Search

Improved Fractional Order Darwinian Particle Swarm Optimization (FODPSO) has been proposed to identify the parameters of solar PV cells and modules. For this purpose, the traditional PSO algorithm has been adapted and an improved one using the fractional order calculus has been especially designed as well. The proposed FODPSO together with the PSO has been applied in both the single and double diode models to describe the specified PV units for purpose of comparison. To examine the advantages of the proposed FODPSO over conventional PSO, two approaches have been performed; the first approach is implementing the FODPSO and PSO algorithms using input data obtained from previous international publications for different types of PV cells/modules, then comparing the FODPSO algorithm's results to the results of PSO and the other previous optimization techniques that were using the same input data and identical PV cells/modules. The second validation approach is achieved by performing real measurements in outdoor conditions for another two types of PV modules (mono and poly crystalline Silicon) and inserting these measurements' readings as input data to the PSO and FODPSO algorithms. A comparative study has also been done for both algorithms' results. Enhanced results have been achieved using the FODPSO technique. It is worth mentioning that during the development of this work, other efforts have been made with different techniques that may result in similar or even better results, yet this paper is still introducing for the first time the FODPSO technique (as a modified technique of the PSO) as applied on the PV modeling problem, in addition the paper presents the benefits of the proposed FODPSO over the conventional PSO and presents a comparison that shows the superiority of the FODPSO over the conventional PSO.

The evaluation of a solar photovoltaic (PV) technology helps to identify its suitability for a specific location. The main objective of the present study is to assess the suitability of mono-crystalline silicon (mc-Si) and poly-crystalline silicon (pc-Si) PV modules with almost similar characteristics under Agadir climatic conditions. Electricity yield of these modules is calculated from the uninterruptible measured current–voltage curves from sunrise to sunset during a year. The influence of weather conditions, global irradiance and temperature, on the performances of the modules is assessed and as a part of considerations in the PV power plant design that the output power from pc-Si PV modules is found greater. Calculated annual average final yield (Yf), and performance ratio (PR) for mc-Si and pc-Si PV systems are (1602.22 kWh/kWp, 0.71), (1691.85 kWh/kWp, 0.75) respectively.

The Adrar site is among sites of the highest solar radiation potential in the world. This region is characterized by high ambient temperature in the summer, which in some days is exceed 45 °C, where the high ambient temperature is affects the solar cells.The aim of this paper is to assessments the PV cells types mono crystalline, poly crystalline, micro crystalline amorphous and tripple junction for meteorological variables of Adrar environment.These models were tested by using input data from meteorological station of (URERMS-Adrar),and these inputs are used in software for PV system (PVsyst) to identify the characteristics of these types of PV module. The comparison between PV cells type mono-crystalline and poly-crystalline of same maximum power (250 W) it show that the cells type poly crystalline it more affected by the temperature of than mono crystalline. Finally, have reached that the assessments the performance of PV module is linked to weather (clear sky, overcast sky, shading, cold and hot).

Decarbonizing the vitality area and diminishing carbon discharges to confine environmental change are the primary worries of twenty-first century. Renewable energy and efficiency interventions, supported by rapid electrification, will provide more than 90% of the reducing $$CO_2$$ emissions planned by 2050. By 2050, the transition to renewable energy will also increase the world’s gross domestic product by 2.5% and the number of jobs by 0.2%.Conventional Poly crystalline roof top solar PV has an efficiency of 22.7%. Tropic of cancer passes through eight states of India, The temperature in summers varies from 40 to 50 $$^{\circ }$$ C which results in decrease in efficiency of solar panel. So we require efficient MPPT controllers to overcome this gap. In Ghaziabad, the experimental test is performed with latitude of 28, 6692 (N) and longitude 77, 4538 (E). Solar PV simulator is designed using LabVIEW software. Effect of variations of temperature, irradiations, series resistance and shunt resistance on solar panel has been studied. Simulated results are tested using experimental setup with the help of arduino interfaced LabVIEW.

