8 research outputs found
Encapsulated biochar-based sustained release fertilizer for precision agriculture: A review
No full textThe excessive use of conventional fertilizers leads to environmental issues associated with the loss of nutrient through leaching, volatilization, denitrification and surface run-off. Biochar-based fertilizer has gained much research interest as it can be used as a slow release fertilizer. Biochar-based fertilizer can alleviate the properties of soil to slow down the nutrient release rate. However, the sustained release mechanism of biochar-based fertilizer is still facing limitations. As a solution to mitigate this issue, the integration of encapsulating technology and biochar-based fertilizer has been introduced to improve the sustained release mechanism. This paper presents an extensive overview on the various formulations of biochar-based fertilizer and encapsulated biochar-based fertilizer. Additionally, the influence of the inorganic mineral, polymer and hydrogel-based fertilizers on the nutrient release behaviour are also critically discussed. The various methods used to synthesize the fertilizers and their effects on soil amendment are also discussed in detail. This paper could be used as a good source of information on the current advances and future perspectives of encapsulated biochar-based sustained release fertilizer for precision agriculture.The authors acknowledge the research grant provided by Universiti Malaysia Sarawak under Cross Disciplinary Research Grant [ F02/CDRG/1830/2019 ].Scopu
Synthesis of tapioca starch/palm oil encapsulated urea-impregnated biochar derived from peppercorn waste as a sustainable controlled-release fertilizer
No full textNutrient leaching and volatilization cause environmental pollution, thus the pursuit of developing controlled-release fertilizer formulation is necessary. Biochar-based fertilizer exhibits slow-release characteristic, however the nutrient release mechanism needs to be improved. To overcome this limitation, the approach of applying encapsulation technology with biochar-based fertilizer has been implemented in this study. Black peppercorn waste was used to synthesize urea-impregnated biochar (UIB). Central composite design was used to investigate the effects of pyrolysis temperature, residence time and urea:biochar ratio on nitrogen content of UIB. The optimum condition to synthesize UIB was at 400 °C pyrolysis temperature, 120 min residence time and 0.6:1 urea:biochar ratio, which resulted in 16.07% nitrogen content. The tapioca starch/palm oil (PO) biofilm formulated using 8 g of tapioca starch and 0.12 µL of PO was coated on the UIB to produce encapsulated urea-impregnated biochar (EUIB). The UIB and EUIB pellets achieved complete release of nitrogen in water after 90 min and 330 min, respectively. The nutrient release mechanism of UIB and EUIB was best described by the Higuchi model and Korsmeyer-Peppas model, respectively. The improvement of water retention ratio of UIB and EUIB pellets was more significant in sandy-textural soil as compared to clayey-textural soil. The EUIB derived from peppercorn waste has the potential to be utilized as a sustainable controlled-release fertilizer for agriculture.The authors acknowledge the research grant funded by Ministry of Higher Education Malaysia under Fundamental Research Grant Scheme FRGS/1/2022/TK05/UNIMAS/02/1
Synthesis of tapioca starch/palm oil encapsulated urea-impregnated biochar derived from peppercorn waste as a sustainable controlled-release fertilizer
No full textNutrient leaching and volatilization cause environmental pollution, thus the pursuit of developing controlled release fertilizer formulation is necessary. Biochar-based fertilizer exhibits slow-release characteristic, however the nutrient release mechanism needs to be improved. To overcome this limitation, the approach of applying encapsulation technology with biochar-based fertilizer has been implemented in this study. Black peppercorn waste was used to synthesize urea-impregnated biochar (UIB). Central composite design was used to investigate the effects of pyrolysis temperature, residence time and urea:biochar ratio on nitrogen content of UIB. The optimum condition to synthesize UIB was at 400 ◦C pyrolysis temperature, 120 min residence time and 0.6:1 urea:biochar ratio, which resulted in 16.07% nitrogen content. The tapioca starch/palm oil (PO) biofilm formulated using 8 g of tapioca starch and 0.12 μL of PO was coated on the UIB to produce encapsulated urea-impregnated biochar (EUIB). The UIB and EUIB pellets achieved complete release of nitrogen in water after 90 min and 330 min, respectively. The nutrient release mechanism of UIB and EUIB was best described by the Higuchi model and Korsmeyer-Peppas model, respectively. The improvement of water retention ratio of UIB and EUIB pellets was more significant in sandy-textural soil as compared to clayey-textural soil. The EUIB derived from peppercorn waste has the potential to be utilized as a sustainable controlled-release fertilizer for agriculture
Atmospheric Temperature anomalies as manifestation of the dark Universe
