Most dams have a low-level outlet that consists of a closed conduit through the dam with a slide gate or valve to regulate flow. These outlets are used mainly for irrigational purposes but also for flushing the reservoir and controlling the reservoir elevation. When discharging through the low-level outlet works, negative pressures can develop on the downstream side of the gate creating a potential for cavitation damage and vibration. To minimize these effects, air vents (vented to the atmosphere) are installed on the downstream side of the gate to limit downstream pressure to something above vapor pressure (i.e., near atmospheric pressure). Previous air venting studies have been mostly limited to large dam outlet geometries, which typically feature a vertical gate in a flat-bottomed discharge tunnel. The large-dam air demand analysis has been based on the Froude number of the supercritical flow at the vena contract (located between the gate and the hydraulic jump) and the water flow rate. Small to medium-sized embankment dams typically utilize a slide gate installed on the sloped upstream face for flow control, followed by a vertical elbow connected to a sloping pipe. With this outlet geometry, there is no 1-D vena contracta flow, no classical hydraulic jump, and no representative Froude number. Additionally, no head-discharge characteristic data have been found for inclined slide gates (vented or non-vented) for small to medium-sized dams. Consequently, unless a flow measurement structure is installed in the discharge channel downstream of the dam, determining the water discharge rate based on gate opening and head on the gate, and consequently the air demand is problematic. This study focuses on quantifying air demand and air vent sizing for the small to medium-sized embankment dam low-level outlet geometries by providing: 1. Cd values as a function of gate openings and air demand; to better estimate flow rates from outlet works of similar geometries. 2. Flow conditions for varying operating conditions. 3. A new relationship for sizing air vents as a function of driving head and gate opening. 4. The magnitude of negative pressures for non-vented conduits. 5. A foundation for future studies and development of air demand research. This thesis presents the findings of this study.

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Spillover research has shown that workday stress hampers commuting safety, while ego depletion research has demonstrated that prior self-regulation leads to performance decrements in subsequent tasks. This study sought to unite these two lines of research by proposing that ego depletion-induced alterations in attention and motivation are the mechanisms by which workday experiences spill over to the commute and impair driving safety. To examine the daily influences of these within-person processes on driving behavior in the post-work commute, this study adopted a daily survey design, wherein participants took an online survey immediately before and after each post-work commute across one work week. In these daily surveys, fifty-six participants (N = 56; n = 250 day-level observations) reported their workday self-regulatory demands; pre-commute levels of attention, motivation, and affective states; and driving behavior during the commute home. Using multilevel path analysis to isolate within-person effects, the current study found no evidence to suggest that workday self-regulatory demands lowered pre-commute attention and motivation, nor did it detect associations of attention and motivation with post-work aberrant driving. Results indicated that an ego depleted state might impair attention and motivation but not driving safety in the commute. Instead, the results pointed to the person-level factor of trait self-control as potentially having a greater impact on post-work aberrant driving than daily experiences. / M.S. / Research has shown that employees tend to drive more unsafely when commuting home after a stressful workday. However, most of this research has examined what about the person makes them drive more unsafely than someone else, but it is also important to understand what about the workday makes someone drive more unsafely one day than another day. I predicted that a workday containing more self-control demands would make an employee drive more unsafely when commuting home from work because facing more self-control demands would lower the employee’s attention and motivation for driving safely. To test this idea, I gave participants two online surveys per day for five consecutive days, Monday through Friday – one at the end of their workday (asking about their workday demands and current levels of attention and motivation), and one at the end of their commute home (asking about their driving behavior during that post-work commute). The data from my final sample of 56 participants (N = 56; n = 250 study days) showed no evidence to support my hypotheses: the amount of workday self-control demands was not found to associate with attention and motivation before driving home, and attention and motivation before driving home were not found to relate to driving safety during that commute home. On the other hand, I did find that a person’s general ability to maintain self-control was associated with their driving safety during the commute home (regardless of workday self-control demands). These results suggest that a person’s character might be more important in determining their day-to-day driving safety during the commute home than the self-control demands they face during the workday.

This paper studies how the perceived work strain of first-line and middle managers affects their leadership towards their own employees. Further, it also examines how the availability of a manager can affect the perceived work strain, as a resource. The study answers the two following questions: “What experiences do first line and middle managers have of factors affecting their work strain and their leadership efficiency?” and “How do first line and middle managers balance demands, expectations, work strain and leadership?” This is a qualitative study based on the theoretical framework “Job-Demands-Resource model”. The data collected from five interviews were analyzed using thematic analysis methods. The findings of this study indicate that work strain can be a positive or negative thing, depending on the allocated resources at hand for the first line or middle managers. Having enough resources makes the high work strain translate to motivation and accomplishment, while high work strain without enough resources leads to a lack of motivation and accomplishment. The biggest effect the high work strain without resources has on leadership is that there is no time to be present with the employees, leading to a negative cycle.

This master’s thesis investigates the contributing factors to Norwegian professional musicians’ psychological distress. Several researchers have pointed out that musicians seem to be a risk group in regards to mental health and work environment. In contrast, research regarding the explanatory variables of their mental health is scarce. Recently, a study indicated a high prevalence of psychological distress in Norwegian musicians. A qualitative study on Norwegian musicians reported a combination of family, social, and personal factors to be of particular importance regarding their mental health. The present study adds to the accumulated research base by conceptualizing contributing factors of musicians’ health in a job demands–resources framework, in which the total model as well as individual predictors are tested with a survey on 1,365 Norwegian professional musicians. Five out of ten hypotheses were supported using a hierarchical multiple regression procedure. Job demands and job control were positively related to psychological distress, whereas job-related social support, emotional stability and sense of mastery were negatively related to psychological distress. Work–nonwork interference, effort–reward imbalance and conscientiousness were not significantly related to the outcome. Unexpectedly, job control was positively related to psychological distress, which may have been influenced by the subjects’ levels of personal resources. Overall, the main findings was that a combination of contextual and personal variables were most influential, but that the work environment concepts investigated were only weakly or non-significantly related to musicians’mental health. The highest single contributors were emotional stability, sense of mastery and general social support, indicating that personal dispositions of emotionality, a strong sense of control over one’s life, and perceived social support from family and friends are of high significance for Norwegian professional musicians’ experience of anxiety and depression-like symptoms.

While many employees are engaged in their jobs, others suffer from poor working conditions and impaired well-being. Research suggests that job demands may impair employee work attitudes and health while both job resources and personal resources can have positive effect. Therefore, the aim of this study was to examine the relative importance of job demands, job resources, and a personal resource (self-efficacy) for employees’ health and motivation at work. Questionnaire data were collected from white-collar employees of a Swedish construction company (n = 156). Results of hierarchical multiple regression analyses showed the relative importance of job demands, job resources and personal resources. The job demands were negatively related to health and motivation at work, while the job resources and the personal resource were linked to better health and motivation. The findings generally supported the hypotheses. The specific types of demands and resources were significant varied across outcomes and, unexpectedly, workload was positively correlated with job performance. The findings contribute to a growing literature which indicates that lower job demands and access to both job resources and personal resources may improve employees' health and motivation at work.