Water efficiency as a means of reducing carbon emissions in Northern Ireland (NI) Water

The water and sewerage sectors' combined emissions account for just over 1% of total UK emissions, while household water heating accounts for a further 5%. Energy use, particularly electricity, is the largest source of emissions in the sector. Water efficiency measures should therefore result in reduced emissions from a lower demand for water and wastewater treatment and pumping, as well as from decreased domestic water heating. Northern Ireland Water (NI Water) is actively pursuing measures to reduce its carbon footprint. This paper investigated the carbon impacts of implementing a household water efficiency programme in Northern Ireland. Assuming water savings of 59.6 L/prop/day and 15% uptake among households, carbon savings of 0.6% of NI Water's current net operational emissions are achievable from reduced treatment and pumping. Adding the carbon savings from reduced household water heating gives savings equivalent to 6.2% of current net operational emissions. Cost savings to NI Water are estimated as 300,000 per year. The cost of the water efficiency devices is approximately 1.6 million, but may be higher depending on the number of devices distributed relative to the number installed. This paper has shown clear carbon benefits to water efficiency, but further research is needed to examine social and cost impacts. © IWA Publishing 2013.

BROAD-BAND EXCITATION AND EMISSION OF SURFACE-PLASMONS

The well known advantages of using surface plasmons, in particular the high sensitivity to surface adsorbates, are nearly always compromised in practice by the use of monochromatic excitation and the consequent lack of proper spectroscopic information. This limitation arises from the angle/wavelength selective nature of the surface plasmon resonance. The work described here uses an elegant broadband excitation/decay scheme in a substrate(silica)-grating profiled photoresist-Ag film geometry. Laser radiation of wavelength 488 nm, incident through the silica substrate, excites by near-field coupling a broad band of surface plasmons at the photoresist-Ag interface within the spectral range of the photoresist fluorescence. With a judicious choice of grating period this mode can cross-couple to the mode supported at the Ag-air interface. This latter mode can, in turn, couple out to light by virtue of the same grating profile. The spectral distribution of the light emitted due to this three-step process has been studied as a function of the angle of emission and depth of the grating profiled surface for each polarization. It is found that the optimum emission efficiency occurs with a groove depth in the region of 65 nm. This is considerably greater than the optimum depth of 40 nm required for surface plasmon-photon coupling at a Ag-air interface or, in other words, for the last step of the process in isolation.

The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy

A new efficient type of gadolinium-based theranostic agent (AGuIX®) has recently been developed for MRI-guided radiotherapy (RT). These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Owing to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, although a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, in the absence of irradiation, the nanoparticles are well tolerated even at very high dose (10 times more than the dose used for mouse treatment). AGuIX particles have been proven to act as efficient radiosensitizers in a large variety of experimental in vitro scenarios, including different radioresistant cell lines, irradiation energies and radiation sources (sensitizing enhancement ratio ranging from 1.1 to 2.5). Pre-clinical studies have also demonstrated the impact of these particles on different heterotopic and orthotopic tumours, with both intratumoural or intravenous injection routes. A significant therapeutical effect has been observed in all contexts. Furthermore, MRI monitoring was proven to efficiently aid in determining a RT protocol and assessing tumour evolution following treatment. The usual theoretical models, based on energy attenuation and macroscopic dose enhancement, cannot account for all the results that have been obtained. Only theoretical models, which take into account the Auger electron cascades that occur between the different atoms constituting the particle and the related high radical concentrations in the vicinity of the particle, provide an explanation for the complex cell damage and death observed.

BRCA1, FANCD2 and Chk1 are potential molecular targets for the modulation of a radiation-induced DNA damage response in bystander cells

Radiotherapy is an important treatment option for many human cancers. Current research is investigating the use of molecular targeted drugs in order to improve responses to radiotherapy in various cancers. The cellular response to irradiation is driven by both direct DNA damage in the targeted cell and intercellular signalling leading to a broad range of bystander effects. This study aims to elucidate radiation-induced DNA damage response signalling in bystander cells and to identify potential molecular targets to modulate the radiation induced bystander response in a therapeutic setting. Stalled replication forks in T98G bystander cells were visualised via bromodeoxyuridine (BrdU) nuclear foci detection at sites of single stranded DNA. γH2AX co-localised with these BrdU foci. BRCA1 and FANCD2 foci formed in T98G bystander cells. Using ATR mutant F02-98 hTERT and ATM deficient GM05849 fibroblasts it could be shown that ATR but not ATM was required for the recruitment of FANCD2 to sites of replication associated DNA damage in bystander cells whereas BRCA1 bystander foci were ATM-dependent. Phospho-Chk1 foci formation was observed in T98G bystander cells. Clonogenic survival assays showed moderate radiosensitisation of directly irradiated cells by the Chk1 inhibitor UCN-01 but increased radioresistance of bystander cells. This study identifies BRCA1, FANCD2 and Chk1 as potential targets for the modulation of radiation response in bystander cells. It adds to our understanding of the key molecular events propagating out-of-field effects of radiation and provides a rationale for the development of novel molecular targeted drugs for radiotherapy optimisation.

