School-based materials for critical reading in English

This research aims to examine Thai students' critical thinking ability in reading English by using materials developed by a research team using a collaborative action research methodology. Initially, a survey of self-percpetions of Thai secondary students on their critical thinking ability was conducted. Then, two Thai teachers were interviewed about their materials and methodology in teaching students to read critically. Lastly, a literature of critical literacy was reviewed to introduce the notions to Thai teachers and Thai students.

Self-assembled natural rubber/multi-walled carbon nanotube composites using latex compounding techniques

Functionalization of multi-walled carbon nanotubes (MWCNTs) plays an important role in eliminating nanotube aggregation for reinforcing polymeric materials. We prepared a new class of natural rubber (NR)/MWCNT composites by using latex compounding and self-assembly technique. The MWCNTs were functionalized with mixed acids (H2SO₄/HNO₃ = 3:1, volume ratio) and then assembled with poly (diallyldimethylammonium chloride) and latex particles. The Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy were used to investigate the assembling mechanism between latex particles and MWCNTs. It is found that MWCNTs are homogenously dispersed in the natural rubber (NR) latex as individual nanotubes since strong self-aggregation of MWCNTs has been greatly depressed with their surface functionalization. The well-dispersed MWCNTs produce a remarkable increase in the tensile strength of NR even when the amount of MWCNTs is only 1 wt.%. Dynamic mechanical analysis shows that the glass transition temperature of composites is higher and the inner-thermogenesis and thermal stability of NR/MWCNT composites are better, when compared to those of the pure NR. The marked improvement in these properties is largely due to the strong interfacial adhesion between the NR phase and MWCNTs. Functionalization of MWCNTs represents a potentially powerful technology for significant reinforcement of natural rubber materials.

Atom probe microscopy of self-assembled monolayers : preliminary results

We have achieved three-dimensional imaging of decanethiol self-assembled monolayers (SAMs) on metal surfaces by atom probe tomography (APT). The present Letter provides preliminary results on Ni [001] and Au [111], shows the analytical potential of APT analysis of SAMs, and details developments in specimen preparation and in data-treatment methodologies. Importantly, the investigation of the mass spectra from analysis of the SAMs revealed no combination of sulfur and hydrogen at the interface between the metal substrates and the organic materials, potentially providing insight about the bonding of the thiols on the substrate.

Architecture of macromolecular network of soft functional materials : from structure to function

An enhanced macromolecular nanofiber network and its implications have been developed by employing the understanding of its formation with an emphasis on its topological aspect. Using agarose aqueous solution as a typical example, the macromolecular nanofiber network of soft functional materials has been clearly visualized for the first time using the developed technique of field emission scanning electronic microscopy coupled with flash-freeze-drying. Both the systematic kinetic study and the image evidence indicates that the nanofiber network in soft functional materials such as agarose turns out to form through a self-expitaxial nucleation-controlled process. This new understanding enables us to engineer ultra functions of soft materials via nanofiber network architecture, which in turn opens up a new direction in nano fabrication.

Engineering molecular self-assembled fibrillar networks by ultrasound

The architecture of self-organized three-dimensionally interconnected nanocrystal fibrillar networks has been achieved by ultrasound from a solution consisting of separate spherulites. The ultrasound stimulated structural transformation is correlated to the striking ultrasonic effects on turning nongelled solutions or weak gels into strong gels instantly, with enhancement of the storage modulus up to 3 magnitudes and up to 4 times more gelling capability. The basic principle involved in the ultrasound-induced structural transformation is established on the basis of the nucleation-and-growth model of a fiber network formation, and the mechanism of seeding multiplication, aggregation suppressing, and fiber distribution and growth promotion is proposed. This novel technique enables us to produce self-supporting gel functional materials possessing significantly modified macroscopic properties, from materials previously thus far considered to be “useless”, without the use of chemical stimuli. Moreover, it provides a general strategy for the engineering of self-organized fiber network architectures, and we are consequently able to achieve the supramolecular functional materials with controllable macroscopic properties.

Microengineering of soft functional materials by controlling the fiber network formation

The engineering of soft functional materials based on the construction of three-dimensional interconnecting self-organized nanofiber networks is reported. The system under investigation is an organogel formed by N-lauroyl-L-glutamic acid di-n-butylamide (GP-1) in propylene glycol. The engineering of soft functional materials is implemented by controlling primary nucleation kinetics of GP-1, which can be achieved by both reducing thermodynamic driving force and/or introducing a tiny amount of specific copolymers (i.e., poly(methyl methacrylate comethacrylic acid)). The primary nucleation rate of GP-1 is correlated to the number density of GP-1 spherulites, which determines the overall rheological properties of soft functional materials. The results show that the presence of a tiny amount of the polymer (0.01-0.06%) can effectively inhibit the nucleation of GP-1 spherulites, which leads to the formation of integrated fiber networks. It follows that with the additive approach, the viscoelasticity of the soft functional material is significantly enhanced (i.e., more than 1.5 times at 40 °C). A combination of the thermal and additive approach led to an improvement of 3.5 times in the viscosity of the gel.

