Pengaruh Sistem Kontrol Solar Cell Berbasis Timer Dengan Acuan Pergerakan Matahari

AbstrakKrisis energi menjadi permasalahan yang sangat besar dan perlu perhatian khusus oleh dunia khususnya untuk negara Indonesia. Energi listrik khusunya yang amat berpengaruh terhadap keberlangsungan hidup manusia saat ini. Peningkatan kebutuhan energi listrik rata 2,2 % pertahun mengakibat listrik sangat perlu diperhatikan, solusi terbaik dengan membuat energi alternatif. Salah satu energi alternatif yang dapat mengatasi kebutuhan energi listrik adalah energi panas matahari, yakni dengan menggunakan solar cell untuk mengubah energi panas matahari menjadi energi listrik. tujuannya dari penelitian ini yaitu mencari performa terbaik dari solar cell, Solusi untuk menambah daya dan efisiensi solar cell dengan penelitian menggunakan metode eksperimental dimana solar cell akan di tambahkan sistem kontrol dengan basis timer sebagai agar dapat mengikuti pergerakan sinar matahari dari pagi hingga sore hari, dengan variasi waktu yang berbeda. Penelitian ini dilakukan dengan menggunakan metode eksperimental dimana solar cell akan dikontrol menjadi sistem solar cell yang mampu mengitkuti pergerakan matahari. Teknik analisa data dalam penelitian ini menggunakan analisis data deskriptif yaitu menggambarkan hasil penelitian dalam bentuk tabel dan grafik. Tujuan dari penelitian ini adalah untuk mengetahui performa solar cell yang menggunakan sistem kontrol berbasis timer dengan acuan pergerkan matahari. Penelitian tentang sistem kontrol solar cell berbasis timer yang dilakukan diharapkan, dapat memperoleh nilai efisiensi solar cell yang tinggi. Penelitian sistem kontrol solar cell berbasis Timer ini memiliki variabel rentang waktu pengambilan selama 15 menit, 30 menit, dan 60 menit. Berdasarkan data pengujian penggunaan variabel terbaik terbaik terdapat pada penggunaan waktu pengambilan selama 15 menit, dikarenakan memiliki nilai persentase efisiensi tertinggi yaitu sebesar 9.62%, dibandingkan dengan variabel rentang waktu pengambilan 30 menit yaitu 9,46% dan rentang waktu 60 menit yaitu 9,23%. Berdasarkan data pengujian semakin kecil rentang waktu pengambilan maka akan berpengaruh terhadap kenaikan efisiensi solar cell. Karena pergerakan solar cell yang di peroleh akan lebih banyak sehingga lebih mengikuti gerak matahari pada setiap harinya.Kata kunci: Kata kunci : Solar Cell, Timer, Efisiensi.Abstract Energy crisis becomes a big problem and need special attention by the world especially for the country of Indonesia. Electric energy is especially influential on the survival of human life today. Increasing the need of electric energy average 2.2% per year due to electricity needs to be considered, the best solution by making alternative energy. One alternative energy that can overcome the need for electrical energy is solar thermal energy, namely by using solar cells to convert solar thermal energy into electrical energy. the goal of this research is to find the best performance from solar cell, Solution to increase power and efficiency of solar cell with research using experimental method where solar cell will be added control system with base timer as to follow the movement of sunshine from morning until afternoon, with different time variations. This research was conducted by using experimental method where solar cell will be controlled to solar cell system capable of mengitkuti movement of the sun. Data analysis techniques in this study using descriptive data analysis that describes the results of research in the form of tables and graphs. The purpose of this research is to know the performance of solar cell that uses timer based control system with the reference of sun movement. Research on solar cell-based control system that is done is expected, can get high efficiency value of solar cell. The research of Timer based solar cell control system has variable of taking time for 15 minutes, 30 minutes, and 60 minutes. Based on the test data the best use of the best variables is found in the use of the retrieval time for 15 minutes, because it has the highest efficiency percentage value of 9.62%, compared with the 30 minute retrieval time variable is 9.46% and the time span 60 minutes is 9.23% . Based on test data the smaller the retrieval time it will affect the increase in solar cell efficiency. Because the movement of solar cells in the gain will be more so that more follow the motion of the sun on each day. Keywords: Solar Cell, Timer,Efficiency

Eikonal Approximation to 5D Wave Equations as Geodesic Motion in a Curved 4D Spacetime

