Denna rapport är utförd på uppdrag av företaget Norrvatten vilka driver vattenverket Görvälnverket i Jakobsberg utanför Stockholm. Studien är uppdelad i tre huvudmål. Det första målet innefattar att utföra en analys av befintlig mätdata från en sensor som sitter inuti vattenverket. Data från verket jämfördes med väderdata för att få fram eventuella samband. Information om samband skulle kunna leda till att Norrvatten kan använda sin mätutrustning mer effektivt. I analysen användes MatLab och vissa samband mellan TOC (Total Organic Carbon), nederbörd och vattenstånd kunde ses och tydliga säsongstrender kunde även urskiljas. Det andra målet var att komma med ett förslag på mätsystem för kartläggning av skiktningen i vattnet utanför vattenverket Görvälnverket. Syftet med kartläggningen är att se om det finns behov av ett nytt, djupare, råvattenintag. Det tredje målet var att komma med ett förslag på ett alternativ på ett sensorbaserat varningssystem för förändrad råvattenkvalitet utanför verket. Systemets syfte är att ge information till verket om förhöjda halter av förorenande ämnen. För varningssystem och kartläggning av skiktning användes ett bedömningssystem för att väga olika alternativ till mätsystem mot varandra. Bedömningssystemet bestod av tre urvalsmatriser vilka vägde in hur många parametrar som kunde mätas, hur väl de kunde mätas samt kostnader. Utifrån urvalsmatriserna valdes de mest lämpade alternativen för respektive mätsystem. För att kartlägga skiktningen valdes ett mätsystem bestående av sensorer sittande på befintliga provtagningsledningar vid intagsledningarna i verket. För det sensorbaserade varningssystem valdes ett system med sensorer från företaget PME. Mätsystem är tänkt att placeras på egenbyggd plattform under vattnet. Det placeras sedan runt verket för att mäta olika parametrar.

Thesis (Ph.D.)--Boston University / The purpose of the present study was to determine whether positive reinforcement, chlorpromazine and secobarbital alter the ability of chronic schizophrenics to maintain sustained attention and whether these affect their psychomotor functioning. Eight male, chronic schizophrenic patients, with an age range of 25-50 and in good physical health, served as the subjects. All subjects had been hospitalized continuously for at least three years. Medication was discontinued for all subjects two months before the study started. In the course of the study, each subject was tested twice under all of the following conditions: no-drug, placebo, chlorpromazine 100 mg, chlorpromazine 200 mg, secobarbital 100 mg, secobarbital 200 mg. The drugs were given once weekly in single doses. A testing day consisted of four sessions: 1/2, 1 1/2, 2 1/2, and 3 1/2 hours post-medication. The different drug conditions were administered according to a modified Latin Square design with each active drug following each other active drug an equal number of times. Half of the trials in each session were reinforced by candy and cigarettes and the other half were not. Two tests were employed: The Continuous Performance Test (CPT), and the Subject Paced Test (SPT). On the CPT, a test of sustained attention, a subject is required to respond, by pulling a lever, to one of twelve letters which are randomly exposed at the rate of 1.10 sec. for a period of .10 second.[TRUNCATED]

No description available.

Biological wastewater treatment is typically aerobic and an energy intensive process, mainly due to the required aeration. Alternative sustainable processes are sought, such as Microbial fuel cells (MFC) where electrogenic bacteria can degrade organic matter present in the waste stream while simultaneously generating electricity. MFCs represent an emerging technology which may deliver the capability to reduce the pollution potential of low strength wastewaters (< 1500 mg COD l-1) while generating electricity which could be used to self-power the process. Waste streams high in volatile fatty acids (VFAs) with high conductivity are particularly preferred substrate streams. These may include the effluent from two stage bio-hydrogen and bio-methane systems, which in this study were treated in a four-module tubular MFC (V=1 l) to reduce the chemical oxygen demand (COD) and recover further energy from the substrate. It was shown that the power increased with increasing organic loading rate (0.036-0.572 g sCOD l-1 d-1), but COD removal efficiency decreased. The Coulombic Efficiency (CE) was found to decrease significantly at OLR ˃ 0.6 g sCOD l-1 d-1 and the energy recovery was 92.95 J l-1 (OLR=0.572 g sCOD l-1 d-1). Also, wash-down waters from a chilled food producing company were treated in the same tubular MFC, reducing the soluble COD content by 84.8%. The low power (≈ 30 W m-3) and cell potential (≈ 0.5 V) makes it necessary to investigate methods such as external capacitors, DC/DC converters or serial and parallel connection to improve the power quality. In this thesis, the use of the intrinsic capacitance was tested by switched mode, open and closed circuit (OC/CC) operation of a 2-module tubular MFC with high surface area carbon veil anode. The charge accumulated during OC and released when switched to CC was dependent on the external resistor (R = 100-3 kΩ) and duty cycle. Short period OC/CC switching further increased potential due to the pseudo-capacitance of the reactor, but only at the expense of energy efficiency, compared to continuous operation (CC) under constant load. Another approach to enhance the practical implementation of MFCs is integration with other processes such as reverse electrodialysis to increase MFC’s cell potential or e.g. desalination. In this study a MFC was integrated with supported liquid membrane technology (SLM) for the first time, for the removal of metal ions of wastewater. A three chamber reactor, with a common cathode/feed phase containing 400 mg Zn2+ l-1, enabled V the simultaneous treatment of organic- and heavy metal containing wastewaters. The MFC/SLM combination produces a synergistic effect which enhances the power performance of the MFC significantly; 0.233 mW compared to 0.094 mW in the control. It is shown that the 165±7 mV difference between the MFC/SLM system and the MFC control is partially attributable to the lower cathode pH in the integrated system experiment, the consequent lower activation overpotential and higher oxygen reduction potential. The system demonstrates that within 72 h, 93±4% of the zinc ions are removed from the feed phase. A further study, with continuously operated cathode/feed chamber (100 mg Zn2+ l-1), showed that an enhanced effect on increasing cell potential was possible and could also be maintained in continuous operation.

