Combustion of Pulverized Biomass Crop Residues and Their Explosion Characteristics

Two Pakistani crop residues bagasse (B) and wheat straw (WS), both with high ash content, were milled to <63µm and the ISO 1 m3 explosion equipment was used to investigate flame propagation in the dispersed cloud of pulverised biomass. Their turbulent flame speed was measured and the Kst (dP/dtmaxV1/3) and comparison was made with two pulverised coal samples. Minimum Explosion Concentration (MEC) values for B and WS were, in terms of the burnt dust mass equivalence ratio (Ø) 0.2Ø to 0.3Ø , which was leaner than for the coal samples. These MEC were lower than had previously been determined using the Hartmann explosion tube, and this was considered to be due to the 10 kJ ignition energy in the 1 m3 equipment and 4J spark energy in the Hartmann explosion tube, which extended the lean limit in the 1 m3 equipment. Peak turbulent flame speeds were 3.8 m/s for B and 3.0 m/s for WS compared with 3.5–5.2 m/s for the two coal samples. The peak Kst was 103 bar m/s for bagasse and 80 bar m/s for wheat straw and the two coal samples had peak Kst of 78 and 120 bar m/s. Overall the agricultural biomass and coal samples had a similar range of reactivity. Thus these agricultural crop residues are a viable renewable fuel for co-firing with coal or as 100% biofuel operation of steam power plants

Flame Propagation of Pulverised Biomass Crop Residues and their Explosion Characteristics

Pulverised agricultural crop residues were investigated using the ISO 1 m3 turbulent explosion vessel. This was modified to enable the spherical flame propagation flame speed and the heat release rate in MW/m2 to be determined. From the turbulent flame speed, the laminar flame speed and laminar burning velocity and global heat release, MW/m2, were determined. In addition the equipment was used to determine the biomass explosibility, Kst (= dP/dtmaxV1/3), and the minimum explosion concentration (MEC). Two Pakistani crop residues bagasse (B) and wheat straw (WS) were investigated. Particle size distribution, elemental and proximate analysis and surface morphology for the raw powders and for their post explosion residues were carried out. It was found that these crop residues have explosibility characteristics comparable to wood biomass powders. MEC values as low as equivalence ratios of 0.18 to 0.3 were found which were lower than for gaseous hydrocarbons, but similar to other measurements for biomass using the Hartmann explosibility equipment. Peak turbulent flame speeds were measured at 3-4 m/s. There was a significant post explosion residue of unburned material which was shown to have an increase in char content relative to the raw biomass, while the volatile content was reduced. The BET surface area of the post explosion residue of bagasse was higher than that of the wheat straw residue, showing a higher release of volatiles for bagasse with a more porous char residue in the burnout indicating higher reactivity. These crop residues are a viable renewable fuel for existing coal power plants or as a basis for a new generation of small scale steam power generators in Pakistan

The TORCH PMT: a close packing, multi-anode, long life MCP-PMT for Cherenkov applications

Photek (U.K.) and the TORCH collaboration are undertaking a three year development program to produce a novel square MCP-PMT for single photon detection. The TORCH detector aims to provide particle identification in the 2–10 GeV/c momentum range, using a Time-of-Flight method based on Cherenkov light. It is a stand-alone R&#38;D project with possible application in LHCb, and has been proposed for the LHCb Upgrade. The Microchannel Plate (MCP) detector will provide a single photon timing accuracy of 40 ps, and its development will include the following properties: (i) Long lifetime up to at least 5 C/cm2; (ii) Multi-anode output with a spatial resolution of 6 mm and 0.4 mm respectively in the horizontal and vertical directions, incorporating a novel charge-sharing technique; (iii) Close packing on two opposing sides with an active area fill factor of 88% in the horizontal direction. Results from simulations modelling the MCP detector performance factoring in the pulse height variation from the detector, NINO threshold levels and potential charge sharing techniques that enhance the position resolution beyond the physical pitch of the pixel layout will be discussed. Also, a novel method of coupling the MCP-PMT output pads using Anisotropic Conductive Film (ACF) will be described. This minimises parasitic input capacitance by allowing very close proximity between the frontend electronics and the MCP detector

The Chromium Resources Of Zimbabwe

An IMR report on Zimbabwe's chromium resources

Hematopoietic Cell Transplantation in Patients With Primary Immune Regulatory Disorders (PIRD): A Primary Immune Deficiency Treatment Consortium (PIDTC) Survey.

Primary Immune Regulatory Disorders (PIRD) are an expanding group of diseases caused by gene defects in several different immune pathways, such as regulatory T cell function. Patients with PIRD develop clinical manifestations associated with diminished and exaggerated immune responses. Management of these patients is complicated; oftentimes immunosuppressive therapies are insufficient, and patients may require hematopoietic cell transplant (HCT) for treatment. Analysis of HCT data in PIRD patients have previously focused on a single gene defect. This study surveyed transplanted patients with a phenotypic clinical picture consistent with PIRD treated in 33 Primary Immune Deficiency Treatment Consortium centers and European centers. Our data showed that PIRD patients often had immunodeficient and autoimmune features affecting multiple organ systems. Transplantation resulted in resolution of disease manifestations in more than half of the patients with an overall 5-years survival of 67%. This study, the first to encompass disorders across the PIRD spectrum, highlights the need for further research in PIRD management

TRAIP promotes DNA damage response during genome replication and is mutated in primordial dwarfism.

