Ozonation of Primary Sludge and Digested Sludge to Increase Methane Production in a Chemically Enhanced Primary Treatment Facility

The purpose of this research was the investigation of the ozonation of sludge as a method to improve anaerobic digestion performance in a chemically enhanced primary treatment facility. Batch tests were conducted to evaluate the effect of ozonation on the physicochemical characteristics of both primary and digested sludge. Then, the performance of semi-continuous anaerobic digesters in combination with ozone treatment was investigated (pre-ozonation and post-ozonation). Ozonation of primary sludge did not increase the soluble COD nor the biodegradable COD, but resulted in the mineralization of a fraction of the organic matter into CO₂. However, the ozonation of anaerobic digested sludge resulted in an increase in soluble COD and biodegradable COD and in a small level of mineralization at the dose of 90 mg O₃/g COD. Pre-ozonation of primary sludge was not effective in enhancing the performance of the anaerobic digester. The coupling of ozonation and anaerobic digestion by means of the post-ozonation of digested sludge was found to be effective in improving methane production (+16%), for COD removal efficiency and for the dewaterability of anaerobic digesters compared to the control digester.     

Extremely regio‐regular poly (3‐alkylthiophene)s from simplified chain‐growth Grignard metathesis polymerisations and the modification of their chain‐ends

A simplified route to regio‐regular poly(3‐alkylthiophene)s (P3AT) with predetermined molecular weights and low molecular weight distributions based on the chain‐growth GRIM polymerisation of 2,5‐dibromo‐3‐alkylthiophenes is detailed. It is proposed by way of in‐depth ¹³C‐, ¹H‐ and two‐dimensional NMR characterisations that the resulting P3ATs are quasi‐100% regio‐regular except for one regio‐irregular pair at one chain‐end. It is probable that chain‐end groups exhibit reduced conjugation with the rest of the polymer. A comparison of the preparation of poly(3‐hexylthiophene) and poly(3‐butylthiophene) (P3BT) is presented. New methods required for the hydrogenation, formylation and bromomethylation of the chain‐ends of P3BT, necessary to overcome its poor solubility and low reactivity, are described. Copyright © 2006 Society of Chemical Industry     

Insertion of a double pigtail ureteral stent for the prevention of urological complications in renal transplantation: a prospective randomized study

PURPOSE: Urologists successfully use ureteral stents to protect the ureterovesical anastomosis in nontransplant patients. MATERIALS AND METHODS: We determined the value of ureteral stents in transplant patients. The frequency of urological complications (leaks, obstructions and urinary tract infections) was compared in a prospective randomized series of 194 kidney transplantations (97 with and 97 without a double pigtail ureteral stent). RESULTS: In the stent group 1 patient had a urinary leak and 35 had urinary tract infections (including 2 cases of Corynebacterium cystitis). In the no stent group 6 patients had urinary leaks, 4 had obstructions and 32 had urinary tract infections. The 1-year patient and graft survival rates were similar in both groups, and renal function at 1 year was also similar (229 versus 208 mumol./l. creatinine in the stent and no stent groups, respectively). A small number of stent related complications occurred (2 stent breakages and 1 stent migration). No stones formed in any case. CONCLUSIONS: Ureteral stent insertion significantly decreases the rate of vesicoureteral leakage and obstruction in renal transplantation.     

A new versatile in-process monitoring system for milling

Tool condition monitoring (TCM) systems can improve productivity and ensure workpiece quality, yet, there is a lack of reliable TCM solutions for small-batch or one-off manufacturing of industrial parts. TCM methods which include the characteristics of the cut seem to be particularly suitable for these demanding applications. In the first section of this paper, three process-based indicators have been retrieved from literature dealing with TCM. They are analysed using a cutting force model and experiments are carried out in industrial conditions. Specific transient cuttings encountered during the machining of the test part reveal the indicators to be unreliable. Consequently, in the second section, a versatile in-process monitoring method is suggested. Based on experiments carried out under a range of different cutting conditions, an adequate indicator is proposed: the relative radial eccentricity of the cutters is estimated at each instant and characterizes the tool state. It is then compared with the previous tool state in order to detect cutter breakage or chipping. Lastly, the new approach is shown to be reliable when implemented during the machining of the test part.     

