A preliminary study on the effect of macro cavities formation on properties of carbon nanotube bucky-paper composites

In this study, we focus on processing and characterizing composite material structures made of carbon nanotubes (CNTs) and reproducibly engineering macro-pores inside their structure. Highly porous bucky-papers were fabricated from pure carbon nanotubes by dispersing and stabilizing large 1 μm polystyrene beads within a carbon nanotube suspension. The polystyrene beads, homogeneously dispersed across the thickness of the bucky-papers, were then either dissolved or carbonized to generate macro cavities of different shape and properties. The impact of adding these macro cavities on the porosity, specific surface area and Young’s modulus was investigated and some benefits of the macro cavities will be demonstrated.

Focused ion beam milling of carbon nanotube yarns and bucky-papers : correlating their internal structure with their macro-properties

Focused ion beam (FIB) milling through carbon nanotube (CNT) yarns and bucky-papers followed by scanning electron microscopy has recently emerged as a powerful tool for eliciting details of their internal structure. The internal arrangement of CNTs in bucky-papers and yarns directly affects their performance and characteristics. Consequently this information is critical for further optimisation of these structures and to tailor their properties for specific applications. This chapter describes in detail FIB milling of CNT yarns and bucky-papers and gives a range of examples where FIB milling has enabled a better understanding of how processing conditions and treatments affect the internal structure. Emphasis is placed on how FIB milling elucidates the influence of fabrication conditions on the internal arrangement of CNTs and how this influences the material's macroscopic properties.

Recent developments in carbon nanotube membranes for water purification and gas separation

Carbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented.

Control of porosity and pore size of metal reinforced carbon nanotube membranes

Membranes are crucial in modern industry and both new technologies and materials need to be designed to achieve higher selectivity and performance. Exotic materials such as nanoparticles offer promising perspectives, and combining both their very high specific surface area and the possibility to incorporate them into macrostructures have already shown to substantially increase the membrane performance. In this paper we report on the fabrication and engineering of metal-reinforced carbon nanotube (CNT) Bucky-Paper (BP) composites with tuneable porosity and surface pore size. A BP is an entangled mesh non-woven like structure of nanotubes. Pure CNT BPs present both very high porosity (>90%) and specific surface area (>400 m2/g). Furthermore, their pore size is generally between 20–50 nm making them promising candidates for various membrane and separation applications. Both electro-plating and electroless plating techniques were used to plate different series of BPs and offered various degrees of success. Here we will report mainly on electroless plated gold/CNT composites. The benefit of this method resides in the versatility of the plating and the opportunity to tune both average pore size and porosity of the structure with a high degree of reproducibility. The CNT BPs were first oxidized by short UV/O3 treatment, followed by successive immersion in different plating solutions. The morphology and properties of these samples has been investigated and their performance in air permeation and gas adsorption will be reported.

Carbon nanotube based composite membranes for water desalination by membrane distillation

New technologies are required to improve desalination efficiency and increase water treatment capacities. One promising low energy technique to produce potable water from either sea or sewage water is membrane distillation (MD). However, to be competitive with other desalination processes, membranes need to be designed specifically for the MD process requirements. Here we report on the design of carbon nanotube (CNT) based composite material membranes for direct contact membrane distillation (DCMD). The membranes were characterized and tested in a DCMD setup under different feed temperatures and test conditions. The composite CNT structures showed significantly improved performance compared to their pure self-supporting CNT counterparts. The best composite CNT membranes gave permeabilities as high as 3.3 x 10-12 kg/(m x s x Pa) with an average salt rejection of 95% and lifespan of up to 39 h of continuous testing, making them highly promising candidates for DCMD.

The Australasian triage scale: examining emergency department nurses' performance using computer and paper scenarios

Study objective: The purpose of this study is to examine emergency nurses' performance using triage scenarios characterized by type of patient population (adult versus pediatric) and mode of delivery (paper versus computer). Methods:   A combination of paper-based (script alone) and computer-based (script plus still photographs) triage scenarios were used. Of the 28 scenarios used, half were written and half were computer based. Within each subgroup, there were 7 adult and 7 pediatric scenarios. Participants were asked to allocate an Australasian Triage Scale category for each triage scenario. Results: One hundred sixty-seven participants completed a total of 2,349 adult scenarios, and 161 participants completed 2,265 pediatric scenarios. Sixty-one percent of the triage decisions made by the nurses were “expected” triage decisions, 18% were “undertriage,” decisions, and 21% were “overtriage” decisions. Nurse triage allocation decisions for the scenarios containing still photographs delivered by computer demonstrated a higher average agreement percentage of 66.2% (κ=0.56; τb=0.77; P<.0001) compared with the average agreement percentage of 55.4% (κ=0.42; τb=0.75; P<.0001) using paper-based (text-only) scenarios. Conclusion: The mode of delivery appeared to have an effect on the nurses' triage performance. It is unclear whether the use of simple still photographs used in the computer mode of delivery resulted in a higher incidence of expected triage decisions and, thus, improved performance. The use of cues such as photographs and video footage to enhance the fidelity of triage scenarios may be useful not only for the education of triage nurses but also the conduct of research into triage decisionmaking. However, further exploration and research in this area are warranted.

Scenes from another life (the paper)

What is my dance now? My body is saturated with images and details. My choreography has become an exorcism of ghosts of “opening-nights past” as I dance out memories and events inscribed on my body. A chorus of my other selves now accompanies my stage performance, live and virtual, real and imagined, past and present.

Questioning the future of paper and online survey questionnaires for management research

The way that we build the foundations of our intellectual capital in management has changed. One example is the steady move in management research from the use of traditional paper-based survey questionnaires to online technology-based formats. This paper considers this shift, particularly focusing on the question of whether the advantages of online survey questionnaires outweigh their potential problems. The historical use of paper-based survey questionnaires has produced a large body of literature on both the advantages and disadvantages in their use, which are reviewed here alongside those of online survey questionnaires. In addition, welI-tested methods are available for increasing survey response rates in paper format, and these should not be thrown out in the quest to utilise online survey methodology. Rather, researchers should aim to exploit the potential benefits of online technologies and increase response rate by thoughtfully combining traditional and new methods. This paper argues for further discussion and research attention on electronic methods of data collection to ensure potential cost savings are not outweighed by either financial or participation costs involved in online survey questionnaire design.