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The circumstances leading to reactive chemicals accidents are often complex, but most of them could have been foreseen by the use of laboratory tests, hazard analysis and chemical reaction engineering techniques. A hazard evaluation and testing strategy that accomplishes these goals will be comprehensive and probably require significant investment of resources. It typically has the following key steps: • Initial hazards review of the process chemistry and unit operations • Identification of potential hazard scenarios • Assessment of the nature and extent of hazard scenarios • Development of prevention strategies • Development of protection strategies • Implementation of prevention and protection measures. Once a hazard has been identified and assessed as a credible threat to safe operation, most companies will take measures to mitigate the hazard. However, for small and mid-sized companies, the initial hazard identification and reactive chemicals assessment continues to be troublesome. This paper presents some specific tools to aid in completing these important first steps. They are straightforward to use and provide the information needed to enable a company to reliably determine and justify the need for further reactive chemical hazard testing. Introduction This paper advances the proposition that an initial chemical reactivity hazards assessment exists that can be performed by small/medium sized chemical manufacturing companies. Given the limited resources of most small and medium sized companies the scope of a chemical reactivity hazards assessment will be limited. The following limitations are proposed as reasonable for an initial review of the new or changed process: • First round assessment takes ≤1 day to complete • Initially no process hazards testing is done • Assessment can be done by trained chemical engineer • Most hazards, but not all, will be identified by the assessment • Conduct hazards testing if need demonstrated by initial assessment No hazard assessment procedure will catch 100% of all hazards present in a process. The intention of this approach is to identify the maximum number of serious potential hazards

I raise, and discuss qualitatively, some conceptual issues concerning the interface between the crystalline solid and superfluid liquid phases of 4He emphasizing, in particular, the fact that the ground-state wave functions of the two phases are prima facie qualitatively quite different, in that the superfluid liquid phase possesses off-diagonal long-range order (ODLRO), while the crystalline solid does not. The fact that the statics and dynamics of the interface do not appear to be particularly sensitive to the presence of ODLRO in the liquid is tentatively explained by the fact that because of a subtlety associated with the Bose statistics obeyed by the atoms, the solid and liquid wave functions are not locally very different.

The Eighth Eugene Feenberg Medal is awarded to Philippe Nozières in recognition of his many pathbreaking contributions to many-body theory, including • His definitive work on the properties of the free electron gas, in particular in the region of realistic metallic densities, • his rigorous development of the theory of a normal Fermi liquid, which provided a firm microscopic foundation for the Landau theory, • his analysis of the nonequilibrium thermodynamics of 3-He solid-liquid mixtures, • his exact solution to the X-ray edge problem, • his elegant formulation of the low-temperature solution to the single-channel Kondo problem in the language of Fermi-liquid theory, • his introduction of the many-channel problem as a new class of quantum impurity systems, and • his innovative work on the static and dynamic behavior of the liquid-solid interface.

The basic principles behind friction force microscopy are described. Applications of friction force microscopy to self-assembled monolayers are reviewed. Work in the author’s laboratory on the frictional properties of self-assembled monolayers is described, and the findings applied in the characterisation of a much more complex material, plasma-treated polyester. Friction force microscopy is found to be a powerful tool for the analysis of the chemical composition and molecular organisation of molecular materials at the nanometre scale.

For a harmonically trapped dilute Bose gas with uniformly repulsive interactions which is assumed to satisfy a certain condition on the extensivity of fluctuations, I find on upper bound on the condensate fraction f. If BEC is defined by the condition that f>const.N−α, α

Nanolithography of self-assembled monolayers (SAMs) has been performed by the new technique of scanning near-field photolithography (SNP). Patterns of parallel lines written by SNP have subsequently either been used to generate compositional chemical patterns or been transferred into the underlying substrate by wet etch techniques. Lateral force microscopy (LFM) and atomic force microscopy (AFM) analysis has indicated that the line width of both compositional chemical patterns in SAMs and structures in gold is limited only by the aperture of the fiber tip used to deliver UV light. Features only 55 ± 5 nm wide have been etched into gold films using this method.