DNA lesions encountered by replicative polymerases threaten genome stability and cell cycle progression. Here we report the identification of mutations in TRAIP, encoding an E3 RING ubiquitin ligase, in patients with microcephalic primordial dwarfism. We establish that TRAIP relocalizes to sites of DNA damage, where it is required for optimal phosphorylation of H2AX and RPA2 during S-phase in response to ultraviolet (UV) irradiation, as well as fork progression through UV-induced DNA lesions. TRAIP is necessary for efficient cell cycle progression and mutations in TRAIP therefore limit cellular proliferation, providing a potential mechanism for microcephaly and dwarfism phenotypes. Human genetics thus identifies TRAIP as a component of the DNA damage response to replication-blocking DNA lesions.This work was supported by funding from the Medical Research Council and the European Research Council (ERC, 281847) (A.P.J.), the Lister Institute for Preventative Medicine (A.P.J. and G.S.S.), Medical Research Scotland (L.S.B.), German Federal Ministry of Education and Research (BMBF, 01GM1404) and E-RARE network EuroMicro (B.W), Wellcome Trust (M. Hurles), CMMC (P.N.), Cancer Research UK (C17183/A13030) (G.S.S. and M.R.H), Swiss National Science Foundation (P2ZHP3_158709) (O.M.), AIRC (12710) and ERC/EU FP7 (CIG_303806) (S.S.), Cancer Research UK (C6/A11224) and ERC/EU FP7 (HEALTH-F2- 2010-259893) (A.N.B. and S.P.J.).This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.345

Using Barkhausen Noise to Measure Coating Depth of Coated High-Speed Steel

Coated high-speed steel tools are widely used in machining processes as they offer an excellent tool life to cost ratio, but they quickly need replacing once the coated layer is worn away. It would be therefore useful to be able to measure the tool life remaining non-destructively and cheaply. To achieve this, the work presented here aims to measure the thickness of the coated layer of high-speed cutting tools by using Barkhausen noise (BHN) techniques. Coated high-speed steel specimens coated with two different materials (chromium nitride (CrN), titanium nitride (TiN)) were tested using a cost-effective measuring system developed for this study. Sensory features were extracted from the signal received from a pick-up coil and the signal features, Root mean square, peak count, and signal energy, were successfully correlated with the thickness of the coating layer on high-speed steel (HSS) specimens. The results suggest that the Barkhausen noise measuring system developed in this study can successfully indicate the different thickness of the coating layer on CrN/TiN coated HSS specimens

Controlo químico de infestantes

Uma planta é considerada infestante quando nasce espontaneamente num local e momento indesejados, podendo interferir negativamente com a cultura instalada. As infestantes competem com as culturas para o espaço, a luz, água e nutrientes, podendo atrasar e prejudicar as operações de colheita, depreciar o produto final e assegurarem a reinfestação nas culturas seguintes. Dado o modo de propagação diferenciado das diversas espécies de infestantes, com as anuais a propagarem-se por semente e as perenes ou vivazes a assegurarem a sua propagação através de órgãos vegetativos (rizomas, bolbos, tubérculos, etc.), assim, também o seu controlo quer químico, quer mecânico terá que ser diferenciado, ou seja, para controlar infestantes anuais será suficiente destruir a sua parte aérea, enquanto para controlar infestantes perenes teremos que destruir os seus órgãos reprodutivos. O controlo de infestantes poderá ser químico, através da utilização de herbicidas, ou mecânico pela utilização de alfaias agrícolas, tais como a charrua de aivecas, a charrua de discos, a grade de discos, o escarificador e a fresa. Quando a técnica utilizada na instalação das culturas é a sementeira directa, o controlo das infestantes terá que ser obrigatoriamente químico, enquanto se o recurso à mobilização do solo for a técnica mais utilizada (sistema de mobilização tradicional ou sistema de mobilização reduzida), o controlo das infestantes tanto poderá ser químico como mecânico. Neste trabalho iremos abordar apenas, o controlo químico de infestantes

Tool life and wear mechanisms of CVD coated and uncoated SiAlON ceramic milling inserts when machining aged Inconel 718.

In this study, an investigation has been conducted to fully characterise for the first time the tribological benefits of adding two different types of chemical vapour deposition (CVD) coatings to silicon aluminium oxynitride milling inserts with a chemical composition of (Si3N4+Al2O3+Y2O3), known by the trade abbreviation “SiAlON”, typically used to cut difficult to machine materials such as Inconel 718. The experimental tests compared the tool life, material removed and wear resistance of the two different CVD coated inserts against that of uncoated SiAlON ceramic milling inserts. Coating A was a multilayer CVD coating and had a composition of (TiN+TiCN+Al2O3), Coating B was a bilayer CVD coating and had a composition of (Al2O3+TiN). It was determined that at 900m/min the uncoated SiAlON ceramic milling inserts exhibited the least amount of wear and variation in cutting force when milling precipitation hardened Inconel 718 samples. Coating A demonstrated significantly lower adhesion to the SiAlON substrate but had higher tool life and material removal rates, Coating B demonstrated excellent adhesion to the SiAlON substrate. The interfacial bonding of Coating B allowed for much higher adhesion to the substrate, but it suffered from much lower tool life and higher rates of rake and flank face wear. The flank wear measurements concluded a cutting speed of 900m/min to be the optimum cutting speed for machining Inconel 718 with uncoated SiAlON ceramic milling inserts