Protection System For the Energy Harvesting from Exercise Machines (EHFEM) Project

The goal of the Energy Harvesting from Exercise Machines (EHFEM) project seeks to harness the energy generated by people using exercise machines and deliver this energy to the electric grid [1]. The implementation consists of a protection system, DC-DC converter, and an inverter. This project involves redesigning the existing DC-DC input protection circuit and current limiter for the EHFEM project [2]. The DC-DC converter takes in the power from the exercise machines and converts it to a manageable voltage level for the inverter. Due to a problem where the inverter may overload the converter, a current limiter sets to limit the current between the two circuits [4]. The inverter demanding more current at a lower voltage than the DC-DC converter can provide causes this overload. The input protection circuit for the DC-DC converter presents another major component of the protection system. The DC-DC converter must operate within set input voltage and current parameters. Concurrent with this project, students Byung Yoo and Sheldon Chu have developed a new DC-DC converter design with an operational range of 6 V to 51 V [7]. This paper proposes a design for an overvoltage protection circuit to limit the input of Yoo’s and Chu’s DC-DC converter to within its operational range. The input protection circuit regulates the incoming voltage from the elliptical machine and filters out any high frequency transient responses with capacitive filtering to generate a smooth DC signal. The circuit also functions to divert excess voltage and current that accumulates during the Enphase Micro-inverter’s startup period where an open load appears across the DC-DC converter leading to an overvoltage level [3]. A current sense circuit ensures the output from the DC-DC converter to the inverter delivers only as much power as the inverter can convert [4]. The device maintains a minimal component count number and lacks any excessively large components permitting easy assembly and installation. The device operates with a minimal loss of energy and minimizes fabrication costs allowing for recuperation of initial production costs over 10 years of normal use

A People-centered Approach to Historic Gardens: The Influence of Social, Political and Economic Factors on Management and Fruition

Historic gardens are heritage properties of great environmental, cultural, social, political and economic value, yet they are also precarious because they are composed of living elements. Their survival, in fact, depends on constant care. This research project seeks to analyze the social, political and economic factors influencing the management and fruition of historic gardens to improve their conservation and ability to contribute to human wellbeing and quality of life. These themes are both missing from existing literature and relevant to current trends in historic garden conservation and fruition made even more evident by the COVID-19 pandemic. Various research methodologies are applied in pursuit of the research aim, including: qualitative interviews providing a first-hand account of the motivations and struggles of those who care for historic gardens; a systematic review of the literature to trace the development of themes and trends in the research and identify significant gaps; document content analysis to make sense of the various political entities and instruments governing historic gardens; spatial analysis to investigate the potential and actual influence of heritage lists on recreational ecosystem service demand; the zonal travel cost method to assess the actual economic value of recreational ecosystem services created by an event in a historic garden. Some of the investigations conducted as part of the dissertation use the city of Palermo (Italy) as a case study to analyze the problems affecting historic garden management and fruition. Palermo’s parks and gardens have been celebrated throughout history, and they still make up most the city’s green spaces. However, they are also recognized as being neglected and deteriorating. Palermo is also a good model for internationally relevant issues related to historic gardens, including the effect of economic and health crises on the management and fruition of green spaces, public austerity, dysfunctional bureaucracy, sustainable development and wellbeing, making the results of these investigations relevant internationally as well as locally. The results of this research provide a people-centered perspective on the management and fruition of historic gardens. By considering the social, political and economic contexts in which they exist, the research identified developments in natural and cultural heritage practice, policy and planning that have important implications for historic garden management and fruition. Recent policy has focused on issues of sustainability and wellbeing, and consequentially put more emphasis on the experiences these heritage sites provide and on the stakeholders they involve. With this perspective, public engagement initiatives organized in historic gardens play an important role in involving the community, creating meaningful experiences and creating economic value. They are human inputs that transform potential cultural ecosystem service benefits into actual benefits. These findings also have implications for the governance, planning management and fruition of other resources valued for their cultural ecosystem services. The research presented here can also be fruitfully applied to investigations of the various cultural ecosystem services provided by such areas as urban green spaces, cultural landscapes and nature reserves. These qualitative, spatial and economic assessments are necessary to ensure that public policy measures, investments, and private or non-profit management strategies are effective in meeting their objectives to contribute to human wellbeing and conserve resources for the future

ECG Classification with an Adaptive Neuro-Fuzzy Inference System

Heart signals allow for a comprehensive analysis of the heart. Electrocardiography (ECG or EKG) uses electrodes to measure the electrical activity of the heart. Extracting ECG signals is a non-invasive process that opens the door to new possibilities for the application of advanced signal processing and data analysis techniques in the diagnosis of heart diseases. With the help of today’s large database of ECG signals, a computationally intelligent system can learn and take the place of a cardiologist. Detection of various abnormalities in the patient’s heart to identify various heart diseases can be made through an Adaptive Neuro-Fuzzy Inference System (ANFIS) preprocessed by subtractive clustering. Six types of heartbeats are classified: normal sinus rhythm, premature ventricular contraction (PVC), atrial premature contraction (APC), left bundle branch block (LBBB), right bundle branch block (RBBB), and paced beats. The goal is to detect important characteristics of an ECG signal to determine if the patient’s heartbeat is normal or irregular. The results from three trials indicate an average accuracy of 98.10%, average sensitivity of 94.99%, and average specificity of 98.87%. These results are comparable to two artificial neural network (ANN) algorithms: gradient descent and Levenberg Marquardt, as well as the ANFIS preprocessed by grid partitioning

