Heat conduction across monolayer and few-layer graphenes

We report the thermal conductance G of Au/Ti/graphene/SiO(2) interfaces (graphene layers 1 ≤ n ≤ 10) typical of graphene transistor contacts. We find G ≈ 25 MW m(-2) K(-1) at room temperature, four times smaller than the thermal conductance of a Au/Ti/SiO(2) interface, even when n = 1. We attribute this reduction to the thermal resistance of Au/Ti/graphene and graphene/SiO(2) interfaces acting in series. The temperature dependence of G from 50 ≤ T ≤ 500 K also indicates that heat is predominantly carried by phonons through these interfaces. Our findings suggest that metal contacts can limit not only electrical transport but also thermal dissipation from submicrometer graphene devices.     

The composition and ultrastructure of sorghum spent grains

The present study aimed to investigate the composition and structure of sorghum spent grains (SSG) as a pre‐requisite for evaluating potential applications of this brewery co‐product. SSG samples sourced from African breweries employing a grist with a proportion of a hammer milled‐unmalted sorghum (Sorghum vulgare cv. Fara Fara) were found to be heterogeneous materials containing remnants of intact grains, and with particles ranging in size from <0.1 to >2 mm. Samples contained a considerable amount of residual starch (4.6–10.0% d.b.), much higher than typically reported for barley‐derived spent grains. This probably arises from the use of grists high in unmalted sorghum, but indicates that improvements in brewing process efficiency could be achieved with improvements, for example, in milling and mashing protocols. The crude protein content of the SSG samples was unexpectedly high (38.0–41.2% d.b.), indicating that this material would have potential value as an animal feed or source of refined protein. Potential reasons for this higher than expected residual protein content are discussed. The remainder of SSG gross composition (mean of five samples) was cellulose (11.4% d.b.), hemicellulose (17.3% d.b.), lipid (8.5% d.b.), lignin (9.4% d.b.) and ash (4.46% d.b.), with a total mass recovery of close to 98% represented by all analysed components. Copyright © 2013 The Institute of Brewing & Distilling     

Ethanol inhibits mitogen activated protein kinase activity and growth of vascular smooth muscle cells in vitro

The intrathecal (i.t.) injection of endothelins to conscious rats was found to cause respiratory arrest. To gain some insights into this central phenomenon, peripheral vascular permeability and lung oedema were measured after i.t. and i.v. injections of these peptides. When injected at T-8 spinal cord level, endothelin-1 (65 and 650 pmol) and endothelin-3 (650 pmol) enhanced vascular permeability in the lungs by 22-fold and 7-fold, respectively, and caused sudden death at the highest dose. Less prominent increases (between 1.4- and 2.2-fold) of vascular permeability were observed in other tissues (trachea, kidney, ears, skin of hind paws and back skin) with endothelin-1. Endothelin-1 (650 pmol) caused a similar increase (27-fold) in lung vascular permeability when injected at T-2, although the response was significantly less (P < 0.05) if injected at the L-4 (15-fold) spinal cord level. Only endothelin-1 produced lung oedema when injected at the T-2 or T-8 level. In contrast, intravenous injection of endothelins-1 and -3 (650 pmol) did not produce lung oedema and the lung vascular permeability was increased by only 1.4-1.6-fold and all rats survived. The prior i.t. injection of 6.5 nmol BQ-123 (cyclo[D-Trp, D-Asp, L-Pro, D-Val, L-Leu]), a selective endothelin ET(A) receptor antagonist, prevented the increases of lung vascular permeability and oedema and the mortality induced by i.t. endothelin-1 (650 pmol). Whereas i.v. treatment with phentolamine (2 mg/kg) or pentolinium (25 mg/kg + 50 mg/kg per h x 15 min) abolished the lung vascular permeability changes evoked by endothelin-1 (650) pmol), atropine (1 mg/kg), NG-nitro-L-arginine (50 mg/kg) or indomethacin (5 mg/kg) had no effect. Moreover, the effects of endothelin-1 were attenuated in capsaicin pretreated rats (125 mg/kg, 10 days earlier) and almost abolished in rats subjected to sympathectomy with 6-hydroxydopamine (100 mg/kg, 24-48 h earlier). All these treatments except atropine and NG-nitro-L-arginine prevented the endothelin-1-induced lung oedema and reduced the lethality by around 50%. These results suggest that the increases of pulmonary vascular permeability and oedema induced by i.t. endothelin-1 are due to an intense pulmonary vasoconstriction mediated by alpha-adrenoceptors following the release of catecholamines in response to the activation of endothelin ET(A) receptor in the spinal cord. This central phenomenon seems to be reflexogenic, including the involvement of primary afferent C-fibers and spinal cord ascending fibers to the brain. Thus, endothelin-1 could play a role in neurogenic pulmonary oedema through a central mechanism.     

Higher radix linear sequential circuit implementation via hybrid U and JK multiple-valued logic primitives

The implementation of a 2-digit modulo-3 linear sequential circuit (LSC) is presented, together with its associated state diagram. Two multiple valued logic (MVL) primitives are identified as suitable building blocks for the realisation of the three basic elements required for higher radix (>2) LSC hardware. Specifically, the hybrid MVL combinational U-gate and the MVL sequential JK flipflop sequencer are identified as vehicles for the implementation of modulo-radix scalars, adders and delayers.<>     

A Centralized Laboratory Maintenance Project

Genome Therapeutics Corp. has implemented a unique maintenance approach for their GenomeVision™ Services 24-by-7 high-throughput Sequencing platform that ensures optimal performance and minimum downtime. A network-enabled software program automatically coordinates and tracks all maintenance tasks, and notifies responsible personnel by e-mail of their upcoming maintenance responsibilities. Production personnel perform all internal scheduled instrumentation maintenance, equipment vendors perform purchased service contracts, and a small in-house group responds to emergency situations. Personnel log completed maintenance tasks and request emergency service by means of a networkbased interface that results in rapid response of appropriate in-house personnel or outside service organizations. The proprietary software program tracks all maintenance activities for each instrument, enabling upgrades to routine maintenance procedures, identification of opportunities for sequencing platform improvements, and more effective instrumentation purchasing decisions.