2,946 research outputs found
Local Author Book Talk: Meet D.M. Pulley author of The Dead Key
No full textLocal Author D.M. Pulley, author of The Dead Key.
2014 Winner — Amazon Breakthrough Novel Award — Grand Prize and Mystery & Thriller Fiction Winner. It’s 1998, and for years the old First Bank of Cleveland has sat abandoned, perfectly preserved, its secrets only speculated on by the outside world.--Source Amazon.com
These books and all Friends of the Library 2021/2022 book selections are on sale at Viking Outfitters, located in the CSU Student Center
Canceled: Local Author Book Talk: Meet D.M. Pulley author of The Dead Key
No full textThis event has been canceled due to the Coronavirus.
Meet Local Author D.M. Pulley, author of The Dead Key.
2014 Winner — Amazon Breakthrough Novel Award — Grand Prize and Mystery & Thriller Fiction Winner. It’s 1998, and for years the old First Bank of Cleveland has sat abandoned, perfectly preserved, its secrets only speculated on by the outside world.--Source Amazon.com
The books titled The Dead Key, No one’s Home, Unclaimed Victim, and The Buried Book will be available for sale by Viking Outfitters at the event. These books and all Friends of the Library 2019/2020 book selections are on sale at Viking Outfitters, located in the CSU Student Center
Role of orography in the distribution of precipitation extremes and in shaping the event predictability: the Vaia storm case study
No full textopenThe Vaia storm, which impacted northeastern Italy from October 27 to 29, 2018, brought extreme winds and heavy rainfall, with some areas receiving over 850 mm of rain within three days. This study has two main objectives: first, to evaluate the accuracy of convection-permitting models (Moloch and WRF) in simulating precipitation during the Vaia storm by comparing them to observational data; and second, to analyze the impact of orography on precipitation patterns, particularly focusing on how orographic complexity influenced the distribution of maximum rainfall.
The results show that the interaction between the airflow and the Alpine barrier played a crucial role in shaping the distribution and intensity of precipitation. Windward slopes experienced increased rainfall due to orographic lifting, while leeward areas were impacted by strong downslope winds.
A key finding of this study is the variation in precipitation estimates across different simulation setups, which highlights the importance of accurately representing topography in numerical weather prediction models. The differences observed between WRF and Moloch simulations, particularly when initialized with GFS or IFS data, emphasize the influence of initial conditions on forecast accuracy. Additionally, the comparison with observed precipitation data allowed for an evaluation of model performance, revealing potential biases that should be considered in future applications.
In conclusion, this research underscores the significance of orographic effects in extreme weather events and emphasizes the need for high-resolution modeling to better understand and predict such phenomena
A techno-economic study of a pump storage hydropower system for ultra-deep level mines applied to Driefontein No. 9 Shaft
No full textMEng (Mechanical Engineering), North-West University, Potchefstroom CampusThe energy required for mineral recovery is a major operational cost and strategic focus for the global mining sector. Power disruptions result in loss of production throughput and deceased profitability. Therefore, mines are required to review their power sources to ensure the sustainability and viability of their operations. In the South African region, the recent electricity tariff increases have had a major effect on energy-intensive users and subsequently significantly impacted investor decisions. The business case for alternative energy sources, which include renewable energy sources, has become far more compelling in the current economic climate. However, renewable energy is characterised by an intermittent supply, but with the selection of an appropriate storage mechanism, power variability can be mitigated and the system?s flexibility is enhanced. Only pumped storage hydropower is capable of meeting the anticipated technological and economic constraints with regard to storage capacity. High energy recovery has been recorded for energy recovery systems in deep level shafts. More than 50 turbines with a combined capacity of over 65 MW have been installed underground in various mines in South Africa. The use of current mine infrastructure of existing deep level mine shafts for underground pumped hydro-electric storage (UPHES) systems reduces the initial system capital cost and the depths of a potential network of tunnels provides potential hydraulic heads exceeding 1000 m. Driefontein No. 9 Shaft, a sub-shaft system consisting of a main shaft with shaft diameter 9.15 m and a shaft depth of 2 095 m, has been under care and maintenance for several years. The shaft is fully equipped with a dedicated production winder, dual-purpose production and men/material winder, shaft steelwork, electrical and communication cabling, various pipe columns and main haulages connecting the main shaft to the sub-vertical and