Usability evaluation of collaborative writing system for education usage is very essential to improve its functionality to make it effective, efficient and satisfactory for future use. In this thesis, the usability of web office (ThinkFree doc) i.e. one of collaborative tool was tested using mix research approach. Usability evaluation was done in step by step process, where usability test was conducted using think aloud protocol and observation during testing was noted down. Test results were then analyzed and questionnaire was designed for quantitative survey. Questionnaires were then distributed among those students who have been using Thinkfree doc for educational collaborative work. Interviews were conducted with all selected participants individually for results validations. During usability evaluation process positive and negative effects regarding software‟s usage were noted down. The result revealed that overall system‟s response is very slow. The software needs to improve its processing speed to make it more efficient for future use. The system also needs to improve overall functionality (e.g. collaborative work, synchronization, uploading and track changes etc) to provide accurate and complete results according users‟ requirements. / First Author: M. Afsar Khan. Mohallah madani masjid nawan killi village & P.O Gujar Garhi District Mardan NWFP Pakistan, Second Author: Sher Hassan. Timergara Dir Lower NWFP Pakisan

Inland waters including streams, rivers, reservoirs and lakes are regarded as a significant site of Organic Carbon (OC) cycling, and greenhouse gas production. As a result, there has been significant recent interest in the rates and fate of fluvial carbon exported from organic soils, such as peatlands. Additionally, peatlands can be subject to substantial degradation resulting in high rates of fluvial OC export, and this has led to efforts to repair degraded peatlands through restoration programmes. As a consequence, the study of degraded areas is useful to quantify the upper values of carbon release, understand processes of transformation, and evaluate the success of restoration programmes. Importantly peatlands are also collection areas for drinking water, which has implications for treatment, and requires better understanding of carbon cycling upstream of treatment works, in headwater rivers, reservoirs and pipes. UK upland blanket peat catchments are a key location in which to consider global questions surrounding fluvial carbon export and transformations, as they are highly degraded, provide a source of drinking water supply, and are currently undergoing pioneering methods of landscape scale restoration. This thesis considers Kinder Scout, an area of highly degraded and gullied blanket peatland in the South Pennines, UK. Using analysis of water samples collected over several years in the Kinder reservoir catchment and plateau, this thesis presents three novel contributions to global questions concerning OC cycling and peatlands. Firstly it provides (to date), the only carbon budget for a reservoir in a peat dominated catchment with high Particulate Organic Carbon (POC) export, which demonstrates that reservoirs may be net sources of Dissolved Organic Carbon (DOC), with the implication that POC-DOC interactions are important OC transformation mechanism in degraded systems. Secondly through use of a unique integrated combination of methods, it considers changes in carbon flux and composition in both river, lake and pipe locations, providing detailed understanding of the relative roles of river reaches, reservoirs and supply pipes, in controlling fluvial carbon cycling in peatland systems, and upstream of water treatment works. An important implication here, is that rate and direction of change in water treatability varies through a catchment. Finally, it includes results from the first widespread monitoring of the catchment scale effects of a new method of peatland revegetation. This restoration approach is being applied at landscape scale and the findings here, are that despite fears to the contrary, it does not lead to short term increases in fluvial carbon loss, which is an important piece of evidence supporting practical conservation approaches in these systems. To further enhance this research, a combination of field and laboratory investigations into carbon transformation processes, and ongoing restoration mentoring should be undertaken.

Denitrification removes large amounts of reactive nitrogen (N) from ecosystems via reduction of nitrate to dinitrogen gas. In aquatic ecosystems, the influences of terrestrial and aquatic sources of organic matter (OM) on denitrification are potentially complex. Terrestrially-derived OM is often less labile than autochthonous OM; it may inhibit denitrification directly via biochemical mechanisms; and it may indirectly inhibit denitrification by reducing light availability to—and thus OM exudation by—aquatic primary producers. Using a natural dissolved OM gradient among rivers of northern Florida, I investigated these mechanisms using laboratory denitrification assays subjected to factorial amendments of NO3- and dextrose, humic acid dosing, and cross-incubations of sediments and water. Results indicated that C-limitation increased with DOC concentrations, consistent with the indirect inhibition hypothesis. Blackwater neither depressed nor stimulated denitrification rates, indicating that this DOC neither directly inhibits nor acts as a usable OM source for denitrifiers.

