829 research outputs found

    Improvement of the Wastewater Biodegradability by Means of Photocatalytic and Wet Oxidation Processes in the Presence of Hydrogen Peroxide

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    In this study, the effectiveness of photocatalytic oxidation (PO) and wet oxidation (WO) processes as a pre-treatment step on improvement of biodegradability and colour removal of mixture of raw domestic and pre-treated industrial wastewaters, have been evaluated. More oxygen was obtained by H2O2 (as an oxidant in WO and PO processes) than stoichiometric demand. PO of the wastewater was carried out by illumination of the wastewater with UV lamp (at room temperature, atmospheric pressure, 16.5 h reaction time) and WO of the wastewater was carried out by means of thermal oxidation at autoclave conditions (at 118–120 oC, 1.9–2 bar, 3 h reaction time). 1 g L–1 TiO2 in PO process and 0.2 mg L–1 Cu++ in WO process were used as catalyst. The results obtained from experiments were not compared with each other due to the difference between the quality and quantity of the used catalyst and the consumed energy. Colour removal efficiency was 33 % for WO process and 77.6 % for PO process. By applying WO process, 72.7 % increase in the reaction rate coefficient describing the degradability of organic compounds in wastewater was obtained, but this value was 34.5 % in PO process

    Microdevices for Continuous Sized Based Sorting by AC Dielectrophoresis

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    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this project, various microfluidic devices are designed for microparticles and cells separation. The dominant regions of dielectrophoresis among other AC Electrokinetic transport mechanisms are predicted. Flow behaviors of particles for each design parameter are modeled and simulated using COMSOL Multiphysics 4.3a software. Lab-on-a-chip devices having a Ti interdigitated electrode layer on a glass substrate and a PDMS microchannel are fabricated to investigate the most effective design solution for separating particles based on their sizes. Polystyrene particles with different diameters of 3.2 μm and 9.8 μm are used in our experiments and experiments with circulating tumor cells (CTCs) are in progress

    Unusual Formation of Point-Defect Complexes in the Ultrawide-Band-Gap Semiconductor β-Ga2 O3

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    Understanding the unique properties of ultra-wide band gap semiconductors requires detailed information about the exact nature of point defects and their role in determining the properties. Here, we report the first direct microscopic observation of an unusual formation of point defect complexes within the atomic-scale structure of β-Ga2O3 using high resolution scanning transmission electron microscopy (STEM). Each complex involves one cation interstitial atom paired with two cation vacancies. These divacancy-interstitial complexes correlate directly with structures obtained by density functional theory, which predicts them to be compensating acceptors in β-Ga2O3. This prediction is confirmed by a comparison between STEM data and deep level optical spectroscopy results, which reveals that these complexes correspond to a deep trap within the band gap, and that the development of the complexes is facilitated by Sn doping through increased vacancy concentration. These findings provide new insight on this emerging material's unique response to the incorporation of impurities that can critically influence their properties

    Clinical and laboratory findings in mad honey poisoning: A single center experience

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    Objective: This study is aimed at analyzing the demographic and clinical characteristics, as well as the hematological.biochemical parameters of patients who admitted to the hospital with the diagnosis of mad honey poisoning.Materials and Methods: A total of 16 patients who were admitted with mad honey intoxication symptoms and treated in Emergency Department of Sakarya Education and Research Hospital between January 2009 and December 2012 were included in the study. Demographic and clinical characteristics of the patients and hematological, biochemical parameters were obtained from hospital records. Heart rate, systolic and diastolic blood pressure on admission and at discharge were obtained retrospectively.Results: Sixteen patients (10 males and 6 females, mean age 58.5 ± 10 years, range between 41 and 79) were included in our study. Heart rate was 42± 6 beats/min, systolic blood pressure was 73 ± 19 mmHg, and diastolic blood pressure was 45 ± 17 mmHg on admission. In the evaluation of the patients' heart rhythms on admission to the emergency room, nine  (56.3%) patients had sinus bradycardia, three (18.8%) patients had nodal rhythm, two (12.5%) patients had first degree atrioventricular block, and two (12.5%) patients had atrial fibrillation. Atropine 1.1 ± 0.4 mg and saline 1125 ± 465 ml were used to treat patients. Patients were discharged with a stable condition after an average 27.7 ±7.2 h of follow.up. Heart rate was 75 ± 8 beats/min, systolic blood pressure was 132 ± 7 mmHg, and diastolic blood pressure was 82 ± 6 mmHg at discharge. Mortality was not observed. Hematological and biochemical parameters measured at the time of admission were within normal ranges.Conclusion: Mad honey poisoning should be considered in previously  healthy patients with unexplained symptoms of bradycardia, hypotension, and cardiac dysrhythmias. Therefore, diet history should carefully be  obtained from the patients admitted with bradycardia and hypotension, and mad honey intoxication should also be considered in the differential  diagnosis, as well as primary cardiac, neurologic, and metabolic disorders. Mad honey poisoning may be presented with life.threatening symptoms without any hematological and biochemical disorder.Key words: clinical and laboratory findings, mad honey, poisonin