WC/CNT, WC/CNT/Pt Composite Material and Preparation Process Therefor and Use Thereof. (International Patent)

(EN)Disclosed are a WC/CNT， WC/CNT/Pt composite material and a preparation process therefor and use thereof. The WC/CNT/Pt composite material comprises mesoporous spherical tungsten carbide with a diameter of 1-5 microns, carbon nanotubes and platinum nano particles, with the carbon nanotubes growing on the surface of the mesoporous spherical tungsten carbide and expanding outward, and the platinum nano particles growing on the surfaces of the mesoporous spherical tungsten carbide and carbon nanotubes. The WC/CNT composite material comprises mesoporous spherical tungsten carbide with a diameter of 1-5 microns, and carbon nanotubes, with the carbon nanotubes growing on the surface of the mesoporous spherical tungsten carbide and expanding outward. The WC/CNT/Pt composite material of the present invention can be used as an electro-catalyst in a methanol flue battery, significantly improving the catalytic conversion rate and the service life of the catalyst. The WC/CNT composite material can be used as an electro-catalyst in the electro-reduction of a nitro aromatic compound, significantly improving the efficiency of organic electro-synthesis.

WC/CNT, WC/CNT/Pt Composite Material and Preparation Process Therefor and Use Thereof. (US patent)

Disclosed are a WC/CNT， WC/CNT/Pt composite material and a preparation process therefor and use thereof. The WC/CNT/Pt composite material comprises mesoporous spherical tungsten carbide with a diameter of 1-5 microns, carbon nanotubes and platinum nano particles, with the carbon nanotubes growing on the surface of the mesoporous spherical tungsten carbide and expanding outward, and the platinum nano particles growing on the surfaces of the mesoporous spherical tungsten carbide and carbon nanotubes. The WC/CNT composite material comprises mesoporous spherical tungsten carbide with a diameter of 1-5 microns, and carbon nanotubes, with the carbon nanotubes growing on the surface of the mesoporous spherical tungsten carbide and expanding outward. The WC/CNT/Pt composite material of the present invention can be used as an electro-catalyst in a methanol flue battery, significantly improving the catalytic conversion rate and the service life of the catalyst. The WC/CNT composite material can be used as an electro-catalyst in the electro-reduction of a nitro aromatic compound, significantly improving the efficiency of organic electro-synthesis.

Generation of 10μW relativistic surface high-harmonic radiation at a repetition rate of 10 Hz

Experimental results on relativistic surface HHG at a repetition rate of 10 Hz are presented. Average powers in the 10?W range are generated in the spectral range of 51 to 26 nm (24-48 eV). The surface harmonic radiation is produced by focusing the second-harmonic of a high-power laser onto a rotating glass surface to moderately relativistic intensities of 3×10 ¹⁹Wcm ^?2. The harmonic emission exhibits a divergence of 26 mrad. Together with absolute photon numbers recorded by a calibrated spectrometer, this allows for the determination of the extreme ultraviolet (XUV) yield. The pulse energies of individual harmonics are reaching up to the μJ level, equivalent to an efficiency of 10 ^?5. The capability of producing stable and intense high-harmonic radiation from relativistic surface plasmas may facilitate experiments on nonlinear ionization or the seeding of free-electron lasers. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Effect of controlled periodic-based illumination on the photonic efficiency of photocatalytic degradation of methyl orange

The use of controlled periodic illumination with UV LEDs for enhancing photonic efficiency of photocatalytic decomposition processes in water has been investigated using methyl orange as a model compound. The impact of the length of light and dark time periods (T _ON/T _OFF times) on photodegradation and photonic efficiency using a UV LED-illuminated photoreactor has been studied. The results have shown an inverse dependency of the photonic efficiency on duty cycle and a very little effect on T _ON or T _OFF time periods, indicating no effect of rate-limiting steps through mass diffusion or adsorption/desorption in the reaction. For this reactor, the photonic efficiency under controlled periodic illumination (CPI) matches to that of continuous illumination, for the same average UV light intensities. Furthermore, under CPI conditions, the photonic efficiency is inversely related to the average UV light intensity in the reactor, in the millisecond time regime. This is the first study that has investigated the effect of controlled periodic illumination using ultra band gap UV LED light sources in the photocatalytic destruction of dye compounds using titanium dioxide. The results not only enhance the understanding of the effect of periodic illumination on photocatalytic processes but also provide a greater insight to the potential of these light sources in photocatalytic reactions. 