ventilation shaft. A concept UPHES system model was produced in Excel and populated with the Driefontein No. 9 Shaft system parameters. The UPHES system configuration consists of a lower reservoir and pump station on 24 level, 2 095 m below datum (BD), a mid-shaft reservoir and pump chamber in mid-shaft - 1 050 m BD and a upper reservoir on intermediate pump chamber level, -150 m BD. The turbine chamber is also located on 24 level. Various assumptions are made, which include operational assumptions, such as when pumps are operational and when turbines are operational and system assumptions, which pertain to the general system components and their associated capacities. The UPHES system model was verified by using a simulation model developed in Engineering Equation Solver (EES). Unlike the Excel model, the EES simulation allows the pump and generating schedules to be varied for weekdays, Saturdays and Sundays. Therefore, the system was optimised using the EES simulation. The first priority for optimising the EES simulation model was to reduce the return on investment (ROI) as it is required that the asset investment is returned in the shortest time possible for the mine to benefit from the system?s energy saving potential. Therefore, in order to optimise the utilisation of existing infrastructure and lower capital costs, the costs dependent on the system output parameters were optimised along with the output parameters. The largest energy savings are achieved by maximising the number of hours of generating electricity during periods in which a peak tariff is charged and maximising the number of hours pumped only in periods in which off-peak tariffs are charged. This strategy maximises the number of hours during the day in which the maximum differential cost between tariffs is charged. Strategically scheduled pump and generating schedules are required to achieve the optimal system energy saving. An optimisation matrix was used to evaluate the pumping and generating schedules and the effect thereof on the number of pumps required per pump chamber, lower reservoir capacity, capital expenditure (CAPEX), electricity savings and ROI. It was determined that a break-even point exists at which the electricity cost savings are negatively affected by a decreased differential between the higher and lower tariff charged, because the cost of power consumed due to pumping cannot be recovered when energy is generated with the turbine. It was determined that if the percentage differential between peak and off-peak tariffs in the low demand season reaches 64% (off-peak tariff as a percentage of the peak tariff) or higher, the system no longer displays any electricity cost savings. Also, the percentage differential between the high demand season standard and peak tariff for the current 2016/2017 Megaflex tariff structure is 188% (standard tariff as a percentage of the off-peak tariff). The break-even point for the high demand season standard and peak tariff differential was calculated as 157% (standard tariff as a percentage of the offpeak tariff), therefore if the percentage differential reaches 157% or lower, the system no longer displays any electricity cost savings.Master
Turbidity dynamics during spring storm events in an urban headwater river system: the Upper Tame, West Midlands, UK
No full textTurbidity is an important water quality variable, through its relation to light suppression, BOD impact, sediment-associated contaminant transport, and suspended sediment effects on organisms and habitats. Yet few published field investigations of wet-weather turbidity dynamics, through several individual and sequenced rainstorms in extremely urbanised headwater basins, have emerged. This paper aims to address this gap through a turbidity analysis of multiple storm events in spring 2001 in an urban headwater basin (57 km2) of the River Tame, central England, the most urbanised basin for its size in the UK ( 42%). Data were collected at 15-min frequency at automated monitoring stations for rainfall, streamflow and six water quality variables (turbidity, EC, temperature, DO, pH, ammonia). Disturbance experiments also allowed estimates of bed sediment storage to be obtained.
Six important and unusual features of the storm event turbidity response were apparent: (1) sluggish early turbidity response, followed by a turbidity ‘rush’; (2) quasi-coincident flow and turbidity peaks; (3) anti-clockwise hysteresis in the discharge–turbidity relationship on all but one event, resulting from Falling-LImb Turbidity Extensions (FLITEs); (4) increases in peak turbidity levels through storm sequences; (5) initial micro-pulses (IMP) in turbidity; and (6) secondary turbidity peaks (STP) or ‘turbidity shoulders’ (TS). These features provided very little evidence of a true ‘first-flush’ effect: instead, substantial suspended solids transport continued right through the flow recessions, and little storm-event sediment exhaustion was evident. A new, dimensionless, hysteresis index, HImid, is developed to quantify the magnitude and direction of hysteresis in a simple, clear, direct and intuitive manner. This allowed the degree of departure from the classic ‘first-flush’, clockwise hysteresis models to be assessed.