A novel dicing technology with high rigidity and hardness was developed for difficult-to-cut materials such as cemented carbide. The highly precise and ultra-thin dicing blade of 20 μm thick and free of crack was manufactured from a round body of polycrystalline diamond (PCD) by an electrical discharge process and ultra-violet assisted polishing. The blade has continuous cutting edges made of crystal grain boundary of PCD. Therefore, fine grooves can be cut in the cemented carbide with ductile-mode. In addition, the autogenous cutting edge regeneration effect was confirmed by partly maintaining the roughness of cutting edge without blunting the PCD surface state. It is speculated that cemented carbide particles detached from the workpiece caused micro-cracks to regenerate the cutting edges on the PCD blade. Finally, it was demonstrated that ultra-fine grooves with high aspect ratio of 20 μm width and 1 mm depth could be cut in a cemented carbide substrate, which has never been achieved in the past.

&nbsp

The performance of the Solar photovoltaic (PV) panel depends mainly on two environmental factors, namely temperature and solar irradiance. These factors affect the PV output parameters such as maximum power, short-circuit current and open circuit voltage. This work investigated the behavior of a polycrystalline solar PV panel's electrical characteristics under variation in temperature and solar irradiance in spring season. This was done through experiment and the results validated with simulation in Matlab software. The experimental results were compared to simulation results and showed that the module electrical outputs change with the variation in temperature and solar irradiance. These two factors affect the PV module performance during the spring seasons and its output is more efficient due to favorable surface temperature and solar irradiance variations striking the module during peak hours of the day.

Characterization of 2 hrs thermal aged AsAgS films deposited on quartz substrate by thermal evaporation technique was investigated. XRD of the as prepared and 423 K 2 hrs thermal aged AsAgS films show poly crystalline nature with preferred orientation 306 and 624. Elevating temperature decreases both the poly crystalline nature and its optical gap from 2.4 to 2.27 eV due to bonds’ breaking. Other optical constants; refractive index and other dispersion parameters were affected as well.

The recent achievements following the application of single-crystalline (SC) cathode material in solid-state batteries are discussed in this mini-review. The characteristics of SC and poly-crystalline (PC) cathode materials are explored, with emphasis on the kinetic and mechanical properties. The critical factors influencing their performance in liquid electrolyte and solid-state battery cells are investigated. Finally, the advantages and disadvantages of both morphologies are discussed and considerations to ensure a fair comparison between SC and PC cathodes in different systems are raised.

In this paper,in-situwetting and spreading behaviours of the binary Sn-Ti alloys with Ti contents were investigated on poly-crystalline CVD diamond plates. The variation of contact angles at increasing temperatures indicated the wettability of Sn-Ti alloys were strongly influenced by the Ti contents. Addition of small amount of Ti (0.5 wt.%) dramatically reduced the contact angle of Sn-Ti alloys; while a relatively high Ti concentration (above 4 wt.%) induced the formation of large refractory intermetallics phase, which reduced the fluidity and impeded the spreading of Sn-Ti alloys.

This paper introduces the outdoor performance of mono and poly c-Si PV modules and array under hot-humid tropical climate. An experimental setup which is portable and flexible is designed for assessing the performance of PV modules under any climate at any location. In this paper, two different types of PV modules were chosen and their outdoor performance is assessed based on various parameters. These parameters include open circuit voltage, short circuit current, maximum power output of a PV array or module, fill factor, I-V and P-V characteristics, and efficiency. Studies were carried out in four different cases: In case 1, only mono crystalline silicon (mono c-Si) PV module parameters were measured with respect to step variations in load. In case 2, only poly crystalline silicon (poly c-Si) PV module parameters were measured with respect to step variations in load. In case 3, one mono and one poly c-Si modules were connected in series combination. In case 4, one mono and one poly c-Si modules were connected in parallel combination. Experimental results shows the performance comparison of two different types of PV modules under similar outdoor field condition in case 1 and case 2. Similarly case 3 and case 4 reveal the performance comparison of series and parallel combination of PV modules. Finally, efficiency of PV module and array, fill factor, I-V and P-V characteristics in each case is analyzed. Influence of outdoor field conditions on these parameters were also investigated, paving a way for efficient utilization of available mono and poly crystalline PV modules for solar power generation.