We first derive the relation between the eikonal approximation to the Maxwell wave equations in an inhomogeneous anisotropic medium and geodesic motion in a three dimensional Riemannian manifold using a method which identifies the symplectic structure of the corresponding mechanics. We then apply an analogous method to the five dimensional generalization of Maxwell theory required by the gauge invariance of Stueckelberg's covariant classical and quantum dynamics to demonstrate, in the eikonal approximation, the existence of geodesic motion for the flow of mass in a four dimensional pseudo-Riemannian manifold. These results provide a foundation for the geometrical optics of the five dimensional radiation theory and establish a model in which there is mass flow along geodesics. Finally we discuss the case of relativistic quantum theory in an anisotropic medium as well. In this case the eikonal approximation to the relativistic quantum mechanical current coincides with the geodesic flow governed by the pseudo-Riemannian metric obtained from the eikonal approximation to solutions of the Stueckelberg-Schr\"odinger equation. This construction provides a model for an underlying quantum mechanical structure for classical dynamical motion along geodesics on a pseudo-Riemannian manifold. The locally symplectic structure which emerges is that of Stueckelberg's covariant mechanics on this manifold.Comment: TeX file. 17 pages. Rewritten for clarit

El nacimiento del Estado Plurinacional de Bolivia, la crisis y la integración regional

Bolivia, during 2008, became a propitious scenario for a coup d'état. A South American nation that was undertaking profound transformations of the status quo, in favor of the inclusion of historically neglected social sectors, saw its democratic institutions put in check by opposition movements. With the study of the founding process of the Movement to Socialism (MAS), the distribution of the actors' capacities in the Bolivian political system and the parameters of the conflict as a starting point, this paper analyses the role that the Union of South American Nations (Unasur) played in the institutional crisis. To do so, it takes as a basis the analysis of primary sources, i.e. documents issued by official bodies of the Bolivian state, as well as declarations and reports from the regional integration bloc. To this end, contributions from the thinking of Bolivian sociologist René Zavaleta Mercado were used, with the aim of theoretically interpreting the specificities of recent Bolivian history. This work verifies a relationship between the construction of Unasur as a space for dialogue and political agreement, and that it was able to resolve the crisis.Bolivia, durante el 2008, se convirtió en un escenario propicio para un golpe de Estado. Una nación sudamericana que emprendía profundas transformaciones del statu quo, en favor de la inclusión de sectores sociales históricamente postergados, veía sus instituciones democráticas puestas en jaque por movimientos opositores. Con el estudio del proceso fundacional del Movimiento al Socialismo (MAS), de la distribución de las capacidades de los actores en el sistema político boliviano y de los parámetros del conflicto como punto de partida, el presente trabajo analiza el rol que tuvo la Unión de las Naciones Suramericanas (Unasur) en la crisis institucional. Para ello, se toma como base el análisis de fuentes primarias, es decir, documentos emitidos por órganos oficiales del Estado boliviano, así como declaraciones e informes del bloque de integración regional. Para tal efecto, se emplearon contribuciones del pensamiento del sociólogo boliviano René Zavaleta Mercado, con el objetivo de interpretar teóricamente las especificidades de la historia reciente boliviana.Este trabajo verifica una relación entre la construcción de Unasur como espacio de diálogo y concertación política, y la crisis que fue capaz de resolver

Casimir forces in Bose-Einstein condensates: finite size effects in three-dimensional rectangular cavities

The Casimir force due to {\it thermal} fluctuations (or pseudo-Casimir force) was previously calculated for the perfect Bose gas in the slab geometry for various boundary conditions. The Casimir pressure due to {\it quantum} fluctuations in a weakly-interacting dilute Bose-Einstein condensate (BEC) confined to a parallel plate geometry was recently calculated for Dirichlet boundary conditions. In this paper we calculate the Casimir energy and pressure due to quantum fluctuations in a zero-temperature homogeneous weakly-interacting dilute BEC confined to a parallel plate geometry with periodic boundary conditions and include higher-order corrections which we refer to as Bogoliubov corrections. The leading order term is identified as the Casimir energy of a massless scalar field moving with wave velocity equal to the speed of sound in the BEC. We then obtain the leading order Casimir pressure in a general three-dimensional rectangular cavity of arbitrary lengths and obtain the finite-size correction to the parallel plate scenario.Comment: 12 pages; no figures; v.2: version accepted for publication in JSTAT v.3: references adde

Pre-analytical and analytical variables affecting the measurement of plasma-derived microparticle tissue factor activity

Elevated levels of tissue factor positive (TF+) microparticles (MPs) are observed in plasma from a variety of patients with an increased risk of thrombosis. We and others have described the measurement of TF activity in MPs isolated from plasma. The aim of this study was to investigate the effects of pre-analytical and analytical variables on TF activity of MPs isolated from blood of healthy volunteers treated ex vivo with or without bacterial lipopolysaccharide

Combining multiple isotopes and metagenomic to delineate the role of tree canopy nitrification in European forests along nitrogen deposition and climate gradients