Of the 15 turbidity events considered, 10 coincided with ammonia spikes of up to 6.25 mg l− 1 at Water Orton (the downstream station): this suggests that spills from combined sewer overflows (CSO) or waste water treatment works (WwTWs) are significant in the throughput of turbid waters here. Substantial ammonia peaks related most strongly to total storm rainfall receipt, of four rainfall variables considered, and significant ammonia peaks were generated even from low-magnitude storms (rainfall totals < 4 mm), indicating that spills are a frequent occurrence. Local bed sediment stores appear to be limited, suggesting that other distal sediment sources, such as road networks and old mineworkings are possibly more important. Biofilms may also play a part in delaying sediment release until late in the hydrograph, and in suppressing late spring turbidity levels. Existing first-flush models appear to be an oversimplification here. Such urban headwater basin responses can provide useful insights into the generation of contaminant waves, and offer vital early-warning systems for pollution events propagating downstream
Gender differences in self-reported late effects, quality of life and satisfaction with clinic in survivors of lymphoma
No full textObjectives: gender differences in perceived vulnerability to late effects and views about follow-up among cancer survivors have received little attention. As lymphoma affects both genders similarly, we compared the consequences of cancer (late effects, perceived vulnerability and quality of life (health-related quality of life (HRQoL)), and satisfaction with clinic visits between genders.Methods: a cohort of 115 younger adults (18–45 years, >5 years disease-free survival), who had been treated for lymphoma participated. Questionnaires (n = 91) were completed before and after (n = 62) routine consultant-led appointments. Survivors (n = 24) without appointments were recruited by post. Questionnaires included HRQoL, late effects, perceived vulnerability, issues survivors wanted to discuss and reported discussing in clinic, time waiting in clinic and consultation satisfaction.Results: there were no gender differences in number of self-reported late effects or perceived vulnerability. Men with more late effects reported worse psychological HRQoL (r = 0.50, p<0.001). While men wanted to discuss more topics than they did, women were able to discuss the topics they wanted (ANOVA, p = 0.01). Multiple regression analyses showed a shorter wait in clinic (r = ?0.46, p = 0.009) and discussing more topics (r = 0.34, p = 0.06) explained 30.6% of the variance in consultation satisfaction for men.Conclusions: issues surrounding follow-up provision are increasingly important given the length of survival in young adults following treatment for lymphoma. Men may experience poor psychological well-being due to distress about unanswered concerns. Consideration of their concerns should be prioritised, given that satisfaction and ultimately continued attendance at clinic and HRQoL may be dependent on the extent to which follow-up meets survivors' expectation
Na-ca Exchange And Ca Fluxes During Contraction And Relaxation In Mammalian Ventricular Muscle
No full textThere are four cellular Ca transport systems which compete to remove Ca from the myoplasm in mammalian ventricular myocytes. These are 1) the SR Ca-ATPase, 2) the sarcolemmal Na-Ca exchange, 3) the sarcolemmal Ca-ATPase and 4) the mitochondrial Ca uniporter. Using multiple experimental approaches we have evaluated the dynamic interaction of these systems during the normal cardiac contraction-relaxation cycle. The SR Ca-ATPase and Na-Ca exchange are clearly the most important, quantitatively; however, the relative roles vary in a species-dependent manner. In particular, the SR is much more strongly dominant in rat ventricular myocytes, where ~ 92% of Ca removal is via SR Ca-ATPase and only 7% via Na-Ca exchange during a twitch. In other species (rabbit, ferret, cat, and guinea pig) the balance is more in the range of 70% SR Ca-ATPase and 25-30% Na-Ca exchange. Ferret ventricular myocytes also exhibit an unusually strong sarcolemmal Ca-ATPase. During the steady state the same amount of Ca must leave the cell as enters