The experimental data from the performance of a 300 W poly and a 300 W mono crystalline solar module are gathered during a year, and then, it is employed to evaluate the relation between the standard deviation of temperature distribution on the surface of module and error in prediction of different simulation approaches. The values of error in prediction of working temperature, current, voltage, and power, as the four main key performance parameters of a solar module are obtained for nominal operating cell temperature, nominal module operating temperature, as well as one, two, and three dimensional numerical modeling approaches, as the most popular methods in the literature during the annual performance. The image-processing refined pictures obtained from a high-resolution thermal imaging camera are also employed for the calculation of the standard deviation of temperature distribution. The results demonstrate that the methods used in the engineering applications, like nominal operating cell temperature and nominal module operating temperature, lose their accuracy at the high level of the standard deviation of temperature distribution, i.e., around 15 °C. In addition, voltage and temperature are found as the parameters with the lowest and highest dependencies on the standard deviation of temperature distribution. The maximum values of error for prediction of power by one, two, and three dimensional numerical modeling approaches are also 14.4, 11.4, and 9.6% for the poly crystalline module, and 8.5, 6.3, and 5.2% for the mono type, respectively.

ZnO/CuO p-n heterojunctions have attracted much attention for device applications, but coherent junctions, which are crucial for controlling electrical properties, still remain a challenge due to different crystal structure. In this work, CuO single-crystalline dots are coherently synthesized on ZnO nanorods by using a proposed two-step process. Transmission electron microscopy images confirm the formation of CuO coherent dots on single-crystalline ZnO nanorods upon annealing the nanorods covered with a poly-crystalline CuxO layer. The coherent dots exhibit two types of epitaxial orientations: CuO [002] ǀǀ ZnO [ 10 1 ¯ 1 ], CuO [111] ǀǀ ZnO [0002], and CuO [002] ǀǀ ZnO [ 10 1 ¯ 1 ¯ ], CuO [111] ǀǀ ZnO [ 000 2 ¯ ]. As the thickness of the as-deposited CuxO layer increases from 10 to 30 nm, the aspect ratio of the resulting CuO dots decreases from 0.43 to 0.21, approaching a film-like morphology. This work provides a route to prepare CuO coherent single-crystalline structures on ZnO, which is one step further toward fabricating excellent CuO/ZnO nanodevices.

International audience; 3C-SiC layers of different microstructures (monocrystalline (100) and (111) oriented and polycrystalline) were implanted with high energy (800 keV) 129Xe++ ions. Implantations were performed at room temperature (RT) and at 500 °C using two different fluences of Φ1 = 1x1016 and Φ2 = 1x1017 at/cm2. Surface blistering was only observed for RT and Φ2 implantations into poly-SiC material while mono-SiC kept rather smooth surface. This was due to more homogeneous Xe bubbles distribution (200 nm deep) in the mono-SiC than in the poly-SiC. Xe retention was found to be almost complete for all samples. Some Xe enhanced diffusion was detected in the poly-SiC material which was attributed to grain boundaries. Some irradiation-induced oxidation effect was evidenced, O element being located at the depth where Xe bubbles are accumulating. This was more pronounced for poly than for mono-SiC. These results demonstrate that SiC microstructure affects many aspects of its behavior upon Xe irradiation.

We investigated the nonlinear optical properties of single- and poly-crystalline optical materials using ultrashort mid-infrared laser pulses between 3 and 4 μm. We compared visible to mid-infrared spectra between the materials. Measured energy conversion into all-order harmonics in polycrystalline materials exceeded 30%.

