Organic matter removal in boiler feed water treatment of a power plant with ozone

The purpose of this work was to test the effectiveness of ozone as a treatment to remove organic matter of the boiler feed water of a power plant. In the experiments carried out in the power plant Endesa in As Pontes (Spain), chlorine was substituted for ozone in the pre‐treatment stage. The use of ozone reduced the organic content of the boiler feed water by an average 20% compared with chlorination and by 50% when ozone was combined with hydrogen peroxide. The latter treatment achieved an organic content in the boiler feed water of less than 40 μg C/L. The ozone treatment also reduced the content of trihalomethanes in the drinking water, produced by the same plant, to values in the range of 10 μg/L and even to undetectable values when ozone was combined with hydrogen peroxide, in spite of the postchlorination applied to this stream to ensure a disinfectant capacity though the distribution system.     

Alzheimer’s Disease Seen through the Eye: Ocular Alterations and Neurodegeneration

Alzheimer’s Disease (AD) is one of the main neurodegenerative diseases worldwide. Unfortunately, AD shares many similarities with other dementias at early stages, which impedes an accurate premortem diagnosis. Therefore, it is urgent to find biomarkers to allow for early diagnosis of the disease. There is increasing scientific evidence highlighting the similarities between the eye and other structures of the CNS, suggesting that knowledge acquired in eye research could be useful for research and diagnosis of AD. For example, the retina and optic nerve are considered part of the central nervous system, and their damage can result in retrograde and anterograde axon degeneration, as well as abnormal protein aggregation. In the anterior eye segment, the aqueous humor and tear film may be comparable to the cerebrospinal fluid. Both fluids are enriched with molecules that can be potential neurodegenerative biomarkers. Indeed, the pathophysiology of AD, characterized by cerebral deposits of amyloid-beta (Aβ) and tau protein, is also present in the eyes of AD patients, besides numerous structural and functional changes observed in the structure of the eyes. Therefore, all this evidence suggests that ocular changes have the potential to be used as either predictive values for AD assessment or as diagnostic tools.     

Anaerobic treatment of azo dye Acid Orange 7 under fed-batch and continuous conditions

Acid Orange 7 (AO7) was treated anaerobically under fed-batch and continuous conditions. Fed-batch assays carried out with and without cosubstrate showed that the removal rate of this dye is highly favourable when glucose is added as cosubstrate. In addition, some intermediates generated after the reductive breakdown of AO7, such as 1-amino-2-naphthol (1A2N), seem to play a significant role as redox mediators, thus increasing the degradation rate of the dye. This effect is evidenced by the fact that, during the first feeding, the maximum AO7 removal rate was achieved after a lag phase, whereas for further AO7 feedings this phase was not observed. This can be explained by the presence of 1-amino-2-naphthol in the medium. During the continuous treatment with UASB reactors, AO7 loading rates of 1.7 mM d(-1) (590 mg l(-1)d(-1)) were achieved, with 92% AO7 removal efficiencies, operating with an influent comprised of AO7 (0.58 mM) and glucose (2 gl(-1)). In addition, when the cosubstrate was limiting (AO7 0.3 mM and glucose 0.25 gl(-1)), AO7 removal was significantly lower (78%).     

Modeling and synthesis of the interdigital/stub composite right/left‐handed artificial transmission line

An efficient design procedure, including both analysis and synthesis, is proposed for Composite Right/Left Handed (CRLH) interdigital/stub structures. Improved models are developed for both the interdigital capacitor and the shorted stub inductor including its ground via hole. Subsequent optimal formulas are recommended to model these components with their parasitic effects. The models and formulas are verified by both full‐wave and experimental results. A CAD program with a friendly GUI, available online, is provided and its operation is described in details. This program allows a very fast design of the CRLH structure, and its synthesis parameters are proven very accurate without any full‐wave optimization. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

Comparison of PCR, culture, and histopathology for diagnosis of tuberculous pericarditis