over a cardiac cycle. This implies that 25-30% of the Ca required to activate contraction must enter the cell, and experiments demonstrate that this amount of Ca may be supplied by the L-type Ca current.779430442Bers, D.M., (1991) Excitation-Contraction Coupling and Cardiac Contractile Force, pp. 1-258. , (Single author monograph.) Kluwer Academic Press. Dordrecht, NetherlandsSutko, J.L., Willerson, J.T., Ryanodine alteration of the contractile state of rat ventricular myocardium. Comparison with dog, cat and rabbit ventricular tissues (1980) Circ. Res., 46, pp. 332-343Bers, D.M., Ca influx and SR Ca release in cardiac muscle activation during postrest recovery (1985) Am. J. Physiol., 248, pp. H366-H381Bers, D.M., Mechanisms contributing to the cardiac inotropic effect of Na-pump inhibition and reduction of extracellular Na (1987) J. Gen. Physiol., 90, pp. 479-504Bers, D.M., Christensen, D.M., Nguyen, T.X., Can Ca entry via Na-Ca exchange directly activate cardiac muscle contraction? (1988) J. Mol. Cell. Cardiol., 20, pp. 405-414Beuckelmann, D.J., Wier, W.G., Mechanism of release of calcium from sarcoplasmic reticulum of guinea pig cardiac cells (1988) J. Physiol., 405, pp. 233-255Fabiato, A., Time and calcium dependence of activation and inactivation of calcium-induced release of calcium from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell (1985) J. Gen. Physiol., 85, pp. 247-290Leblanc, N., Hume, J.R., Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum (1990) Science, 248, pp. 372-376Levi, A.J., Spitzer, K.W., Kohmoto, O., Bridge, J.H.B., Depolarization-induced Ca entry via Na-Ca exchange triggers SR release in guinea pig cardiac myocytes (1994) Am. J. Physiol., 266, pp. H1422-H1433Kohmoto, O., Levi, A.J., Bridge, J.H.B., Relation between reverse sodium-calcium exchange and sarcoplasmic reticulum calcium release in guinea pig ventricular cells (1994) Circ. Res., 74, pp. 550-554Bassani, R.A., Bassani, J.W.M., Bers, D.M., Mitochondrial and sarcolemmal Ca transport can reduce [Ca]i during caffeine contractures in rabbit cardiac myocytes (1992) J. Physiol., 453, pp. 591-608Bassani, J.W.M., Bassani, R.A., Bers, D.M., Relaxation in rabbit and rat cardiac cells: Species-dependent differences in cellular mechanisms (1994) J. Physiol., 476, pp. 279-293Bassani, R.A., Bassani, J.W.M., Bers, D.M., Relaxation in ferret ventricular myocytes: Unusual interplay among calcium transport systems (1994) J. Physiol., 476, pp. 295-308Bers, D.M., Bridge, J.H.B., Relaxation of rabbit ventricular muscle by Na-Ca exchange and sarcoplasmic reticulum Ca-pump: Ryanodine and voltage sensitivity (1989) Circ. Res., 65, pp. 334-342Bridge, J.H.B., Relationships between the sarcoplasmic reticulum and transarcolemmal Ca transport revealed by rapidly cooling rabbit ventricular muscle (1986) J. Gen. Physiol., 88, pp. 437-473Bers, D.M., Bridge, J.H.B., Spitzer, K.W., Intracellular Ca transients during rapid cooling contractures in guinea-pig ventricular myocytes (1989) J. Physiol., 417, pp. 537-553Bers, D.M., Lederer, W.J., Berlin, J.R., Intracellular Ca transients in rat cardiac myocytes: Role of Na/Ca exchange in excitation-contraction coupling (1990) Am. J. Physiol., 258, pp. C944-C954Hryshko, L.V., Stiffel, V.M., Bers, D.M., Rapid cooling contractures as an index of SR Ca content in rabbit ventricular myocyte (1989) Am. J. Physiol., 257, pp. H1369-H1377Hove-Madsen, L., Bers, D.M., SR Ca uptake and thapsigargin sensitivity in permeabilized rabbit and rat ventricular myocytes (1993) Cir. Res., 73, pp. 820-828Bassani, J.W.M., Bassani, R.A., Bers, D.M., Twitch-dependent SR Ca accumulation and release in rabbit ventricular myocytes (1993) Am. J. Physiol., 265, pp. C533-C540Bassani, R.A., Bers, D.M., Rate of diastolic Ca release from the sarcoplasmic reticulum of intact rabbit and rat ventricular myocytes (1995) Biophys. J., 68, pp. 2015-2022Bassani, J.W.M., Yuan, W., Bers, D.M., Fractional SR Ca release is altered by trigger Ca and SR Ca content in cardiac myocytes (1995) Am. J. Physiol., 268, pp. 1313-1319Gatto, C., Milanick, M.A., Inhibition of the red blood cell calcium pump by eosin and other fluorescein analogues (1993) Am. J. Physiol., 264, pp. C1577-C1586Gatto, C., Hale, C.C., Milanick, M.A., Eosin, a