Application of laser radiation for the treatment of waste materials using a photocatalyst

One effective approach is to destroy industrial waste and pollution is the use of a semiconductor photocatalysis system. To date such, photocatalysis systems have employed conventional linear light sources. Initial results from a study of a photocatalysis system incorporating a tripled Nd:YAG laser are reported. The laser light not only played a roll as a light source for activating the photocatalyst(TiO₂), but also destroyed the organic species directly via a photochemical process. The reaction intermediates and changes in their concentrations are monitored using HPLC. The relationship between the power of laser and kinetics of photoreaction are discussed.

A novel experimental approach to investigate radiolysis processes in liquid samples using collimated radiation sources

Here is detailed a novel and low-cost experimental method for high-throughput automated fluid sample irradiation. The sample is delivered via syringe pump to a nozzle, where it is expressed in the form of a hanging droplet into the path of a beam of ionising radiation. The dose delivery is controlled by an upstream lead shutter, which allows the beam to reach the droplet for a user defined period of time. The droplet is then further expressed after irradiation until it falls into one well of a standard microplate. The entire system is automated and can be operated remotely using software designed in-house, allowing for use in environments deemed unsafe for the user (synchrotron beamlines, for example). Depending on the number of wells in the microplate, several droplets can be irradiated before any human interaction is necessary, and the user may choose up to 10 samples per microplate using an array of identical syringe pumps, the design of which is described here. The nozzles consistently produce droplets of 25.1 ± 0.5 μl.

A Numerical and Experimental Assessment of the Use of a Turbine Utilizing Splitter Blades for an Automotive Variable Geometry Turbocharger

Automotive manufacturers require improved part load engine performance to further improve fuel economy. For a swing vane VGS (Variable Geometry Stator) turbine this means a more closed stator vane, to deal with the low MFRs (Mass Flow Rates), high PRs (Pressure Ratios) and low rotor rotational speeds. During these conditions the turbine is operating at low velocity ratios. As more energy is available at high pressure ratios and during lower turbocharger rotational speeds, a turbine which is efficient at these conditions is desirable. Another key aspect for automotive manufacturers is engine responsiveness. High inertia designs result in “turbo lag” which means an increased time before the target boost pressure is reached. Therefore, designs with improved performance at low velocity ratios, reduced inertia or an increased swallowing capacity are the current targets for turbocharger manufacturers.

To try to meet these design targets a CFD (Computational Fluid Dynamics) study was performed on a turbine wheel using splitter blades. A number of parameters were investigated. These included splitter blade merdional length, blade number and blade angle distribution.

The numerical study was performed on a scaled automotive VGS. Three different stator vane positions have been analysed. A single passage CFD model was developed and used to provide information on the flow features affecting performance in both the stator vanes and turbine.

Following the CFD investigation the design with the best compromise in terms of performance, inertia and increased MFP (Mass Flow Parameter) was selected for manufacture and testing. Tests were performed on a scaled, low temperature turbine test rig. The aerodynamic flow path of the gas stand was the same as that investigated during the CFD. The test results revealed a design which had similar performance at the closed stator vane positions when compared to the baseline wheel. At the maximum MFR stator vane condition a drop of −0.6% pts in efficiency was seen. However, 5.5% increase in MFP was obtained with the additional benefit of a drop in rotor inertia of 3.7%, compared to the baseline wheel.