No description available.

beta-Carbolines are tricyclic compounds deriving from the condensation of indoleamines or tryptophan with fairly electrophilic carbonylic compounds to form a fused benzene-pyrrole-pyridine ring system (Pictet-Spengler reaction). Previous investigation carried out with model systems proved the facile formation of various tetrahydro-beta-carboline-3-carboxylic acids (beta-CCA) from tryptophan and reactive carbonyls present in wood smoke, under conditions simulating those of foods during their smoking process. The present work has been undertaken to investigate and confirm the actual occurence of such compounds in real smoked foodstuffs of animal origin. Five representative beta-CCA were selected taking into account the high content of their precursor aldehydes in smoke (formaldehyde, acetaldehyde, glycolaldehyde) and/or the facility of their formation during the model system experiments (benzaldehyde and salicylaldehyde derivatives). They were synthesized following methods based on the Pictet-Spengler reaction as they were described in the literature, or by slightly modifying and altering them. The structure of the synthesised products was confirmed using spot tests, melting points, elemental analysis and spectrometric methods such as fluorescence, UV, 1HNMR, MS and 13CNMR spectroscopy. A method was developed for the isolation of these compounds from smoked solid foods. The samples were extracted with an aqueous acidic medium containing semicarbazide to prevent artifactual formation of beta-CCA. The extract was purified on an XAD-4 resin containing, clean-up column. The eluate was concentrated, further purified by extraction with CHaCla and analysed by high performance liquid chromatography on a Spherisorb ODS1 reversed phase column with gradient elution and fluorescence detection. The quantitation was based on calculating the ratio of the peek area of each compound to the peak area of the internal standard (serotonin creatinine sulphate). The mean recovery of the method was about 76% for the more hydrophilic derivatives of formaldehyde, acetaldehyde and glycol aldehyde and 11% for the more hydrophobic derivatives of benzaldehyde and salicylaldehyde. Higher concentrations of analytes in the samples led to decreased recoveries. The detection limit was lower than 25 mug/kg for the more hydrophilic and 2 mg/kg for the more hydrophobic group of compounds. Thirty four samples of miscellaneous smoked food products such as dry salamis, heat processed comminuted meat products, cured meats (heat processed or not), raw or heat processed fish, hard cheese, were analysed. The beta-CCA concentration in them was variable depending on many factors such as pH value, heavy or light smoking and maturation time. Dry, fermented comminuted meat products contained the higher concentrations. Tetrahydro-beta-carboline-3-carboxylic acid prevailed in all samples examined and was detected at a level of 0.86 up to 22.63 mg/kg in dry salamis, whereas in other samples it ranged from 16 to 680 mug/kg. The levels of 1-methyl- and 1- hydroxymethyl-tetrahydro-beta-carboline-3-carboxylic acids were much lower (0-881 mug/kg and 0-444 mug/kg respectively). The occurence of benzaldehyde and salicylaldehyde derivatives was not definitely proved. The synthesised beta-CCA were tried for mutagenicity using the Ames test. None of them was mutagenic to Salmonella typhimurium TA-100, TA-98, TA-97 strains with and without metabolic activation, end without preincubation. At concentrations higher than 100 mug/plate, 1-hydroxymethyl- and unsubstituted tetrahydro-beta-carboline-3-carboxylic acids were toxic to strains TA-98 and TA-100. B-Carbolines are biologically active compounds and their detection in smoked foods might help to prevent potential implications to the consumers' health.