CdTe based thin film solar cells have shown to be competitive in terms of efficiency and low cost, but the polycrystalline structure and low minority carrier lifetime constrain CdTe based devices from reaching the theoretical efficiency limit. In this work, the effect of Se and Cl segregation in polycrystalline CdSeTe photovoltaic devices was studied. We demonstrated using two-photon time-resolved photoluminescence (TRPL) that the Se alloyed CdSeTe absorber layer shows high minority carrier lifetime, and used density functional theory (DFT) calculations to explain the origin of such high lifetime.

Outdoor degradation rates (DR) of PV modules for ten years were calculated by means of multi reference linear interpolation/extrapolation method (MRLIM), which utilizes many outdoor measured I-V curve data. Transitions of monthly translated I-V curves under the STC, which are created by MRLIM, indicates how PV module degrades. The DR of maximum power (Pm), short circuit current, open circuit voltage, fill factor, and series resistance were calculated from translated I-V curves. As a result, a poly crystalline Si case, annual DR of Pm was calculated as -0.53 %/year. In addition, the accuracy of this method was calculated by comparing with indoor measurement results.

End of life photovoltaic panels of different technologies (poly crystalline Si, amorphous Si, and CdTe) were treated mechanically in pilot scale by single shaft shredder minimizing the production of fine fractions below 0.4 mm (18% weight). Grounded material was sieved giving: an intermediate fraction (0.4-1 mm) of directly recoverable glass (18% weight); a coarse fraction (which should be further treated for encapsulant removal), and fine fractions of low-value glass (18%), which can be treated by leaching for the removal of metal impurities. Encapsulant removal from coarse fraction was successfully performed by solvent treatment using cyclohexane at 50 °C for 1 h giving high-grade glass (52% weight), which can be reused for panel production. Experimental results of solvent treatment were compared with those from thermal treatment by economic analysis and Life Cycle Assessment, denoting in both cases the advantages of solvent treatment in recovering high-value glass.

Highly conducting and transparent thin films of La x Ba1 − x SnO3 (x = 0, 0.01 and 0.05) were grown on quartz substrates via pulsed laser deposition. Conductivity increases in orders of magnitude upon vacuum annealing of the as–deposited films. This is attributed to the significant enhancement in carrier concentration due to the increased oxygen vacancy defects (V O ∙ ∙ ). Enhanced carrier concentration improves the metallicity in the films at room temperature. Metal to semiconductor transition (MST) is observed in the films with n e ⩾ 1019 cm−3 at low temperatures. The MST shifts towards absolute zero temperature as the carrier concentration in the film increases. Low–temperature resistivity analysis suggests that the charge transport is mainly governed by strong electron–electron interaction. UV–Vis spectroscopy confirms a 60%–80% transmittance in the visible range (400–800 nm) for all the films. Due to the large change in carrier concentration, Burstein Moss (BM) shift is observed, and the bandgap ranges between 3.65–3.98 eV. The effective mass of electron and refractive index estimated from the BM shift and transmittance are found to be 0.6 m e and 2, respectively.

