Modelling of Organic Rankine Cycle for Waste Heat Recovery Process in Supercritical Condition

Organic Rankine Cycle (ORC) is the most commonly used method for recovering energy from small sources of heat. The investigation of the ORC in supercritical condition is a new research area as it has a potential to generate high power and thermal efficiency in a waste heat recovery system. This paper presents a steady state ORC model in supercritical condition and its simulations with a real engine’s exhaust data. The key component of ORC, evaporator, is modelled using finite volume method, modelling of all other components of the waste heat recovery system such as pump, expander and condenser are also presented. The aim of this paper is to investigate the effects of mass flow rate and evaporator outlet temperature on the efficiency of the waste heat recovery process. Additionally, the necessity of maintaining an optimum evaporator outlet temperature is also investigated. Simulation results show that modification of mass flow rate is the key to changing the operating temperature at the evaporator outlet.

Low cycle fatigue properties of CLAM steel at room temperature

The low cycle fatigue (LCF) properties and the fracture behavior of China Low Activation Martensitic (CLAM) steel have been studied over a range of total strain amplitudes from 0.2 to 2.0%. The specimens were cycled using tension-compression loading under total strain amplitude control. The CLAM steel displayed initial hardening followed by continuous softening to failure at room temperature in air. The relationship between strain and fatigue life was predicted using the parameters obtained from fatigue test. The factors effecting on low cycle fatigue of CLAM steel consisted of initial state of matrix dislocation arrangement, magnitude of cyclic stress, magnitude of total strain amplitude and microstructure. The potential mechanisms controlling the stress response, cyclic strain resistance and low cycle fatigue life have been evaluated.

Microstructure and high cycle fatigue fracture surface of a Ti-5Al-5Mo-5V-1Cr-1Fe titanium alloy

Because of the requirements for the damage tolerance and fatigue life of commercial aircraft components, the high cycle fatigue (HCF) properties of Ti–5Al–5Mo–5V–1Cr–1Fe titanium alloy forgings are important. The effects of microstructure types of the α+β titanium alloy on fatigue properties need to be understood. In this paper, by analysing the fracture surfaces of the titanium alloy having four types of microstructure, the effects of microstructure are investigated. The differences of initiation areas and crack propagation among different microstructures were studied. It was found that the area of the initiation region decreases in the order of coarse basketweave, fine basketweave, Widmanstätten, and bimodal microstructure.

Reducing Parametric Uncertainty in Limit Cycle Oscillations

The assimilation of discrete higher fidelity data points with model predictions can be used to achieve a reduction in the uncertainty of the model input parameters which generate accurate predictions. The problem investigated here involves the prediction of limit-cycle oscillations using a High-Dimensional Harmonic Balance method (HDHB). The efficiency of the HDHB method is exploited to enable calibration of structural input parameters using a Bayesian inference technique. Markov-chain Monte Carlo is employed to sample the posterior distributions. Parameter estimation is carried out on both a pitch/plunge aerofoil and Goland wing configuration. In both cases significant refinement was achieved in the distribution of possible structural parameters allowing better predictions of their
true deterministic values.

Prokineticin ligands and receptors are expressed in the human fetal ovary and regulate germ cell expression of COX2

CONTEXT: Fetal ovarian development and primordial follicle formation underpin future female fertility. Prokineticin (PROK) ligands regulate cell survival, proliferation and angiogenesis in adult reproductive tissues including the ovary. However, their expression and function during fetal ovarian development remains unclear.

OBJECTIVE: To investigate expression and localization of the PROK ligands, receptors and their downstream transcriptional targets in the human fetal ovary.

SETTING: This study was conducted at the University of Edinburgh.

PARTICIPANTS: Ovaries were collected from 37 morphologically normal human fetuses.

DESIGN AND MAIN OUTCOME MEASURES: mRNA and protein expression of PROK ligands and receptors was determined in human fetal ovaries using qRT-PCR, immunoblotting and immunohistochemistry. Functional studies were performed using a human germ tumour cell line (TCam-2) stably transfected with PROKR1.

RESULTS: Expression of PROK1 and PROKR1 was significantly higher in mid-gestation ovaries (17-20 weeks) than at earlier gestations (8-11 and 14-16 weeks). PROK2 significantly increased across the gestations examined. PROKR2 expression remained unchanged. PROK ligand and receptor proteins were predominantly localised to germ cells (including oocytes within primordial follicles) and endothelial cells, indicating these cell types to be the targets of PROK signalling in the human fetal ovary. PROK1 treatment of a germ cell line stably-expressing PROKR1 resulted in ERK phosphorylation, and elevated COX2 expression.

