Background: Compared to the general United States (U.S.) population, Arizona counties along the U.S.-Mexico border have a higher prevalence of dental caries, which can be reduced with adequate fluoride exposure. Because of concern regarding local tap water quality, fluoride-free bottled water consumption is common in this region, raising concern that families are not receiving adequate fluoride to promote dental health. Objective: To evaluate the levels of fluoride in tap and bottled water as well as the use of fluoride supplements in an Arizona border community. Methods: Low-income Latino households (n = 90) who report use of bottled water as their primary source of water intake were recruited. Participants completed a questionnaire about their and their children's dental histories and use of fluoride supplements. Water samples (bottled and tap) were collected from a subset of households (n = 30) for analysis of fluoride. Results: Fluoride detection levels were significantly greater (p = 0.02, Fisher's exact test) in tap water (average = 0.49 mg/dL) than in bottled water, yet, the majority (22/30) were below the range for optimal dental health (0.7-1.2 mg/L). Concentration of fluoride in the majority (29/30) of bottled water samples was below the quantitative detection limit of 0.4 mg/L. Children were significantly less likely to have dental caries if they received fluoride varnishing treatments (p = 0.01, Fisher's exact test), lived in households that reported using fluoridated mouthwash (p < 0.001, Fisher's exact test), their parents received fluoride education (p = 0.01, Fisher's exact test), and their parents reported visiting a dentist yearly (p < 0.001, Fisher's exact test). Furthermore, none of the participants reported receiving recommendations from health-care providers about fluoride supplementation or variance in content by the type of water consumed. Conclusion: Although fluoride was significantly more likely to be detected in tap than bottled water, neither water source in this border community is likely to provide enough fluoride for optimal dental health. Low-income children in this region may benefit from regular access to fluoride varnishing treatments and/or use of fluoridated mouthwash, interventions that could be tested in future well-designed trials.

In this paper numerical flow calculations with respect to the annular gaps with added radial grooves normaly used on the spools of directional control valves were carried out. The impact of various annular gap geometries and radial grooves during variable pressure conditions, and while using different hydraulic fluids, on the flows through annular gaps were investigated for different flow regimes. Samples with different geometries and numbers of radial groves on the spool of the directional control valve were also made for the purpose of carrying out flow measurements. The two different hydraulic fluids that were used in the numerical simulations and for the flow measurements were a hydraulic mineral oil and tap water. The results of the numerical calculations for the different models of the radial grooves with axially symmetric geometries show their impact on the internal leakage with respect to three different regimes of flow. The results of the numerical calculations based on the use of a hydraulic oil show a trend that was established by the experimental investigation.

The use of treated waste water for irrigation of vegetable crops is on the increase in Botswana especially in the Glen Valley farms, a peri-urban settlement of Gaborone city. However, the effects of this practice on heavy metals uptake by vegetable crops are uninvestigated. Chromium and nickel have been reported to be accumulating in Gaborone crop soils and cultivating vegetables in these soils with treated waste water could potentially lead to an increased bio-availability of the heavy metals in the vegetable crops. The main aim of this study was therefore to compare the uptake of chromium and nickel in tomato plants, a vegetable grown in sludge amended Glen Valley soils, to those grown in sludge absent Glen Valley soils using treated waste water at different pH values and tap water for irrigation. The high water uptake and high water consumption rate of tomato plants made it suitable for this study. Twenty five pots each containing 2.5 kg sludge amended Glen Valley soils and 5 pots each containing 2.5 kg sludge absent soils were utilized. Fresh treated waste water in a 50 L plastic container on a need by need basis was used. For the control experiments 5 pots each containing 2.5 kg standard commercial soils and fresh tap water were used. The potted tomato plants were cultivated from early May to middle of October 2009. One leaf and one fruit from each tomato plant was harvested and tested in this study. The highest uptakes of chromium (0.819 mg/L) and nickel (0.327 mg/L) were experienced in the leaves where the tomato plant were cultivated in standard commercial soil and irrigated with tap water at pH 7.0. The least uptake of chromium (0.052 mg/L) and that of nickel (-0.030 mg/L) was found in the fruits, where the tomatoes were grown in sludge amended Glen Valley soil and irrigated with normal Glen Valley treated waste water at pH 8.5. Increasing the pH of the treated waste water from 5.0 to 6.0 caused increased bio-accumulation of chromium and nickel in the leaves and the fruits of the tomato plants. Normal treated waste water (pH 8.5) and treated waste water at pH 9.0, however, reduced the chromium and the nickel uptake by the tomato plants. Treated waste water at pH 10.0 bio-accumulate more chromium and more nickel in the leaves and fruits of tomato plants. The pH variation experiments suggested that the fruit tissues accumulated more chromium and the leaf tissues accumulated more nickel. The mean chromium uptake in the tomato plants exceeded the Food and Agriculture Organization permissible limits but the Botswana Bureau of Standards effluent limit was not exceeded. The mean nickel concentrations were below the threshold limits for both local and international standards. Statistical analysis showed no significant difference between the mean chromium and the mean nickel concentration in the leaves and the fruits of the tomatoes at the 5% significant level. It can be concluded from this study that cultivating tomatoes with sludge amended Glen Valley soil combined with normal treated waste water at pH 8.5 could reduce the uptake of chromium and nickel uptake in tomato plants. However, an increase in the uptake of chromium and nickel in the leaves and fruits of the tomato plants could be triggered at slightly low pH (pH 5.0 and pH 6.0) and high pH (pH 10.0) of the treated waste water. It is recommended that the current practices of using treated waste water combined with sludge amended Glen Valley soil to cultivate tomatoes at the Glen Valley farm is good practice and should be continued. Nonetheless, further studies need to be carried out at the farm to establish possible phytotoxicity effects of these heavy metals on tomatoes when using treated waste water combined with sludge amended and sludge absent soils. / Dissertation (MSc)--University of Pretoria, 2011. / Chemical Engineering / unrestricted

