Modeling and Analysis of Bimorph Piezoelectromagnetic Energy Harvester

Piezoelectric energy harvesting is one of the methods of obtaining energy from environment. It is often a cantilever beam with or without tip mass poled with piezoelectric material. The fixed end of cantilever beam is subjected to either base excitation or translation as occurring from an environmental source such as automobile or vibrating engine. The piezoelectric energy harvester generates maximum energy when it is excited at resonance frequency and the little variation below or above the resonance frequency will drastically reduce the power output. In this line, present work studies a broadband nonlinear piezoelectric energy harvester driven by periodic and random oscillations. The simulated response to the base excitation is illustrated in terms of harvested power. By introducing magnetic force, we can broaden the frequency zone so as to capture more energy even the beam do not vibrate close to source frequency. A magnetic tip is included at the free end of the cantilever beam and is excited by two permanent magnets fixed on either sides laterally. The symmetric bimorph cantilever beam piezoelectric energy harvester with magnetic tip is modeled as Single-degree of freedom lumped parameter system. The time domain history and frequency response diagrams for the cantilever displacement, voltage and power at the constant load resistance gives a stability picture as well as the amount of energy harvested. The effect of various parameters of energy harvester system on induced voltage and output power is studied. The distributed parameter model is formulated by using Euler-Bernoulli beam theory and Galerkin’s approximation technique. The finite element modeling equations are presented with piezoelectric coupling terms. Novelty in the work include; (i) adding a magnetic force in the system to make it as broadband harvester (ii) validation of approximation solutions with spring-mass modeling

Co-designing for common values:creating hybrid spaces to nurture autonomous cooperation

This paper concerns the development of digitally-mediated technologies that value social cooperation as a common good rather than as a source of revenue and accumulation. The paper discusses the activities that shaped a European participatory design project which aims to develop a digital space that promotes and facilitates the ‘Commonfare’, a complementary approach to social welfare. The paper provides and discusses concrete examples of design artifacts to address a key question about the role of co- and participatory design in developing hybrid spaces that nurture sharing and autonomous cooperation: how can co-design practices promote alternatives to the commodification of digitally-mediated cooperation? The paper argues for a need to focus on relational, social, political and ethical values, and highlights the potential power of co- and participatory design processes to achieve this. In summary, the paper proposes that only by re-asserting the centrality of shared values and capacities, rather than individual needs or problems, co-design can reposition itself thereby encouraging autonomous cooperation

People’s Republic of Bolzano or how digital artifacts can be adversarial to misinformation

Design scholars have been focusing more of their attention to public controversial “things”, through the focus on “making public things” or on the “formation of publics” in relation to design projects. With this in mind, this paper describes a design case contrasting and challenging the main media narrative through the production of digital artifacts. The design intervention we describe, aimed at counteracting the racist stereotyping which targets the local Chinese community of Bolzano. The project People’s Republic of Bolzano reshapes the identity of the local Chinese community through digital media, in order to restore more transparent and balanced information, allowing a broader audience to inform itself on such a complex and multifaceted issue. This small project is part of an emergent phenomenon to counterbalance misrepresentation, in this case over the issue of migration

Use of Extracted Green Inhibitors as a Friendly Choice in Corrosion Protection of Low Alloy Carbon Steel

Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants), and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polysaccharides (galactomannan) from locust bean gum (also known as carob gum, carob bean gum) extracted from the seed of carob tree is used. Corrosion protection efficiency of these extracted green inhibitors was tested for carbon steel marked as: steel 39, steel 44, and iron B 500 (usually applied as reinforcing bars to concrete). Sulfuric acid solution in the presence of chloride ions was used as corrosion media. The composition of corrosion acid media used was 1 mol L^-1 H₂SO₄ and 10^-3 mol L^-1 Cl^- (in the form of NaCl). Electrochemical techniques such as potentiodynamic polarization methods were used for inhibitor efficiency testing

Winter thermal comfort and indoor air quality in Swedish grade school classrooms, as assessed by the children

This paper presents results from a pilot thermal comfort study in five Swedish grade school classrooms in three different buildings during winter 2015/16. The study includes measurements of environmental parameters (air temperature, globe temperature, relative humidity, air speed, CO2) and questionnaire surveys designed to match the children’s cognitive level. The questionnaire includes questions about thermal perception, air quality and air movement, as well as the children’s clothing level. The aim of this study is to investigate whether recently found differences in thermal sensation between children and adults outside the heating season also apply to the winter season. Children’s assessment is compared to the objective measurements during the surveys, to winter design criteria for school classrooms and to comfort temperatures from previous studies. The results agree with the previously found warmer sensation of children compared to adults’ predicted thermal sensation based on the currently used PMV model, although this time the difference is smaller. Regarding air quality, no relationship was found between children’s assessment and CO2 levels

