Bioenergy

In contrast to fossil fuels, the use of biofuels for thermal applications and power generation provides significant environmental advantages. Since Bio-Oil is extracted from organic wastes, it is a CO2 Neutral technique and can generate CO2 credits. In the present scenario energy sectors and individual entrepreneurs can opt a new way of power generation using the most abundantly available renewable source of energy in the form of Biomass wastes. Rice husks, groundnut shells, powdery husks, sugar cane (baggasse), corn cobs are some of the carbonaceous biomass fuels. Among the Biomass resources Coconuts are the abundant renewable resource of Energy available all around the world. Literature review showed that limited research studies had been carried out on yielding the product from coconut shell pyrolysis. The objective of present work is to envisage the methodology of generating power from biomass wastes using pyrolysis techniques. Pyrolysis is a thermal decomposition technique which decomposes carbonaceous biowastes into liquids, gases, and char (solid residue) in the absence of oxygen. Bio-Oil can be used as a fuel in diesel engine with modifications in fuel pump, linings, and the injection system. High carbonaceous Bio-Oil extracted from pyrolysis of coconut shell can be used in oil burners for thermal applications and in combustion boilers to generate electricity. Also can be blended with standard diesel fuels to form a pollution free green bio-diesel fuel. Hence biofuels based power generation system would be a boon to the energy crisis in an environmental friendly way using coconut shells for rural electrification

LEARNING HORTICULTURE WITH TAKE HOME MUSHROOM KITS DURING THE COVID-19 LOCKDOWN

PROBLEM Pre-COVID-19 lockdown (2019), we usually organise a mushroom growing practical in the laboratory (lab). After a lab demonstration, students practice culturing mushroom mycelium, spawn and compost preparation. The compost mixed with spawn in plastic bags are incubated in the Mushroom Research Unit for 2 weeks. Once established, students take the compost bags back home to harvest mushrooms. During the COVID-19 lockdown (2020), face to face laboratory mushroom practicals were no longer possible with social distancing requirements (4 sqm per person). We had to live-stream the practical sessions on Zoom to the students from the lab. We were not satisfied with just live-streaming practicals as the students did not get hands-on experience with growing the mushrooms. PLAN During the COVID-19 lockdown, the first author was invited to speak on Nick Kilvert’s ABC Urban Castaway series and was interviewed by ABC Radio National and ABC News online about self-sufficiency and people’s ability to hunt, forage and live off the local land. In the ABC Urban Castaway series (Week 3), there was a feature on growing our own mushrooms to be self-sufficient and how this could be an educational experience during the lockdown. Hence, at the end of May 2020, mushroom kits, with established mycelial colony in compost were provided to the students with instructions for care so that they could have hands-on learning experience of growing and eating their own mushrooms at home. ACTION We provided the students with a mushroom kit each so that they could practice growing mushrooms as well as a food subsistence during the lockdown. They could also practice time-lapse photography on the mushroom growth stages (from pinning, button and mature stages). If they did a good job, they could get 2 or 3 flushes of mushrooms (usually three flushes are harvested commercially). REFLECTION The students learnt how to grow their own mushrooms during the lockdown and post-lockdown as this is a life skill that they can use in the future. Live-streamed practicals provided useful information on how students can collect the spores and produce spawn to grow more of their own mushrooms in the future, becoming potentially self-sufficient in mushrooms! In addition to learning the theory of mushroom production, students gain the life skills to produce their own mushrooms at home

The student perspective in developing graduate attributes through problem-based learning in first year agricultural science

To meet university proclamations, academic staff are required to include graduate attributes in student learning. The approach adopted in this first year agricultural science course was to utilise problem-based learning to develop discipline knowledge and graduate attributes in a seamless manner. Rather than giving the students a questionnaire with options for students to indicate what graduate attribute they had learned, a structured learning journal was used to question students about their learning without specifically asking about any graduate attributes. Analysis of the learning journals revealed that significant numbers of students perceived that they had learned or practiced a range of graduate attributes, including teamwork, research, social responsibility, personal attributes, writing abilities, time management, problem solving, leadership, and multidisciplinary skills. These student perceptions exceeded the teachers’ expectations and revealed that problem-based learning in teams can be used for learning discipline knowledge and developing graduate attributes