The objective of this thesis was to reconstruct the Sedimentary, Cryostratigraphic and Paleoclimatic history of Two Moose Lake, central Yukon using a new analytical technique for dating ice wedges using Dissolved Organic Carbon (DOC). During two field seasons in August 2013 and April 2014, 442 samples were collected from a newly exposed headwall of a thaw slump with 7 ice wedges and over 4m of sediment. Using cryostratigraphy, granulometry, stable isotopes and 18 14C-DOC ages, 4 stratigraphic units were delineated: 1) a sediment-rich ice layer inferred to be of glacial origin (>32ka BP); 2) a silt-rich layer deposited during the Holocene Thermal Maximum (~10 to 8.2ka BP); 3) a silt with organics layer deposited from ~8ka to 6.4ka BP, and 4) a paleo-active layer and modern active layer. 14C-DOC dating indicated two periods of ice wedge activity at Two Moose Lake, the first during the late Pleistocene (31,608 to 12,990 yr cal BP) and from the mid-Holocene to present (6,328 to 892 yr cal BP). The presence of late-Pleistocene aged ice wedges at Two Moose Lake supports the common belief of an unglaciated central Yukon during the most recent McConnell glaciation from 29.6 to 13ka BP. Values for δ18O from the Holocene- and Pleistocene-aged ice wedges were 2-3‰ and 5-9‰ depleted compared those of modern precipitation from Mayo (-22.32‰). Medium-resolution (2-4cm) sampling along with multiple 14C-DOC samples along a transect allowed for the creation of a continuous δ18O and temperature age profile to be developed from multiple ice wedges, showing a strong consistency between overlapping ages. The reconstruction of the paleoclimate of Two Moose lake is consistent with known events from southern Yukon including the Boutellier Inderstadial, a cold unglaciated central Yukon during the McConnell Glaciation, warming during the Holocene Thermal Maximum (HTM) followed by an extreme cooling event at 8.2ka BP, a cooling event at 4.2ka BP, and the subsequent warming to present temperatures.

Increased DOC and Fe concentrations from terrestrial landscapes has led to the browning of boreal surface waters. The negative societal and ecological impacts of brownification are increased cost of water purification, increased presences of algae and cyanobacteria, loss of ecosystem services and reduced recreational value. Impacts of climate change, changes in land use and reduced sulfur deposition have been identified as drivers of brownification. While it has been recognized that DOC and Fe from terrestrial landscapes is increasing, little has been done to understand the impact of different land use practices on brownification. This research aims at evaluating the DOC and Fe runoff from spruce plantations, clear-cuts and wetland landscapes and determining the export of DOC from these landscapes into humic lakes. To do that, streams running through these three different land use types were sampled for water colour, pH, temperature, conductivity, DOC and Fe both at upstream and downstream of each land use type. Further, water discharge was calculated with the help of flow speed measurements and stream profiling (width, depth and channel shape). DOC (but not Fe) concentrations changed significantly depending on land use type. Wetlands lead to reduced DOC concentrations, whereas especially spruce plantations lead to increased stream water DOC concentrations.

During recent decades the brownification through leaching of organic carbon into Northern hemisphere water bodies has become apparent. This is considered a problem because of the implications it has on ecosystems and freshwater sources used for drinking water. It could be beneficial if wetlands can be used for reducing brownification but also detrimental if wetlands instead increase it as construction of wetlands is common practice for treating agricultural runoff in Sweden.  This study compares inlet and outlet absorbance in five wetlands in Kalmar County in Sweden and finds that one removes colour, two increases colour and two does not change the colour of the water at all. The study also compares absorbance values with variables concerning flow and temperature and concludes that a higher absorbance at inlet increases removal similar to how nutrient removal in wetlands work. Inlet absorbance is also dependent on flow with higher flow resulting in higher absorbance. Periods of no flow did not contribute to any changes in absorbance, but this could be because of a limited sample pool. Future recommendations for research include a more extensive look into periods of no flow and affecting variables to ensure wetlands do not contribute to brownification.