Nucleic acid amplification techniques for the diagnosis of tuberculosis (TB) are rapidly being developed. Scant work, however, has focused on pericardial TB. Using cryopreserved specimens from a prior study of pericarditis, we compared PCR to culture and histopathology for the diagnosis of tuberculous pericarditis in 36 specimens of pericardial fluid and 19 specimens of pericardial tissue from 20 patients. Fluid and tissue were cultured on Lowenstein-Jensen and Middlebrook solid media and in BACTEC radiometric broth. Tissue specimens were stained with hematoxylin-eosin, Ziehl-Neelsen, auramine O, and Kinyoun stains and were examined for granuloma formation and acid-fast bacilli. PCR was performed with both fluid and tissue with IS6110-based primers specific for the Mycobacterium tuberculosis complex by published methods. Sixteen of the 20 patients had tuberculous pericarditis and 4 patients had other diagnoses. TB was correctly diagnosed by culture in 15 (93%) patients, by PCR in 13 (81%) patients, and by histology in 13 of 15 (87%) patients. PCR gave one false-positive result for a patient with Staphylococcus aureus pericarditis. Considering the individual specimens as the unit of analysis, M. tuberculosis was identified by culture in 30 of 43 specimens (70%) from patients with tuberculous pericarditis and by PCR in 14 of 28 specimens (50%) from patients with tuberculous pericarditis (P > 0.15). The sensitivity of PCR was higher with tissue specimens (12 of 15; 80%) than with fluid specimens (2 of 13; 15%; P = 0.002). In conclusion, the overall accuracy of PCR approached the results of conventional methods, although PCR was much faster. Therefore, PCR merits further development in this regard. The sensitivity of PCR with pericardial fluid was poor, and false-positive results with PCR remain a concern.     

Comparison of hypertensive and non-hypertensive lacunar infarcts

INTRODUCTION: Arterial hypertension and hypohyalinosis of the arterias perforantes are said to be the commonest cause of lacunar infarcts, although other etiological factors and anatomo-pathological lesions are described more and more frequently. We designed a study to compare the clinical topographic and prognostic characteristics of patients with hypertensive and non-hypertensive lacunar infarcts. MATERIAL AND METHODS: We selected 51 patients with lacunar infarcts: in 23 (45%) arterial hypertension was the only etiological factor recognized. In 28 (55%) other risk factors (16 diabetes mellitus, 17 cardiopathy, 8 hyperlipemia, 13 cigarette smoking and 11 alcoholism) were seen. We evaluated the form of presentation, the type of infarct and whether this was associated with headache. The degree of defect was determined on admission using the Canadian scale. The size of the infarct was measured on CT or RM, using whichever measurement was greater. The evolution of the condition was determined on the Canadian scale and the index of Barthel after three months. RESULTS: Age and sex distribution was similar to both groups. Motor hemiparesia was the commonest lacunar syndrome and the distribution was similar. There was no difference in form of onset, association with headache or neurological defect between the hypertensive and non-hypertensive lacunar infarcts. The topographical distribution, the presentation of single or multiple lesions, the size of the infarcts and the prognosis were similar in both groups. CONCLUSIONS: Lacunar infarcts, whether hypertensive or not, show no differences regarding clinical, neuro-radiological or evolutionary characteristics.     

Construction process performance variability: Focus on labour productivity

The authors claim that unlike most other studies, in which the variability of productivity data was shown to fall within a specific distributional shape, this work has brought into light a distribution which is flexible and yet represents in a simple form most productivity distributions. This was shown in the contrasting distributional shapes of concreting and excavation productivity distributions.     

Study of the browning and gelation kinetics in a concentrated sheep milk and sucrose system

Browning and gelation kinetics of a sheep milk and sucrose model system with 70% total solids (simulating dulce de leche) and the influence of temperature and sucrose content on this process were studied. The Kubelka–Munk index and subjective heat stability tests were used to monitor nonenzymatic browning and to determine gelation time. Browning and gelation processes showed different kinetics where gelation was shown to occur much faster than browning. Both independent variables (temperature and sucrose content) had a significant influence in both processes, where temperature had the higher impact.     

Comparison between the conventional anaerobic digestion of sewage sludge and its combination with a chemical or thermal pre-treatment concerning the removal of pharmaceuticals and personal care products.

Many novel treatment technologies, usually representing a pre-treatment prior to the biological degradation process, have been developed in order to improve the recycling and reuse of sewage sludge. Among all the methods available, a chemical (alkaline) and a thermal treatment have been considered in this study. The behaviour of 13 substances belonging to different therapeutic classes (musks, tranquillisers, antiepileptic, anti-inflammatories, antibiotics, X-ray contrast media and estrogens) has been studied during the anaerobic digestion of sewage sludge combined with these pre-treatments (advanced operation) in comparison with the conventional process. Two parameters have been analysed: the temperature (mesophilic and thermophilic conditions) and the sludge retention time. While organic matter solubilization was higher with the alkaline process (55-80%), no difference between both pre-treatments was observed concerning volatile solids solubilization (up to 20%). The removal efficiencies of solids and organic matter during anaerobic digestion ranged from 40-70% and 45-75%, respectively. The higher removal efficiencies of pharmaceuticals and personal care products were achieved for the antibiotics, Naproxen and the natural estrogens (>80%). For the other compounds, the values were in the range 20-70%, except for Carbamazepine, which was not removed at any condition tested.