Phenols in anaerobic digestion processes and inhibition of ammonia oxidising bacteria (AOB) in soil

This study focuses on the presence of phenols in digestate from seven Swedish large-scale anaerobic digestion processes and their impact on the activity of ammonia oxidising bacteria (AOB) in soil. In addition, the importance of feedstock composition and phenol degradation capacity for the occurrence of phenols in the digestate was investigated in the same processes. The results revealed that the content of phenols in the digestate was related to the inhibition of the activity of AOB in soil (EC(50)=26 microg phenols g(-1) d.w. soil). In addition, five pure phenols (phenol, o-, p-, m-cresol and 4-ethylphenol) inhibited the AOB to a similar extent (EC(50)=43-110 microg g(-1) d.w. soil). The phenol content in the digestate was mainly dependent on the composition of the feedstock, but also to some extent by the degradation capacity in the anaerobic digestion process. Swine manure in the feedstock resulted in digestate containing higher amounts of phenols than digestate from reactors with less or no swine manure in the feedstock. The degradation capacity of phenol and p-cresol was studied in diluted small-scale batch cultures and revealed that anaerobic digestion at mesophilic temperatures generally exhibited a higher degradation capacity compared to digestion at thermophilic temperature. Although phenol, p-cresol and 4-ethylphenol were quickly degraded in soil, the phenols added with the digestate constitute an environmental risk according to the guideline values for contaminated soils set by the Swedish Environmental Protection Agency. In conclusion, the management of anaerobic digestion processes is of decisive importance for the production of digestate with low amounts of phenols, and thereby little risks for negative effects of the phenols on the soil ecosystem.     

Anomalous weak values via a single photon detection

Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre-and...     

Assessment of pitting corrosion in bare and passivated (wet scCO2-induced patination and chemical passivation) hot-dip galvanized steel samples with SVET,FTIR, and SEM (EDS)

In this study, the local electrochemical activity of untreated and passivated (natural or chemical passivation) zinc specimens was observed during immersion in a 0.1-M NaCl solution. The localized anodic activity during the exposure, measured with the scanning vibrating electrode technique, was linked to zinc dissolution by the pitting corrosion mechanism. It was correlated to specific corrosion products characterized by Fourier transmission infrared (FTIR) microscopy. FTIR molecule maps were produced from individual pitting corrosion sites (100–200 µm in width). With argon ion beam milling and latest energy-dispersive X-ray spectroscopy (EDS) technology, element maps with a high spatial resolution (≪100 nm) were recorded from abrasion- and beam-sensitive corrosion products, showing a residual layer structure. This study demonstrates the capability of FTIR mapping, cross-section polishing, and state-of-the-art scanning electron microscopy imaging, and EDS element mapping to produce high-resolution elemental, molecular, and visual information about pitting corrosion mechanisms on a hot-dip galvanized steel sample.     

The effects of laser patterning 10CeTZP-Al2O3 nanocomposite disc surfaces: Osseous differentiation and cellular arrangement in vitro

Customized square grid arrangements of different groove depths (1.0, 1.5 and 3.0?µm) and separations (10 and 30?µm) were successfully laser patterned, using a nanosecond pulsed fibre laser, on the surface of 10?mol% ceria-stabilized zirconia and alumina (10CeTZP-Al₂O₃) nanocomposite discs (diameter: 10?mm; thickness: 1.5?mm). The patterned surfaces and the in vitro biological response of osteoblasts (SAOS-2) towards them were thoroughly analysed. In terms of composition, the laser treatment was found to cause superficial monoclinic-tetragonal zirconia phase transformation and alumina evaporation. In vitro, the most effective grid configuration for osseous differentiation was found to be 1.5?µm groove depth and 10?µm groove separation, and confocal microscopy revealed that the cells show a tendency to be sorted as groove depth increases. It is thought that custom-made patterns could be produced to guide cell attachment in vivo, which could favour implant integration and reduce healing time.     

Through a narrow window: Sample size and the perception of correlation.