The Diesel Oxidation Catalyst (DOC) is subjected to harsh conditions, causing its performance to diminish over time as the result of different aging mechanisms, which either decreases or lowers the accessibility to the catalyst’s active sites. Previous work using chemisorption to quantify aging progression has resulted in a reproducibility of 17%. In this study it has been attempted to lower this, while also performing performance evaluations to see if correlations exist between dispersion and Light-Off Temperature (LOT). Two catalysts have been investigated, LLC (Low Loading Catalyst) and HLC (High Loading Catalyst). These were hydrothermally aged at 600 C, 700 C and 800 C. In addition to these, two HLC engine cell samples were also investigated. To ensure sample homogeneity, different sample preparation methods were investigated. Catalyst samples were crushed, or had their washcoat layer removed, or were milled and then sieved. A total of 5 runs were done using fresh catalysts of LLC and HLC to calculate the standard deviation. Evaluation of performance was done on all samples using Synthetic Catalyst Activity Testing (SCAT). It was deemed that the only viable sample preparation method was to mill and sieve as other methods would be hard to reproduce. The results showed that the reproducibility for LLC was %STD = 4% and for HLC %STD = 2%. For LLC, a correlation between catalytic activity and dispersion was found. The activity dropped with respect to the dispersion in a close to linear fashion without a large effect on BET surface area. For HLC the dispersion decreased largely upon hydrothermal aging, however no correlation was found with the activity; only when aged at 800 C a significant change in LOT was noted. The BET surface area measurements were inconsistent. Lower dispersion sometimes resulted in higher surface area. Engine cell samples exhibited notable decrease in dispersion, but not in surface area, and did not correlate to the hydrothermally aged catalysts, which might be due to other effects inhibiting CO chemisorption during measurements. / Dieseloxidationskatalysatorn (DOC) utsätts för tuffa förhållanden, vilket medför att dess prestanda minskar med tiden på grund av olika åldringsmekanismer, vilka antingen minskar dess aktiva säten eller minskar tillgängligheten till dessa. Tidigare studier då kemisorption använts för att kvantifiera vilken utsträckning katalysatorn har blivit deaktiverad har resulterat i en reproducerbarhet på 17%. Denna studie har syftat till att minska detta, men även till att utföra prestandamätningar för att se om det existerar korrelationer mellan dispersion och tändtemperatur (LOT). Två katalysatorer undersöktes, LLC (lågladdad katalysator) och HLC (högladdad katalysator), både som färska, men även som hydrotermiskt åldrade i 600 C, 700 C and 800 C. Dessutom undersöktes två motorcellsprover av HLC. För att säkerställa provhomogenitet undersöktes olika provprepareringsmetoder. Katalysatorprover krossades, eller fick washcoat avlägsnat eller maldes samt siktades. Totalt fem körningar gjordes på färska katalysatorer (LLC och HLC). Prestandamätningar gjordes på samtliga prov i Synthetic Catalyst Activity Testing (SCAT). Det bedömdes att den enda gångbara provprepareringsmetoden var att mala samt sikta katalysatorn då de andra metoderna skulle bli svåra att upprepa på ett reproducerbart sätt. Resultaten visade att reproducerbarheten för LLC var %STD = 4% och för HLC %STD = 2%. LLC visade på korrelation mellan katalytisk aktivitet och dispersion. Aktiviteten minskade linjärt utan större förluster i BETytarea. För HLC minskade dispersionen i hög grad med ökad åldringstemperatur, däremot kunde ingen korrelation med katalytisk aktivitet påvisas; enbart då katalysatorn åldrades vid 800 C ändrades LOT signifikant. Förändringarna i BET-ytarean var inte beroende av åldringstemperatur då lägre dispersion ibland resulterade i högre ytarea. För motorcellsproverna uppmättes en märkbart låg dispersion, medan ytarean var relativt oförändrad. Dessa resultat kunde inte korreleras till de hydrotermiskt åldrade proverna, vilket kan bero på att andra effekter inhiberat CO kemisorptionen.