potent inhibitor of the plasma membrane Ca pump, does not inhibit the cardiac Na-Ca exchanger (1995) Biochemistry, 34, pp. 965-972Bassani, R.A., Bassani, J.W.M., Bers, D.M., Relaxation in ferret ventricular myocytes: Role of the sarcolemmal Ca ATPase (1995) Pflüg. Arch., 430, pp. 573-579Hove-Madsen, L., Bers, D.M., Passive Ca buffering and SR Ca uptake in permeabilized rabbit ventricular myocytes (1993) Am. J. Physiol., 264, pp. C677-C686Negretti, N., O'Neill, S.C., Eisner, D.A., The relative contributions of different intracellular and sarcolemmal systems to relaxation in rat ventricular myocytes (1993) Cardiovasc. Res., 27, pp. 1826-1830Crespo, L.M., Grantham, C.J., Cannell, M.B., Kinetics, stoichiometry and role of the Na-Ca exchange mechanism in isolated cardiac myocytes (1990) Nature, 345, pp. 618-621Puglisi, J.L., Bassani, R.A., Bassani, J.W.M., Amin, J.N., Bers, D.M., Temperature and the relative contributions of Ca transport systems in cardiac myocyte relaxation (1996) Am. J. Physiol., , In pressDelbridge, L.M., Bassani, J.W.M., Bers, D.M., Steady-state twitch Ca fluxes and cytosolic Ca buffering in rabbit ventricular myocytes (1996) Am. J. 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Significant-hail-producing storms in Finland:Convective-storm environment and mode
No full textThe environmental characteristics and convective mode of significant hailstorms (those storms producing reported hail 5 cm or larger in diameter) in Finland during 1972–2011 were analyzed. Altogether, 23 significant- hail-day environments were analyzed by modifying radiosonde data from proximity soundings in the observed data archives of the Finnish Meteorological Institute. Convective parameters derived from the environmental soundings were compared between a set of significant-hail soundings and a null set of nonsevere-thunderstorm soundings. A subset of 13 significant-hail days was examined using data from a network of Doppler radars during 1999–2011. Convective-storm mode and storm characteristics (e.g., hook echo, bounded weak-echo region) were determined for the 18 significant-hail-producing storms during these days. Most (78%) of these storms producing significant hail in Finland occurred with supercells. Of the significant-hail days, 39% (9 out of 23) did not have the minimum of 15 m s21 of deep-layer (0–6 km) shear commonly expected for supercells. Convective parameters of significant-hail and thunderstorm-day environments were substantially different from each other. Specifically, significant-hail environments had a mean most-unstable convective available potential energy (MUCAPE) of 1464 J kg21 and deep-layer shear of 17.5 m s21, whereas thunderstorm days had a MUCAPE of 593 J kg21 and deep-layer shear of 10.2 m s21. Larger hail was associated with higher values of MUCAPE. The lifetimes and track lengths of significant-hail-producing storms were related to the convective mode and storm environment. Specifically, larger deep-layer shear seemed to support longer lifetimes and track lengths. Nonsupercells had shorter lifetimes, shorter stormtrack lengths, and lower speeds than supercells. The value of deep-layer shear was smaller for nonsupercells than for supercells. Discrete supercells had higher speeds, longer lifetimes, and longer track lengths than cluster supercells
Recovery of plant and butterfly communities 3 years after Vaia storm in the Veneto region (Italy)
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Beyond Lesson Studies and Design Experiments: Using theoretical tools in practice and finding out how they work
No full textThis paper aims to illustrate how fruitful insights into the link between school teaching practice and student learning outcomes can be theoretically grounded by the variation theory from the field of phenomenography; and from this framework demonstrate how a 'pedagogy of awareness' can be implemented in the classroom. In this study, five teachers and 162 students at Primary Four level of school education in Hong Kong participated and the practice of the 'learning study' was adopted. By comparing the results of pre- and posttests, a significant gain was observed in the students learning outcomes.
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