CONCLUSIONS: Developmental changes in expression and regulation of COX2 and pERK by PROK1 suggest that PROK ligands may be novel regulators of germ cell development in the human fetal ovary, interacting within a network of growth and survival factors prior to primordial follicle formation.

Developmentally regulated IL6-type cytokines signal to germ cells in the human fetal ovary

Fetal ovarian development and primordial follicle formation are imperative for adult fertility in the female. Data suggest the interleukin (IL)6-type cytokines, leukaemia inhibitory factor (LIF), IL6, oncostatin M (OSM) and ciliary neurotrophic factor (CNTF), are able to regulate the survival, proliferation and differentiation of fetal murine germ cells (GCs) in vivo and in vitro. We postulated that these factors may play a similar role during early human GC development and primordial follicle formation. To test this hypothesis, we have investigated the expression and regulation of IL6-type cytokines, using quantitative reverse transcription polymerase chain reaction and immunohistochemistry. Expression of transcripts encoding OSM increased significantly across the gestational range examined (8-20 weeks), while expression of IL6 increased specifically between the first (8-11 weeks) and early second (12-16 weeks) trimesters, co-incident with the initiation of meiosis. LIF and CNTF expression remained unchanged. Expression of the genes encoding the LIF and IL6 receptors, and their common signalling subunit gp130, was also found to be developmentally regulated, with expression increasing significantly with increasing gestation. LIF receptor and gp130 proteins localized exclusively to GCs, including oocytes in primordial follicles, indicating this cell type to be the sole target of IL6-type cytokine signalling in the human fetal ovary. These data establish that IL6-type cytokines and their receptors are expressed in the human fetal ovary and may directly influence GC development at multiple stages of maturation.

Sandwich nanoarchitecture of LiV3O8/graphene multilayer nanomembranes via layer-by-layer self-assembly for long-cycle-life lithium-ion battery cathodes

A lack of suitable high-performance cathode materials has become the major barrier to their applications in future advanced communication equipment and electric vehicle power systems. In this paper, we have developed a layer-by-layer self-assembly approach for fabricating a novel sandwich nanoarchitecture of multilayered LiV₃O₈ nanoparticle/graphene nanosheet (M-nLVO/GN) hybrid electrodes for potential use in high performance lithium ion batteries by using a porous Ni foam as a substrate. The prepared sandwich nanoarchitecture of M-nLVO/GN hybrid electrodes exhibited high performance as a cathode material for lithium-ion batteries, such as high reversible specific capacity (235 mA h g^-1 at a current density of 0.3 A g^-1), high coulombic efficiency (over 98%), fast rate capability (up to a current density of 10 A g^-1), and superior capacity retention during cycling (90% capacity retention with a current density of 0.3 A g^-1 after 300 cycles). Very significantly, this novel insight into the design and synthesis of sandwich nanoarchitecture would extend their application to various electrochemical energy storage devices, such as fuel cells and supercapacitors.

In situ preparation of 3D graphene aerogels@hierarchical Fe3O4 nanoclusters as high rate and long cycle anode materials for lithium ion batteries

We describe a novel strategy for in situ fabrication of hierarchical Fe₃O₄ nanoclusters-GAs. Fe₃O₄ NCs-GAs deliver excellent rate capability (the reversible capacities obtained were 1442, 392 and 118 mA h g^-1 at 0.1C, 12C and 35C rates), and a high reversible capacity of 577 mA h g^-1 over 300 cycles at the current density of 5.2 A g^-1 (6C).

Few-cycle driven relativistically oscillating plasma mirrors:A source of intense isolated attosecond pulses

The conditions required for the production of isolated attosecond pulses from relativistically oscillating mirrors (ROM) are investigated numerically and experimentally. In simulations, carrier-envelope-phase-stabilized three-cycle pulses are found to be sufficient to produce isolated attosecond pulses, while two-cycle pulses will predominantly lead to isolated attosecond pulses even in the absence of carrier-envelope stabilization. Using a state-of-the-art laser system delivering three-cycle pulses at multiple-terawatt level, we have generated higher harmonics up to 70 eV photon energy via the ROM mechanism. The observed spectra are in agreement with theoretical expectations and highlight the potential of few-cycle-driven ROM harmonics for intense isolated attosecond pulse generation for performing extreme ultraviolet-pump extreme ultraviolet-probe experiments. © 2012 American Physical Society.

