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Single- and multiple-nanopore membranes are both highly interesting for biosensing and separation processes, as well as their ability to mimic biological membranes. The density of pores, their shape, and their surface chemistry are the key factors that determine membrane transport and separation capabilities. Here, we report silicon nitride (SiN) membranes with fully controlled porosity, pore geometry, and pore surface chemistry. An ultrathin freestanding SiN platform is described with conical or double-conical nanopores of diameters as small as several nanometers, prepared by the track-etching technique. This technique allows the membrane porosity to be tuned from one to billions of pores per square centimeter. We demonstrate the separation capabilities of these membranes by discrimination of dye and protein molecules based on their charge and size. This separation process is based on an electrostatic mechanism and operates in physiological electrolyte conditions. As we have also shown, the separation capabilities can be tuned by chemically modifying the pore walls. Compared with typical membranes with cylindrical pores, the conical and double-conical pores reported here allow for higher fluxes, a critical advantage in separation applications. In addition, the conical pore shape results in a shorter effective length, which gives advantages for single biomolecule detection applications such as nanopore-based DNA analysis.

Nanopore-based DNA analysis is a new single-molecule technique that involves monitoring the flow of ions through a narrow pore, and detecting changes in this flow as DNA molecules also pass through the pore. It has the potential to carry out a range of laboratory and medical DNA analyses, orders of magnitude faster than current methods. Initial experiments used a protein channel for its pre-defined, precise structure, but since then several approaches for the fabrication of solid-state pores have been developed. These aim to match the capabilities of biochannels, while also providing increased durability, control over pore geometry and compatibility with semiconductor and microfluidics fabrication techniques. This review summarizes each solid-state nanopore fabrication technique reported to date, and compares their advantages and disadvantages. Methods and applications for nanopore surface modification are also presented, followed by a discussion of approaches used to measure pore size, geometry and surface properties. The review concludes with an outlook on the future of solid-state nanopores.

Nanopore-based DNA analysis is a single-molecule technique with revolutionary potential. It promises to carry out a range of analyses, orders of magnitude faster than current methods, including length measurement, specific sequence detection, single-molecule dynamics and even sequencing. The concept involves using an applied voltage to drive DNA molecules through a narrow pore that separates chambers of electrolyte solution. This voltage also drives a flow of electrolyte ions through the pore, measured as an electric current. When molecules pass through the pore, they block the flow of ions and, thus, their structure and length can be determined based on the degree and duration of the resulting current reductions. In this review, I explain the nanopore-based DNA analysis concept and briefly explore its historical foundations, before discussing and summarizing all experimental results reported to date. I conclude with a summary of the obstacles that must be overcome for it to realize its promised potential.

Purpose - This paper seeks to investigate the role of information systems integration in Irish small and medium-sized enterprises operating in the manufacturing sector.Design methodology approach - Research was conducted through a review of literature and subsequent primary research involving qualitative (semi-structured interviews) and quantitative (questionnaires) research strategies.Findings - The paper reveals the sophistication of internal IT infrastructure within Irish manufacturing SMEs and whether the IT systems are integrated with one another, and, if so, how well that integration is done. Moreover, the owner-managers' and senior managers' attitude to IS integration issues is explored, including the reasons that prompt them to integrate IT systems within their businesses, their expectations of IS integration, the challenges they recognise when integrating the systems and their criteria regarding IS integration.Research limitations implications - The research focuses on manufacturing SMEs operating in Ireland; other sectors are not investigated.Practical implications - The paper helps the owner-managers and senior managers to understand the issues of IS integration and points towards possible solutions to the problem of disparate IT systems.Originality value - The negative impact of disparate systems and the benefits of integrating them in an SMEs environment have not been thoroughly examined to date.

A lesser-known cold-extrusion metal-forming technique, flowforming, makes seamless, near-net, complex, hollow metal parts. The process eliminates welds, which reduces the need for testing, and uses less energy than other manufacturing methods because it wastes less material. Flowforming is similar to metal spinning in that it forms metal against a hardened mandrel. Flowforming entails rotating and compressing the pre-form against the hardened mandrel. Metal is trapped between the mandrel and a set of two, three, or four forming wheels. The gap between the mandrel and wheels determines the finished-part thickness. Because flowforming is conducted at ambient temperatures, many materials \"cold work\" due to strain introduced to the metal during the process. Because the original specification may have been designed based on the starting material's attributes, strain hardening is not necessarily an asset. Fortunately, flowformed parts can be heat treated (fully annealed) to restore the material's original mechanical properties.

Concerning the very good analysis by Ian Cranstone, I support his conclusion that the two railway pictures were taken in Ottawa. My research was done in the C. Robert Craig Memorial Library, located in the City of Ottawa Archives building on Stanley Avenue. First, the lead article in the Canadian Rail's July/August 1966 issue, \"Ottawa Union station closes,\" by Omer Lavallee, contains a drawing entitled \"Grand Trunk Railway, Ottawa Terminals, 1911,\" which shows the track layout at that time.