Scale-Space Image Analysis Based on Hermite Polynomials Theory

The Hermite transform allows to locally approximate an image by a linear combination of polynomials. For a given scale σ and position ξ, the polynomial coefficients are closely related to the differential jet (set of partial derivatives of the blurred image) for the same scale and position. By making use of a classical formula due to Mehler (late 19th century), we establish a linear relationship linking the differential jets at two different scales σ and positions ξ involving Hermite polynomials. For multi-dimensional images, anisotropic excursions in scale-space can be handled in this way. Pattern registration and matching applications are suggested.We introduce a Gaussian windowed correlation function K (ν) for locally matching two images. When taking the mutual translation parameter ν as an independent variable, we express the Hermite coefficients of K (ν)interms of the Hermite coefficients of the two images being matched. This new result bears similarity with the Wiener-Khinchin theorem which links the Fourier transform of the conventional (flat-windowed) correlation function with the Fourier spectra of the images being correlated. Compared to the conventional correlation function, ours is more suited for matching localized image features.Numerical simulations using 2D test images illustrate the potentials of our proposals for signal and image matching in terms of accuracy and algorithmic complexity.First online version published in June, 2005     

Exposure to elevated levels of dietary fat attenuates psychostimulant reward and mesolimbic dopamine turnover in the rat.

Recent studies indicate that decreased central dopamine is associated with diet-induced obesity in humans and in animal models. In the current study, the authors assessed the hypothesis that diet-induced obesity reduces mesolimbic dopamine function. Specifically, the authors compared dopamine turnover in this region between rats fed a high-fat diet and those consuming a standard low-fat diet. The authors also assessed behavioral consequences of diet-induced obesity by testing the response of these animals in a conditioned place paradigm using amphetamine as a reinforcer and in an operant conditioning paradigm using sucrose reinforcement. Results demonstrate that animals consuming a high-fat diet, independent of the development of obesity, exhibit decreased dopamine turnover in the mesolimbic system, reduced preference for an amphetamine cue, and attenuated operant responding for sucrose. The authors also observed that diet-induced obesity with a high-fat diet attenuated mesolimbic dopamine turnover in the nucleus accumbens. These data are consistent with recent hypotheses that the hormonal signals derived from adipose tissue regulate the activity of central nervous system structures involved in reward and motivation, which may have implications for the treatment of obesity and/or addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A system to simulate gas exchange in humans to control quality of metabolic measurements

The present experiments were designed to compare the behavior of cerebral blood flow (CBF) during acute moderate and severe hypotensive episodes induced by either ventricular tachycardias (VT) or by hemorrhage. Using the microsphere method CBF was determined in 20 Sprague-Dawley rats during sinus rhythm (Group A), in 28 animals during high-rate VT (Group B) and in 10 animals after hemorrhage (Group C). According to the decrease in blood pressure and with respect to the lower threshold of cerebral autoregulation Group B was divided into 2 subgroups (B1: 80-130 mmHg; B2: 50-80 mmHg) retrospectively. While CBF remained constant in Group B1 (0.98 +/- 0.3 ml g-1 min-1 vs. 1.01 +/- 0.32 in controls, NS), CBF decreased markedly during severely hypotensive VT in Group B2 (0.52 +/- 0.2 ml g-1 min-1, p < 0.001 vs. A; p < 0.05 vs. C) and during hypovolemic hypotension in Group C (0.77 +/- 0.22 ml g-1 min-1 vs. A; NS). Cerebrovascular resistance and autoregulation indices indicated a maintenance of CBF regulation during hypovolemic hypotension and a failure during normovolemic hypotension. These findings indicate that the autoregulatory ability of the brain is substantially more stable during hypovolemic hypotension than during normovolemic hypotension. Therefore, the hemodynamic sequelae of acute hypotensive episodes on CBF depend on the underlying cause of hypotension.     

Linux：移动创新的未来

Linux融合了功能强大、安全、可靠的平台支持和中立性、灵活性、低成本性的优势。Linux有潜力为移动生态系统中的每个参与者带来价值,并能够推动移动市场的快速发展。让我们面对事实,多数手机及其应用软件均索然无味。移动运营商及其手机供应商总是努力使自己的产品在竞争中脱颖而出,他们多半通过硬件性能来实现上述目的。手机体积变得越来越小,具有彩色屏幕、摄像头,甚至可以播放音乐和视频。     

The 65-nm 16-MB Shared On-Die L3 Cache for the Dual-Core Intel Xeon Processor 7100 Series

The 16-way set associative, single-ported 16-MB cache for the Dual-Core Intel Xeon Processor 7100 Series uses a 0.624 mum² cell in a 65-nm 8-metal technology. Low power techniques are implemented in the L3 cache to minimize both leakage and dynamic power. Sleep transistors are used in the SRAM array and peripherals, reducing the cache leakage by more than 2X. Only 0.8% of the cache is powered up for a cache access. Dynamic cache line disable (Intel Cache Safe Technology) with a history buffer protects the cache from latent defects and infant mortality failures