Understanding in-vivo abrasion fatigue or common suture materials used in arthroscopic and open shoulder surgery

In orthopaedic surgery the reattachment of tendon to bone requires suture materials that have stable and durable properties to allow healing at the tendon-bone interface. Failure rates of this type of surgery can be as high as 25%. While the tissue suture interface is a weak link, proportions of these failures are caused by in-vivo abrasion of the suture with bone and suture anchor materials. Abrasion of the suture material results from the movement of the suture through the eyelet by the surgeon during surgery, or with limb movement after surgery as the suture is not rigidly restrained within the eyelet. During movement the suture is subjected to bending and frictional forces that can lead to fatigue induced failure. This paper investigates the mechanism of bending abrasion fatigue induced failure of number two grade braided sheath only and braided sheath/multifilament core sutures. Sutures were oscillated over a stainless steel wire at low frequency under load in a dry state to simulate the bending and frictional forces between suture and eyelet. Failure mechanism was determined by video microscopy of the suture during abrasion combined with optical microscopy analysis of partially and fully abraded sutures. Braided only structures had high friction loading on the small number of fibres at the abrasion interface. This caused rapid single fibre breakages that accumulate to cause suture failure. The addition of ultra-high molecular weight polyethylene core fibres to a braided suture distributed the applied load across multiple fibres at the abrasion interface. This improved abrasion resistance by 15-20 times that of braided sheath alone.

Electrospun spinel LiNi0.5Mn1.5O4 hierarchical nanofibers as 5 v cathode materials for lithium-ion batteries

Spinel LiNi0.5Mn1.5O4 hierarchical nanofibers with diameters of 200–500 nm and lengths of up to several tens of micrometers were synthesized using low-cost starting materials by electrospinning combined with annealing. Well-separated nanofiber precursors impede the growth and agglomeration of Li-Ni0.5Mn1.5O4 particles. The hierarchical nanofibers were constructed from attached LiNi0.5Mn1.5O4 nanooctahedrons with sizes ranging from 200 to 400 nm. It is proven that these Li-Ni0.5Mn1.5O4 hierarchical nanofibers exhibit a favorable electrochemical performance. At a 0.5C (coulombic) rate, it shows an initial discharge capacity of 133 mAhg_1 with a capacity retention over 94% after 30 cycles. Even at 2, 5, 10, and 15C rates, it can still deliver a discharge capacity of 115, 100, 90, and 80 mAhg_1, respectively. Compared with self-aggregated nanooctahedrons synthesized using common sol–gel methods, the LiNi0.5Mn1.5O4 hierarchical nanofibers exhibit a much higher capacity. This is owing to the fact that the self-aggregation of the unique nanooctahedron-in-nanofiber structure has been greatly reduced because of the attachment of nanopolyhedrons in the long nanofibers. This unique microstructured cathode results in the large effective contact areas of the active materials, conductive additives and fully realize the advantage of nanomaterial-based cathodes.

Tuning the amino acid sequence of minimalist peptides to present biological signals via charge neutralised self assembly

Nanofibrous materials yielded by the self-assembly of peptides are rich in potential; particularly for the formation of scaffolds that mimic the landscape of the host environment of the cell. Here, we report a novel methodology to direct the formation of supramolecular structures presenting desirable amino acid sequences by the self-assembly of minimalist peptides which cannot otherwise yield the desired scaffold structures under biologically relevant conditions. Through the rational modification of the pK?, we were able to optimise ordered charge neutralised assembly towards in vivo conditions.

A parallel-group, randomised controlled trial of a multimedia, self-directed, coping skills training intervention for patients with cancer and their partners: design and rationale

Introduction:

Synthesis and self-assembly of hybrid amphiphilic block copolymers

This thesis focused on the synthesis and self-assembly of novel block copolymers for the purpose of drug delivery. The block copolymers achieved comprise of a synthetic block and a peptide block and self-assemble into nano sized particles which can act as drug containers.

In vitro response to functionalized self-assembled peptide scaffolds for three-dimensional cell culture

Nanomaterials are rich in potential, particularly for the formation of scaffolds that mimic the landscape of the host environment of the cell. This niche arises from the spatial organization of a series of biochemical and biomechanical signals. Self-assembling peptides have emerged as an important tool in the development of functional (bio-)nanomaterials; these simple, easily synthesized subunits form structures which present the properties of these larger, more complex systems. Scaffolds based upon these nanofibrous matrices are promising materials for regenerative medicine as part of a new methodology in scaffold design where a "bottom-up" approach is used in order to simulate the native cellular milieu. Importantly, SAPs hold the potential to be bioactive through the presentation of biochemical and biomechanical signals in a context similar to the natural extracellular matrix, making them ideal targets for providing structural and chemical support in a cellular context. Here, we discuss a new methodology for the presentation of biologically relevant epitopes through their effective presentation on the surface of the nanofibers. Here, we demonstrate that these signals have a direct effect on the viability of cells within a three-dimensional matrix as compared with an unfunctionalized, yet mechanically and morphologically similar system. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 197-205, 2014.

Trustworthiness: self-assessment of an institutional repository against ISO 16363-2012

Today, almost every document we create and the output from almost every research-related project, is a digital object. Not everything has to be kept forever, but materials with scholarly or historical value should be retained for future generations. Preserving digital objects is more challenging than preserving items on paper. Hardware becomes obsolete, new software replaces old, storage media degrades. In recent years, there has been significant progress made to develop tools and standards to preserve digital media, particularly in the context of institutional repositories. The most widely accepted standard thus far is the Trustworthy Repositories Audit and Certification: Criteria and Checklist (TRAC), which evolved into ISO 16363-2012. Deakin University Library undertook a self-assessment against the ISO 16363 criteria. This experience culminated in the current report, which provides an appraisal of ISO 16363, the assessment process, and advice for others considering embarking on a similar venture.