Offshore wind energy climate projection using UPSCALE climate data under the RCP8.5 emission scenario

MARKUS SEBASTIAN GROSS (2016, [Artículo])

In previous work, the authors demonstrated how data from climate simulations can be utilized to estimate regional wind power densities. In particular, it was shown that the quality of wind power densities, estimated from the UPSCALE global dataset in offshore regions of Mexico, compared well with regional high resolution studies. Additionally, a link between surface temperature and moist air density in the estimates was presented. UPSCALE is an acronym for UK on PRACE (the Partnership for Advanced Computing in Europe)-weather-resolving Simulations of Climate for globAL Environmental risk. The UPSCALE experiment was performed in 2012 by NCAS (National Centre for Atmospheric Science)- Climate, at the University of Reading and the UK Met Office Hadley Centre. The study included a 25.6-year, five-member ensemble simulation of the HadGEM3 global atmosphere, at 25km resolution for present climate conditions. The initial conditions for the ensemble runs were taken from consecutive days of a test configuration. In the present paper, the emphasis is placed on the single climate run for a potential future climate scenario in the UPSCALE experiment dataset, using the Representation Concentrations Pathways (RCP) 8.5 climate change scenario. Firstly, some tests were performed to ensure that the results using only one instantiation of the current climate dataset are as robust as possible within the constraints of the available data. In order to achieve this, an artificial time series over a longer sampling period was created. Then, it was shown that these longer time series provided almost the same results than the short ones, thus leading to the argument that the short time series is sufficient to capture the climate. Finally, with the confidence that one instantiation is sufficient, the future climate dataset was analysed to provide, for the first time, a projection of future changes in wind power resources using the UPSCALE dataset. It is hoped that this, in turn, will provide some guidance for wind power developers and policy makers to prepare and adapt for climate change impacts on wind energy production. Although offshore locations around Mexico were used as a case study, the dataset is global and hence the methodology presented can be readily applied at any desired location. © Copyright 2016 Gross, Magar. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reprod

atmosphere, climate change, Europe, Mexico, sampling, time series analysis, university, weather, wind power, climate, risk, theoretical model, wind, Climate, Models, Theoretical, Risk, Wind CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

The impact of 1.5 °C and 2.0 °C global warming on global maize production and trade

Wei Xiong Tariq Ali (2022, [Artículo])

Future Climate Scenario Data Yield Reduction Risk CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CLIMATE CHANGE GREENHOUSE EFFECT MAIZE MITIGATION SIMULATION ACCLIMATIZATION ADAPTATION GLOBAL WARMING

Energy and economic efficiency of climate-smart agriculture practices in a rice–wheat cropping system of India

Manish Kakraliya Deepak Bijarniya Parbodh Chander Sharma ML JAT (2022, [Artículo])

Intensive Tillage Conventional Rice–Wheat Systems Energy Efficiency On-Farm Studies Climate-Smart Agricultural Practices CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CLIMATE-SMART AGRICULTURE RICE WHEAT CROPPING SYSTEMS

Dipole-wind interactions under gap wind jet conditions in the Gulf of Tehuantepec, Mexico: A surface drifter and satellite database analysis

MAURO WILFRIDO SANTIAGO GARCIA (2019, [Artículo])

Gap wind jets (Tehuano winds) trigger supersquirts of colder water and mesoscale asymmetric dipoles in the Gulf of Tehuantepec (GT). However, the effects of successive gap wind jets on dipoles and their effects inside eddies have not yet been studied. Based on the wind fields, geostrophic currents, and surface drifter dispersion, this research documented three dipoles triggered and modified by Tehuano winds. Once a dipole develops, successive gap wind jets strengthen the vortices, and the anticyclonic eddy migrates southwestward while the cyclonic eddy is maintained on the east side of the GT. During the wind relaxation stage, the cyclonic eddy may propagate westward, but due to the subsequent re-intensification of the Tehuano winds, the vortex could break down, as was suggested by surface drifter dispersion pattern and geostrophic field data. The effect of the Tehuano winds was evaluating via eddy-Ekman pumping. Under Tehuano wind conditions, Ekman downwelling (upwelling) inside the anticyclonic (cyclonic) eddies may reach ~ -2.0 (0.5) m d-1 and decrease as the wind weakens. In the absence of Tehuano winds, Ekman downwelling inside the anticyclonic eddy was ~ 0.1 (-0.1) m d-1. The asymmetry of downwelling and upwelling inside eddies during Tehuano wind events may be associated with Tehuano wind forcing. © 2019 Santiago-García et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