No full textWe are investigating the possible origin of small-scale anomalies, like the annual stratospheric temperature anomalies. Unexpectedly within known physics, their observed planetary "dependency", does not match concurrent solar activity, whose impact on the atmosphere is unequivocal; this points at an additional energy source of exo-solar origin. A viable concept behind such observations is based on possible gravitational focusing by the Sun and its planets towards the Earth of low-speed invisible streaming matter; its influx towards the Earth gets temporally enhanced. Only a somehow "strongly" interacting invisible streaming matter with the small upper atmospheric screening can be behind the observed temperature excursions. Ordinary dark matter (DM) candidates like axions or WIMPs, cannot have any noticeable impact. The associated energy deposition is . The atmosphere has been uninterruptedly monitored for decades. Therefore, the upper atmosphere can serve as a novel (low-threshold) detector for the dark Universe, with built-in spatiotemporal resolution while the solar system gravity acts temporally as a signal amplifier. Interestingly, the anomalous ionosphere shows a relationship with the inner earth activity like earthquakes. Similarly investigating the transient sudden stratospheric warmings within the same reasoning, the nature of the assumed "invisible streams" could be deciphered
Coulomb breakup of 17Ne from the viewpoint of nuclear astrophysics
No full textBy the Coulomb breakup of 17Ne, the time-reversed reaction 15O(2p,γ)17Ne has been studied. This reaction might play an important role in the rp process, as a break-out reaction of the hot CNO cycle. The secondary 17Ne ion beam with an energy of 500 MeV/nucleon has been dissociated in a Pb target. The reaction products have been detected with the LAND-R3B experimental setup at GSI. The preliminary differential and integral Coulomb dissociation cross section sCoul has been determined, which then will be converted into a photo-absorption cross section sphoto, and a two-proton radiative capture cross section σcap. Additionally, information about the structure of the 17Ne, a potential two-proton halo nucleus, will be received. The analysis is in progress. \ua9 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
Coulomb breakup of 17Ne from the viewpoint of nuclear astrophysics [Elektronisk resurs]
No full textBy the Coulomb breakup of 17Ne, the time-reversed reaction 15O(2p,γ)17Ne has been studied. This reaction might play an important role in the rp process, as a break-out reaction of the hot CNO cycle. The secondary 17Ne ion beam with an energy of 500 MeV/nucleon has been dissociated in a Pb target. The reaction products have been detected with the LAND-R3B experimental setup at GSI. The preliminary differential and integral Coulomb dissociation cross section sCoul has been determined, which then will be converted into a photo-absorption cross section sphoto, and a two-proton radiative capture cross section σcap. Additionally, information about the structure of the 17Ne, a potential two-proton halo nucleus, will be received. The analysis is in progress. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
A selfless response to an illusory world : a comparative study of Śāntideva and Śaṅkara
No full textThis thesis compares the ethical theories of two 8th century Indian philosophers, Śāntideva and Śaṅkara. In order to construct their ethics from philosophical premises, a metaphysical approach has been taken. A comparison of these two philosophers has never been made, nor has there been any major comparative study of the ethics of their two traditions, Indian Madhyamaka Buddhism and Advaita Vedānta. In opening the way for further comparisons between these two schools, I wish to question the manner in which scholars have consistently divided them along self/non-self (ātman/anātman) lines. The key to the comparison is thus the notion of individuated self (jīva) rather than the less personal ātman. Once the full implications of Advaita metaphysics are understood, whereby all consciousness is ultimately that of the one brahman, then, at the individuated level of consciousness, the ethical situation is strangely similar to the Buddhist with their notion of non-self (anātman). We thus have two rival schools positing a radical notion of the individual as having no unified centre of moral agency. Both schools adopt a methodology of Two Truths, the relative and the ultimate, in order to allow for both a provisional ethical framework and the potential for world transcendence. It was decided that the most convenient form of ethical comparison was a qualified form of altruism, here called “constructive altruism”. This is a form of other-regarding ethics which allows for the concept of a non-giver, i.e. a person who has realised selflessness and has seen through the “illusion” of individuation. This person then takes it upon himself to construct the other so as to gain a focus for the compassionate activity of teaching. The aim of such teaching is the liberation (mokṣa) of freedom-seeking disciples from this cyclic existence (saṃsāra) and its prevalent potential for suffering (duḥkha)
First results of the CAST-RADES haloscope search for axions at 34.67 µeV
No full textWe present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67 µeV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of ga¿ ¿ 4 × 10-13 GeV-1 over a mass range of 34.6738 µeV < ma< 34.6771 µeV is set. This constitutes a significant improvement over the current strongest limit set by CAST at this mass and is at the same time one of the most sensitive direct searches for an axion dark matter candidate above the mass of 25 µeV. The results also demonstrate the feasibility of exploring a wider mass range around the value probed by CAST-RADES in this work using similar coherent resonant cavities. © 2021, The Author(s)
