Solvothermal Synthesis of a Nano-sized Aza-aromatic Base Adduct of a Cadmium(II) 4,4-Difluoro-1-phenyl-1,3-butandionate Coordination Compound

A new nano-structured cadmium(II) coordination compound, [Cd(phen)(dfpb)₂] (1) (phen?=?1,10-phenanthroline, dfpb?=?4,4-difluoro-1-phenyl-1,3-butandion), was synthesized by a solvothermal method and produced a coordination polymer in the nano-size range. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction elemental analysis and IR spectroscopy. Compound 1 was structurally characterised by single crystal X-ray diffraction. The single crystal structure shows a coordination number for the Cd ion of six with two N-donor atoms from the phen ligand and four O-donors from the two dfpb moieties. Self-assembly occurs by CH····F–C and π–π stacking interactions. The supramolecular features in these complexes are controlled by weak directional intermolecular interactions.     

Principal component based diffeomorphic surface mapping

We present a new diffeomorphic surface mapping algorithm under the framework of large deformation diffeomorphic metric mapping (LDDMM). Unlike existing LDDMM approaches, this new algorithm reduces the complexity of the estimation of diffeomorphic transformations by incorporating a shape prior in which a nonlinear diffeomorphic shape space is represented by a linear space of initial momenta of diffeomorphic geodesic flows from a fixed template. In addition, for the first time, the diffeomorphic mapping is formulated within a decision-theoretic scheme based on Bayesian modeling in which an empirical shape prior is characterized by a low dimensional Gaussian distribution on initial momentum. This is achieved using principal component analysis (PCA) to construct the eigenspace of the initial momentum. A likelihood function is formulated as the conditional probability of observing surfaces given any particular value of the initial momentum, which is modeled as a random field of vector-valued measures characterizing the geometry of surfaces. We define the diffeomorphic mapping as a problem that maximizes a posterior distribution of the initial momentum given observable surfaces over the eigenspace of the initial momentum. We demonstrate the stability of the initial momentum eigenspace when altering training samples using a bootstrapping method. We then validate the mapping accuracy and show robustness to outliers whose shape variation is not incorporated into the shape prior.     

Factorial optimisation of the effects of extrusion temperature profile and polymer grade on as-spun aliphatic–aromatic co-polyester fibres III: mechanical properties

The effect of extrusion temperature profile in the melt‐spinning process of as‐spun linear aliphatic–aromatic co‐polyester (AAC) fibres upon their mechanical properties and process productivity was modelled by using factorial experimental designs. After the viscoelastic and morphology characteristics of the polymer were considered using Differential Scanning Calorimetry and Melt Flow Index (MFI), the rheological data were used to determine the enhanced melt‐spinning temperature of the six heating zones in the process. Tensile strength, elongation at break, modulus and fibre productivity (g/min) of the melt‐spinning process have been quantitatively assessed as responses to polymer grades and extrusion zone temperature. The optimisation of mechanical properties and productivity helps in understanding and controlling the most desired properties in the produced fibre. It has been noted that the die head temperature (spinning temperature), the polymer grade and their interaction are the most significant factors affecting the mechanical properties. Analysis of the fibre productivity shows that the polymer grade and its interaction with the die head temperature is significant in terms of influencing the output of the melt‐spinning process, which could be related to the polymer molecular weight and polymer structure. There is an interaction between polymer grade and feeding zone temperature which is related to the material supply action in the feeding zone. The friction between the screw and the material is affected by heating action, which affects the moisture content and the molten material rheology. By adjusting the extrusion temperature profile and selecting the more applicable spin‐able polymer grade through a statistical forecasting model, the combination of the cost related to material grade and processing cost controls the fibre production cost. The fibre made of low MFI grade has better structure and mechanical properties than that made of the higher MFI grade, and the former will be preferred for future work. With previous work related to the effects of extrusion temperature profile on the fibre structure, the present paper will help in developing the production process of biodegradable linear AAC fibres.     