A theoretical analysis (Y. Kareev, 1995b) of the sampling distribution of correlations led to the surprising conclusion that the use of small samples has a potential advantage for the early detection of a correlation. This is so because the distribution is highly skewed, and the smaller the sample size, the more the distribution is skewed. This article describes 2 experiments that were designed as empirical tests of this conclusion. In Experiment 1 (N?=?112), the authors compared the predictions of participants differing in their working-memory capacity (hence in the size of the samples they were likely to consider). In Experiment 2 (N?=?144), the authors compared the predictions of participants who viewed samples of different sizes, whose size was determined by the authors. The results fully supported Y. Kareev's conclusion: In both experiments, participants with lower capacity (or smaller samples) indeed perceived the correlation as more extreme and were more accurate in their predictions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microprocessor Adaptive Control of Oil Temperature for Robot Arm Valves: A Practical Implementation

An assembly line quality control robotic arm has to have a very accurate regulation of the hydraulic oil temperature. An adaptive control strategy is designed and implemented, based on on-line parameter identification and optimum integral compensation realization. Design details, implementation, and performance data are presented.     

Parotid pleomorphic adenomas: delayed CT enhancement

BACKGROUND AND PURPOSE: Weak or absent CT enhancement in pleomorphic adenomas of the parotid gland has been observed immediately after i.v. contrast administration. This feature can result in poor lesion conspicuity relative to both normal parotid tissue and other parotid abnormalities. The purpose of this study was to document the delayed CT enhancement characteristics of parotid pleomorphic adenomas and to preliminarily compare these results with the enhancement characteristics of other parotid gland tumors. METHODS: Preoperative CT scans from 18 pathologically proved parotid gland neoplasms were reviewed retrospectively. Lesions included eight pleomorphic adenomas, four Warthin's tumors, two squamous cell carcinomas, two mucoepidermoid cancers, one acinic cell carcinoma, and one melanoma metastasis. In all cases, axial CT was performed after the administration of 100 to 150 mL of i.v. contrast material, followed by delayed (average, 24 minutes; range, 13 to 34 minutes) coronal CT scanning. The mean normalized Hounsfield unit (HU) attenuation of each lesion was computed by drawing a region of interest around the entire mass and dividing the resulting HU value by that of the contralateral uninvolved parotid gland. RESULTS: For all eight pleomorphic adenomas, the degree of contrast enhancement increased and became progressively more uniform with time. Mean normalized axial lesion enhancement averaged 1.20 +/- 0.35 at 8 minutes, compared with 2.30 +/- 0.66 on the coronal scans at 24 minutes. For the 10 nonpleomorphic adenomas, no significant change was found in either the degree or pattern of contrast enhancement between the immediate and delayed CT scans. In these tumors, peak enhancement was reached early, during axial scanning. CONCLUSION: Delayed CT contrast enhancement is observed in parotid pleomorphic adenomas, increasing in both degree and homogeneity with time. This feature may be useful in selecting an appropriate contrast delay when scanning possible pleomorphic adenomas to improve lesion conspicuity and, potentially, to better distinguish these tumors from other parotid abnormalities.     

Electron microscopy studies of amphiphilic self-assemblies on vitreous ice

The structure of self-assemblies of amphiphiles formed at the air–aqueous solution interface can be determined by cryo transmission electron microscopy (Cryo-TEM). The method is based on fast vitrification of the thin layer of aqueous solution covered with amphiphilic monolayer by plunging the specimen into liquid ethane at its freezing point. During the process of fast cooling the aggregates maintain their two-dimensional crystalline integrity and structure, as demonstrated by comparative studies involving grazing incidence X-ray diffraction (GID) at the air-solution interface, and the Cryo-TEM measurements of the same amphiphilic systems on vitreous ice. Bright-field and dark-field images from the Cryo-TEM observations provide more detailed information than from epifluorescence and Brewster angle microscopy. Furthermore, the electron diffraction patterns have the additional advantage that they allow structural characterization of the crystallites almost at a molecular level, and furnish data on micro twinning and defects occurring between crystalline domains. Cryo-TEM has been applied to elucidate the structure of 2-D and 3-D self-aggregates of amphiphilic alcohols, acids and their cadmium salts, bola-amphiphiles and mixed monolayers. Epitaxial crystallization of hexagonal ice underneath the monolayer of long chain alcohol was also directly demonstrated by this method.