article, dipole, leisure, Mexico, cold, ecosystem, factual database, geographic mapping, hurricane, Mexico, satellite imagery, season, water flow, wind, sea water, Cold Temperature, Cyclonic Storms, Databases, Factual, Ecosystem, Geographic Mapping, CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Simulación y validación de la reparación de ductos en servicio por la deposición directa de soldadura

LUIS DANTE MELENDEZ MORALES (2023, [Tesis de doctorado])

El transporte de hidrocarburos por ductos enterrados es la forma más segura, confiable y económica para su suministro, estos pueden extenderse grandes longitudes territoriales e inclusive atravesar países con tal de satisfacer la demanda energética. No obstante, los ductos pueden sufrir daños provocados por el ambiente, su operación o bien provocados por terceros, siendo necesario que sean intervenidos reemplazando las secciones dañadas. Las regulaciones nacionales y tratados internacionales desalientan la liberación de grandes cantidades de gas natural a la atmósfera, por demás de que un paro de suministro conlleva a desabasto energético, multas y a costosas operaciones asociadas con la rehabilitación del ducto, forzando a soldar envolventes y accesorios sin detener la operación de los ductos, esto se conoce como “soldadura en servicio”. La soldadura en servicio es un proceso tecnológico, por el cual se puede efectuar la interconexión y la reparación de ductos mientras están en operación, previo a realizar estas actividades, se requiere que dos riesgos sean evaluados: agrietamiento por hidrógeno y quemada pasante. Las simulaciones actuales y validaciones evalúan estos riesgos de forma independiente, pero debido a su interdependencia estos riesgos deben evaluarse en conjunto. Un método de reparación que no es normalmente empleado, pero con un alto potencial debido a su simplicidad y versatilidad, es la deposición directa de soldadura. En la presente investigación, se realizó una simulación numérica fluido-termo-mecánica acoplada con validación experimental, de la reparación de un tubo con flujo presurizado conteniendo un defecto interno por la deposición directa de soldadura. Por medio de la cual, es posible predecir el comportamiento estructural del ducto mientras se realiza la reparación.

La simulación numérica se efectuó con el apoyo del software ANSYS versión académica 22R2, siendo esta una herramienta de última generación capaz de contribuir en la predicción de mecanismos complejos como lo es la soldadura en servicio, incrementando con ello la seguridad y confiabilidad de estas operaciones. Cabe hacer mención, que la regulación nacional prohíbe la reparación de defectos internos por la deposición directa de soldadura, esto se debe principalmente a la falta de investigaciones validadas que respalden su viabilidad. Los resultados demostraron la efectividad de emplear este método de reparación para restaurar la resistencia mecánica de los ductos. Las inspecciones por pruebas no destructivas superficiales, subsuperficiales y volumétricas, evidenciaron que no ocurrió agrietamiento inmediatamente al finalizar la reparación y retardada (posterior a por lo menos 12 horas después de haberse finalizada la reparación, tiempo suficiente para permitir la difusión de hidrógeno atómico a hidrógeno molecular). Las curvas de tendencia de temperatura mostraron buena aproximación teniéndose una diferencia máxima de 5.09% entre los resultados numéricos y experimental. Los resultados numéricos y experimentales de la deformación perimetral a lo largo de la longitud de la tubería mostraron un comportamiento similar con una diferencia significativa del 17.7% entre los valores numéricos atribuidos a la falta de información de entrada para las propiedades de la soldadura. El análisis estructural efectuado en este estudio emplea la estimación del riesgo de quemada pasante bajo presión interna, determinado por la ocurrencia de abultamiento radial localizado. Los resultados numéricos indican que no ocurre deformación plástica relevante. Se hace una fuerte recomendación para que las evaluaciones de análisis térmico empleen la morfología actual del defecto y no solo consideren el espesor remanente del tubo. De acuerdo con la revisión bibliográfica realizada y recientemente publicada, este tipo de simulación numérica acoplada con validación experimental de la reparación de ductos en servicio por deposición directa de soldadura para la reparación de defectos internos contemplando la prevención de quemada pasante y agrietamiento por hidrógeno no ha sido realizada con anterioridad.

