Biodegradation of Plastics in Compost Prepared at Different Composting Conditions

Maximum temperature during the thermophilic phase and moisture content were controlled in the course of composting to examine the effects of these composting conditions on the quality of the compost used for the evaluation of the biodegradability of plastics. The moisture content during composting was controlled at 65%, while keeping the maximum temperature below 46°C, 58°C and 70°C, respectively. In turn, the maximum temperature was controlled to be below 58°C, while maintaining the moisture content at 45%, 55% and 65% respectively. The number of microbial cells was examined in the five compost samples thus prepared. Biodegradation of cellulose, polycaprolactone and poly(butylene succinate-co-butylene adipate) was conducted in the five compost samples, and the consistency and reproducibility of the test results were explored.     

Output Characteristics of High-Power Continuous Wave Raman Fiber Laser at 1239 nm Using Phosphosilicate Fiber

A high-power singlemode Raman fiber laser (RFL) with maximum output power of 4.11 W and maximum power conversion efficiency of 47.40% at 1239 nm is realized using continuous wave 8.4 W Yb-doped double-clad fiber laser as a pump, 700 m phosphosilicate fiber, and a Raman cavity formed by a pair of fiber Bragg grating mirrors at 1239 nm. The output characteristics of the RFL at 1239 nm for different fiber lengths and output mirror reflectance are reported. Theoretical simulation is done to numerically optimize for fiber length and output coupler reflectivity to obtain maximum first Stokes power.     

Methoxy[meso‐5,10,15,20‐tetrakis(2,6‐difluorophenyl)porphyrinato]­iron(III), [Fe(TDFPP)(OCH3)]

The crystal structure of the title compound, [Fe(C₄₄H₂₀F₈N₄)(CH₃O)], has been determined. The Fe atom lies 0.485 (1) Å out of the plane of the four N atoms to which it is coordinated and from the inversion centre at the origin of the unit cell. The methoxy group is axially coordinated to the Fe atom with O—Fe—N angles of 106.3 (2) and 102.4 (2)°, a C—O—Fe angle of 128.3 (5)° and an Fe—O distance of 1.788 (5) Å. Di­fluoro­phenyl rings are tilted from the porphyrin (por) plane with torsion angles of ?68.1 (6) and 77.7 (5)° across the two C_por—­C—C—C_ar systems.     

Synthesis and Evaluation of Potentiometric Properties of Pyridylthiazole Derivatives

Synthesis of 2-pyridylthiazole ethers 2, 3), 4-nonyl-2-pyridylthiazole 4), 2-nonyl-4-pyridylthiazole 5) and 2-pyridylthiazole imine 6), potentially useful as effective cation-binding ligands, is described. The potentiometric properties of ion-selective membranes prepared with 30–32 wt% PVC, 66 wt% 2-nitrophenyloctyl ether and 2–4 wt% pyridylthiazole derivatives have been examined. While the membranes containing 2-pyridylthiazole ethers 1-4) exhibited high selectivity toward silver(I) ion, that prepared with 2-pyridylthiazole imine 6) resulted in negligible potentiometric reponse to most mono- and divalent cations.     

AnM/M/c queue with impatient customers

This paper considers theM/M/c queue in which a customer leaves when its service has not begun within a fixed interval after its arrival. The loss probability can be expressed in a simple formula involving the waiting time probabilities in the standardM/M/c queue. The purpose of this paper is to give a probabilistic derivation of this formula and to outline a possible use of this general formula in theM/M/c retrial queue with impatient customers. This research was supported by the INTAS 96-0828 research project and was presented at the First International Workshop on Retrial Queues, Universidad Complutense de Madrid, Madrid, September 22–24, 1998.     

Thermal rearrangement of 1,3-thiazolidine sulfoxides: Thiolsulfinate and thioaldehyde intermediates

Stereospecific ring opening of the sulfoxides cis- 13 and trans- 14 in refluxing toluene gave the corre sponding sulfenic acids 9 , 10 intermediates respectively. The sulfenic acid 9 dimerized to the thiolsulfinate 17 by dual function of the sulfenic acid as S-nucleophile/S-electrophile with loss of water while the sulfenic acid 10 was unchanged. The stereospecific recyclization of 10 to the parent sulfoxide 14 increases the higher pi-electron density of the double. The thermolysis of the thiolsulfinate 17 gave the transient sulfenic acid 9 , which dimerized again to repeat the process and unisolable thioaldehyde 21 . The thioaldehyde 21 was con verted to either pyrrole 15 by the action of a sulfinic acid 20 catalyst formed inevitably by hydrolysis of 17 under the reaction conditions, or thiazole 18 under neutral conditions. In these rearrangements, the amide carbonyl group facilitated the elimination of a neighboring hydrogen.     

Ethanol production using concentrated oak wood hydrolysates and methods to detoxify

Ethanol production from concentrated oak wood hydrolysate was carried out to obtain a high ethanol concentration and a high ethanol yield. The effect of added inhibitory compounds, which are typically produced in the pretreatment step of steam-explosion on ethanol fermentation, was also examined. p-Hydroxybenzoic aldehyde, a lignin-degradation product, was the most inhibitory compound tested in this study. Compounds with additional methyl groups had reduced toxicity and the aromatic acids were less toxic than the corresponding aldehydes. The lignin-degradation products were more inhibitory than the sugar-derived products, such as furfural and 5-hydroxymethylfurfural (HMF). Adaptation of yeast cells to the wood hydrolysate and detoxification methods, such as using charcoal and overlime, had some beneficial effects on ethanol production using the concentrated wood hydrolysate. After treatment with charcoal and low-temperature sterilization, the yeast cells could utilize the concentrated wood hydrolysate with 170 as well as 140 g/L glucose, and produce 69.9 and 74.2 g/L ethanol, respectively, with a yield of 0.46–0.48 g ethanol/g glucose. In contrast, the cells could not completely utilize untreated wood hydrolysate with 100 g/L glucose. Low-temperature sterilization, with or without charcoal treatment, was very effective for ethanol production when highly concentrated wood hydrolysates were used. Low-temperature sterilization has advantages over traditional detoxification methods, such as using overlime, ion exchange, and charcoal, because of the reduction in the total cost of ethanol production.     

Ligand Sensitized Flourometric Determination of Dysprosium(III) Ion Using Terephthalic Acid

Several trivalent lanthanide ions are known to exhibit excellent luminescence characteristics when they are coordinated with appropriate organic ligands. Various analytical methods have been developed to determine lanthanide ions or organic compounds by taking advantage of these luminescence characteristics. The luminescence enhancement of the lanthanide ions by complexation with organic ligands has been explained on the basis of a ligand to metal energy transfer process.