371 |
Economic and grid potentials of implementing an energy storage system : A case study of the benefits of peak shaving if implementing an energy storage systemArvidsson, Maria, Ericson, Sara, Söderlind, Alicia January 2020 (has links)
Morgongåva is an urban centre in Sweden, with several challenges in the electrical power grid. In order to use the power grid more efficiently, this report investigates potentials of installing a battery energy storage system (BESS). Focus lies on finding economic and technical benefits of reducing power peaks, which occur during high demand hours when transmitting energy is more expensive. This method is referred to as peak shaving. Further, economic calculations if installing a BESS are based on electricity pricing data. Calculations regarding technical benefits are based on net power demand data. Further, the study shows that the usage of the grid, which was measured with the load factor, would increase and thus allow installation of more power sources and connecting more load to the grid. The load factor was estimated to increase by an average of 2.12 percent each month in 2019. In one year, the economic profit was estimated to be 91,000 kr. The conclusion is that there are economic profits for Sala-Heby Energi of installing a BESS, but more importantly a BESS has technical consequences in the power grid. Where technical benefits are important in order to reach the goals of Agenda 2030 but also to obtain a more reliable grid for the customers. A sensitivity analysis shows that the model is robust. Thus, the conclusion is that Sala-Heby Energi and the local electricity grid in Morgongåva would benefit from installing a BESS.
|
372 |
Proposed Revisions to Procedures for Testing and Evaluating Radiating Noise Sources from Small Firearms, including the ANSI/ASA S12.42-2010 ProcedureSarray, Sadreddine 26 May 2020 (has links)
The escalating cost of claims for Noise Induced Hearing Loss (NIHL) in the Canadian Armed Forces (CAF) supports the need to review and upgrade current hearing conservation practices.
The rise of these escalating costs and the need to protect the military personnel when training in extreme noise conditions has initiated an engineering investigation within the Department of National Defence (DND) and in collaboration with the University of Ottawa, to review the existing standards in the field of hearing protection test and evaluation, to propose technical recommendations and to identify the possible technical problems and gaps impacting the quality of the existing procedures.
This study dealt with the estimation of the protection capability of Hearing Protection Devices (HPDs) in the case of high-level impulse noise from small firearms weapons that are a particularly damaging source of noise in military environments, representing an important cause of NIHL.
Testing and evaluation based on a system engineering approach have been used in this work introducing:
- A new testing approach, based on ANSI/ASA S12.42-2010, for testing HPDs when the impulse noise is generated by a small firearm; - A new evaluation approach for HPD performance, introducing a characterization approach using a sub-band analysis for dealing with impulse noise generated by a small firearm.
The effectiveness of HPDs, taking into account the physiological human limitations induced by Bone Conduction (BC), is computed by using an innovative method attempting to better prevent the risk of NIHL when using small firearms.
|
373 |
Stacked-Value of Battery Storage: Effect of Battery Storage Penetration on Power DispatchJanuary 2020 (has links)
abstract: In this work, the stacked values of battery energy storage systems (BESSs) of various power and energy capacities are evaluated as they provide multiple services such as peak shaving, frequency regulation, and reserve support in an ‘Arizona-based test system’ - a simplified, representative model of Salt River Project’s (SRP) system developed using the resource stack information shared by SRP. This has been achieved by developing a mixed-integer linear programming (MILP) based optimization model that captures the operation of BESS in the Arizona-based test system. The model formulation does not include any BESS cost as the objective is to estimate the net savings in total system operation cost after a BESS is deployed in the system. The optimization model has been formulated in such a way that the savings due to the provision of a single service, either peak shaving or frequency regulation or spinning reserve support, by the BESS, can be determined independently. The model also allows calculation of combined savings due to all the services rendered by the BESS.
The results of this research suggest that the savings obtained with a BESS providing multiple services are significantly higher than the same capacity BESS delivering a single service in isolation. It is also observed that the marginal contribution of BESS reduces with increasing BESS energy capacity, a result consistent with the law of diminishing returns. Further, small changes in the simulation environment, such as factoring in generator forced outage rates or projection of future solar penetration, can lead to changes as high as 10% in the calculated stacked value. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020
|
374 |
Modelling the Dynamics and Forcesof Wave Energy Converters using WEC-SimJohansson, David January 2020 (has links)
The waves traveling on the surface of the world’s oceans carry atremendous amount of energy. The ability to convert this energy forhuman use has the potential to help solves the worlds energy problem. Adirect-drive linear generator point absorber is a wave energy converter(WEC) that aims to reduce the complexity of the overall system andshelter the most vulnerable parts of the system by placing them on theseabed. This concept builds around the buoy moving up and down indifferent sea-states which leads to a correlating vertical movement of thestroke in the generator resulting in the conversion of mechanical energyto power. This report aims to explore the possibility to use the open codeWEC-Sim to model the Uppsala University direct-drive linear generatorWEC in extreme sea states and to identify the resulting extreme loads. Theconstructed WEC-Sim model constrained the buoys motion in heave andsurge and limited its range of motion by modeling the generators upperend-stop spring. Simulations were run for different sea-states and theresulting forces on the system were analyzed. The peak line force for thedifferent sea states was calculated and compared to previous studies. Theresults validated the model as they showed a good correlation for mostsea-states. It was only for larger significant wave heights that there was adivergence compared to the results in previous studies.