Hydrocarbon transportation by buried pipelines is the safest, most reliable, and economical way for its supply; these can extend long territorial distances and even cross countries with the purpose of satisfying the energy demand. However, the pipelines can suffer damages caused by their environment, their operation, or provoked by third parties, making necessary interventions to replace the damaged sections. National regulations and international agreements discourage the release of large quantities of natural gas into the atmosphere; moreover, a stop in its supply entails an energetic shortage, fines, and expensive operations associated with the pipeline rehabilitation, forcing to weld sleeves and fittings without stop the pipeline operation, this is known as “In-Service Welding”. In-Service welding is a technological process for which interconnection and repair of pipelines can be made while they are in operation; before making it, two main risks need to be assessed: hydrogen cracking and burn-through. Current simulations and validations assess these risks independently, but due to their interdependence, these risks need to be assessed in conjunction. A repair method not normally used but with high potential due to its simplicity and versatility is the direct deposition of the weld. In the present research, a fluid-thermo-mechanical coupled numerical simulation with experimental validation was done of a repair on a pipe with pressurized flow having an internal defect by direct deposition of the weld. It is possible predict the structural behavior of a pipeline while the reparation is performed.

The numerical simulation was done with the support of ANSYS software academic version 22R2, the latest generation tool able to contribute to the prediction of complex mechanisms, as is in-service welding, increasing the security and confidence of these operations. It is worth mentioning that national regulation forbids the reparation of internal defects for direct deposition of the weld; the main reason is the lack of validated investigations supporting its viability. The results demonstrated the effectiveness of using this repair method to restore the mechanical strength of pipelines. Surface, sub-surface, and volumetric non-destructive inspections evidenced no cracking immediately to finish the repair and delayed (after at least 12 hours of having finished the repair, time enough to allow the hydrogen diffusion from atomic hydrogen to molecular hydrogen). Temperature tendency curves showed good approximations, having a maximum difference of 5.09 % between numerical and experimental. Perimeter deformation along the pipe length between numerical and experimental results displayed a similar behavior with a significant difference of 17.7% against numerical values attributed to the lack of input data for weld properties. The structural analysis performed in this study used the approach of the risk of burn-through under internal pressure determined by the occurrence of localized radial bulging. Numerical results indicated no relevant plastic strain occurs. It is strongly recommended that thermal analysis assessments using the actual defect morphology be performed, not only considering the remaining thickness of the pipe. According to the bibliographic revision performed and recently published, this kind of coupled numerical simulation of in-service repair or pipelines by direct deposition for repairing internal defects considering the prevention of burn-through and hydrogen cracking has not been done.

Ducto Soldadura en servicio Quemada pasante Agrietamiento por hidrógeno Reparación de soldadura Simulación numérica Pipeline In-service welding Burn-through Hydrogen cracking Weld repair Numerical simulation INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS

Oportunidad de aplicación de la metodología FRONT END LOADING en la expansión de gasoductos en el sureste mexicano: una evaluación

Opportunity to apply the front end loading methodology in the expansion of gas pipelines in the mexican southeast: an evaluation

Raúl Enrique Trejo Alvarado Luis Rolando Méndez Miguel (2023, [Artículo])

Con la finalidad de impulsar el desarrollo de la región sureste de México, la actual administración del gobierno federal se ha propuesto la ampliación de la red nacional de gasoductos hacia esa zona del país, con el fin de suministrar energía a los megaproyectos de la región. No obstante, estas obras presentan actualmente retrasos, evidenciando la necesidad de metodologías de gestión que permitan solucionar este problema de raíz. Una de las metodologías más prometedoras en esta materia es la front-end loading (FEL), ampliamente aplicada en el sector extractivo y energético. El propósito del articulo estriba en evaluar la posibilidad de aplicar la metodología FEL a los proyectos de expansión del Sistema Nacional de Gasoductos en el sureste mexicano.

