Enhancement of β phase crystals formation with the use of nanofillers in PVDF films and fibres

Nanoclay and carbon nanotubes (CNT) have been in focus recently as means of enhancing β phase crystals formation in poly(vinylidene fluoride)(PVDF). Dominantly, the so-far work has been carried out on films/thin sheets filled with nanoclay. It has been found, mainly from combined XRD and DSC data, that nanoclay influences the PVDF structure, and particularly the β phase crystals formation is enhanced. Results published by various groups are in fairly good agreement. There are no results for nanoclay filled melt-spun PVDF fibres.The influence of CNT on PVDF structure has been less studied. XRD data indicating an enhancing role of multi-wall carbon nanotubes (MWNT) on β phase crystals formation in solution compounded PVDF films are available. Published results for MWNT/PVDF films are not in good agreement. The only study into single-wall carbon nanotube (SWNT)/PVDF has been made on electrospun nanofibres.We explore above findings towards melt-spun nanofilled PVDF fibres. We present new results obtained by us for melt-spun PVDF fibres containing non-functionalized and amino-functionalized double-wall carbon nanotubes (DWNT). The key finding is that amino-DWNT can influence the β to α polymorphic balance.     

Investigation of reactions between vanadium oxide and plasma-sprayed yttria-stabilized zirconia coatings

The phase evolution occurring during the reaction between corrosive V₂O₅ (T_m = 690 °C) and a plasma-sprayed 7 wt.% Y₂O₃–ZrO₂ (YSZ) coating from 700 to 900 °C has been investigated in situ by X-ray diffraction. The temperature and time of interaction between the V₂O₅ and YSZ coating determines the phases observed. Between 700 and 750 °C, reaction products of ZrV₂O₇ and YVO₄ were observed within minutes of reaching the test temperature. m-ZrO₂ was observed after 220 and 60 min at 700 and 750 °C, respectively. The simultaneous formation of both ZrV₂O₇ and YVO₄ at the beginning of the reaction along with the delay of the m-ZrO₂ formation suggests similar reactivity between both Zr and Y with V₂O₅. The weight percent of the ZrV₂O₇ phase began to diminish after 150 and 60 min at 700 and 750 °C, respectively. For reaction temperatures of 800 and 900 °C, there is a rapid decrease in the amount of t′-ZrO₂ and a rapid increase in the amount of m-ZrO₂ with reaction time. YVO₄ was also observed at these reaction temperatures. SEM and TEM microstructural observations confirmed the phases detected from the in situ XRD experiments. Reactions between YSZ and V₂O₅ suggest that the formation of a liquid phase due to the high solubility of both zirconia and yttria in vanadia is the dominate mechanism that damages the coating. The thermal conductivity of a plasma-sprayed YSZ coating reacted with up to 1 wt.% V₂O₅ did not significantly change due to the small volume affected.     

Critical pathways to enhanced innovation diffusion and business performance in Australian design firms

This paper presents a study that extends on previous empirical research, which examined the role of enabling ‘climate for innovation’ constructs in determining the level of innovation diffusion outcomes, and subsequent business performance in architectural and engineering design (AED) firms. Whilst this previous study elucidated the relationships between broad theoretical constructs, the present study was focused on targeting the significant enabling factor interrelationships with the core outcomes that result from the innovation diffusion process. To achieve this objective, a sequential mixed-method research design combining quantitative and qualitative analysis techniques was employed. The quantitative techniques included a correlation analysis to identify the strong factor relationships, followed by Structural Equation Modelling (SEM) to determine the critical pathways for enhancing innovation diffusion and ultimately heightened levels of client satisfaction. Following path model extraction, qualitative interviews with five Australian AED firms were conducted. The interview findings confirmed the uncovered significant pathways, and provided in-depth insights into how the improvement of critical enabling factors could leverage improved innovation diffusion outcomes and business performance.     

Stress-Induced Phase Transformation in Single Crystal Titanium Carbide

Single-crystal ingots of TiC were cut into wafer substrates for heteroepitaxial growth of SiC films. During wafer sectioning by abrasive machining, a subsurface damage zone was created. TEM observations of the damage zone revealed a stress-induced martensitic transformation from cubic TiC to rhombohedral and hexagonal structures, both involving an 8.0% contraction normal to the {111} habit plane and a shear along     . It is proposed that the transformed structure is governed by the Ti sublattice, and that carbon atoms remain in octahedral coordination. The transformed phase coarsened to form a lamellar structure consisting of periodic quadlayer twins. The twins imparted hexagonal symmetry, and the lamellar phase was designated 8H. A strain gradient tensor was employed to describe the mapping of atom coordinates between the two phases. The present account constitutes the first report of this transformation in TiC.     

History of Drainage in the Bureau of Reclamation

In the early days of the Reclamation Service, the criteria for irrigability of lands generally consisted of two elements: (1) is water available? and (2) can we get the water to the land? Within a few years, many of the early projects were experiencing reduced agricultural productivity and reduced ability to repay construction loans because the soils were becoming waterlogged and saline. By 1915, construction of subsurface drainage facilities had been initiated on several projects. However, at the time, subsurface drainage was more of an art than a science. Much of the world’s experience with agricultural drainage had been gained in humid areas which were quite different from arid areas. With no standards and limited knowledge of ground water movement, these early drainage efforts met with varying degrees of success. This paper summarizes the development of scientific methods to ensure successful application of drainage in a sustainable irrigated agriculture. Reclamation has introduced these methods to solve irrigated drainage problems at the international level. This paper will address the international experience, and how the same design and construction methods and procedures are now being used to design corrective drainage facilities for dams and other major structures and to support environmental enhancement programs.     

项目经理的乐观主义

在过去12个月里我讨论了项目经理的领导力及他们对项目成功的影响.上期我考察了项目经理面对的压力及其应对机制.通常人们认为项目工作和项目经理的角色是处于压力之下的.目前我正在做关于项目导向型组织中人力资源管理的研究,其中调查的一个问题就是项目导向型组织中员工的幸福状况.     

Simulation with Object Oriented Programming

Simulation with Object Oriented Programming (SW-OOP) is a library of software modules (classes) designed to provide the software constructs necessary for programming general purpose discrete event computer simulations in Pascal.

Systems modeling and simulation has been cited by those disciplined in operations research and management science as one of the skills most frequently applied to the study, understanding and improvement of systems in industry (Law 1991).

This paper presents SW-OOP and discusses how it is used to facilitate systems modeling and simulation when computer software is developed to study a particular problem.     

Unexpected transient creep behavior of tin alloys strengthened by high volume fractions of SbSn

An unexpected transient creep behavior characterized by a stress exponent of 1 was observed at low stresses in tin alloys strengthened by large volume fractions (>15 pct) of the precipitate SbSn. By way of solid-state precipitation, SbSn forms as high-aspect ratio whiskers. At large volume fractions, whiskers are both directly and indirectly observed to be in direct contact with multiple other whiskers. The transient creep behavior is attributed to a phase-boundary-enhanced diffusional creep mechanism, possibly diffusional creep along continuous phase-boundary paths between tin grain boundaries. It is thought that the creep behavior is, in fact, a “steady-state” behavior characteristic of the initial microstructure. The ultimate transient nature is due to precipitate coarsening occurring with time during the creep test.