Water is a precious and limited resource. The demand for water is projected to increase in the future while the supply may be adversely affected by global factors such as climate change. This results in an increasing need to use water more wisely. The Government and the water industry are encouraging the adoption of water conservation measures. One component of these water conservation measures, among many others, is to use rainwater and greywater (water from sinks, baths and showers) as a source of water to reduce water consumption. This paper provides an outline of the main considerations for the use of rainwater or greywater, identifying its contribution to sustainable water management and discusses the issues that need to be overcome to encourage the wider uptake of the technology. The matters outlined in this paper are expanded upon in a series of reports available from CIRIA.

I present the motivation for experiments which attempt to generate, and verify the existence of, quantum superpositions of two or more states which are by some reasonable criterion `macroscopically' distinct, and show that various a priori objections to this programme made in the literature are flawed. I review the extent to which such experiments currently exist in the areas of free-space molecular diffraction, magnetic biomolecules, quantum optics and Josephson devices, and sketch possible future lines of development of the programme.

Contact mode scanning force microscopy (SFM) has been employed to induce wear in a controlled fashion on thin plasma polymerized hexane (ppHex) films. Such thin films are not readily amenable to characterization techniques such as nanoindentation, whereas the information from the outer surface that SFM provides in wear mode is ideally suited to the examination of these thin films. Nanowear of viscous ppHex films takes the form of grooves at the edges and accumulation of material in the center of the scanned area, whereas films with higher cross link density show damage uniformly across the worn area. A parameter termed the critical load is developed to enable a comparative investigation of deposits in and downstream of the plasma. Here, the critical load is defined as the load necessary to introduce a change in the topography of the scanned area in comparison to the surroundings. Films collected downstream of the plasma show viscous behavior and have a relatively low critical load independent of the depos...

I review three sets of experiments conducted in the last decade, in which superfluid 3He was irradiated with high-energy particles and the nucleation either of vorticity or of the A–B phase transition reported. I consider how far the known atomic physics constrains possible scenarios for such nucleation, and comment on two such scenarios which have appeared in the literature, namely the “baked-Alaska” and “cosmological” (Kibble–Zurek–Volovik) models. I point out that there is a fundamental difference between the problems of nucleation of vorticity on the one hand and the B phase on the other: and that as a result, it is by no means necessary that the same scenario should describe both phenomena. In an appendix I discuss possible sinks of energy in the calorimetric (Grenoble–Lancaster) experiment, with the conclusion that it is entirely consistent with the data to assume that no vorticity at all was produced in this experiment.

Starting in 1982, the federal credit union regulator allowed credit unions to add multiple membership groups. The policy was disallowed by the U.S. Supreme Court in 1998, but revalidated by the U.S. Congress later that year. Allowing credit unions to attach multiple membership groups has contributed significantly to rapid growth in the industry. As credit unions add unrelated groups and expand, the prospects for separation between ownership and control increases, creating potential agency control problems. This potential is compounded by the one member, one vote governance structure of credit unions. This research finds empirical evidence that agency problems grow as credit unions add membership groups and members. If a credit union takes on more than one membership group, and as membership increases, management is apparently able to channel residual earnings away from members (in the form of higher net interest margins) toward itself (higher salaries and operating expenses).

Nanoindentation and SFM tip-induced wear (nanotribology) have shown clear differences in the mechanical properties of plasma-polymerised coatings when compared to conventional thermoplastics. Plasma polymers deposited in-plasma are much harder, stiffer and wear resistant than conventional polymers. Plasma polymers deposited downstream at low plasma power exhibit viscous behaviour. They are susceptible to nanowear and the resulting morphology of the worn region is completely different to what is observed on conventional polymers such as poly(ethylene terephthalate) and polystyrene.

Nanoindentation and nanoscratch testing have revealed large differences in nanomechanical behaviour on uniaxially and biaxially drawn poly(ethylene terephthalate) films. Differences can be ascribed to the processing history of the film. The biaxial material exhibited significantly higher hardness and elastic modulus than the uniaxial film, presumably due to increased crystallinity from the second draw. The biaxially drawn material was also less susceptible to creep deformation. The plasticity index, the ratio of the dissipated energy to the total indentation energy, was greater on the uniaxial film, indicating that it exhibits less plastic deformation than the biaxially stretched film. The differences in processing also affected the resistance of the films to nanoscratching wear. The wear resistance of the films correlated with the ratio of the hardness to the modulus.

