25 research outputs found
Energy yield simulations of perovskite/c-Si tandem modules in real-world conditions
No full textPerformance of photovoltaic modules are widely expressed using their efficiency at Standard Test Conditions (STC). Although, real world conditions largely differ from this standard. Energy yield of photovoltaic modules at a certain location gives a clear indication of the performance of the module exposed to varying weather conditions. Photovoltaic Materials and Devices (PVMD) Toolbox developed at Delft University of Technology and implemented in MATLAB®, aims to simulate energy yield of photovoltaic modules while providing the flexibility of modifying cell-level to module-level parameters of the device. Accurately determining the irradiance falling on the module at a certain location and simulating the electrical properties of a solar cell at realistic conditions is crucial in determining the yield generated by a module. Due to the promising results displayed by the technology, in this study, energy yield of perovskite/c-Si tandem modules are simulated using newly developed daylight and parameter extraction models in PVMD toolbox. Due to high computational efficiency and functionality offered, Preetham daylight model is implemented as an improvement to Perez model currently used in PVMD toolbox. The model considers the effect of Rayleigh and Mie scattering, and turbidity of atmosphere in determining the distribution of diffuse irradiance across the skydome. By implementing the model, three factors can now be determined: luminance distribution, RGB co-ordinates and relative spectral power distribution over the skydome for any location. Luminance is calculated for every point in sky using Perez parametric function that use coefficients derived from simulated data for different sun directions and turbidity values. For all locations considered, Preetham model calculates higher luminance over the year by ~2%. Calculated luminance values normalized against zenith luminance is used to derive CIE xyY values and consecutively, the RGB co-ordinates that are rendered real-time to create images of the skydome for every hour in chosen timeframe. By calculating the relative spectral power distribution, analysis of incident light falling on the module from all points of the skydome is possible which especially deems useful for modelling tandem modules. To accurately simulate electrical properties of solar cell under varying operating conditions, parameter extraction model for simulated ASA J-V curves is implemented using an analytical method. For the c-Si and perovskite cells considered in the study, the reconstructed curves using extracted parameters fits ASA curve with RMSE or 1.98% and 3.02% respectively at STC. Using these models introduced in this study, energy yield of mono-facial and bi-facial 2T/4T tandem modules are calculated and analyzed for Rome, Reykjavik and Alice Springs. Depending on air mass of a location, perovskite thickness of mono-facial 2T tandem devices are optimized to produce maximum specific yield. All considered modules generate highest yield at Alice Springs due to high insolation at the location. The yield difference between modules while using the two daylight models is insignificant at <1%. With an increase in perovskite thickness, energy yield of 2T bi-facial modules increase significantly for high albedo while it drops beyond the optimum thickness due to current mismatch for low albedo. Bi-facial 4T module on high albedo (albedo= 0.85) surfaces show best performance out of all the modules producing 36% higher yield than mono-facial 4T module for Rome.Electrical Engineering | Sustainable Energy Technolog
Returning the anti-colonial to philosophy
No full textThis essay presents a view of thinking – of the doing of philosophy - as a praxis of anti-colonial encounter. Through this perspective of encounter we bring to view the opposition between the two locations of being-thinking corresponding to the two actualities described above: 1) the (post)colonial location from which are (re)presented and enforced (b)orders of subjectification; 2) the anti-colonial locations from which are confronted frontlines of desubjectification. This counterposing of the (post)colonial border and the anti-colonial frontline serves to demarcate the (post)colonial and anti-colonial as incommensurable philosophical orientations as they stand in enunciative and interpretive confrontation; what this reveals is the function of the “post-colonial” as a discursive category which operates to normalise the (b)orders of contemporary global coloniality. As such, to think from anti-colonial frontlines is to repudiate the assumptions of author-ity inherent in colonial philosophies that continue to organise and narrate the post-colonial World as a (b)ordered totality. From this re-appropriation of philosophical author-ity we might affirm the many insurgent struggles for the material transformation of worlds as indeed continuing the legacy of anti-colonial hope and imagination – to ‘be-otherwise’ – in the face of (post)colonial closure
Unsupervised Approach to Word Sense Disambiguation in Malayalam
No full textAbstractWord Sense Disambiguation (WSD) is the task of identifying the correct sense of a word in a specific context when the word has multiple meaning. WSD is very important as an intermediate step in many Natural Language Processing (NLP) tasks, especially in Information Extraction(IE), Machine Translation(MT) and Question/Answering Systems. Word sense ambiguity arises when a particular word has more than one possible sense. The peculiarity of any language is that it includes a lot of ambiguous words. Since the sense of a word depends on its context of use, disambiguation process requires the understanding of word knowledge. Automatic WSD systems are available for structured languages like English, Chinese, etc. But Indian languages are morphologically rich and thus the processing task is very complex. The aim of this work is to develop a WSD system for Malayalam, a language spoken in India, predominantly used in the state of Kerala. The proposed system uses a corpus which is collected from various Malayalam web documents. For each possible sense of the ambiguous word, a relatively small set of training examples (seed sets) are identified which represents the sense. Collocations and most co-occurring words are considered as training examples. Seed set expansion module extends the seed set by adding most similar words to the seed set elements. These extended sets act as sense clusters. The most similar sense cluster to the input text context is considered as the sense of the target word