Thin-film transistors (TFTs) with a high channel mobility for both electrons and holes are required for the three-dimension large scale integrations or system-on-panels. Lower temperature process is more favorable for TFT fabrication because the application of plastic substrate to system-on-panels is expected to add the flexibility function. Germanium (Ge) has higher hole and electron mobilities than Si, suggesting that large-grain poly-crystalline or single-crystalline Ge thin films lead to high channel mobility TFTs. This paper describes unseeded growth of poly-crystalline Ge with well-oriented large-size grains on insulator from amorphous Ge by scanning pulsed green laser annealing. In experimental, a 50-nm-thick amorphous Ge layer was deposited on a Si substrate with a 50-nm-thick SiO2 film. The Ge layer was patterned to narrow stripes of 2-µm-width. Then a capping layer of 650-nm-thick SiO2 was deposited. For this processed template, a scanning pulse green laser annealing was performed. Q-switch Nd:YAG laser beam with the following properties was used for annealing; a Gaussian line beam of 70 x 1400 µm2 at a laser wavelength of 532 nm, a pulse frequency of 7.5 kHz, a scanning velocity of 150 µm/s, and energy densities from 0.5 to 0.7 J/cm2. The Ge stripes were crystallized by a single scanning, where the beam was scanned perpendicular to the longitudinal direction of the beam. The Ge stripes crystallized at the optimum energy of 0.56 J/cm2 by the scanning pulsed laser annealing was characterized by electron back scattering diffraction patterns (EBSD). The EBSD mapping of normal direction to the sample surface indicates that the crystallized Ge film has (111) surface orientation in the 600 µm-long stripe. The (111) Ge crystal begins within only 2 µm after the starting point of the laser scanning. It was observed that the crystal orientation was recovered to (111) even if the prior part of crystalized Ge film was rotated from (111) surface. In the mapping of rolling direction, which corresponds to the laser scanning direction, two types of grains are dominant. One shows (101) and the other shows (112) for the laser scanning direction. From the normal direction and rolling direction images of EBSD, the Ge stripes were crystallized with the grains of 2 µm wide and ~10 µm long. The maximum grain length of 20 µm was also observed. Raman scattering was measured to evaluate the crystalline quality of the (111) surface-oriented Ge stripes. The full-width at half-maximum of 2.35 cm-1 shows good crystal quality of the film, which is smaller than the values of 3.2-3.3 cm-1 for the single crystalline Ge film obtained by lateral liquid-phase epitaxy from a Si seed. For laser fluence dependence, Ge stripes were not crystallized when the fluence was smaller than 0.56 J/cm2, and Ge stripes show non-oriented crystal with a long grain boundary in the center of stripe width when the fluence was larger than 0.67 J/cm2. Simulation analyses of thermal diffusion reveal the crystallization process. The pulse laser irradiation heats the Ge stripe and melts it. Simultaneously the underlying Si in the outside region of the Ge stripe patterns absorbs the laser energy and is also heated up. During the cooling period after each pulse a temperature gradient between the edge and the center is produced in the molten Ge stripe, because of suppression of cooling at the edge. Then the temperature at the center of the Ge stripe drops below the solid point first rather than the center. Crystal growth occurs from the center to the edges, resulting that random nucleation at the edge is suppressed and crystal growth proceeds with controlled orientation in the Ge stripe. This crystallization method is promising to realize high-mobility (111) Ge TFTs and easily extended to the glass or plastic substrate by making amorphous Si layer, which works as a laser absorbing layer, and SiO2, which works as a heat insulating layer, on the substrate.

An electrical signals of a conventional radiation medical imaging sensor are obtained by charge integration method. In this study, the polycrystalline cadmium telluride(p-CdTe) film was fabricated by a thermal evaporation method for the photon counting sensor development with excellent resolution in low exposure dose. From the fabricated p-CdTe sensor, the physical properties(SEM, XRD) and the electrical properties(leakage current, x-ray sensitivity, SNR) were evaluated. As a result, the leakage current of below 5 nA/cm 2 and 7 μC/cm 2 -R of the X-ray sensitivity were showed in below 1 V/㎛. In addition, the signal to noise ratio showed the values of above 5000 at operating voltage. Key Words : photon counting, polycrystalline, cadmium telluride, charge collection efficiency, thermal evaporation 요 약 종래의 방사선 의료영상 센서는 방사선에 의해 생성된 전하신호를 화소내에서 적분하는 방식이다. 본 연구에서는 저선량에서 우수한 해상력이 가능한 광계수형 영상센서를 개발하기 위해 진공 열증착법을 이용하여 다결정 CdTe(p-CdTe) 필름을 제작하였다. 또한, 광계수형 센서의 성능평가를 위하여 물리적 특성(SEM, XRD) 및 전기적 특성(leakage current, x-ray sensitivity, SNR) 평가를 하였다. 측정 결과, 1 V/㎛ 이하의 인가전압에서 5 nA/cm

