and Li fragments produced in the Fe-C and Fe-Pb collisions at 1.88 GeV/u
The LS (laboratory system) emission angles theta for 2188 and 298 Li fragments, produced inclusively in relativistic Fe-C and Fe-Pb collisions, have been measured in reference to incident Fe-ion beam tracks nearby in nuclear emulsion. An empirical differential frequency formula, dN(cot theta) = exp (a + b cot theta)d(cot theta) is obtained with the constant b approx. = -0.026 at 1.88 GeV/u, which seems to be independent on the kinds of target nucleus as well as on the kinds of projectile fragments
Simulating the nanomechanical response of cyclooctatetraene molecules on a graphene device
We investigate the atomic and electronic structures of cyclooctatetraene
(COT) molecules on graphene and analyze their dependence on external gate
voltage using first-principles calculations. The external gate voltage is
simulated by adding or removing electrons using density functional theory (DFT)
calculations. This allows us to investigate how changes in carrier density
modify the molecular shape, orientation, adsorption site, diffusion barrier,
and diffusion path. For increased hole doping COT molecules gradually change
their shape to a more flattened conformation and the distance between the
molecules and graphene increases while the diffusion barrier drastically
decreases. For increased electron doping an abrupt transition to a planar
conformation at a carrier density of -810 e/cm is observed.
These calculations imply that the shape and mobility of adsorbed COT molecules
can be controlled by externally gating graphene devices
Changing rooms in NICU : a comparative descriptive study of parental perceptions of the physical environment of neonatal intensive care units : a thesis presented in partial fulfilment of the requirements for the degree in Master of Philosophy in Nursing at Massey University
The physical environment of a neonatal intensive care unit (NICU) is unique and can be challenging and stressful for families. As infant survival rates and technology improved, many NICUs became 'busy', overcrowded, noisy environments. New directions in the design of newborn nurseries highlight the potential for the physical environment to support parental needs and optimise the parenting experience. In October 2004 the NICU at National Women's Hospital (NWH) in Auckland (New Zealand), relocated to a new facility at Auckland City Hospital (ACH). A key principle in the design of the new NICU was improvement of family space at the cot side. This non-experimental study sought to describe and compare parental perceptions of the physical environment of a traditional NICU configuration with a new custom built NICU. A sample of parents with infants hospitalised in NICU from NWH (n = 30) and a different group of parents from ACH (n = 30) completed a self report Likert-type questionnaire (with a scale from 1 = strongly disagree to 7 = strongly agree). Qualitative data was sought using open ended questions. Significant differences were found between the old NWH NICU and the newly designed ACH NICU. Parents perception of the space at the cot-side was more adequate (p = 0.001), lighting levels more comfortable (p = 0.002), the cot-side was quieter (p = 0.02) and technology less intrusive (p = 0.03) at ACH NICU when compared to NWH NICU. Impact of these design changes on privacy, sense of belonging, and socialisation of parents did not show significant differences. Lack of cot-side space for NWH parents was the predominate theme from the open-ended questions. Parents viewed the family space and aesthetics of the new ACH rooms positively. Providers of newborn services contemplating redesign need to consider that increasing cot side space and decreasing infant numbers in clinical rooms can significantly improve a parent's view of NICU and therefore provide an environment that is supportive to parent's needs
- …