Solubilization of spider silk proteins and its structural analysis using Fourier transform infrared spectroscopy
No full textThe politics of hope and the other-in-the-world : thinking exteriority
No full textThe paper offers a critical interrogation of the politics of hope in relation to suffering in the world. It begins with a critique of the assumptions and aspirations of ‘philosophies of hope’ that assume a Levinasian responsibility for the suffering-Other. Such approaches to thinking hope reveal an underlying coloniality of ontology, of totality/exteriority, which defines Being and Non-Being, presence and absence, in totality. Consistent with past colonial rationalities, the logics of salvation and rescue define, still, these contemporary envisionings of the ‘white man’s burden’ in relation to the suffering Other. A decolonial ontology of Exteriority, of an incommensurable radical Other-Being against Totality, is instead presented. The focus here shifts from the passive suffering-Other that is the object of rescue, to the Radical Other that is the author of encounter. By returning Exteriority (the Radical Other-in-the-World) to theory and by opening up theory’s locations of enunciation, the implications of responsibility, in thinking hope, become open also to interrogation and vulnerable to unsatisfactory conclusions
AnglaBharati to AnglaMalayalam: An Experience with English to Indian Language Machine Translation
No full textNGC 3256: Kinematic Anatomy of a Merger
No full textWe have used the Australia Telescope Compact Array to image the neutral hydrogen in the merging system NGC 3256, to test the idea that globular clusters (GCs) form during the interactions and mergers of disk galaxies. We compare our observations with hydrodynamical numerical simulations from the literature to examine the hypothesis that the H I fragments with masses greater than 107±1 M⊙ are sites of GC formation. We appear to have detected detached H I fragments in the vicinity of NGC 3256. These fragments, with masses ∼107 M⊙ may have little dark matter content, which is also a characteristic of globular clusters, and so our observations support the hypothesis that globular clusters form in the type of interaction that resulted in NGC 3256
Investigating the Relationship of Adaptive Leadership and Leadership Capabilities on Leadership Effectiveness in Sarawak Schools
No full textAbstractWhen the National Educational Blueprint was launched in 2013, it had explicitly articulated its intention to provide an education system that would take into account the challenges of the 21st century. Adaptive leadership which originates from evolutionary biological sciences perspective has made significant strides toward the understanding of leadership in Knowledge-Era as an adaptive process in an unpredictable 21st century environment (Heifetz, 2004). This research was an attempt to take the first step toward the integration of leadership competence with capability that might lead to anticipated leadership effectiveness leadership in Sarawak schools. First, this paper defined the adaptive leadership (Heifetz, Karnia & Kramer, 2004). Second, it explained how leadership capabilities (Hazy, 2004) could be used to compliment leadership competency in adaptive leadership to ensure leadership effectiveness. Third, this paper explained the leadership effectiveness processes based on Vanderbilt assessment for leadership effectiveness in schools (Porter, Polikoff, Goldring, Murphy, Elliot & May, 2010). Finally, it discussed the implications of adaptive leadership and leadership capabilities on leadership effectiveness in Sarawak schools particularly
Web Page Ranking Using Multilingual Information Search Algorithm - A Novel Approach
No full textAbstractThe goal of an information retrieval system is to provide the information that is relevant to the user's query. In some cases the information relevant to the user request may not exist in the user's native language. Situations may also arise where the user is able to read documents in languages different from the native one, but might have difficulty in formulating queries in them. The main intention behind Multilingual Information Retrieval is to find the relevant information available irrespective of the language used in the query
Real Time Suppression of Howling Noise in Public Address System
No full textAbstractHowling noise is a common phenomenon in a public address system. It is built up due to the acoustic coupling between the speaker system and the microphone when it creates a positive feedback. Real time implementation of howling noise detection and suppression was implemented using TMS320C6713 DSK starter kit. The whole implementation was done based on direct memory access (DMA) feature of the DSP processor. The method uses the properties of howling noise for efficient detection and has the advantage of suppressing the noise. Howling detection is performed based on spectral flatness measure (SFM) of each input speech frame. For frames without howling, the input is passed as such to the output. Howling suppression is performed by making output samples as zero if the presence of howling noise is detected