Plasmonic waveguides are a promising platform for integrated nanophotonic circuits and nanoscale quantum optics. Their use is however often hampered by the limited propagation length of the guided surface plasmon modes. A detailed understanding of the influence of the material quality and the waveguide geometry on the complex mode index is therefore crucial. In this letter, we present interferometric near-field measurements at telecommunication wavelength on plasmonic slot waveguides fabricated by focused ion beam milling in single- and poly-crystalline gold films. We observe a significantly better performance of the slot waveguides in the single-crystalline gold film for slot widths below $100\,\mathrm{nm}$. In contrast for larger slot widths, both gold films give rise to comparable mode propagation lengths. Our experimental observations indicate that the nature of the dominant loss channel changes with increasing gap size from Ohmic to leakage radiation. Our experimental findings are reproduced by three dimensional numerical calculations., 4 figures

Investigating submerged Solar Photovoltaics (SPV) has significant benefits in harvesting the useful amount of underwater solar energy. Earlier, the authors analysed the amorphous, mono- and poly-crystalline silicon solar cells with varying underwater conditions (Enaganti 2020). The findings indicated that SPV has a wide potential to utilize in underwater conditions for diverse applications. This has motivated us to explore the behaviour of solar cells underwater considering other parameters, like solar spectral range, as well. Evidently, the solar spectral range gets narrower and the solar radiation gets reduced in underwater conditions with an increasing in water depths. Herein, the performance of mono- and poly-crystalline silicon solar cells has been investigated underwater with varying regions of the spectral ranges from the Standard AM 1.5 solar simulator using optical colour glass filters. The obtained results manifest that even with the limited spectral ranges, mono- and polycrystalline solar cells showed 44.8% and 39.34% decrease in the maximum power output respectively at 20 cm water depth using band pass filter. This power decay was witnessed to be very less compared to the other filters and also without using filter as the water readily absorbs the IR portion of the light.

People can make solar energy alternative energy by employing solar panels to generate electricity. The utilization of solar energy on a solar panel to generate electricity is affected by the weather and the duration of the radiation, and they will affect the solar panel’s temperature. There are various types of solar panels that can be found on the market today, including Mono-Crystalline and Poly-Crystalline. The difference in the material used needs to be observed in terms of temperature changes in the solar module. Our study’s findings showed that a change in the temperature would impact the solar panel’s output voltage, and the solar panel’s output voltage would change when it was connected to the load although the measured temperatures were almost the same.

Poly-crystalline diamond (PCD) is an extremely tough, synthetically produced cutting tool material, which offers outstanding capabilities concerning wear behavior in abrasive cutting environments. Currently, the primary application of PCD cutting tools is the machining of non-ferrous materials, as the diamond&rsquo, s carbon high affinity towards iron causes diffusion effects while cutting steel with rising temperature. This effect significantly reduces tool life. To lower the occurring temperature of the cutting process, and therefore avoid the reaction of carbon and iron, a thermal functionalization of the cutting inserts has been investigated. The results give insight into making PCD cutting tools economically usable for the machining of iron-carbon materials.

This paper is present the degradation of Mono crystalline Photovoltaic (PV) module, Poly crystalline PV module and Thin-film are 2 PV modules (CdTe) by short-term outdoor exposures testing at Bangkuntien, bangkok, Thailand. Every month are sampling measured in 180 days by Visual inspection test, Insulation test, Wet leaked test and Electric performance with Standard testing condition (STC). The results showed a Thin-film module failed in Wet leaked test of 60 days in outdoor exposures test. However, in finished test 180 day the maximum power (P max ) degradation Thin-film less than the crystalline module. In spite of the other research are report the crystalline PV module is power degradation less than thin-film module technology by crystalline structure condition. Therefore, the results of this research pave the way for an investigation of the advantages of thin-film modules on long-term degradation phenomena in significant research and development.