Recognition of O6MeG lesions by MGMT and mismatch repair proficiency may be a prerequisite for low-dose radiation hypersensitivity

Low-dose hyper-radiosensitivity (HRS) is the phenomenon whereby cells exposed to radiation doses of less than approximately 0.5 Gy exhibit increased cell killing relative to that predicted from back-extrapolating high-dose survival data using a linear-quadratic model. While the exact mechanism remains to be elucidated, the involvement of several molecular repair pathways has been documented. These processes in turn are also associated with the response of cells to O6-methylguanine (O6MeG) lesions. We propose a model in which the level of low-dose cell killing is determined by the efficiency of both pre-replicative repair by the DNA repair enzyme O6-methylguanine methyltransferase (MGMT) and post-replicative repair by the DNA mismatch repair (MMR) system. We therefore hypothesized that the response of cells to low doses of radiation is dependent on the expression status of MGMT and MMR proteins. MMR (MSH2, MSH6, MLH1, PMS1, PMS2) and MGMT protein expression signatures were determined in a panel of normal (PWR1E, RWPE1) and malignant (22RV1, DU145, PC3) prostate cell lines and correlated with clonogenic survival and cell cycle analysis. PC3 and RWPE1 cells (HRS positive) were associated with MGMT and MMR proficiency, whereas HRS negative cell lines lacked expression of at least one (MGMT or MMR) protein. MGMT inactivation had no significant effect on cell survival. These results indicate a possible role for MMR-dependent processing of damage produced by low doses of radiation.

Radiation to control transgene expression in tumors

Significant evidence has accumulated indicating that certain genes are induced by ionising radiation. An implication of this observation is that their promoter regions include radiation-responsive sequences. These sequences have been isolated in the promoter of several genes including Erg-1, p21/WAF-1, GADD45alpha and t-PA. The mechanism by which radiation induces gene expression remains unclear but involves putative binding sites for selected transcription factors and/or p53. Consensus CC(A/T)6GG sequences have been localized in the Erg-1 promoter and are referred to as serum response elements or CArG elements. The tandem combination of CArG elements has been shown to improve gene expression levels, with a 9-copy motif conferring maximum inducibility. The response of these genes to ionising radiation appears to follow a sigmoid relationship with time and dose. Therapeutic induction of suicide genes and significant cytotoxicity can be achieved at clinically relevant x-rays doses both in vitro and in vivo but was found to be cell-type dependent. Radiation-inducible gene therapy can be potentially enhanced by exploiting hypoxia through the inclusion of hypoxia-response element motifs in the expression cassette, the use of the anaerobic bacteria or the use of neutron irradiation. These results are encouraging and provide significant evidence that gene therapy targeted to the radiation field is a reasonably attractive therapeutic option and could help overcome hypoxic radioresistant tumors.

A radiation-damped R -matrix approach to the electron-impact excitation of helium-like ions for diagnostic application to fusion and astrophysical plasmas

Electron-impact excitation collision strengths for transitions between all singly excited levels up to the n = 4 shell of helium-Eke argon and the n = 4 and 5 shells of helium-like iron have been calculated using a radiation-damped R-matrix approach. The theoretical collision strengths have been examined and associated with their infinite-energy limit values to allow the preparation of Maxwell-averaged effective collision strengths. These are conservatively considered to be accurate to within 20% at all temperatures, 3 x 10(5)-3 x 10(8) K forAr(16+) and 10(6)-10(9) K for Fe24+. They have been compared with the results of previous studies, where possible, and we find a broad accord. The corresponding rate coefficients are required for use in the calculation of derived, collisional-radiative, effective emission coefficients for helium-like lines for diagnostic application to fusion and astrophysical plasmas. The uncertainties in the fundamental collision data have been used to provide a critical assessment of the expected resultant uncertainties in such derived data, including redistributive and cascade collisional-radiative effects. The consequential uncertainties in the parts of the effective emission coefficients driven by excitation from the ground levels for the key w, x, y and z lines vary between 5% and 10%. Our results remove an uncertainty in the reaction rates of a key class of atomic processes governing the spectral emission of helium-like ions in plasmas.

Protein disulphide isomerase as a target for nanoparticle-mediated sensitisation of cancer cells to radiation

Radiation resistance and toxicity in normal tissues are limiting factors in the efficacy of radiotherapy. Gold nanoparticles (GNPs) have been shown to be effective at enhancing radiation-induced cell death, and were initially proposed to physically enhance the radiation dose deposited. However, biological responses of GNP radiosensitization based on physical assumptions alone are not predictive of radiosensitisation and therefore there is a fundamental research need to determine biological mechanisms of response to GNPs alone and in combination with ionising radiation. This study aimed to identify novel mechanisms of cancer cell radiosensitisation through the use of GNPs, focusing on their ability to induce cellular oxidative stress and disrupt mitochondrial function. Using N-acetyl-cysteine, we found mitochondrial oxidation to be a key event prior to radiation for the radiosensitisation of cancer cells and suggests the overall cellular effects of GNP radiosensitisation are a result of their interaction with protein disulphide isomerase (PDI). This investigation identifies PDI and mitochondrial oxidation as novel targets for radiosensitisation.