In order to achieve high local biological activity and reduce the risk of side effects of antibiotics in the treatment of periodontal and bone infections, a localised and temporally controlled delivery system is desirable. The aim of this research was to develop a functionalised and resorbable surface to contact soft tissues to improve the antibacterial behaviour during the first week after its implantation in the treatment of periodontal and bone infections. Solvent-cast poly(d,l-lactide-co-glycolide acid) (PLGA) films were aminolysed and then modified by Layer-by-Layer technique to obtain a nano-layered coating using poly(sodium4-styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) as polyelectrolytes. The water-soluble antibiotic, metronidazole (MET), was incorporated from the ninth layer. Infrared spectroscopy showed that the PSS and PAH absorption bands increased with the layer number. The contact angle values had a regular alternate behaviour from the ninth layer. X-ray Photoelectron Spectroscopy evidenced two distinct peaks, N1s and S2p, indicating PAH and PSS had been introduced. Atomic Force Microscopy showed the presence of polyelectrolytes on the surface with a measured roughness about 10nm after 20 layers' deposition. The drug release was monitored by Ultraviolet-visible spectroscopy showing 80% loaded-drug delivery in 14 days. Finally, the biocompatibility was evaluated in vitro with L929 mouse fibroblasts and the antibacterial properties were demonstrated successfully against the keystone periodontal bacteria Porphyromonas gingivalis, which has an influence on implant failure, without compromising in vitro biocompatibility. In this study, PLGA was successfully modified to obtain a localised and temporally controlled drug delivery system, demonstrating the potential value of LbL as a coating technology for the manufacture of medical devices with advanced functional properties.

We describe a fast, simple method for the fabrication of reusable, robust gold nanostructures over macroscopic (cm(2)) areas. A wide range of nanostructure morphologies is accessible in a combinatorial fashion. Self-assembled monolayers of alkylthiolates on chromium-primed polycrystalline gold films are patterned using a Lloyd's mirror interferometer and etched using mercaptoethylamine in ethanol in a rapid process that does not require access to clean-room facilities. The use of a Cr adhesion layer facilitates the cleaning of specimens by immersion in piranha solution, enabling their repeated reuse without significant change in their absorbance spectra over two years. A library of 200 different nanostructures was prepared and found to exhibit a range of optical behavior. Annealing yielded structures with a uniformly high degree of crystallinity that exhibited strong plasmon bands. Using a combinatorial approach, correlations were established between the preannealing morphologies (determined by the fabrication conditions) and the postannealing optical properties that enabled specimens to be prepared "to order" with a selected localized surface plasmon resonance. The refractive index sensitivity of gold nanostructures formed in this way was found to correlate closely with measurements reported for structures fabricated by other methods. Strong enhancements were observed in the Raman spectra of tetra-tert-butyl-substituted phthalocyanine. The shift in the position of the plasmon band after site-specific attachment of histidine-tagged green fluorescent protein (His-GFP) and bacteriochlorophyll a was measured for a range of nanostructured films, enabling the rapid identification of the one that yielded the largest shift. This approach offers a simple route to the production of durable, reusable, macroscopic arrays of gold nanostructures with precisely controllable morphologies.