Forest canopies influence our climate through carbon, water and energy exchanges with the atmosphere. However, less investigated is whether and how tree canopies change the chemical composition of precipitation, with important implications on forest nutrient cycling. Recently, we provided for the first time isotopic evidence that biological nitrification in tree canopies was responsible for significant changes in the amount of nitrate from rainfall to throughfall across two UK forests at high nitrogen (N) deposition [1]. This finding strongly suggested that bacteria and/or Archaea species of the phyllosphere are responsible for transforming atmospheric N before it reaches the soil. Despite microbial epiphytes representing an important component of tree canopies, attention has been mostly directed to their role as pathogens, while we still do not know whether and how they affect nutrient cycling. Our study aims to 1) characterize microbial communities harboured in tree canopies for two of the most dominant species in Europe (Fagus sylvatica L. and Pinus sylvestris L.) using metagenomic techniques, 2) quantify the functional genes related to nitrification but also to denitrification and N fixation, and 3) estimate the contribution of NO3 derived from biological canopy nitrification vs. atmospheric NO3 input by using \u3b415N, \u3b418O and \u3b417O of NO3in forest water. We considered i) twelve sites included in the EU ICP long term intensive forest monitoring network, chosen along a climate and nitrogen deposition gradient, spanning from Fennoscandia to the Mediterranean and ii) a manipulation experiment where N mist treatments were carried out either to the soil or over tree canopies. We will present preliminary results regarding microbial diversity in the phyllosphere, water (rainfall and throughfall) and soil samples over the gradient. Furthermore, we will report differences between the two investigated tree species for the phyllosphere core microbiome in terms of relative abundance of bacterial and Archaea classes and those species related to N cycling. Finally we will assess whether there are differences among tree species and sites in the number of functional genes related to N cycling and how they are related to the N deposition and/or climate. [1] Guerrieri et al. 2015 Global Change and Biology 21 (12): 4613-4626

G-CORE a core for future graph query languages

We report on a community effort between industry and academia to shape the future of graph query languages. We argue that existing graph database management systems should consider supporting a query language with two key characteristics. First, it should be composable, meaning, that graphs are the input and the output of queries. Second, the graph query language should treat paths as first-class citizens. Our result is G-CORE, a powerful graph query language design that fulfills these goals, and strikes a careful balance between path query expressivity and evaluation complexity

Hydrogen peroxide is involved in the acclimation of the Mediterranean shrub, Cistus albidus L., to summer drought

This study evaluated the possible role of hydrogen peroxide (H2O2) in the acclimation of a Mediterranean shrub, Cistus albidus L., to summer drought growing under Mediterranean field conditions. For this purpose, changes in H2O2 concentrations and localization throughout a year were analysed. H2O2 changes in response to environmental conditions in parallel with changes in abscisic acid (ABA) and oxidative stress markers, together with lignin accumulation, xylem and sclerenchyma differentiation, and leaf area were also investigated. During the summer drought, leaf H2O2 concentrations increased 11-fold, reaching values of 10 μmol g−1 dry weight (DW). This increase occurred mainly in mesophyll cell walls, xylem vessels, and sclerenchyma cells in the differentiation stage. An increase in ABA levels preceded that of H2O2, but both peaked at the same time in conditions of prolonged stress. C. albidus plants tolerated high concentrations of H2O2 because of its localization in the apoplast of mesophyll cells, xylem vessels, and in differentiating sclerenchyma cells. The increase in ABA, and consequently of H2O2, in plants subjected to drought stress might induce a 3.5-fold increase in ascorbic acid (AA), which maintained and even decreased its oxidative status, thus protecting plants from oxidative damage. After recovery from drought following late-summer and autumn rainfall, a decrease in ABA, H2O2, and AA to their basal levels (∼60 pmol g−1 DW, ∼1 μmol g−1 DW, and ∼20 μmol g−1 DW) was observed

Rule-Selection and Action-Selection have a Shared Neuroanatomical Basis in the Human Prefrontal and Parietal Cortex

The human capacity for voluntary action is one of the major contributors to our success as a species. In addition to choosing actions themselves, we can also voluntarily choose behavioral codes or sets of rules that can guide future responses to events. Such rules have been proposed to be superordinate to actions in a cognitive hierarchy and mediated by distinct brain regions. We used event-related functional magnetic resonance imaging to study novel tasks of rule-based and voluntary action. We show that the voluntary selection of rules to govern future responses to events is associated with activation of similar regions of prefrontal and parietal cortex as the voluntary selection of an action itself. The results are discussed in terms of hierarchical models and the adaptive coding potential of prefrontal neurons and their contribution to a global workspace for nonautomatic tasks. These tasks include the choices we make about our behavior