To boost the development of the southeast region of Mexico, the current federal government administration has proposed the expansion of the national gas pipeline network to this area of the country, to supply energy to the region's mega-projects. However, these projects are currently experiencing delays, demonstrating the need for management methodologies to solve this problem at its root. One of the most promising methodologies in this area is front-end loading (FEL), which has been widely applied in the extractive and energy sector. The aim of this paper is to evaluate the possibility of applying the FEL methodology to the expansion projects of the National Gas Pipeline System in the southeastern México.

Gas natural Sector energético Front end loading (FEL) Evaluación de proyectos Sureste mexicano Natural gas Energy sector Project evaluation Mexican southeast INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Transición de leña a gas licuado a presión (GLP) en el sur de México, oportunidad para la mitigación del cambio climático en la región menos desarrollada del país

Transition from biomass to LP gas in southern Mexico, an opportunity for climate change mitigation in the least developed region in the country

Elio Guarionex Lagunes Díaz María Eugenia González Rosende Alfredo Ortega Rubio (2015, [Artículo])

"En los estados del sur de México, entre un 25% y un 55% de los hogares dependen de la leña para cocinar, lo cual trae consecuencias en el ambiente, el desarrollo y la salud. No obstante, el conocimiento de estas consecuencias y la migración hacia combustibles modernos ha permanecido relegada de las políticas de desarrollo. En este trabajo, partiendo de una descripción del panorama de uso de leña en el país y su importancia como fuente de energía, se presenta una aproximación para estimar ahorros en emisiones de CO2 logrables por la transición a gas licuado a presión (GLP), los cuales pueden alcanzar 3.14 Mt CO2e, 26% menos que el escenario base. Se finaliza con una discusión de la transición hacia combustibles modernos, las barreras que la impiden y los logros y fallos de la distribución de estufas ahorradoras de leña, la principal iniciativa gubernamental para aliviar el consumo de leña en el país."

"Between 25% and 55% of households in southern Mexico depend on biomass for cooking, which carries serious consequences on the environment, development and health. In spite of the knowledge of these consequences, transition from biomass to modern fuels has remained outside energy and development policies. In the present work, after describing the panorama of fuelwood use in the country and its importance as an energy source, an approach is presented for estimating CO2 savings achievable by transition to pressurized liquefied gas (LP). These savings can reach 3.14 Mt CO2e, 26% less than the baseline scenario. At the end we discuss on the transition to modern fuels in Mexico, the barriers that hinder it and the achievements and failures of the distribution of fuelwood saving cookstoves, as the only and most important governmental initiative to alleviate biomass use, comparing it with other priorities in the government's agenda."

Transición energética, cambio climático, política energética. Energy transition, climate change, energy policy. CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO METEOROLOGÍA CONTAMINACIÓN ATMOSFÉRICA CONTAMINACIÓN ATMOSFÉRICA

Modeling the growth, yield and N dynamics of wheat for decoding the tillage and nitrogen nexus in 8-years long-term conservation agriculture based maize-wheat system

C.M. Parihar Dipaka Ranjan Sena Prakash Chand Ghasal Shankar Lal Jat Yashpal Singh Saharawat Mahesh Gathala Upendra Singh Hari Sankar Nayak (2024, [Artículo])

