Contactless digital tachometer using microcontroller

Tachometer is a device that used for counting or for the measuring purpose of the number of revolutions (that is the total number rotations made by the device in unit of measuring time) of an object in unit time. It is expressed in the unit of RPS or RPM, the model uses a set of infrared transducer receiver to count the RPM pulses, and the Arduino microcontroller is used for the implementation of the project. The individual pulses are counted by the microcontroller to give the final output of the RPM

Kinetics of thermal decomposition of some metal oxalates

The thermal decomposition kinetics of oxalates of ZnII, NiII and ThIV have been studied in air by isothermal and non-isothermal thermogravimetry. The isothermal kinetic results suggest that the mechanism of decomposition of the zinc compound involves rapid nucleation followed by two dimensional growth in the acceleratory region, while in the case of thorium oxalate, the initial nucleation occurs by a chain mechanism on the surface of the reactant followed by the growth of the product from the surface towards the interior. The results on nickel oxalate could not be interpreted in an unambiguous manner. The activation energy and the frequency factor obtained from TG curves compare well with those obtained from the isothermal method. The activation energies for the dehydration of these oxalates have also been evaluated from the thermogravimetric curves

Extraction and Physico-Chemical Characterization of Pineapple Crown Leaf Fibers (PCLF)

Apart from the widely discussed pineapple leaf fibers, normally referred to as PALF, fibers from other parts of the plant also exist, particularly those in the fruit crown, which are known as pineapple crown leaf fibers (PCLF). In this work, PCLF were characterized using thermogravimetric analysis (TGA), Fourier transform IR spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicated that the properties of PCLF do not greatly differ from those observed for PALF. In particular, a cellulose content of over 67% was observed, with approximately 76% crystallinity. The main degradation phenomena of the fibers took place between 230 and 380 degrees C, peaking at 324 degrees C, which is in line with observations in other fibers which have similar cellulose and crystalline contents. There was 13.4% residue at 680 degrees C. Bare mechanical retting of PCLF, although not allowing a full and thorough degumming, which would only be achieved through more aggressive chemical treatment, enabled aspect ratios of over 10(3) to be obtained. This indicates some potential for their application as short fibers in composites. In this respect, the considerable roughness of PCLF when compared to other leaf-extracted fibers, and in particular when compared to PALF, could suggest an ability to obtain a sufficiently sound fiber-matrix interface

Simulation of various DC-DC converters for photovoltaic system

This work explains the comparison of various dc-dc converters for photovoltaic systems. In recent day insufficient energy and continues increasing in fuel cost, exploration on renewable energy system becomes more essential. For high and medium power applications, high input source from renewable systems like photovoltaic and wind energy system turn into difficult one, which leads to increase of cost for installation process. So the generated voltage from PV system is boosted with help various boost converter depends on the applications. Here the various converters are like boost converter, buck converter, buck-boost converter, cuk converter, sepic converter and zeta converter are analysed for photovoltaic system, which are verified using matlab / simulink

Accelerated Short-Term Techniques to Evaluate Corrosion in TiC Reinforced AA6063 Composites

AA6063-TiC composites have several weight percentages up to 9 wt. % were fabricated by using stir casting route method. The effects of the weight percentage of TiC particles on the microstructures and corrosion behavior of AA6063-TiC composites were studied. The results revealed that the AA6063-TiC composites exhibited higher density than the AA6063 matrix. The accelerated corrosion tests of AA6063-TiC composites in 3.5 wt. % NaCl aqueous solution at room temperature, the AA6063-TiC composites have better corrosion resistance than the AA6063 matrix. Increasing the weight percentage of the TiC particles to reduces the corrosion rate of the AA6063-TiC composites. In this process corrosion rate of 0.4402 mm/year for AA6063 matrix, 0.3891 mm/year for 3 wt. % , 0.3568 mm/year for 6 wt. % and 0.3062 mm/year for 9 wt. % of TiC particles respectively. The poor corrosion resistance of the composites can be attributed to the galvanic effects between the AA6063 matrix and TiC reinforcement

インドタミールナドゥ州の北東モンスーン降水にあたえるENSO（エルニーニョ南方振動）とインド洋ダイポールの影響

Tamil Nadu state, located in the southeastern part of Peninsular India receives most of its rainfall during October through December which is referred to as Northeast monsoon rainfall (NEMR). The onset and distribution of NEMR plays a crucial role on both agriculture and economy of the Tamil Nadu State of Indian subcontinent. It is interesting to note that Tamil Nadu Southwest monsoon rainfall (SWMR) received between June and September months has positive correlation with SOI, while NEMR shows negative correlation with SOI. A study was undertaken to investigate the relationship between global tele-connection signals viz. El-Nino- Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD), and precipitation over Tamil Nadu during the northeast monsoon season. The results indicated that NEMR of Tamil Nadu had the highest positive correlation with Nino-3 SST for the month of July indicating that whenever there is a rise in sea surface temperature in Nino-3 region, there is an increase in NEMR and vice-versa. The results also indicated that under extreme negative July SOI condition Tamil Nadu received 17.7 % more than the normal NEMR and that of the extreme positive condition 17.9 % less than the normal NEMR. To understand the relationship and/or local dynamic structure, composites of circulation field for the extreme El Nino/La Nina years are compared with the mean state. Composite circulation analysis clearly showed that in extreme El Nino years (SOI 10), which resulted in weak NE monsoon.和文のものは、洋文の内容の要約となっている

A review on the classification of organic/inorganic/carbonaceous hole transporting materials for perovskite solar cell application

This is the final version. Available on open access from Elsevier via the DOI in this recordThe rapid increase in the efficiency of perovskite solar cells (PSCs) in last few decades have made them very attractive to the photovoltaic (PV) community. However, the serious challenge is related to the stability under various conditions and toxicity issues. A huge number of articles have been published in PSCs in the recent years focusing these issues by employing different strategies in the synthesis of electron transport layer (ETL), active perovskite layer, hole transport layer (HTL) and back contact counter electrodes. This article tends to focus on the role and classification of different materials used as HTL in influencing long-term stability, in improving the photovoltaic parameters and thereby enhancing the device efficiency. Hole Transport Materials (HTMs) are categorized by dividing into three primary types, namely; organic, inorganic and carbonaceous HTMs. To analyze the role of HTM in detail, we further divide these primary type of HTMs into different subgroups. The organic-based HTMs are subdivided into three categories, namely; long polymer HTMs, small molecule HTMs and cross-linked polymers and the inorganic HTMs have been classified into nickel (Ni) derivatives and copper (Cu) derivatives based HTMs, p-type semiconductor based HTMs and transition metal based HTMs. We further analyze the dual role of carbonaceous materials as HTM and counter electrode in the perovskite devices. In addition, in this review, an overview of the preparation methods, and the influence of the thickness of the HTM layers on the performance and stability of the perovskite devices are also provided. We have carried out a detailed comparison about the various classification of HTMs based on their cost-effectiveness and considering their role on effective device performance. This review further discusses the critical challenges involved in the synthesis and device engineering of HTMs. This will provide the reader a better insight into the state of the art of perovskite solar devices.Coimbatore Institute of Technology, Coimbatore, IndiaWestern Norway University of Applied Science