Performance evaluation of neural network assisted motion detection schemes implemented within indoor optical camera based communications

This paper investigates the performance of the neural network (NN) assisted motion detection (MD) over an indoor optical camera communication (OCC) link. The proposed study is based on the performance evaluation of various NN training algorithms, which provide efficient and reliable MD functionality along with vision, illumination, data communications and sensing in indoor OCC. To evaluate the proposed scheme, we have carried out an experimental investigation of a static indoor downlink OCC link employing a mobile phone front camera as the receiver and an 8 x000D7; 8 red, green and blue light-emitting diodes array as the transmitter. In addition to data transmission, MD is achieved using a camera to observe userx02019;s finger movement in the form of centroids via the OCC link. The captured motion is applied to the NN and is evaluated for a number of MD schemes. The results show that, resilient backpropagation based NN offers the fastest convergence with a minimum error of 10x02212;5 within the processing time window of 0.67 s and a success probability of 100 x00025; for MD compared to other algorithms. We demonstrate that, the proposed system with motion offers a bit error rate which is below the forward error correction limit of 3.8 x000D7; 10x02212;3, over a transmission distance of 1.17 m

The first tests of smartphone camera exposure effect on optical camera communication links

In this paper, we study the effect of smartphone camera exposure on the performance of optical camera communications (OCC) link. The exposure parameters of image sensor sensitivity (ISO), aperture and shutter speed are included. A static OCC link with a 8×8 red, green and blue (RGB) LED array employed as the transmitter and a smartphone camera as the receiver is demonstrated to verify the study. Signal-to-noise ratio (SNR) analysis at different ISO values, the effect of aperture and shutter speed on communication link quality is performed. While SNRs of 20.6 dB and 16.9 dB are measured at 1 m and 2 m transmission distance, respectively for a ISO value of 100, they are decreased to 17.4 dB and 13.32 dB for a ISO of 800. The bit error rate (BER) of a 1 m long OCC link with a camera’s shutter speed of 1/6000 s is 1.3×10 −3 (i.e., below the forward error correction BER limit of 3.8×10 −3 ) and is dropped to 0.0125 at a shutter speed of 1/20 s. This study provides insight of the basic smartphone settings and the exposure adjustment for further complex OCC links

Participatory design, beyond the local

This workshop aims at stimulating and opening a debate around the capacity of Participatory Design (PD) and other co-design approaches to deliver outcomes and methodologies that can have an impact and value for reuse well beyond the local context in which they were originally developed. This will be achieved by stimulating the submission of position papers by researchers from the PD community and beyond.These papers will be discussed during the workshop in order to identify challenges, obstacles but also potentials for scaling up PD processes and results from the local to the global.</p

Evaluation of multistress tolerant maize varieties for sustainable intensification in northern Guinea Savanna of north eastern Nigeria

Maize productivity is limited by multiple stresses in the savannas of West and Central Africa. Field trials were conducted in northern Guinea savanna of Nigeria in 2011 and 2012 to evaluate the performance of multi-stress tolerant maize varieties. Thirteen varieties including Local Check replicated three times were tested in randomized complete block design. Plant and ear heights were significantly higher for LNTP x LNP-WC3 and 2004 TZE-W DTSTRC4 than POOL 18-SR, 2009 TZE-W POP-STR, EVDT 99-W STR; and EVDT 2000-Y STRQPM, respectively. Striga count was significantly lower for EVDT 99-W STR and LNTP x LNP-WC3 than all the other entries. Days to 50% tassel and 50% silk were each significantly earlier for EVDT 99STR W-STR QPM, DT-W STR SYN, EVDT-99W STR and 2009 TZEW DT STR than the Local Check. Anthesis Silk Interval (ASI) was significantly lower for TZE COMP3 DT-WC2, 2009 TZEW DT STR, and EVDT 99-W STR than Local Check. Number of ears plant-1 was significantly higher for 2008 DTMA-Y STR than Local Check. Grain yield ha-1 was significantly superior for DT-Y STR SYN, 2008 DTMA-Y STR, 2004 TZE-W DTSTR C4, 2009 TZEW DT STR and EVDT 99-W STRQPM, respectively. Plant height was positively correlated with ASI and ear height, while ear height was positively associated with ears plant-1, days to 50% silk and 50% tassel. Grain yield ha-1 was positively correlated with ears plant-1, days to 50 % silk, days to 50% tassel and ear height, while ears plant-1 was negatively correlated with ear weight. Farmer selection criteria for acceptance of variety were in the order: Striga tolerance > nutrient value > drought tolerance > flour value > good taste > high yield > early maturity. The five varieties: DTY STR SYN, 2008 DTMA-Y STR, 2004 TZE-W DT STRC4, 2009 TZEW DT STR and EVDT 99-W STRQPM satisfied farmers criteria and were promising and thus nominated for on-farm demonstration and subsequent adoption in the region