94 research outputs found

    Physical properties of large cardamom cultivated in north eastern Himalayan region of Sikkim, India

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    The large cardamom is one of the most important spice crops grown in Himalayan region of Sikkim, India.  The capsules of the harvested large cardamom are dried before consumption.  The paper presents the physical properties of  freshly harvested and dried large cardamom capsules.  The geometrical mean diameter, sphericity, bulk density and mean values of angle of repose of the freshly harvested large cardamom capsules were observed to be 18.53±1.73 mm, 0.76, 332.21±14.24 kg m-3 and 28.74±4.04°, respectively.  Whereas for dried large cardamom capsules the values were found to be 11.113±0.92 mm, 0.56, 393.109±9.622 kg m-3 and 29.84±2.93°, respectively.  The peak static coefficient of friction of freshly harvested large cardamom over mild steel, plywood and plastic film surfaces were 0.386, 0.463 and 0.359, respectively.  However, for dried large cardamom capsules, the observed values were 0.436, 0.394 and 0.155, respectively.   Keywords: large cardamom, spice crop, physical propertie

    A new framework for sign language alphabet hand posture recognition using geometrical features through artificial neural network (part 1)

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    Hand pose tracking is essential in sign languages. An automatic recognition of performed hand signs facilitates a number of applications, especially for people with speech impairment to communication with normal people. This framework which is called ASLNN proposes a new hand posture recognition technique for the American sign language alphabet based on the neural network which works on the geometrical feature extraction of hands. A user’s hand is captured by a three-dimensional depth-based sensor camera; consequently, the hand is segmented according to the depth analysis features. The proposed system is called depth-based geometrical sign language recognition as named DGSLR. The DGSLR adopted in easier hand segmentation approach, which is further used in segmentation applications. The proposed geometrical feature extraction framework improves the accuracy of recognition due to unchangeable features against hand orientation compared to discrete cosine transform and moment invariant. The findings of the iterations demonstrate the combination of the extracted features resulted to improved accuracy rates. Then, an artificial neural network is used to drive desired outcomes. ASLNN is proficient to hand posture recognition and provides accuracy up to 96.78% which will be discussed on the additional paper of this authors in this journal

    Associating Facial Expressions and Upper-Body Gestures with Learning Tasks for Enhancing Intelligent Tutoring Systems

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    Learning involves a substantial amount of cognitive, social and emotional states. Therefore, recognizing and understanding these states in the context of learning is key in designing informed interventions and addressing the needs of the individual student to provide personalized education. In this paper, we explore the automatic detection of learner’s nonverbal behaviors involving hand-over-face gestures, head and eye movements and emotions via facial expressions during learning. The proposed computer vision-based behavior monitoring method uses a low-cost webcam and can easily be integrated with modern tutoring technologies. We investigate these behaviors in-depth over time in a classroom session of 40 minutes involving reading and problem-solving exercises. The exercises in the sessions are divided into three categories: an easy, medium and difficult topic within the context of undergraduate computer science. We found that there is a significant increase in head and eye movements as time progresses, as well as with the increase of difficulty level. We demonstrated that there is a considerable occurrence of hand-over-face gestures (on average 21.35%) during the 40 minutes session and is unexplored in the education domain. We propose a novel deep learning approach for automatic detection of hand-over-face gestures in images with a classification accuracy of 86.87%. There is a prominent increase in hand-over-face gestures when the difficulty level of the given exercise increases. The hand-over-face gestures occur more frequently during problem-solving (easy 23.79%, medium 19.84% and difficult 30.46%) exercises in comparison to reading (easy 16.20%, medium 20.06% and difficult 20.18%)

    Opportunities and challenges in the use of coal fly ash for soil improvements – a review

