Production of electronics and photovoltaics using a reel-to-reel process

Reel to reel manufacturing is a mature technology that involves the passing of a flexible substrate or web continuously through one or more processes. The web is typically much longer than it is wide, and the width in turn is much greater than its thickness. It is a continuous process that results in high output at a low unit cost when compared with other production methods. Historically this has included newspaper printing and textile manufacture, but more recent research is being conducted in developing printed electronics, such as solar cells (Organic Photo-Voltaic or OPV), and wearable tech and flexible screens (Polymer LEDs or PLEDs). These devices consist of up to five layers, with a separate printing or coating process needed for each. Greater accuracy is necessary than for traditional industries and advances are required in three areas: control of the web; measurement and registration of the printed web; and flexible semi-conductor materials. In this paper we present a new methodology to improve printing accuracy by combining an advanced metrology system with an innovative process design

Predicting the effects of sand erosion on collector surfaces in CSP plants

This paper presents a methodology to predict the optical performance and physical topography of the glass collector surfaces of any given CSP plant in the presence of sand and dust storms, providing that local climate conditions are known and representative sand and dust particles samples are available. Using existing meteorological data for a defined CSP plant in Egypt, plus sand and dust samples from two desert locations in Libya, we describe how to derive air speed, duration, and sand concentrations to use within the Global CSP Laboratory sand erosion simulation rig at Cranfield University. This then allows us to predict the optical performance of parabolic trough collector glass after an extended period by the use of accelerated ageing. However the behavior of particles in sandstorms is complex and has prompted a theoretical analysis of sand particle dynamics which is also described in this paper

Photogrammetry for concentrating solar collector form measurement, validated using a coordinate measuring machine

Concentrating solar power systems currently have a high capital cost when compared with other energy generating systems. The solar energy is captured in the form of thermal energy rather than direct electrical, which is attractive as thermal energy is more straightforward and currently more cost-effective to store in the amounts required for extended plant operation. It is also used directly as industrial process heat, including desalination and water purification. For the technology to compete against other generating systems, it is crucial to reduce the electrical energy cost to less than $0.10 per kilowatt-hour. One of the significant capital costs is the solar field, which contains the concentrators. Novel constructions and improvements to the durability and lifetime of the concentrators are required to reduce the cost of this field. This paper describes the development and validation of an inexpensive, highly portable photogrammetry technique, which has been used to measure the shape of large mirror facets for solar collectors. The accuracy of the technique has been validated to show a whole surface measurement capability of better than 100 mm using a large coordinate measuring machine. Qualification of facets of the MATS plant was performed during its installation phase, giving results of the shape, slope and intercept errors over each facet

Grinding processes and their effects on surface integrity

The introduction of high performance grinding machines in combination with the latest superabrasive technology has the potential to impact significantly on existing process chains. The aim of the research was to look at both the high and low rate removal grinding processes and their effects on the surface integrity, as a means to exploit the above technologies. A major objective was to determine the feasibility of High Efficiency Deep Grinding (HEDG) in cylindrical plunge grinding. HEDG is a high speed removal process which differs from conventional forms of grinding in that it uses large depths of cut together with high feedrates. Together, these changes affect the thermal energy partitioning within the work zone. Through this work an understanding of the process conditions enabled the development of this process, such that prevention of thermal damage to the finished workpiece surface is achievable. At the opposite extreme to the high material removal rates of HEDG, kvdrk was carried out in the high precision finish grinding regime. Developments *ere undertaken to look at the implementation of a modified path into the normal cylindrical plunge grinding action, in a process referred to as Superfinish Grinding. The aim of this process being to demonstrate an improvement to the surface texture primarily through a reduction in grinding directionality. Surface integrity is an important consideration in the development of any grinding process. Damage as a result of grinding is predominately of a thermal nature and results in changes to the material properties in the near surface region. One such change is the residual stress, which was measured using Barkhausen Noise intensity instrumentation, which provided a reliable early indication to a build up in thermal energy. Developments in thermal modelling supported by temperature measurements provided a better understanding of the HEDG regime. The model employed new energy partitioning theories together with circular arc modelling of conditions along the contact length. A model was derived to predict the surface finish produced with the Superfinish Grinding approach, this again provided an increased understanding of the grinding process. Industrial trials have shown how HEDG can be implemented on standard production machine tools for the cylindrical plunge grinding of crankshaft components. The process demonstrated the potential for improved surface integrity, whilst maintaining surface finish and form accuracy. The same grinding machine was also used to generate high quality surfaces using a Superfinish Grinding process. Roughness values of the order of 0.11um RQ were routinely obtained exhibiting reduced levels of grinding directionality. Thus, using a single machine tool and a single set-up, exceptionally high stock removal rates are achievable in a roughing cycle followed by superfinishing to generate the required surface characteristics and profile.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The evaluation of renal ischaemic damage: the value of CD10 monoclonal antibody staining and of biochemical assessments of tissue viability