The Fast Beam Condition Monitor (BCM1F) is used in CMS to measure beam induced background and precision luminosity. The system in its current implementation was first installed in 2014, equipped with single-crystalline (sCVD) diamond sensors. After some radiation damage, erratic occurrence of HV instabilities required lowering of the operational HV and the system became inefficient, resulting in unstable measurements. The system was replaced in 2017 with poly-crystalline (pCVD) diamond sensors and silicon (Si) sensors. Both new sensor types show significantly better operational stability. The luminosity performance of pCVD and Si based luminosity measurement is discussed.

We demonstrate poly-crystalline silicon waveguide devices on deep-trench isolation in a commercial bulk 180nm SiGe BiCMOS process without any process modifications or post-processing. At 1550 nm, the measured loss for the poly-crystalline silicon waveguide and an MMI compatible with the waveguide are around 3.0 dB/mm and 0.38 dB, respectively.

This paper analyzes and compares the actual measured and simulated performance of a 3.2 kWp grid-connected photovoltaic system. The system is located at the Outdoor Research Facility (34.01°S, 25.67°E) at the Nelson Mandela Metropolitan University (NMMU), South Africa. The system consists of 14 poly crystalline silicon modules connected in two strings of 7 series-connected modules, each facing north at a fixed tilt of 34°. The data presented in this study were measured in the year 2013, where the system supplied a total of 5757 kW h to the local electric utility grid. The performance of the system was simulated using PVsyst software using measured and Meteonorm derived climate data sets (solar radiation, ambient temperature and wind speed). The comparison between measured and simulated energy yield are discussed. Although, both simulation results were similar, better comparison between measured and predicted monthly energy yield is observed with simulation performed using measured weather data at the site. The measured performance ratio in the present study is 84% which is slightly higher than values of 74%, 81.5%, 67.4%, 70% and 64.5% reported is Khatkar-Kalan (India), Dublin (Ireland), Crete (Greece), Karnataka (India) and Malaga (Spain), respectively.

The work discussed here is a continuation of the study presented in [1], in which a customized test apparatus was presented that was capable of conducting tribological related experiments on sliding components commonly used in hydrokinetic devices such as bearings, drive shaft and seals. The wear on critical sliding components introduces unnecessary clearances which can significantly reduce the performance and reliability of hydrokinetic devices. In the previous study [1], four types of bearings, namely Vesconite, CIP, Feroform T814, and Poly Crystalline Diamond (PCD) coated bearings were tested for 60 h in clean water. The data showed that PCD bearings outperformed polymer based bearings in terms of wear and frictional resistance. In the present study, the same set of bearings were tested for 60 h in fresh sedimented water. The experimental data revealed that PCD bearings had higher wear resistance as compared to its polymer based counterparts. In addition to wear on bearing surface, a significant amount of wear on the drive shaft was observed. These results reveal that (in addition to high wear resistant polymer bearings) a surface hardened shaft may increase the longevity of bearing-shaft assembly in sedimented water.

This paper presents the investigation of partial shading characteristics of mono-crystalline and poly-crystalline photovoltaic module connected in series. Simulink models are developed to assist the investigation to determine the ideality factor for mono-crystalline and poly-crystalline photovoltaic module. Commercially available mono-crystalline and poly-crystalline photovoltaic module are used to extract measurable parameters for the model to study the behaviour of I-V curve. Measurements have been conducted for the investigation includingmono-crystalline only, poly-crystalline only, both unshaded, mono-crystalline shaded and poly-crystalline shaded. This paper contributes to the understanding of partial shading characteristics of different materials presence in photovoltaic string.