|
375 |
The Use of the Isometric Squat as a Measure of Strength and ExplosivenessBazyler, Caleb D., Beckham, George K., Sato, Kimitake 01 May 2015 (has links)
The use of the isometric squat as a measure of strength and explosiveness. J Strength Cond Res 29(5): 1386–1392, 2015—The isometric squat has been used to detect changes in kinetic variables as a result of training; however, controversy exists in its application to dynamic multijoint tasks. Thus, the purpose of this study was to further examine the relationship between isometric squat kinetic variables and isoinertial strength measures. Subjects (17 men, 1-repetition maximum [1RM]: 148.2 ± 23.4 kg) performed squats 2 d·wk−1 for 12 weeks and were tested on 1RM squat, 1RM partial squat, and isometric squat at 90° and 120° of knee flexion. Test-retest reliability was very good for all isometric measures (intraclass correlation coefficients > 0.90); however, rate of force development 250 milliseconds at 90° and 120° seemed to have a higher systematic error (relative technical error of measurement = 8.12%, 9.44%). Pearson product-moment correlations indicated strong relationships between isometric peak force at 90° (IPF 90°) and 1RM squat (r = 0.86), and IPF 120° and 1RM partial squat (r = 0.79). Impulse 250 milliseconds (IMP) at 90° and 120° exhibited moderate to strong correlations with 1RM squat (r = 0.70, 0.58) and partial squat (r = 0.73, 0.62), respectively. Rate of force development at 90° and 120° exhibited weak to moderate correlations with 1RM squat (r = 0.55, 0.43) and partial squat (r = 0.32, 0.42), respectively. These findings demonstrate a degree of joint angle specificity to dynamic tasks for rapid and peak isometric force production. In conclusion, an isometric squat performed at 90° and 120° is a reliable testing measure that can provide a strong indication of changes in strength and explosiveness during training.
|
376 |
Estimating Peak Water Demand in Buildings with Efficient Fixtures: Methods, Merits, and ImplicationsOmaghomi, Toritseju O. 01 October 2019 (has links)
No description available.
|
377 |
AC Power Combining Strategy with Application to Efficient Linear Power AmplifiersBendig, Rudi Matthew 01 June 2014 (has links)
With the ongoing push for wireless systems to accommodate more users and support higher data rates more efficient modulation schemes have been created that are more advanced than simple FM and AM modulation used for radio broadcasting. These modulation schemes, such as orthogonal frequency division multiplexing (OFDM), suffer from high peak to average power ratios. Standard Class A and Class AB amplifiers cannot simultaneously achieve good linearity and efficiency, and therefore there has been an increase in the development of new topologies to combat this issue. Common features to these circuits is power combining of two or more separate transistors.
In this work, we consider various ways of two-source power combining and identify four topologies of interest. We notice that linear power-efficient amplifiers reported to date are based upon two of the identified combining strategies. We believe that no amplifiers have been reported that leverage the other two alternatives. This work produces a fully-functional amplifier based on one of these alternatives. The prototypes are intended to serve as concept verification of the architecture and hence are implemented at lower (1 MHz) frequencies.
|
378 |
Modelování povodňových vln v horní části povodí řeky Jihlavy / Evaluation of Flood Waves in the Upper Part of Jihlava River BasinKozel, Tomáš January 2014 (has links)
This thesis is about construction of forecasting models for prediction of flood flows of systems measuring profile Batelov – Dvorce, Dvorce – Ptáčov and Batelov – Ptáčov on the river Jihlava. For forecasting flood flows were used classic hydrological forecasting models. Another forecasting models contained neural networks. Data for construction of forecasting models were used for years 1960 – 2010. Evaluation was made in the end of thesis. The thesis also containes theoretical line of flood flows volume.