Novel microtubule-targeting agents, pyrrolo-1,5-benzoxazepines, induce cell cycle arrest and apoptosis in prostate cancer cells

Advanced hormone-refractory prostate cancer is associated with poor prognosis and limited treatment options. Members of the pyrrolo-1,5-benzoxazepine (PBOX) family of compounds exhibit anti-cancer properties in cancer cell lines (including multi-drug resistant cells), ex vivo patient samples and in vivo mouse tumour models with minimal toxicity to normal cells. Recently, they have also been found to possess anti-angiogenic properties in vitro. However, both the apoptotic pathways and the overall extent of the apoptotic response induced by PBOX compounds tend to be cell-type specific. Since the effect of the PBOX compounds on prostate cancer has not yet been elucidated, the purpose of this study was to investigate if PBOX compounds induce anti-proliferative effects on hormone-refractory prostate cancer cells. We examined the effect of two representative PBOX compounds, PBOX-6 and PBOX-15, on the androgen-independent human prostate adenocarcinoma cell line, PC3. PBOX-6 and -15 displayed anti-proliferative effects on PC3 cells, mediated initially through a sustained G2/M arrest. G2/M arrest, illustrated as DNA tetraploidy, was accompanied by microtubule depolymerisation and phosphorylation of anti-apoptotic proteins Bcl-2 and Bcl-xL and the mitotic spindle checkpoint protein BubR1. Phosphorylation of BubR1 is indicative of an active mitotic checkpoint and results in maintenance of cell cycle arrest. G2/M arrest was followed by apoptosis illustrated by DNA hypoploidy and PARP cleavage and was accompanied by degradation of BubR1, Bcl-2 and Bcl-xL. Furthermore, sequential treatment with the CDK1-inhibitor, flavopiridol, synergistically enhanced PBOX-induced apoptosis. In summary, this in vitro study indicates that PBOX compounds may be useful alone or in combination with other agents in the treatment of hormone-refractory prostate cancer.

The United Kingdom, the United Nations Human Rights Council and the first cycle of the Universal Periodic Review

The introduction of the Universal Periodic Review (UPR) mechanism as an innovative component of the new Human Rights Council in 2006 has suffered little academic scrutiny. This is partly because it holds as its objective an improvement in human rights situations on the ground, a goal that is difficult to test amongst so many possible causal factors attributable to law reform and policy change, and partly due to the fact that the mechanism has only completed one full cycle of review. This article seeks to remedy this absence of analysis by examining the experience of the United Kingdom during its first review. In doing so, the article first considers the conception of the UPR, before progressing to examine the procedure and recommendations made to the UK by its peers. Finally, the article considers the five year review of the UPR which occurred as a subset of the Human Rights Council Review in 2011 and the resulting changes to the process modalities.

Techno-Economic and Life Cycle Assessment on Lignocellulosic Biomass Thermochemical Conversion Technologies: A Review

Bioenergy derived from biomass provides a promising energy alternative and can reduce the greenhouse gas (GHG) emissions generated from fossil fuels. Biomass-based thermochemical conversion technologies have been acknowledged as apt options to convert bioresources into bioenergy; this bioenergy includes electricity, heat, and fuels/chemicals in solid, liquid, and gaseous phases. In this review, the techno-economic and life cycle assessment of these technologies (combustion, gasification, pyrolysis, liquefaction, carbonization, and co-firing) are summarized. Specific indicators (production costs in a techno-economic analysis, functional units and environmental impacts in a life cycle analysis) for different technologies were compared. Finally, gaps in research and future trends in biomass thermochemical conversion were identified. This review could be used to guide future research related to economic and environmental benefits of bioenergy.

HES6 drives a critical AR transcriptional programme to induce castration-resistant prostate cancer through activation of an E2F1-mediated cell cycle network

Castrate-resistant prostate cancer (CRPC) is poorly characterized and heterogeneous and while the androgen receptor (AR) is of singular importance, other factors such as c-Myc and the E2F family also play a role in later stage disease. HES6 is a transcription co-factor associated with stem cell characteristics in neural tissue. Here we show that HES6 is up-regulated in aggressive human prostate cancer and drives castration-resistant tumour growth in the absence of ligand binding by enhancing the transcriptional activity of the AR, which is preferentially directed to a regulatory network enriched for transcription factors such as E2F1. In the clinical setting, we have uncovered a HES6-associated signature that predicts poor outcome in prostate cancer, which can be pharmacologically targeted by inhibition of PLK1 with restoration of sensitivity to castration. We have therefore shown for the first time the critical role of HES6 in the development of CRPC and identified its potential in patient-specific therapeutic strategies.