FIRST YEAR AGRICULTURAL SCIENCE STUDENT PERSPECTIVES IN GRADUATE ATTRIBUTE DEVELOPMENT THROUGH PROBLEM-BASED LEARNING

Academic staff are required to include graduate attributes like inquiry and problem-solving in student learning to meet university proclamations. In response to student evaluations that a traditional lecture-based first year agriculture science course was not effective in motivating students, a new course introduced inquiry orientated learning primarily to motivate and engage students, to promote deep learning and problem-solving skills. The approach adopted problem-based learning to develop discipline knowledge and graduate attributes in a seamless manner. Instead of giving the students a questionnaire with options for students to indicate what graduate attribute they had learned, a structured learning journal was used to question students about their learning without specifically asking about any graduate attributes. Analysis of the learning journals revealed that significant numbers of students perceived that they had learned or practiced a range of graduate attributes, including teamwork, research, personal attributes, writing abilities, time management, problem solving, leadership, and multidisciplinary skills. The students had learned and practiced these graduate attributes while engaging in authentic problem-solving activities as groups in online and face-to-face environments. These student perceptions exceeded the teachers’ expectations and revealed that problem-based learning in teams can be used for learning discipline knowledge and developing graduate attributes

Improved DIQKD protocols with finite-size analysis

The security of finite-length keys is essential for the implementation of device-independent quantum key distribution (DIQKD). Presently, there are several finite-size DIQKD security proofs, but they are mostly focused on standard DIQKD protocols and do not directly apply to the recent improved DIQKD protocols based on noisy preprocessing, random key measurements, and modified CHSH inequalities. Here, we provide a general finite-size security proof that can simultaneously encompass these approaches, using tighter finite-size bounds than previous analyses. In doing so, we develop a method to compute tight lower bounds on the asymptotic keyrate for any such DIQKD protocol with binary inputs and outputs. With this, we show that positive asymptotic keyrates are achievable up to depolarizing noise values of $9.33\%$, exceeding all previously known noise thresholds. We also develop a modification to random-key-measurement protocols, using a pre-shared seed followed by a "seed recovery" step, which yields substantially higher net key generation rates by essentially removing the sifting factor. Some of our results may also improve the keyrates of device-independent randomness expansion.Comment: Improved threshold with more data points, discussion of conjecture in [SGP+21], correction regarding results of [MDR+19

Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge

Using a novel electrochemical phase-field model, we question the common belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which may explain the superior rate capability and long cycle life of nano-LiFePO4 cathodes.Comment: 27 pages, 8 figure

Evaluation of rate law approximations in bottom-up kinetic models of metabolism.

BackgroundThe mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question.ResultsIn this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations.ConclusionsOverall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches

Realization of a universal hydrodynamic semiconductor in ultra-clean dual-gated bilayer graphene

Hydrodynamic electronic transport is of fundamental interest due to its presence in strongly correlated materials and connections to areas outside of condensed matter physics; its study will be facilitated by identifying ambipolar hydrodynamic materials in which collisions between thermally activated electrons and holes determine conductivity. Here we present a comprehensive experimental and theoretical study of hydrodynamics in bilayer graphene, and consider the effects of an induced bandgap. For zero bandgap, conductivity at charge neutrality is temperature-independent; its magnitude determined by Planckian dissipation. With a bandgap, conductivity at charge neutrality collapses onto a universal curve. These results demonstrate that electron-hole collision limited transport in bilayer graphene can be readily detected at room temperature using straightforward DC conductivity measurements, providing an easily accessible platform for hydrodynamic investigations