|
379 |
A Qualitative Study of EMaaS Performance in California SchoolsJanuary 2020 (has links)
abstract: In recent years, many school districts, community colleges, and universities in California have implemented energy management-as-a-service (EMaaS). The purpose of this study was to analyzes how EMaaS has been realized in California schools, including how performance expectations and service guarantees have been met, how value is created and captured, and which trends are emerging in the pay-for-performance models. This study used a qualitative research design to identify patterns in the collected data and allow theories to be drawn from the emergent categories and themes. Ten in-depth interviews were conducted with a diverse pool of facility managers, energy practitioners, superintendents, and associate superintendents working with EMaaS. Four themes emerged (1) peak shaving overperformance, (2) low risk/reward, (3) performance exactly as expected, and (4) hope in future flexibility. This study reveals medium to high levels of performance satisfaction from the customers of cloud-enabled and battery-based EMaaS in California schools. Value has been captured primarily through peak shaving and intelligent bill management. Large campuses with higher peaks are especially good at delivering energy savings, and in some instances without pairing batteries and solar. Where demand response participation is permitted by the utility companies, the quality of demand response performance is mixed, with performance being exactly as expected to slightly less than expected. The EMaaS business model is positioned to help California schools implement and achieve many of their future sustainability goals in a cost-effective way. / Dissertation/Thesis / Masters Thesis Construction Management 2020
|
380 |
Zero in on Key Open Problems in Automated NMR Protein Structure DeterminationAbbas, Ahmed 12 November 2015 (has links)
Nuclear magnetic resonance (NMR) is one of the main approaches for protein struc- ture determination. The biggest advantage of this approach is that it can determine the three-dimensional structure of the protein in the solution phase. Thus, the natural dynamics of the protein can be studied. However, NMR protein structure determina- tion is an expertise intensive and time-consuming process. If the structure determi- nation process can be accelerated or even automated by computational methods, that will significantly advance the structural biology field. Our goal in this dissertation is to propose highly efficient and error tolerant methods that can work well on real and noisy data sets of NMR.
Our first contribution in this dissertation is the development of a novel peak pick- ing method (WaVPeak). First, WaVPeak denoises the NMR spectra using wavelet smoothing. A brute force method is then used to identify all the candidate peaks. Af- ter that, the volume of each candidate peak is estimated. Finally, the peaks are sorted according to their volumes. WaVPeak is tested on the same benchmark data set that was used to test the state-of-the-art method, PICKY. WaVPeak shows significantly better performance than PICKY in terms of recall and precision.
Our second contribution is to propose an automatic method to select peaks pro- duced by peak picking methods. This automatic method is used to overcome the limitations of fixed number-based methods. Our method is based on the Benjamini- Hochberg (B-H) algorithm. The method is used with both WaVPeak and PICKY to automatically select the number of peaks to return from out of hundreds of candidate peaks. The volume (in WaVPeak) and the intensity (in PICKY) are converted into
p-values. Peaks that have p-values below some certain threshold are selected. Ex- perimental results show that the new method is better than the fixed number-based method in terms of recall. To improve precision, we tried to eliminate false peaks using consensus of the B-H selected peaks from both PICKY and WaVPeak. On average, the consensus method is able to identify more than 88% of the expected true peaks, whereas less than 17% of the selected peaks are false ones.
Our third contribution is to propose for the first time, the 3D extension of the Median-Modified-Wiener-Filter (MMWF), and its novel variation named MMWF*. These spatial filters have only one parameter to tune: the window-size. Unlike wavelet denoising, the higher dimensional extension of the newly proposed filters is relatively easy. Thus, they can be applied to denoise multi-dimensional NMR-spectra. We tested the proposed filters and the Wiener-filter, an adaptive variant of the mean-filter, on a benchmark set that contains 16 two-dimensional and three-dimensional NMR- spectra extracted from eight proteins. Our results demonstrate that the adaptive spatial filters significantly outperform their non-adaptive versions. The performance of the new MMWF* on 2D/3D-spectra is even better than wavelet-denoising.
Finally, we propose a novel framework that simultaneously conducts slice picking and spin system forming, an essential step in resonance assignment. Our framework then employs a genetic algorithm, directed by both connectivity information and amino acid typing information from the spin systems to assign the spin systems to residues. The inputs to our framework can be as few as two commonly used spectra, i.e., CBCA(CO)NH and HNCACB. Different from existing peak picking and resonance assignment methods that treat peaks as the units, our method is based on slices, which are one-dimensional vectors in three-dimensional spectra that correspond to certain (N, H) values. Experimental results on both benchmark simulated data sets and four real protein data sets demonstrate that our method significantly outperforms the state-of-the-art methods especially on the more challenging real protein data sets,
while using a less number of spectra than those methods. Furthermore, we show that using the chemical shift assignments predicted by our method for the four real proteins can lead to accurate calculation of their final three-dimensional structures by using CS-ROSETTA server.
|
Page generated in 0.0371 seconds