Distance to the IBEX Ribbon Source Inferred from Parallax

Maps of Energetic Neutral Atom (ENA) fluxes obtained from Interstellar Boundary Explorer (IBEX) observations revealed a bright structure extending over the sky, subsequently dubbed the IBEX ribbon. The ribbon had not been expected from the existing models and theories prior to IBEX, and a number of mechanisms have since been proposed to explain the observations. In these mechanisms, the observed ENAs emerge from source plasmas located at different distances from the Sun. Since each part of the sky is observed by IBEX twice during the year from opposite sides of the Sun, the apparent position of the ribbon as observed in the sky is shifted due to parallax. To determine the ribbon parallax, we found the precise location of the maximum signal of the ribbon observed in each orbital arc. The obtained apparent positions were subsequently corrected for the Compton-Getting effect, gravitational deflection, and radiation pressure. Finally, we selected a part of the ribbon where its position is similar between the IBEX energy passbands. We compared the apparent positions obtained from the viewing locations on the opposite sides of the Sun, and found that they are shifted by a parallax angle of $0.41^\circ\pm0.15^\circ$, which corresponds to a distance of $140^{+84}_{-38}$ AU. This finding supports models of the ribbon with the source located just outside the heliopause.Comment: 26 pages, 10 figures, 1 table, submitted to Ap

A possible generation mechanism for the IBEX ribbon from outside the heliosphere

The brightest and most surprising feature in the first all-sky maps of Energetic Neutral Atoms (ENA) emissions (0.2-6 keV) produced by the Interstellar Boundary Explorer (IBEX) is an almost circular ribbon of a ~140{\deg} opening angle, centered at (l,b) = (33{\deg}, 55{\deg}), covering the part of the celestial sphere with the lowest column densities of the Local Interstellar Cloud (LIC). We propose a novel interpretation of the IBEX results based on the idea of ENA produced by charge-exchange between the neutral H atoms at the nearby edge of the LIC and the hot protons of the Local Bubble (LB). These ENAs can reach the Sun's vicinity because of very low column density of the intervening LIC material. We show that a plane-parallel or slightly curved interface layer of contact between the LIC H atoms (n_H = 0.2 cm^-3, T = 6000-7000 K) and the LB protons (n_p = 0.005 cm^-3, T ~ 10^6 K), together with indirect contribution coming from multiply-scattered ENAs from the LB, may be able to explain both the shape of the ribbon and the observed intensities provided that the edge is < (500-2000) AU away, the LIC proton density is (correspondingly) < (0.04-0.01) cm^-3, and the LB contains ~1% of non-thermal protons over the IBEX energy range. If this model is correct, then IBEX, for the first time, has imaged in ENAs a celestial object from beyond the confines of the heliosphere and can directly diagnose the plasma conditions in the LB.Comment: Accepted by Ap.J.Lett

A systematic literature review of historic garden management and its economic aspects

Historic gardens are important parts of humanity’s built heritage within the designed landscape, providing many environmental, economic and socio‐cultural benefits. Management is a key part of their conservation, perhaps the most difficult because it is costly, must be continual, and requires a skilled workforce. This systematic review looks at the literature addressing historic garden management, with special attention regarding the social, economic and environmental aspects of sustainability. Academic studies on this subject come from many different disciplines, making it both stimulating and fragmented. It is now time to consolidate these interdisciplinary efforts into a clear vision, including a framework of key themes and research methods so as to better coordinate efforts and make the information and innovation generated more accessible to the garden managers “in the trenches”. With this aim, reviewed studies are classified according to 10 criteria: supply or demand orientation; management phase involved; primary sustainability processes addressed; geographic criteria; number of sites covered; policy documents referred to; kind of data collected; study methods employed; possibility of bias specifically regarding historic gardens; garden use. An analysis of these criteria shows that historic garden management literature focuses on describing the gardens themselves, with few studies interested in the people supporting them. Future research should follow recent policy documents’ lead and pay more attention to community value and involvement

Lunar and Asteroid Composition Using a Remote Secondary Ion Mass Spectrometer

Laboratory experiments simulating solar wind sputtering of lunar surface materials have shown that solar wind protons sputter secondary ions in sufficient numbers to be measured from low-altitude lunar orbit. Secondary ions of Na, Mg, Al, Si, K, Ca, Mn, Ti, and Fe have been observed sputtered from sample simulants of mare and highland soils. While solar wind ions are hundreds of times less efficient than those used in standard secondary ion mass spectrometry, secondary ion fluxes expected at the Moon under normal solar wind conditions range from approximately 10 to greater than 10(exp 4) ions cm(sup -2)s(sup -1), depending on species. These secondary ion fluxes depend both on concentration in the soil and on probability of ionization; yields of easily ionized elements such as K and Na are relatively much greater than those for the more electronegative elements and compounds. Once these ions leave the surface, they are subject to acceleration by local electric and magnetic fields. For typical solar wind conditions, secondary ions can be accelerated to an orbital observing location. The same is true for atmospheric atoms and molecules that are photoionized by solar EUV. The instrument to detect, identify, and map secondary ions sputtered from the lunar surface and photoions arising from the tenuous atmosphere is discussed

IMAGING TIME-OF-FLIGHT ION MASS SPECTROGRAPH

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The primary objective of this project was to develop and demonstrate a new type of time-of-flight mass spectrometer having a duty cycle of unity, which is a factor of 10{sup 3}-10{sup 4} better than conventional time-of-flight spectrometers. The spectrometer concept was demonstrated, and an additional pre-filtration technique was developed and demonstrated. The two techniques are patents pending