New Flower-Shaped Lead(II) Coordination Polymer at the Nano Scale: Synthesis, Structural Characterization and DFT Calculations of [Pb(o-phen)(N3)2] n Containing the Pb-(μ1,1-N3)(μ1,3-N3) Motif

A new nano-flower lead(II) azido coordination polymer from the ligand, orthophenanthroline (o-phen), [Pb(o-phen)(μ_1,1-N₃)(μ_1,3-N₃)] _n (1), was synthesized by a sonochemical method. Compound 1 was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), elemental analyses and IR spectroscopy. Single crystalline material was obtained using a heat gradient applied to a solution of the reagents. The structure of 1 is a coordination polymer of lead(II) containing the Pb-(μ_1,1-N₃)(μ_1,3-N₃) motif, formed of one-dimensional chains. The structure of the 1 was optimized by density functional theory. Structural parameters and IR spectra for 1 are consistent with the crystal structure. Pure phase PbO nanoparticles were obtained by thermolysis of 1 with oleic acid as a surfactant at 180 and 200 °C an air. PbO nanoparticles were characterized by XRD and SEM.     

From IP to Start-up： Building a Robust Life Science Incubator

An incubator is an organization that supports new ventures to grow and survive during the early stages. Mainly dedicated to information technology, life science may appear to be the next hot spot for incubators. Are there stabilized good practices？ Are the business models in information technology and in life science comparable when it goes to start-ups＇ incubation？ Leveraging our experience as practitioner in this field and using an inductive methodology, this paper tends to propose simple principles to help build robust incubators in life science, and to contribute to disseminate an entrepreneurial approach through an industry still dominated by blue chips.     

The Effect of Ti Addition on Microstructure and Magnetic Properties of Nanocrystalline FeAl40 Alloy Powders Prepared by Mechanical Alloying

Powder Metallurgy and Metal Ceramics - Recent research on nanocrystalline FeAl alloys has shown that these alloys are of high importance due to their promising structural and mechanical properties,...     

An exponential SRGM with a bound on the number of failures

An exponential software reliability growth model (SRGM) incorporating a situation where more than one failure can be attributed to one fault/error has been proposed. Different model parameters have been estimated and an optimal release policy which minimizes the software cost, subject to achieving a given level of reliability, has been discussed. Finally, a numerical example illustrating the applicability of the model and a few practical situations where this model can be applied are also given.     

Observations on seminal vesicle dynamics in an in vivo rat model

PURPOSE: To gain understanding of the seminal vesicle as a muscular organ, seminal vesicle compliance and contractile properties were quantified with an in vivo, microsurgical rat model. MATERIALS AND METHODS: Microsurgical dissection was performed on anesthetized rats to enable simultaneous organ filling and monitoring of intraluminal pressures. The reliability and reproducibility of post-ganglionic hypogastric nerve-induced ipsilateral (4 rats) and bilateral (5 rats) seminal vesicle contractile responses were assessed during repeated nerve stimulation. Seminal vesicle resting compliance was assessed during a constant saline infusion (10 rats). Functional performance curves were obtained at fixed fill-volumes by measuring organ contraction after nerve stimulation (4 rats). RESULTS: A reproducible seminal vesicle contractile response was obtained with a nerve stimulation interval > 15 minutes. Bilateral seminal vesicle responses were observed with unilateral nerve stimulation. The resting organ compliance curve with saline filling exhibited a characteristic, triphasic response. Functional performance studies revealed that contractile performance improves as the fill-volume increases until the distensibility limit of the organ is reached. CONCLUSIONS: A reliable, in vivo, rat model of seminal vesicle organ compliance and contractility is described. The seminal vesicle is a highly contractile, compliant smooth muscular organ with dynamic properties analogous to that of the urinary bladder. This experimental system may allow for the investigation of pharmacologic and other physiological influences on in vivo organ activity.     

Modeling and performance analysis of a new secure address resolution protocol

Address Resolution Protocol (ARP) is an essential protocol for the operation of local area networks. It is used for mapping the logical address to the physical address. However, ARP was designed without any security features. Therefore, ARP is vulnerable to many ARP spoofing attacks, such as the host impersonation, man‐in‐the‐middle (MITM), and denial of service (DoS) attacks. Many techniques were introduced in the literature for mitigating ARP spoofing attack. However, they could not provide protection against the host impersonation and DoS attacks. This work introduces a new technique to secure address resolution protocol called ARP Authentication (ARP‐A). The proposed technique provides authentication for ARP messages and entities. In addition, it converts ARP from a stateless to a stateful protocol. To evaluate the performance of ARP‐A, it was implemented on Linux. To investigate the scalability of ARP‐A, a new analytical model was designed for it using stochastic reward nets. The results show that, compared with other related schemes introduced in the literature, ARP‐A is more efficient in terms of security and performance.