Context: Agricultural field experiments are costly and time-consuming, and their site-specific nature limits their ability to capture spatial and temporal variability. This hinders the transfer of crop management information across different locations, impeding effective agricultural decision-making. Further, accurate estimates of the benefits and risks of alternative crop and nutrient management options are crucial for effective decision-making in agriculture. Objective: The objective of this study was to utilize the Crop Environment Resource Synthesis CERES-Wheat model to simulate crop growth, yield, and nitrogen dynamics in a long-term conservation agriculture (CA) based wheat system. The study aimed to calibrate the model using data from a field experiment conducted during the 2019-20-2020-21 growing seasons and evaluation it with independent data from the year 2021–22. Method: Crop simulation models, such as the Crop Environment Resource Synthesis CERES-Wheat (DSSAT v 4.8), may provide valuable insights into crop growth and nitrogen dynamics, enabling decision makers to understand and manage production risk more effectively. Therefore, the present study employed the CERES-Wheat (DSSAT v 4.8) model and calibrated it using field data, including plant phenological phases, leaf area index, aboveground biomass, and grain yield from the 2019-20-2020-21 growing seasons. An independent dataset from the year 2021–22 was used for model evaluation. The model was used to investigate the relationship between growing degree days (GDD), temperature, nitrate and ammonical concentration in soil, and nitrogen uptake by the crop. Additionally, the study explored the impact of contrasting tillage practices and fertilizer nitrogen management options on wheat yields. The experimental site is situated at ICAR-Indian Agricultural Research Institute (IARI), New Delhi, representing Indian Trans-Gangetic Plains Zone (28o 40’N latitude, 77o 11’E longitude and an altitude of 228 m above sea level). The treatments consist of four nitrogen management options, viz., N0 (zero nitrogen), N150 (150 kg N ha−1 through urea), GS (Green seeker based urea application) and USG (urea super granules @150 kg N ha−1) in two contrasting tillage systems, i.e., CA-based zero tillage (ZT) and conventional tillage (CT). Result: The outcomes exhibited favorable agreement between the model’s simulations and the observed data for crop phenology (With less than 2 days variation in 50% onset of flowering), grain and biomass yield (Root mean square error; RMSE 336 kg ha−1 and 649 kg ha−1, respectively), and leaf area index (LAI) (RMSE 0.28 & normalized RMSE; nRMSE 6.69%). The model effectively captured the nitrate-N (NO3−-N) dynamics in the soil profile, exhibiting a remarkable concordance with observed data, as evident from its low RMSE = 12.39 kg ha−1 and nRMSE = 13.69%. Moreover, as it successfully simulated the N balance in the production system, the nitrate leaching and ammonia volatilization pattern as described by the model are highly useful to understand these critical phenomena under both conventional tillage (CT) and CA-based Zero Tillage (ZT) treatments. Conclusion: The study concludes that the DSSAT-CERES-Wheat model has significant potential to assess the impacts of tillage and nitrogen management practices on crop growth, yield, and soil nitrogen dynamics in the western Indo-Gangetic Plains (IGP) region. By providing reliable forecasts within the growing season, this modeling approach can facilitate better planning and more efficient resource management. Future implications: The successful implementation of the DSSAT-CERES-Wheat model in this study highlights its applicability in assessing crop performance and soil dynamics. Future research should focus on expanding the model’s capabilities by reducing its sensitivity to initial soil nitrogen levels to refine its predictions further. Moreover, the model’s integration with decision support systems and real-time data can enhance its usefulness in aiding agricultural decision-making and supporting sustainable crop management practices.

Nitrogen Dynamics Mechanistic Crop Growth Models Crop Simulation CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA NITROGEN CONSERVATION AGRICULTURE WHEAT MAIZE CROP GROWTH RATE SIMULATION MODELS

Bundling subsurface drip irrigation with no-till provides a window to integrate mung bean with intensive cereal systems for improving resource use efficiency

Manish Kakraliya madhu choudhary Mahesh Gathala Parbodh Chander Sharma ML JAT (2024, [Artículo])