Photosynthesis converts absorbed solar energy to a protonmotive force, which drives ATP synthesis. The membrane network of chlorophyll–protein complexes responsible for light absorption, photochemistry and quinol (QH2) production has been mapped in the purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides using atomic force microscopy (AFM), but the membrane location of the cytochrome bc1 (cytbc1) complexes that oxidise QH2 to quinone (Q) to generate a protonmotive force is unknown. We labelled cytbc1 complexes with gold nanobeads, each attached by a Histidine10 (His10)-tag to the C-terminus of cytc1. Electron microscopy (EM) of negatively stained chromatophore vesicles showed that the majority of the cytbc1 complexes occur as dimers in the membrane. The cytbc1 complexes appeared to be adjacent to reaction centre light-harvesting 1-PufX (RC–LH1–PufX) complexes, consistent with AFM topographs of a gold-labelled membrane. His-tagged cytbc1 complexes were retrieved from chromatophores partially solubilised by detergent; RC–LH1–PufX complexes tended to co-purify with cytbc1 whereas LH2 complexes became detached, consistent with clusters of cytbc1 complexes close to RC–LH1–PufX arrays, but not with a fixed, stoichiometric cytbc1–RC–LH1–PufX supercomplex. This information was combined with a quantitative mass spectrometry (MS) analysis of the RC, cytbc1, ATP synthase, cytaa3 and cytcbb3 membrane protein complexes, to construct an atomic-level model of a chromatophore vesicle comprising 67 LH2 complexes, 11 LH1–RC–PufX dimers & 2 RC–LH1–PufX monomers, 4 cytbc1 dimers and 2 ATP synthases. Simulation of the interconnected energy, electron and proton transfer processes showed a half-maximal ATP turnover rate for a light intensity equivalent to only 1% of bright sunlight. Thus, the photosystem architecture of the chromatophore is optimised for growth at low light intensities.

A new cysteine-based methacrylic monomer (CysMA) was conveniently synthesized via selective thia-Michael addition of a commercially available methacrylate-acrylate precursor in aqueous solution without recourse to protecting group chemistry. Poly(cysteine methacrylate) (PCysMA) brushes were grown from the surface of silicon wafers by atom-transfer radical polymerization. Brush thicknesses of ca. 27 nm were achieved within 270 min at 20 °C. Each CysMA residue comprises a primary amine and a carboxylic acid. Surface zeta potential and atomic force microscopy (AFM) studies of the pH-responsive PCysMA brushes confirm that they are highly extended either below pH 2 or above pH 9.5, since they possess either cationic or anionic character, respectively. At intermediate pH, PCysMA brushes are zwitterionic. At physiological pH, they exhibit excellent resistance to biofouling and negligible cytotoxicity. PCysMA brushes undergo photodegradation: AFM topographical imaging indicates significant mass loss from the brush layer, while XPS studies confirm that exposure to UV radiation produces surface aldehyde sites that can be subsequently derivatized with amines. UV exposure using a photomask yielded sharp, well-defined micropatterned PCysMA brushes functionalized with aldehyde groups that enable conjugation to green fluorescent protein (GFP). Nanopatterned PCysMA brushes were obtained using interference lithography, and confocal microscopy again confirmed the selective conjugation of GFP. Finally, PCysMA undergoes complex base-catalyzed degradation in alkaline solution, leading to the elimination of several small molecules. However, good long-term chemical stability was observed when PCysMA brushes were immersed in aqueous solution at physiological pH.

High sensitivity and spectral resolution XPS, polarisation-modulation reflection FTIR and static SIMS have been used in this investigation of the interfacial chemistry between poly(acrylic acid) (PAA) and an aluminium oxyhydroxide surface. The pseudoboehmite oxyhydroxide surface is used as a model for the chemistry found at the surface of the air-formed film after ambient exposure of aluminium metal. Conversion of carboxylic acids to monodentate carboxylate species at the PAA–AlOOH interface has been identified using reflection absorption FTIR. By virtue of the very low concentration of surface carbon on hydrothermally formed AlOOH, quantification of the interfacial carboxylate concentration was achieved by curve fitting the C1s core level. Through analysis of a range of PAA overlayer thicknesses, a limit to interfacial carboxylate formation with the surface was identified. To determine the reason for this limit, monoacids that chemisorb to the AlOOH surface exclusively through carboxylate bonds were analysed. It is proposed that steric and/or conformational hindrance, associated with the polymer backbone, prevent reaction of all carboxylic acid groups in PAA with surface hydroxyl functionalities to form carboxylate complexes. The implications of this finding for the application of PAA as an adhesion promotion pretreatment are considered.

Repeated scanning of biaxially oriented poly(ethylene terephthalate) (PET) film surfaces in contact mode scanning force microscopy leads to sample wear. At low to moderate loads (

The author presents a tutorial review of some ideas that are basic to our current understanding of the phenomenon of Bose-Einstein condensation (BEC) in the dilute atomic alkali gases, with special emphasis on the case of two or more coexisting hyperfine species. Topics covered include the definition of and conditions for BEC in an interacting system, the replacement of the true interatomic potential by a zero-range pseudopotential, the time-independent and time-dependent Gross-Pitaevskii equations, superfluidity and rotational properties, the Josephson effect and related phenomena, and the Bogoliubov approximation.