In natural ecosystems, like deciduous and coniferous forests, soil CO2 flux or soil respiration is highly variable and influenced by multiple factors including temperature, precipitation, dissolved soil organic carbon (DOC), dissolved organic matter (DOM), and bacterial and fungal biomass and diversity. However, as the human population continues to grow rapidly, so too do urbanized landscapes with unknown consequences to soil respiration. To determine the extent urbanization influences seasonal shifts in microorganisms and environmental drivers alter soil respiration, we evaluated bacterial and fungal communities, soil physiochemical characteristics, and respiration in forested and urbanizing ecosystems in three watersheds across northern Utah, USA. Based on the next-generation sequencing of the 16s DNA and RNA, we found that montane bacteria were predominantly structured by season while urban bacteria were influenced by degree of urbanization. There was no apparent effect of season on montane fungi, but urban fungal communities followed patterns similar to urban bacterial communities. Bacterial diversity was sensitive to seasonality, especially in montane ecosystems, declining 21-34% from spring to summer and staying relatively low into fall, and fungal diversity was generally depressed in spring. Urban bacterial communities were differentiated by substantially more bacterial taxa with 62 unique OTUs within families structing phylogenetic differences compared with only 18 taxa differentiating montane communities. Similar to bacteria and fungi, DOC and ammonium concentrations fluctuated predominantly by season while these same parameters where highly variable among urban soils among the three watersheds. Structural components of DOM via parallel factor analysis (PARAFAC) of fluorescence excitation-emission matrices show varying patterns between montane and urban systems with humic substance resistance to biodegradability found more dominantly in montane systems. Incorporating all soil chemical parameters, daily temperature and moisture, and fungal and bacterial diversity and richness in mixed linear effects models describing daily CO2 over all seasons, we found that a single model best described montane soil respiration, while individual watershed models best described urban respiration. Montane respiration was related to the availability of DOC, different DOM components, and rRNA-based bacterial diversity . Alternatively, urban respiration was influenced by either bacterial diversity and richness in our rapidly urbanizing environment, DOM characteristics and soil O2 in the more agricultural urban soils, or the DOM parameter humification index (HIX) in highly urbanized soils. Our results suggest that urbanization creates distinct bacterial and fungal communities with a single soil biotic or chemical parameter structuring soil respiration, while montane ecosystems select for similar bacterial and fungal communities with respiration sensitive to fluctuations in soil moisture, bacteria and the recalcitrance of carbon (C) resources.

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Variation of dissolved of organic carbon concentration in stream water is a consequence of process changes in the surrounding terrestrial environment. This study will focus on 1) Identify significant environmental factors controlling the spatial and temporal variation of DOC in terrestrial ecosystems of a watershed southeast of Boston, Massachusetts; 2) Model the DOC leaching from different land cover and examine the relationship between leaching flux and in-stream DOC. Our hypothesis is variations of in stream DOC is closely related to watershed properties and environmental factors at annual, seasonal, and daily scales, especially land cover type, watershed size and hydrology. To explore the relationship of hydrology and DOC variation at ungauged sub-basin, we examined the effectiveness of using simulated stream flow from Soil Water Assessment Tool (SWAT) to study terrestrial DOC dynamics. Our results demonstrated that streamflow, drainage area, and percent of wetland and forest were particularly strong predictors in watersheds with a large proportion of developed area. The resulting linear model is able to explain about 70.2% (R2=0.702) and 65.1% (R2=0.651) of the variance of in-stream DOC concentrations at seasonal and annual scales respectively. Results also suggest that more frequent DOC sampling is necessary to establish the quantitative relationship between simulated stream flows from the SWAT and in-stream DOC concentrations at daily scale. The physically based ecosystem model developed in this study shows that DOC leaching from various land cover are highly correlated (up to 80%) with in-stream DOC by using ecological process with incorporated different hydrological pathways. It shows that leaching of DOC from soil is a significant contributor to the in-stream DOC. The production of DOC is largely controlled by the vegetation type and soil texture. Considering the hydrologic control on DOC transport with different pathways of water at finer spatial and temporal scale highlights the need to identify the quantitative relationships between water and carbon flux.