Since snowmelt runoff is important in the mountainous parts of the world, substantial efforts have been made to develop snowmelt models with many different levels of complexity to simulate the processes at the ground, within the snow, and at the interface with the atmosphere. The land-atmosphere interactions and processing influencing heat transfer to and from a snowpack are largely variable and the conceptual representation of this temporal and spatial variability is difficult. A physically based, two layer point model, is applied to calculate the energy and mass balance of snowmelt in the Upper Karasu Basin, eastern part of Turkey during 2002-2004 snow seasons. The climate data are provided from automated weather stations installed and upgraded to collect quantitative and qualitative data with automated transfer. Each form of energy transfer is evaluated to understand the key processes that have major impact on the snow simulation during accumulation and ablation in two-hourly timesteps. The model performance is evaluated as accurate according to the results, compared with observed snow water equivalents, snow depth and lysimeter runoff yield. In the second part, calculated snowmelt values based on energy and mass balance at the automated stations are related to radiation index model through regression. Then, the spatial patterns of snow water equivalent, solar illumination, albedo and air temperature are used to predict the melt at each grid cell over the whole watershed. The results of distributed model application are evaluated in terms of snow covered area of satellite products, observed snow water equivalent at points through snow pillows and discharge values at the outlet runoff station.

The objective of this research is to develop a system capable of simulating snow depth and snow water equivalent in the Sherbrooke to Mount-Megantic area of Quebec's Eastern Townships using meteorological and digital terrain data as input.The working hypothesis is that meteorological data may drive a point energy and mass balance snow cover model.The model used was developed by the Hydrologic Research Lab (National Weather Service) which was calibrated for local conditions using field data collected during two winters at several sites on Mount-Megantic. Snow water equivalent and depth are used for calibration and validation of the model. Automated snow sensors were also used to obtain temperature calibration data.The snow surveys and correction of the air temperature for elevation improves the estimates of snow depth and water equivalent.The results suggest that data from the Sherbrooke meteorological stations can be used to estimate the snow cover over the area of Eastern Townships. Air temperature extrapolation across the field area is a challenge. However the simulated snow cover conforms generally well with data observed at several stations throughout the region.

<p>Traditionally, textiles were dried outdoors with the wind and the sun enhancing the drying process. Tumble dryers offer a fast and convenient way of drying textiles independent of weather conditions. Tumble dryers, however, consume large amounts of electrical energy. Over 4 million tumble dryers are sold each year in Europe and a considerable amount of energy is used for drying of clothes. Increasing energy costs and the awareness about environmental problems related to a large energy use has increased the demand for dryers with better energy efficiency. The aim with this thesis is to show how to improve the energy efficiency of domestic tumble dryers.</p><p>Two types of tumble dryers are available on the market today: the open cycle dryer and the closed cycle dryer. In the open cycle dryer room air is heated and led into the drying drum. The exhaust air leaves the dryer and is often evacuated outside the building. In the closed cycle dryer an internal airflow is recirculated inside the dryer. When the hot air has passed through the drying drum it is led through a heat exchanger where the water vapour is condensed before the air is heated again and led to the drum. The heat exchanger is cooled with room air.</p><p>Drying at low temperature has been shown to reduce the specific energy use for an open cycle tumble dryer. In Paper I a correlation between the specific energy use, the drying time and the heat supply was established for a specific load by using the exhaust air temperature. It was shown that the total drying time and specific energy use could be predicted from data during the first hour of the process. This result indicated a possibility to create a control system that makes it possible for the user to choose between low energy use or short drying time.</p><p>The focus of Paper II is to reduce the energy use for a closed cycle tumble dryer. Energy and mass balances were established in order to determine feasible improvements. Energy and mass flows in the dryer indicated that reducing leakage from the internal system of the dryer gave the largest reduction of specific energy use. Insulation of the back cover of the dryer and opening the internal system during the falling drying rate period also gave positive results on the energy use. In total a feasible reduction of the energy use of approximately 17% was calculated.</p>

Traditionally, textiles were dried outdoors with the wind and the sun enhancing the drying process. Tumble dryers offer a fast and convenient way of drying textiles independent of weather conditions. Tumble dryers, however, consume large amounts of electrical energy. Over 4 million tumble dryers are sold each year in Europe and a considerable amount of energy is used for drying of clothes. Increasing energy costs and the awareness about environmental problems related to a large energy use has increased the demand for dryers with better energy efficiency. The aim with this thesis is to show how to improve the energy efficiency of domestic tumble dryers. Two types of tumble dryers are available on the market today: the open cycle dryer and the closed cycle dryer. In the open cycle dryer room air is heated and led into the drying drum. The exhaust air leaves the dryer and is often evacuated outside the building. In the closed cycle dryer an internal airflow is recirculated inside the dryer. When the hot air has passed through the drying drum it is led through a heat exchanger where the water vapour is condensed before the air is heated again and led to the drum. The heat exchanger is cooled with room air. Drying at low temperature has been shown to reduce the specific energy use for an open cycle tumble dryer. In Paper I a correlation between the specific energy use, the drying time and the heat supply was established for a specific load by using the exhaust air temperature. It was shown that the total drying time and specific energy use could be predicted from data during the first hour of the process. This result indicated a possibility to create a control system that makes it possible for the user to choose between low energy use or short drying time. The focus of Paper II is to reduce the energy use for a closed cycle tumble dryer. Energy and mass balances were established in order to determine feasible improvements. Energy and mass flows in the dryer indicated that reducing leakage from the internal system of the dryer gave the largest reduction of specific energy use. Insulation of the back cover of the dryer and opening the internal system during the falling drying rate period also gave positive results on the energy use. In total a feasible reduction of the energy use of approximately 17% was calculated.