    Functional brain plasticity following childhood maltreatment: A longitudinal fMRI investigation of autobiographical memory processing

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    Altered autobiographical memory (ABM) processing characterizes some individuals with experiences of childhood maltreatment. This fMRI study of ABM processing evaluated potential developmental plasticity in neural functioning following maltreatment. Adolescents with (N = 19; MT group) and without (N = 18; Non-MT group) documented childhood maltreatment recalled specific ABMs in response to emotionally valenced cue words during fMRI at baseline (age 12.71 ± 1.48) and follow-up (14.88 ± 1.53 years). Psychological assessments were collected at both timepoints. Longitudinal analyses were carried out with BOLD signal changes during ABM recall and psychopathology to investigate change over time. In both groups there was relative stability of the ABM brain network, with some developmental maturational changes observed in cortical midline structures (ventromedial PFC (vmPFC), posterior cingulate cortex (pCC), and retrosplenial cortex (rSC). Significantly increased activation of the right rSC was observed only in the MT group, which was associated with improved psychological functioning. Baseline group differences in relation to hippocampal functioning, were not detected at follow-up. This study provides preliminary empirical evidence of functional developmental plasticity in children with documented maltreatment experience using fMRI. This suggests that altered patterns of brain function, associated with maltreatment experience, are not fixed and may reflect the potential to track a neural basis of resilience

    Trust and childhood maltreatment: evidence of bias in appraisal of unfamiliar faces

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    Background: Child maltreatment is associated with poorer social functioning and increased risk of mental health problems in adolescence and adulthood, but the processes underlying these associations remain unclear. Although crucial for establishing and maintaining relationships, trust judgements have not been experimentally investigated in children who have experienced abuse and neglect. Methods: A community-based sample of 75 children aged 8– 16 years with maltreatment documented on the basis of social services records, and a group of 70 peers matched on age, gender, cognitive ability, socioeconomic status, and ethnicity took part in the study. Children completed a trustworthiness face-judgement task in which they appraised the trustworthiness of unfamiliar facial stimuli varying along a computationally modelled trustworthiness dimension. Results: In line with clinical observations that childhood maltreatment is associated with an atypical pattern of trust processing, children with maltreatment experience were significantly less likely than their peers to rate unfamiliar faces as trustworthy. Moreover, they were more variable in their trust attributions than their peers. Conclusions: The study provides compelling experimental evidence that children with documented maltreatment perceive others as less trustworthy than their peers and are less consistent in their estimates of trustworthiness in others. Over time, alterations in trust processing may disrupt the development of social bonds and contribute to ‘social thinning’ (a reduction in the extent and quality of social relationships), leaving children more vulnerable to environmental stressors, increasing risk of mental health difficulties

    Acoustic and mechanical properties of luffa fiber-reinforced biocomposites

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    This chapter presents an overview of acoustic and mechanical behaviors of luffa fiber reinforced biocomposites. A growing number of studies are examining the composites of biodegradable fibers such as flax, hemp, kenaf and luffa due to the adverse effects of chemical materials on nature. The low cost and superior acoustic and acceptable mechanical properties of biocomposites make them very attractive for practical applications such as sound and vibration isolation. However, the acoustic and mechanical characteristics of biocomposites and their dynamic behaviors should be fully determined before considering them for practical applications. In this chapter, acoustic properties, such as sound absorption and transmission loss, and mechanical properties, such as damping and elasticity of luffa fiber reinforced composites, are presented. The variations in acoustic and mechanical properties due to different samples and manufacturing process are explored.WOS:000532438200017Scopus - Affiliation ID: 60105072Book Citation Index- ScienceArticle; Book ChapterOcak2019YÖK - 2018-1

    Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels

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    Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) were studied by exposing plants to six salinity levels (0–500 mM NaCl range) for 70 d. Salt stress was administered either by pre-mixing of the calculated amount of NaCl with the potting mix before seeds were planted or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment in old leaves and between 80% and 85% of osmotic adjustment in young leaves was achieved by means of accumulation of inorganic ions (Na+, K+, and Cl–) at these NaCl levels, whilst the contribution of organic osmolytes was very limited. Consistently higher K+ and lower Na+ levels were found in young, as compared with old leaves, for all salinity treatments. The shoot sap K+ progressively increased with increased salinity in old leaves; this is interpreted as evidence for the important role of free K+ in leaf osmotic adjustment under saline conditions. A 5-fold increase in salinity level (from 100 mM to 500 mM) resulted in only a 50% increase in the sap Na+ content, suggesting either a very strict control of xylem Na+ loading or an efficient Na+ removal from leaves. A very strong correlation between NaCl-induced K+ and H+ fluxes was observed in quinoa root, suggesting that a rapid NaCl-induced activation of H+-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K+ leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na+ sequestration, control of Na+ and K+ xylem loading, and their transport to the shoot
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