The Master´s thesis solves question about sanitation installations in factory in Přelouč. The theoretical part deals with pumping technique and pumping of wastewater. The work also focuses on possible solutions of the given specialization. The project part solves the sanitation installation of this factory in the selected variant. It is a large hall with administrative part.

In this paper numerical flow calculations with respect to the annular gaps with added radial grooves normaly used on the spools of directional control valves were carried out. The impact of various annular gap geometries and radial grooves during variable pressure conditions, and while using different hydraulic fluids, on the flows through annular gaps were investigated for different flow regimes. Samples with different geometries and numbers of radial groves on the spool of the directional control valve were also made for the purpose of carrying out flow measurements. The two different hydraulic fluids that were used in the numerical simulations and for the flow measurements were a hydraulic mineral oil and tap water. The results of the numerical calculations for the different models of the radial grooves with axially symmetric geometries show their impact on the internal leakage with respect to three different regimes of flow. The results of the numerical calculations based on the use of a hydraulic oil show a trend that was established by the experimental investigation.

In view of the fact that most of the synthetic refrigerants, in case of leakage or release, are harmful to the environment by contributing in global warming or depleting stratospheric ozone layer, many research works have been done recently to find alternative refrigerants posing no or negligible threat to the environment. Among alternative refrigerants, ammonia, a natural refrigerant with zero Global Warming Potential (GWP) and Ozone Depletion Potential (ODP), can be a sensible choice.Although ammonia has been used for many years in large industrial systems, its application in small units is rare. In this project a small heat pump with about 7 kW heating capacity at -5 °C and +40 °C evaporation and condensation temperatures is designed and built to work with ammonia as refrigerant. The heat pump is expected to produce enough heat to keep a single-family house warm in Sweden and to provide tap hot water for the house. After successful completion of this project, it is planned to install the heat pump in a house to test it throughout a heating season to study its performance in real working conditions.Since ammonia is flammable and toxic in high concentrations, the refrigerant charge is tried to be kept low in the heat pump to reduce the risk of fire or poisoning in case of unwanted release of refrigerant to the surroundings. The compact design of the heat pump helps reducing the refrigerant charge. Besides, considering the limited space normally reserved for installation of a heat pump in a house, the compact design of the heat pump is necessary.

Microplastics are an emerging environmental contaminant. One of the ways microplastics can get into the environment is by the breakdown of larger plastics. These plastics can come from industrial practices, discarded fabrics, agriculture, and general plastic waste. As these plastics are broken down microplastics leach into the environment. The widespread use of plastics has resulted in the spread of microplastic contaminants all over the world. Microplastics have been reported to be in drinking water, so this paper is looking at the presence of microplastics in local communities of different demographics and socioeconomic statuses. In other studies of different drinking water contamination, minority, and low-income communities had worse quality water. In this paper, methods for sampling, extraction, and analysis with Laser Direct Infrared Spectroscopy were used. Out of Cities A, B, and C, City A, with the largest population, higher percentage of minorities, and worse off socioeconomic status, had the highest particle count. More research is needed in this field to find how socioeconomic status can affect exposure to microplastic contamination.