>Magister Scientiae - MSc / Over the last decade polysulfone membranes have been demonstrated to be one of the best membrane types in wastewater treatment, especially in ultrafiltration, owing to its mechanical robustness, structural and chemical stability. Regrettably these membranes are mostly hydrophobic by nature and therefore highly vulnerable to fouling due to chemosorptive mechanisms. Fouling may be caused by cake formation on the surface of the membrane or by surface assimilation of the foulants. Many studies have been directed at improving hydrophilic properties of polysulfone membranes by introducing different types of nanoparticle composite such as TiO2, ZnO2, Au and Ag nanoparticles to the polymer matrix, in order to reduce fouling potential and increase membrane performance. In the present investigation a hydrogel material was developed by crosslinking polyvinyl alcohol (PVA) with polysulfone (PSF), using glutaraldehyde as crosslinker. PVA has excellent film formation, emulsifying and adhesive properties, it is highly flexible and has high tensile strength. Introducing PVA into the PSF polymer matrix was expected to impart its advantageous properties onto the resulting membrane and enhance hydrophilic characteristics of the membrane. The cross linking of PVA and PSF was controlled at three different ratios to evaluate the effect of the PSF contribution i.e. 25:75, 50:50 and 75:25. The crosslinked polymer composites produced three unique hydrogel materials, which were evaluated for the separation of selected small organic molecules, under hydrodynamic conditions, using rotating disk electrochemistry. The hydrogel thin film behaved as a chemical sensor for the oxidation of tannic acid in aqueous solution, with negligible shift in peak potential as a function of concentration. The nanomaterials prepared were characterised using spectroscopic, morphological and electrochemical techniques. Hydrogel performance in the presence of analyte molecule was evaluated by hydrodynamic voltammetry and electrochemical impedance spectroscopy. From calibration curves based on cyclic voltammetry, hydrodynamic, macroscopic and spectroscopic techniques, the 75% polysulfone and 25 % polyvinyl alcohol hydrogel (75:25 PSF-PVA) presented the best performance for quantitative detection and best sensitivity toward alginic acid and tannic acid than the corresponding composites (50:50 and 25:75 PSF-PVA). Optical results (contact angle) show an agreement with spectroscopic (EC) and microscopic (AFM) result. A decrease in contact angle gives an increase in roughness and diffusion coefficient. High surface roughness was linked to improved hydrophilicity of the polysulfone.

In many biological reactors' bicarbonate ions are the major species determining pH buffering capacity, or alkalinity. In anaerobic digesters the bicarbonate levels should be within 10 to 50mM to ensure stable operation. Bicarbonate concentration in wastewater treatment processes is routinely measured off-line by titration with standard acid to a set pH value. However along with the bicarbonate/carbonate system, the phosphate, ammonia, sulphides and volatile fatty acids systems are present in anaerobic process. These systems can exert a significant influence on the accuracy of bicarbonate titration's to a set pH. An overload of 4.7 to 13.6 kgCODm-3d-1 1 administered to a 5m3 pilot scale anaerobic filter reactor showed that bicarbonate alkalinity, measured off-line by titration responded rapidly to the organic overload, decreasing by 10% after only 1 hour of the overload initiation. The propionic acid concentration (often regarded as the best indicator of instability in anaerobic digestion) increased from 170ppm to 190 ppm in the same period, which corresponds to an increase of 12%. At present the use of anaerobic digestion as a waste treatment method is partly limited because of the lack of reliable control procedures. This thesis introduces a simple on-line instrument for direct determination of bicarbonate concentration especially for automatic control of anaerobic digesters. The proposed method is based on a continuous flow rate measurement of carbon dioxide evolved from a continuous stream of sampled (&lt;15cm3min-1 ) solution after saturation with gaseous C02 and subsequent acidification with excess acid. Measurement of bicarbonate in this way eliminates the interferences of the phosphate, ammonia, sulphides and volatile fatty acids systems and removes the need for a pH probe which are subject to fouling.

Despite the level of concern generated by adolescents who repeatedly self-harm, there is a dearth of empirically validated interventions for this client group. In the adult domain, dialectical behaviour therapy (DBT; Linehan, 1993) is the only evidence-based intervention for individuals at high risk of repetition, and preliminary research has suggested its utility with adolescents. This study employed a qualitative methodology to evaluate an existing inpatient DBT programme for adolescents with multiple presenting problems including deliberate self-harm. Four female adolescents were interviewed in depth about their experiences and the perceived impact of receiving DBT. Transcripts were analysed for significant and recurrent themes using interpretative phenomenological analysis. Overall, the results supported existing quantitative data indicating that this client group can benefit from DBT. Participants emphasised the role of applying DBT skills in gaining a sense of control over internal experiences and overt behaviours (including self-harm). However, there were marked individual differences in the degree to which such control was attained. Furthermore, for most participants, the effective use of DBT skills was at least partially dependent upon the continued receipt of therapy. Motivation to engage in and comply with therapy appeared to be significantly influenced by participants' perceptions of staff and peers within the inpatient unit. A sense of connection or identification with others emerged as an important source of learning and inspiration, as well as serving to normalise participants' difficulties. The role of social comparison was particularly salient in participants' attempts to make sense of the changes in self since entering DBT. The findings are discussed in relation to the existing literature, with particular emphasis on the extent to which therapeutic processes deemed important by DBT theory were concordant with participants' experiences. Implications for clinical practice are highlighted and directions for future research suggested.

No description available.