Scanning force microscopy has been used to characterize the surface structure and properties of poly(ethylene terephthalate) (PET) films. Two types of biaxially oriented film have been studied: one (Melinex O) is free of additives while the other (Mylar D) contains particulate additives at the surface. Contact mode characterization of both materials provide clear images of the polymer surface and (in the case of Mylar D) the additives. Phase images reveal substantial nanoscale morphological detail, including small features thought to be crystallites. To model the adhesive properties of polymer surfaces, mixed self-assembled monolayers containing polar and methyl terminated adsorbates were studied using chemical force microscopy. It was found that the strength of the tip-sample adhesion increased with the fraction of polar terminated adsorbates at the surface when a carboxylic acid terminated tip was employed, while the trend was reversed when a methyl terminated tip was used. Adhesion forces measured for plasma treated PET increased with treatment time, and linearly with the cosine of the water contact angle, illustrating the chemical selectivity of chemical force microscopy. However, friction forces were found to vary in a non-linear fashion, indicating that changes to the polymer surface mechanical properties following treatment were important.

A thorough, in-depth understanding of the reactive nature of chemical processing operations is the first step to accomplishing the reduction of risks of these operations to a tolerable level. This understanding may be obtained through a laboratory evaluation using recognized and accepted process safety testing technologies as well as the conventional process hazards analysis. A systematic process safety testing program characterizes the reactive nature of both the desired and undesired chemistry. These data are needed to define the critical limits of temperature, pressure, power output, concentration, and dosing rates of processes involving reactive chemicals. The minimum basic data are the variation of energy (or power), temperature and pressure as a function of time, and reaction mass composition. The realistic use of these data requires an understanding of both the limitations of some laboratory data for scale-up and acceptable safety margins for industrial size operations. This paper will briefly review the current regulatory environment for chemical process safety, describe the integration of various calorimetric test techniques, and illustrate the use of data from isothermal differential scanning, and adiabatic calorimetry for improving process safety. An example, taken from the investigation of an accident involving the reaction between an amine and chlorine-substituted derivative, demonstrates the use of calorimetric data in understanding the origin and progress of the accident. Suggestions for how to improve process safety, based on the calorimetric information are also presented.

Scanning force microscopy has been used in contact mode to induce wear of thin plasma polymerised hexane (ppHex) films. The extent of wear observed can be used to qualitatively assess the mechanical properties of such thin films. The wear-resistance of the ppHex films varies greatly with the deposition power. They are harder than conventional polymers when deposited at high power and considerably softer when deposited at low power. On continued scanning, the morphology of the ppHex films is modified, leading to the formation of two parallel ridges that gradually merge into one larger central ridge. This behaviour differs significantly from that observed on tip-induced wear of conventional polymer films where patterns of many ridges and troughs often form. Tip-induced wear was more extensive at higher applied load, lower scan rate and at higher scan line densities. The scan speed dependence is different from that observed for conventional polymers, and may be explained in terms of the viscoelastic behaviour of the materials.

Friction force measurements have been made using friction force microscopy for a series of self-assembled monolayers (SAMs) of alkanethiols of varying chain lengths and terminal groups adsorbed on gold. The chemistry of the tip was controlled by the deposition of a SAM. When carboxylic acid terminated tips were employed, the friction coefficients of hydroxyl and carboxylic acid terminated SAMs were found to be greater than those of methyl terminated SAMs. However, although the friction coefficients of short-chain methyl terminated SAMs were significantly greater than those of long-chain methyl terminated SAMs, there was not a significant difference between the values determined for short- and long-chain SAMs with polar terminal groups. When methyl terminated tips were employed, there was no difference between the behavior observed for hydroxyl and carboxylic acid terminated SAMs of equal chain length, but methyl terminated SAMs exhibited increased friction coefficients which were larger for short-chain ad...