The future of South Asia’s major production system (rice–wheat rotation) is at stake due to continuously aggravating pressure on groundwater aquifers and other natural resources which will further intensify with climate change. Traditional practices, conventional tillage (CT) residue burning, and indiscriminate use of groundwater with flood irrigation are the major drivers of the non-sustainability of rice–wheat (RW) system in northwest (NW) India. For designing sustainable practices in intensive cereal systems, we conducted a study on bundled practices (zero tillage, residue mulch, precise irrigation, and mung bean integration) based on multi-indicator (system productivity, profitability, and efficiency of water, nitrogen, and energy) analysis in RW system. The study showed that bundling conservation agriculture (CA) practices with subsurface drip irrigation (SDI) saved ~70 and 45% (3-year mean) of irrigation water in rice and wheat, respectively, compared to farmers’ practice/CT practice (pooled data of Sc1 and Sc2; 1,035 and 318 mm ha−1). On a 3-year system basis, CA with SDI scenarios (mean of Sc5–Sc8) saved 35.4% irrigation water under RW systems compared to their respective CA with flood irrigation (FI) scenarios (mean of Sc3 and Sc4) during the investigation irrespective of residue management. CA with FI system increased the water productivity (WPi) and its use efficiency (WUE) by ~52 and 12.3% (3-year mean), whereas SDI improved by 221.2 and 39.2% compared to farmers practice (Sc1; 0.69 kg grain m−3 and 21.39 kg grain ha−1 cm−1), respectively. Based on the 3-year mean, CA with SDI (mean of Sc5–Sc8) recorded −2.5% rice yield, whereas wheat yield was +25% compared to farmers practice (Sc1; 5.44 and 3.79 Mg ha−1) and rice and wheat yield under CA with flood irrigation were increased by +7 and + 11%, compared to their respective CT practices. Mung bean integration in Sc7 and Sc8 contributed to ~26% in crop productivity and profitability compared to farmers’ practice (Sc1) as SDI facilitated advancing the sowing time by 1 week. On a system basis, CA with SDI improved energy use efficiency (EUE) by ~70% and partial factor productivity of N by 18.4% compared to CT practices. In the RW system of NW India, CA with SDI for precise water and N management proved to be a profitable solution to address the problems of groundwater, residue burning, sustainable intensification, and input (water and energy) use with the potential for replication in large areas in NW India.

Direct Seeded Rice Subsurface Drip Irrigation Economic Profitability Energy and Nitrogen Efficiency CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE RICE SUBSURFACE IRRIGATION IRRIGATION SYSTEMS WATER PRODUCTIVITY ECONOMIC VIABILITY ENERGY EFFICIENCY NITROGEN-USE EFFICIENCY

Fabrication of PVDF/PMMA Polymer for Sustainable Energy Harvesting .

JOSE RAYMUNDO LEPPE NEREY FERNANDO ZENAIDO SIERRA ESPINOSA MIGUEL ANGEL BASURTO PENSADO JOSE ALFREDO RODRIGUEZ RAMIREZ (2023, [Artículo])

The synthesis of blends that combine properties of two or more polymeric materials is increasingly investigated due to the versatility of the synthesis and its growing potential for many applications, including sustainability. Their characteristics are defined mainly by the synthesis conditions. Therefore, this paper details the synthesis process of easy-to-handle films using mixing method. The procedures and drawbacks found during the preparation of composite films are described. Polymeric compounds formed by the mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) are addressed, varying the concentration, and evaluating their impact on the piezoelectric capacity. Films were formed through the spin-coating technique and characterized by optical and holographic microscopes. The results showed that composites with a concentration of 50 wt.% or larger of PVDF in the blend acquire a morphology with a granular appearance, however at lower concentrations they present a homogeneous morphology similar to that of PMMA. A homogeneous distribution of PVDF in the PMMA stands out. However, excessive contents of PMMA are associated to peaks and non-uniformities detected like multicolored regions by digital holography. Controlled strength-strain laboratory tests allowed to evaluate the film blends performance. The results indicate noticeable improvements in voltage output for a composition 70wt% PVDF and 30 wt% PMMA.

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS Polymer blends, Power generation, Energy harvesting, Piezoelectricity,