Release of K,Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100 kW moving grate pilot facility. The results from the bench-scale reactor indicate that S and K release are not significantly affected by secondary reactions, while Cl is partly recaptured by secondary reactions in the char. A linear increase in K-release was observed from 50% at 906 °C to almost 80 wt.% at 1234 °C when firing only corn stover. A similar release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234 °C with a linear increase from 70% at 906 °C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of corn stover with wood chips is expected to decrease the absolute release of KCl due to the lower feedstock quantity of Cl, however, increase the relative release of Cl as KCl.     

Light-induced cytotoxicity of a photochromic spiropyran

In this work we present a novel water soluble spiropyran photoswitch that can be photonically activated inside live cells from a form that has no significant effect on the cellular survival to a form that induces a dramatic toxic response.     

Data and signal processing using photochromic molecules

Photochromes are chromophores that are reversibly isomerized between two metastable forms using light, or light and heat. When photochromes are covalently linked to other chromophores, they can act as molecular photonic analogues of electronic transistors. As bistable switches, they can be incorporated into the design of molecules capable of binary arithmetic and both combinatorial and sequential digital logic operations. Small ensembles of such molecules can perform analogue signal modulation similar to that carried out by transistor amplifiers. Examples of molecules that perform multiple logic functions, act as control elements for fluorescent reporters, and mimic natural photoregulatory functions are presented.     

High pressure equipment for food processing

Abstract

Processing food with pressure improves the quality and shelf life of the product. The pressure required is normally 600 to 900 MPa (approximately 6000 to 9000 atm). Equipment for high pressure food processing is available today from ABB Pressure Systems AB. The plant can have a through-put of 300 to 6000 litres per hour at 600 MPa pressure depending on the size of the press. The processing cost at 600 MPa is between 3 to 20 pence per litre depending on production capacity. Processing at 900 MPa instead of 600 MPa will increase the cost 50%, while prolonging the processing time from 3 minutes to 6 minutes at 600 MPa, i.e. introducing a hold time, increases the cost 100%. Pressure is thus cheaper than time. The food is prepacked in flexible material and loaded into the high pressure vessel. Pure water is used as pressure transmitting medium. The pressure is increased to the value required. After decompression the food is ready for distribution.     

A Fluorescent Kinase Inhibitor that Exhibits Diagnostic Changes in Emission upon Binding

The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase is described. Fluorescent properties were realised through the inclusion of a prodan‐derived fluorophore into the pharmacophore of an ATP‐competitive kinase inhibitor. Fluorescence titration experiments demonstrate the solvatochromic properties of the inhibitor, in which dramatic increase in emission intensity and hypsochromic shift in emission maxima are clearly observed upon binding LCK. Microscopy experiments in cellular contexts together with flow cytometry show that the fluorescence intensity of the inhibitor correlates with the LCK concentration. Furthermore, multiphoton microscopy experiments demonstrate both the rapid cellular uptake of the inhibitor and that the two‐photon cross section of the inhibitor is amenable for excitation at 700 nm.     

Goldfish Geodesics and Hamiltonian Reduction of Matrix Dynamics

We describe the Hamiltonian reduction of a time-dependent real-symmetric N×N matrix system to free vector dynamics, and also provide a geodesic interpretation of Ruijsenaars–Schneider systems. The simplest of the latter, the goldfish equation, is found to represent a flat-space geodesic in curvilinear coordinates.      

The synthetic utility of heteroaromatic azido compounds. Part VI. Preparation of some 1H-1,2,3-triazolo[1,5-a]thieno[3,2-d]pyrimidines

Some 1,2,3-triazolo[1,5-a]thieno[3,2-d]pyrimidines have been prepared by the reaction of active methylene nitriles with 3-azido-2-substituted thiophenes. Thus, for example the 3-carboxy derivative 5 was prepared by condensation of 3-azido-2-formylthiophene dimethyl acetal ( 1 ) with ethyl cyanoacetate, followed by intramolecular cyclization. Decarboxylation of 5 led to the unsubstituted parent compound 6 . The structure of the triazole-fused compounds is discussed.     

Photonic switching of photoinduced electron transfer in a dihydropyrene-porphyrin-fullerene molecular triad

Photonic control of photoinduced electron transfer has been demonstrated in a dimethyldihydropyrene (DHP) porphyrin (P) fullerene (C(60)) molecular triad. In the DHP-P-C(60) form of the triad, excitation of the porphyrin moiety is followed by photoinduced electron transfer to give a DHP-P(*)(+)-C(60)(*)(-) charge-separated state, which evolves by a charge shift reaction to DHP(*)(+)-P-C(60)(*)(-). This final state has a lifetime of 2 micros and is formed in an overall yield of 94%. Visible (>or=300 nm) irradiation of the triad leads to photoisomerization of the DHP moiety to the cyclophanediene (CPD). Excitation of the porphyrin moiety of CPD-P-C(60) produces a short-lived (<10 ns) CPD-P(*)(+)-C(60)(*)(-) state, but charge shift to the CPD moiety does not occur, due to the relatively high oxidation potential of the CPD group. Long-lived charge separation is not observed. Irradiation of CPD-P-C(60) with UV (254 nm) light converts the triad back to the DHP form. Thermal interconversion of the DHP and CPD forms is very slow, photochemical cycling is facile, and in the absence of oxygen, many cycles may be performed without substantial degradation. Thus, light is used to switch long-lived photoinduced charge separation on or off. The principles demonstrated by the triad may be useful for the design of molecule-based optoelectronic systems.     

Fluorometric determination of non-fluorescent amines by ion-pair extraction

Summary An ion pair extraction method is described for quantitative fluorometric determination in the ng/ml range of non-fluorescent amines used as drugs. As counter ion, reagent, anthracene-2-sulphonate was used. Its extracting ability of ion pairs with amines was studied by determination of extraction constants and its fluorescence properties by determination of quantum yield of fluorescence. The properties of a suitable organic solvent is discussed and methylene chloride was found to be advantageous. Conditions for quantitative extraction and determination are given and the method was applied to determination of amitriptyline in the range 10–100 ng/ml giving an extraction degree of 100% and a precision of 5%.

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Fluorimetrische Bestimmung nicht fluorescierender Amine durch Ionenpaarextraktion

Zusammenfassung Die untersuchten Amine finden Verwendung als Arzneimittel und können in Mengen von ng/ml bestimmt werden. Anthracen-2-sulfonat dient als Gegenion. Die Eignung zur Ionenpaarextraktion wird durch Bestimmung der Extraktionskonstanten geprüft. Die Fluorescenzeigenschaften werden durch Messung der Quantenausbeuten der Fluorescenz bestimmt. Die erforderlichen Eigenschaften eines Lösungsmittels werden diskutiert. Methylenchlorid erweist sich dabei als gut geeignet. Die Bedingungen für quantitative Extraktion und Bestimmung werden angegeben. Die Methode wurde für die Bestimmung von Amitriptyline im Bereich 10–100 ng/ml ausgearbeitet, wobei sich ein Extraktionsgrad von 100% und eine Präzision von 5% ergaben.