The Eighth Eugene Feenberg Medal is awarded to Philippe Nozieres in recognition of his many pathbreaking contributions to many-body theory, including• His definitive work on the properties of the free electron gas, in particular in the region of realistic metallic densities,• his rigorous development of the theory of a normal Fermi liquid, which provided a firm microscopic foundation for the Landau theory,• his analysis of the nonequilibrium thermodynamics of 3-He solid-liquid mixtures,• his exact solution to the X-ray edge problem,• his elegant formulation of the low-temperature solution to the single-channel Kondo problem in the language of Fermi-liquid theory,• his introduction of the many-channel problem as a new class of quantum impurity systems, and• his innovative work on the static and dynamic behavior of the liquid-solid interface.

A 25-year-old male was admitted to the Accident and Emergency department with a history of a deliberate ingestion of 150–200 ml of 20% Gramaxone (paraquat) solution. Patient’s written informed consent was obtained on admission. Initial qualitative testing of vomitus and urine were strongly positive for paraquat. Activated charcoal therapy was commenced and initial arterial blood gas analysis showed pH 7.30, PaO2 12 kPa, PaCO2 5.0 kPa and base excess −3.9. Paraquat levels were 1.4 µg/ml at 4.5-h post-ingestion and 0.3 µg/ml at 16 h. These levels confirmed that a potentially lethal dose of paraquat had been consumed.1 The patient’s renal function began to deteriorate and he was transferred to the intensive care unit and commenced on continuous renal replacement therapy. The following intravenous treatment regimes were initiated: ascorbic acid 1 g every 6 h; n -acetylycysteine 1200 mg daily; methylprednisolone 1 g daily for 3 days and dexamethasone 8 mg every 8 h.2,3 On day 2 of admission to intensive care, intravenous cyclophosphamide 1 g daily for 2 days and α-tocopherol (vitamin E) were added.2,3 Unfortunately, despite these interventions, the patient’s condition …

These lectures address Bose and Fermi ultracold dilute alkali gases. For Bose gases I discuss general BEC concepts, superfluidity, the Josephson effect, and issues related to the establishment of a "phase standard". For Fermi gases I discuss prospects for Cooper pairing and its detection. The four lectures on alkali Bose gases which I actually gave at the School were based on a review paper in preparation for Reviews of Modern Physics. In order to avoid extensive duplication of the contents of that review, what I present here, condensed into three lectures, is a melange of informal commentary on the results presented there and some material which for space and other reasons had to be omitted. This material is ideally read in conjunction with the review. The fourth lecture, on the Fermi alkali gases, is presented here in (nearly) the form in which it was actually given.

Whilst beach-profile surveying is a relatively long-established and widely utilised shoreline monitoring technique, a considerable gap exists between theoretical and practical requirements from, and uses of, beach-profile data. The paper bridges this gap by providing a summary of the key elements of beach-profile measurement, theory and analysis. The benefits of applying these elements to practical coastal management are given in three case studies. The first case study presents results from beach-profile analysis on a regional scale in East Anglia. The second case study applies both analytical and theoretical techniques to investigate erosional problems along a coastal bay in Jersey. The third case study assesses the performance of two major sand-replenishment schemes in Poole Bay (on the south coast of England) based upon beach-profile volumetric analyses. Most importantly, the paper demonstrates that beach-profile measurement, theory and analysis can provide information of practical use in coastal management.

Bulk-filled uniaxially oriented poly(ethylene terephthalate) film surfaces have been investigated by scanning force microscopy. Comparison with additive-free films shows that the addition of filler particles during manufacture increases the final surface roughness of the films. Filler particles at or near the surface are accompanied by deep depressions aligned in the direction of draw. Raised plate-like features oriented diagonally to the draw direction are present on all the films. Lateral Force Microscopy shows that this overlayer region is of lower friction and phase imaging shows that it is of higher phase shift than the surrounding polymer. The observations imply that the raised material is more crystalline than the surrounding background.