<p>Abstract</p> <p>Background</p> <p>It is well recognised that there is often a disparity between the structural changes observed in the kidney following renal injury and the function of the organ. For this reason, we carried out studies to explore possible means of studying and quantifying the severity of renal ischaemic damage using a laboratory model.</p> <p>Methods</p> <p>To do this, freshly isolated rabbit kidney tissue was subjected to warm (37°C) or cold (1°C) ischaemia for 20 hours. Following this, the tissue was stained using Haematoxylin and Eosin (H+E), Periodic Schiff reagent (PAS) and the novel monoclonal antibody CD10 stain. Additionally, ischaemic damage to the kidneys was assessed by biochemical tests of tissue viability using formazan-based colorimetry.</p> <p>Results</p> <p>CD 10 antibody intensely stained the brush border of control kidney tissue with mild or no cytoplasmic staining. Cell injury was accompanied by a redistribution of CD10 into the lumen and cell cytoplasm. There was good correlation between a score of histological damage using the CD 10 monoclonal antibody stain and the biochemical assessment of viability. Similarly, a score of histological damage using traditional PAS staining correlated well with that using the CD10 antibody stain.</p> <p>In particular, the biochemical assay and the monoclonal antibody staining techniques were able to demonstrate the efficacy of Soltran (this solution is used cold to preserve freshly isolated human kidneys prior to transplantation) in preserving renal tissue at cold temperatures compared to other randomly selected solutions.</p> <p>Conclusion</p> <p>We conclude that the techniques described using the CD10 monoclonal antibody stain may be helpful in the diagnosis and assessment of ischaemic renal damage. In addition, biochemical tests of viability may have an important role in routine histopathological work by giving additional information about cellular viability which may have implications on the function of the organ.</p

Single Hit Energy-resolved Laue Diffraction

In-situ white light Laue diffraction has been successfully used to interrogate the structure of single crystal materials undergoing rapid (nanosecond) dynamic compression up to megabar pressures. However, information on strain state accessible via this technique is limited, reducing its applicability for a range of applications. We present an extension to the existing Laue diffraction platform in which we record the photon energy of a subset of diffraction peaks. This allows for a measurement of the longitudinal and transverse strains in-situ during compression. Consequently, we demonstrate measurement of volumetric compression of the unit cell, in addition to the limited aspect ratio information accessible in conventional white light Laue. We present preliminary results for silicon, where only an elastic strain is observed. VISAR measurements show the presence of a two wave structure and measurements show that material downstream of the second wave does not contribute to the observed diffraction peaks, supporting the idea that this material may be highly disordered, or has undergone large scale rotation

Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy

Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA), resulting from low levels of ubiquitously-expressed survival motor neuron (SMN) protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant), gastrocnemius (intermediate vulnerability), and tibialis anterior (vulnerable) muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1), was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1), rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo

Functional Analysis of the Cathepsin-Like Cysteine Protease Genes in Adult Brugia malayi Using RNA Interference

Filarial nematodes are an important group of human pathogens, causing lymphatic filariasis and onchocerciasis, and infecting around 150 million people throughout the tropics with more than 1.5 billion at risk of infection. Control of filariasis currently relies on mass drug administration (MDA) programs using drugs which principally target the microfilarial life-cycle stage. These control programs are facing major challenges, including the absence of a drug with macrofilaricidal or permanent sterilizing activity, and the possibility of the development of drug-resistance against the drugs available. Cysteine proteases are essential enzymes which play important roles in a wide range of cellular processes, and the cathepsin-like cysteine proteases have been identified as potential targets for drug or vaccine development in many parasites. Here we have studied the function of several of the cathepsin-like enzymes in the filarial nematode, B. malayi, and demonstrate that these cysteine proteases are involved in the development of embryos, show similar functions to their counterparts in C. elegans, and therefore, provide an important target for future drug development targeted to eliminate filariasis

Grinding metre scale mirror segments for the E-ELT ground based telescope

The next generation of ground based telescopes require many hundreds of metre scale off-axis mirrors. In this paper the grinding of a 1.45m scale Zerodur® mirror segment for the European Extremely Large Telescope (E-ELT) is introduced. Employing an R-theta grinding mode with a multi stage grinding process material removal rates of up to 187.5mm3/s are achieved, whilst typically removing up to 1mm depth of material in total. Results show a RMS form error of <1μm, with subsurface damage <10μm, and a production cycle time under