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    Coal fly ash (CFA), a by-product of coal combustion has been regarded as a problematic solid waste, mainly due to its potentially toxic trace elements, PTEs (e.g. Cd, Cr, Ni, Pb) and organic compounds (e.g. PCBs, PAHs) content. However, CFA is a useful source of essential plant nutrients (e.g. Ca, Mg, K, P, S, B, Fe, Cu and Zn). Uncontrolled land disposal of CFA is likely to cause undesirable changes in soil conditions, including contamination with PTEs, PAHs and PCBs. Prudent CFA land application offers considerable opportunities, particularly for nutrient supplementation, pH correction and ameliorating soil physical conditions (soil compaction, water retention and drainage). Since CFA contains little or no N and organic carbon, and CFA-borne P is not readily plant available, a mixture of CFA and manure or sewage sludge (SS) is better suited than CFA alone. Additionally, land application of such a mixture can mitigate the mobility of SS-borne PTEs, which is known to increase following cessation of SS application. Research analysis further shows that application of alkaline CFA with or without other amendments can help remediate at least marginally metal contaminated soils by immobilisation of mobile metal forms. CFA land application with SS or other source of organic carbon, N and P can help effectively reclaim/restore mining-affected lands. Given the variability in the nature and composition of CFA (pH, macro- and micro-nutrients) and that of soil (pH, texture and fertility), the choice of CFA (acidic or alkaline and its application rate) needs to consider the properties and problems of the soil. CFA can also be used as a low cost sorbent for the removal of organic and inorganic contaminants from wastewater streams; the disposal of spent CFA however can pose further challenges. Problems in CFA use as a soil amendment occur when it results in undesirable change in soil pH, imbalance in nutrient supply, boron toxicity in plants, excess supply of sulphate and PTEs. These problems, however, are usually associated with excess or inappropriate CFA applications. The levels of PAHs and PCBs in CFA are generally low; their effects on soil biota, uptake by plants and soil persistence, however, need to be assessed. In spite of this, co-application of CFA with manure or SS to land enhances its effectiveness in soil improvements

    Calcium orthophosphate-based biocomposites and hybrid biomaterials

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    Biogenic calcium carbonate: calcite crystals of variable morphology by the reaction of aqueous Ca<SUP>2+</SUP> ions with fungi

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    The biological synthesis of CaCO<SUB>3</SUB> crystals of variable morphology by challenging non-calcareous microorganisms such as fungi with aqueous Ca<SUP>2+</SUP> ions has been described. Many fungi are known to produce reasonable amounts of CO<SUB>2</SUB> during growth. We show here that CO<SUB>2</SUB> and characteristic proteins released from the fungi Fusarium oxysporum and Trichothecium sp. may be reacted with aqueous Ca<SUP>2+</SUP> ions to produce truly biogenic CaCO<SUB>3</SUB> crystals. While calcite crystals are obtained with both fungi, significant differences in the morphology of the crystals is observed, indicating that the proteins secreted by the fungi play a crucial role in directing the morphology of the calcite crystals. The action of specific proteins secreted by the microorganisms in directing calcite crystal morphology as well as the more complex issue of synergistic action of mixtures of proteins in directing crystal structure and morphology has been addressed

    Biosynthesis of zirconia nanoparticles using the fungus Fusarium oxysporum

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    Zirconia nanoparticles may be produced by challenging the fungus Fusarium oxysporum with aqueous ZrF6 ²¯ anions; extra-cellular protein-mediated hydrolysis of the anionic complexes results in the facile room temperature synthesis of nanocrystalline zirconia. Extracellular hydrolysis of the metal anions by cationic proteins of molecular weight around 24 to 28 kDa, which are rather similar in nature to silicatein, is shown to be responsible for the synthesis of zirconia nanoparticles, opening up the exciting possibility of large-scale biological synthesis of technologically important oxide materials

    Bioleaching of sand by the fungus fusarium oxysporum as a means of producing extracellular silica nanoparticles

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    A plant pathogenic fungus, Fusarium oxysporum, can be used as a biological model system for the extracellular bioleaching of hollow spherical silica nanoparticles (see Figure) from sand. The room-temperature synthesis of oxide nanomaterials using microorganisms starting from potential waste materials could lead to eco-friendly and economically viable methods for the large-scale synthesis of nanomaterials

    Biological synthesis of strontium carbonate crystals using the fungus Fusarium oxysporum

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    The total biological synthesis of SrCO3 crystals of needlelike morphology arranged into higher order quasi-linear superstructures by challenging microorganisms such as fungi with aqueous Sr2+ ions is described. We term this procedure "total biological synthesis" since the source of carbonate ions that react with aqueous Sr2+ ions is the fungus itself. We believe that secretion of proteins during growth of the fungus Fusarium oxysporum is responsible for modulating the morphology of strontianite crystals and directing their hierarchical assembly into higher order superstructures
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