In attempted transamination reactions involving [Al2(NMe2)6] and the amines, N,N′-dimethylethylenediamine, DMEDA, or diethylenetriamine, DETA, insoluble white powders were formed. Two unexpected compounds, trinuclear [AlCl(MeNCH2CH2NMe)2(Al(NMe2)Cl)(Al(NMe2)2)] (1) and adamantane-like [Al4Cl2(NMe2)6(NMe)O] (2) were isolated in similar reactions where the aluminium amide sample [Al2(NMe2)6] contained some 1% residual chloride. Compound 2 was also identified (by NMR and mass spectroscopy) as the major product from the reaction between Al2Cl6 and LiNMe2 (1:5) in the presence of traces of water. The compounds 1 and 2 have been characterized by X-ray crystallography, mass spectroscopy and NMR. Variable temperature solution phase proton NMR shows that there is inversion at nitrogen in the bridging amides in adamantanoid structure 2.

Murine 3T3 fibroblasts and primary human osteoblasts have been cultured on self-assembled monolayers (SAMs) formed by the adsorption of alkanethiols of varying terminal group and alkyl chain length on gold. It has been found that the interactions of both cell types with SAMs are influenced by surprisingly subtle changes in adsorbate structure. Both the nature of the adsorbate terminal group and the length of the alkyl chain have a significant influence on cellular attachment and growth. For both cell types, attachment and growth on the carboxylic acid terminated SAMs was extensive and was accompanied by a high degree of cell spreading. In contrast, attachment and growth on long-chain methyl terminated SAMs were poor. Attachment and growth on short-chain methyl terminated SAMs were intermediate, with reasonable numbers of attached cells being observed and some degree of cell spreading. Sharply contrasting behaviour was observed for the two cell types when cultured on hydroxy terminated SAMs. It was found that fibroblasts attached poorly to these surfaces, while osteoblasts attached and grew nearly as successfully on short-chain hydroxy terminated SAMs as on carboxylic acid terminated SAMs. Osteoblasts attached less well to long-chain hydroxy terminated SAMs, but better than to methyl terminated SAMs.

This paper discusses four different chemical processing accidents that resulted from plant mal-operations. Each incident was relatively minor yet provided valuable information about the stability and/or vulnerability of the process to upset conditions. The reaction classes involved were: Polyester polymerization Secondary amine formation followed by decomposition Oxidation of poly-alkylated aromatic hydrocarbon Base catalyzed oligomerization The paper describes the ‘after-the-fact’ data that was obtained by calorimetric hazards testing. We will discuss how the information was used, in each case to improve the process safety of the particular operation. We also describe an incident database that may be used by chemical companies to provide an on-going ranked and categorized record of accidents and incidents that have occurred. The value of the database information lies in the fact that the actual and potential severity of each accident is estimated from the data of the incident events. This information can be used to distinguish processes that may be responsible for the majority of the minor incidents from those processes where more severe, but infrequent, accidents occur. The information is also valuable in providing a focus with which to drive process safety improvement efforts.

Compositional mapping of a polyester film surface, Mylar D, was performed utilizing a combination of scanning force microscopy techniques. Lateral force microscopy revealed that additives embedded in the surface had a lower coefficient of friction than the surrounding polymeric material. Force-volume imaging showed that they were less adhesive. Tapping mode and phase imaging revealed that the additives affect the local microstructure of the polymer surface. Their presence directs the orientation in the surrounding polymer; the small features (possibly crystallites) at the polymer surface are oriented virtually parallel to the nearest edge of the silicate inclusions. Force modulation microscopy and phase imaging at moderate tapping both show that the additives are stiffer than the surrounding polymer regions.

The frictional properties of heterogeneous organic materials have been investigated by atomic force microscopy. There is a good correlation between measurements of the friction coefficient in air and the cosines of the advancing water contact angles for mixed self-assembled monolayers composed of polar and nonpolar groups. The friction force is proportional to the surface free energy for these chemically heterogeneous materials. For mixed monolayers containing short and long chain thiols with methyl terminal groups there is a large increase in friction, attributed to alkyl chain disorder rather than a surface energy effect. There is a nonlinear relation between friction coefficient measurements in air and the cosines of the advancing water contact angles on plasma-treated polyester films. This is thought to reflect a contribution from the changed mechanical properties of the plasma-treated film surface in addition to the observed surface energy increase on these more complex materials.