Tenerife is experiencing challenges with its drinking water resources because of climate change and overtourism. The prior lone use of groundwater as drinking water source must now be complemented by desalinated saltwater. This has resulted in an increased use of drinking water on plastic bottles, which has led to large amounts of plastic waste on the island. Even with an implemented deposit system for plastic bottles in the capital, a high consumption of plastic bottles for drinking water remains. This study thereby aims to research tourists and locals’ habits and opinions of tap water consumption on Tenerife. The study aims to answer why tourists and locals do not drink the tap water on the island today and what their opinions are towards a reduced use of plastic bottles for drinking water consumption on Tenerife. The study also answers which actions could be taken to change tourists’ and locals’ consumption of drinking water in plastic bottles towards a primary consumption of tap water. A literature study was conducted to explore water consumption and plastic waste on Tenerife. A survey study was performed on 155 respondents of tourists and locals’ habits and opinions considering drinking water and plastic bottle waste. The results showed that most of the respondents avoid tap water with fear of food poisoning or insecurity of how it will affect their long-term health. Most of the respondents are positive towards a reduced use of plastic bottles for drinking water on Tenerife. Both tourists and locals answered that they would drink the tap water if they knew that it was safe and had a good taste. Actions that can be taken for changing the habits of using plastic bottles for drinking water are; informing the locals and tourists on the safety of the tap water and developing the water systems to improve the taste of the tap water. The study indicates the need for actions to increase the assurance in the quality and safety of tap water on Tenerife. This could improve the transition towards a more sustainable consumption of drinking water, help reduce the use of plastic bottles on the island and, is a step in the right direction towards the Sustainable development goals.

Waterworks typically refer to a system or facility for supplying, storing, and treating water. It encompasses the infrastructure and machinery used to collect, purify, and 
distribute water to homes, businesses, and other users. The term can also mean starting to cry, especially to gain sympathy or attention. Additionally, it can refer to the organs of the body through which urine is passed. The climate crisis presents significant challenges to water filtration. Extreme weather events can contaminate sources. Harmful algal blooms, saltwater intrusion and toxins further complicate filtration. We might have to rethink how we take clean tap water for granted. This home water filtration unit that via acoustics filters the water, reimagines our relationship to drinking water and the habits around it, and the new behaviors and rituals that would emerge from this new normal. / Waterworks avser vanligtvis ett system eller en anläggning för att tillhandahålla, lagra och behandla vatten. Det omfattar infrastrukturen och tekniken som används för att samla in, rena och distribuera vatten till hem, företag och andra användare. Termen kan också betyda att börja gråta, särskilt för att få sympati eller uppmärksamhet. Dessutom kan det referera till kroppens organ genom vilka urin passerar. Klimatkrisen innebär betydande utmaningar för vattenfiltrering. Extrema väderhändelser kan förorena dricksvattentäkter. Skadlig algblomning, saltvattenintrång och gifter försvårar filtreringen ytterligare. Vi kanske måste tänka om kring hur vi idag tar rent kranvatten för givet. Denna filtreringsenhet, som via akustik filtrerar vattnet, belyser vårt förhållande till dricksvatten och de nya beteenden och ritualer som skulle uppstå ur en ny klimatmässig normalsituation.

For water suppliers, using chlorine is necessary to ensure water bacteriological quality from the treatment plant to the consumers' tap. However, chlorine flavour is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between chlorine flavour perception and tap water consumption is an issue in drinking water habits studies. Since the sensory mechanisms involved in chlorine flavour perception remained largely unknown, the main objective of this thesis work was to first highlight those mechanisms and then to identify potential lever chlorine flavour sensory neutralisation.In a first step, we demonstrated that hypochlorous acid associated, which is likelyresponsible of chlorine flavour in tap water, could activate the olfactory system at low concentrations and the trigeminal system for concentrations up to 4 mg/L Cl2. Additionally, our results suggested that tap water consumption does not seem to be related to sensitivity to chlorine flavour but rather to consumers' tap water representation.In a second stage, we explored the impact of water mineral matrix on chlorine flavour perception. We demonstrated first that water molarity and cationic content variations modulate drinking water taste. We also evidenced that chlorine flavour intensity is modulated according to water composition. Nevertheless, our data suggest that physico-chemical, in- mouth physiological and sensory mechanisms are likely involved in such modulation.In the last part of the Thesis work, we investigate the putative influence of aroma perceptionon chlorine flavour. Our results showed that beyond chemical reactions between hypochlorous acid and odorants, aromas at peri-threshold concentration enhance chlorine flavour and decrease tap water acceptability