The eastern end of the Jubilee Line Extension comes out of the ground at Canning Town and runs for 3·5 km at ground level to Stratford via West Ham. The extremely confined route meant that the engineering challenges on the at-grade section were no less than those on the tunnelled sections. The construction meant closing the North London line for a year while it was rebuilt alongside the extension and literally sliding a 25001 elevated platform in between two live railways at Canning Town. This paper discusses the complex advance works required throughout the route and then focuses on the design and construction of Canning Town station.

Contact mode imaging of plasma-treated poly(ethylene terephthalate) films using bare silicon nitride tips yields poor image resolution because of tip-induced disruption of the surface structure. Deposition of a hydrophobic self-assembled monolayer onto the tip enables the minimisation of the interfacial free energy of the tip-sample contact, with such good effect that images are obtained in contact mode with comparable resolution to that observed in tapping mode. Control of tip chemistry therefore presents an important strategy for the imaging of delicate polymer structures by scanning force microscopy.

Human keratinocytes were cultured on plasma copolymers (PCPs), self-assembled monolayers (SAMs), and tissue culture poly(styrene) (TCPS). Plasma copolymerization was used to deposit films with controlled concentrations of carboxylic acid functional groups (

Credit unions are cooperatively owned financial institutions, where input suppliers (savers) are also the consumers of the outputs (borrowers). A key issue is the allocation of benefits between savers and borrowers. Additionally, credit unions can add unrelated groups to their membership. If the orientation of unrelated groups differs from the core group, the allocation of benefits could be altered. Empirical evidence suggests that both single and multiple bond federal credit unions are saver oriented. Single bond credit unions have a stronger saver orientation than multiple bond credit unions. The study provides mixed evidence on the existence of a clientele effect.

This paper presents quantitative evidence for the effectiveness of a meso- to macro-tidal open coast salt marsh in attenuating incoming waves over a range of tidal and meteorological conditions. Field measurements of wind waves at three locations on a sand flat to salt marsh cross-shore transect showed that wave energy dissipation rates over the salt marsh were significantly higher (at an average of 82%) than over the sand flat (at an average of 29%). The difference in water depth between the sand flat and salt marsh sections of the transect was not sufficient to account for the difference in wave attenuation, indicating that an increase in surface friction is the primary reason for increased wave attenuation over the salt marsh. Comparison of the field results with a numerical model based on theoretical wave energy dissipation suggests that surface friction factors of the order of ≤0·4 are responsible for the high values of wave attenuation over the salt marsh. The results provide empirical support, both for maintaining salt marshes in front of existing sea defence lines and for creating new salt marsh as part of coastal set-back/shoreline realignment schemes.

The ground state of a rotating Bose-Einstein condensate with attractive interaction in a quasi-one-dimensional torus is studied in terms of the ratio $\gamma$ of the mean-field interaction energy per particle to the single-particle energy-level spacing. The plateaus of quantized circulation are found to appear if and only if $\gamma, Comment: 4 pages, 2 figures, Accepted for publication in Physical Reveiw Letters

I conjecture that the mechanism of superconductivity in the cuprates is a saving, due to the improved screening resulting from Cooper pair formation, of the part of the Coulomb energy associated with long wavelengths and midinfrared frequencies. This scenario is shown to provide a plausible explanation of the trend of transition temperature with layering structure in the Ca-spaced compounds and to predict a spectacularly large decrease in the electron-energy-loss spectroscopy cross-section in the midinfrared region on transition to the superconducting state, as well as less spectacular but still surprisingly large changes in the optical behavior. Existing experimental results appear to be consistent with this picture.

Without relying on any ``model'' of the in-plane behavior of the electrons in either the normal or the superconducting state, I show that for identically doped members of the same homologous series, as a result of the interplane Coulomb interaction, the difference $\ensuremath{\Delta}{T}_{c}^{(n)}$ of the transition temperature for the $n$th member from the single-layer value is given by $\ensuremath{\Delta}{T}_{c}^{(n)}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{const}\ifmmode\times\else\texttimes\fi{}(1\ensuremath{-}1/n)$. On taking the constant from experiment, I predict large changes in the electron-energy-loss spectroscopy and optical properties in the midinfrared regime on entering the superconducting state, and further infer that the basic mechanism of superconductivity in the cuprates has a large contribution from the small- $q$ regime.