Sustainable Diels–Alder syntheses in imidazolium ionic liquids

<p>An effective and simple protocol for the Diels–Alder reactions catalyzed and mediated by ionic liquid in conjunction with Lewis acid was studied. Diels–Alder adduct of the reaction of 1,4-benzoquinone with isoprene and 2,3-dimethyl-1,3-butadiene was obtained in good to excellent yields within the time span of 5.00–4.00 min under microwave irradiation. Due to the excellent activity of 2,3-dimethyl-1,3-butadiene as a diene, its efficiency was further analyzed by performing against four different dienophiles under various reaction conditions. The ionic liquid, 3-methyl-1-octyl-imidazolium tetrachloroaluminate mixed with Lewis acids, could be recycled and reused for consecutive cycles. The recovered ionic liquid in conjunction with Lewis acid displayed almost similar activity without any significant loss. This system is an essential upgrade and related to the reactions consuming common organic solvents at high temperatures and longer duration. Diels–Alder reactions under solventless conditions have also been investigated for the aforesaid reactions.</p

Effect of injection timing on combustion, emission and performance characteristics of safflower methyl ester in CI engine

Biodiesel, as a renewable fuel, holds great promise, yet its high viscosity presents significant challenges when used in diesel engines. To address these challenges, this study delved into the effects of injection timing on the combustion, emissions, and performance of safflower methyl ester (SAME) in a compression ignition (CI) engine. The experimentation involved testing at three different injection timings: the standard 23° BTDC, advanced 27° BTDC, and retarded 19° BTDC. The results yielded valuable insights. Retarded injection timing notably extended ignition delay by 18 % and reduced the heat release rate by 5 % compared to the standard timing, leading to a substantial decrease in NOx emissions by up to 28 %, a 25 % reduction in CO emissions, and a 5 % decrease in smoke opacity. However, it came at the cost of a 10 % reduction in brake thermal efficiency. Conversely, advanced timing increased NOx emissions by 4 % but concurrently lowered smoke opacity by 3 %. This study underscores the critical importance of optimizing injection timing to balance emissions and performance, mainly when dealing with high-viscosity biodiesels like SAME in diesel engines. The results also highlight the potential of SAME as a viable alternative fuel source, provided that injection timing is judiciously managed to account for its unique viscosity and combustion characteristics. In the quest for sustainable energy solutions, such research is pivotal in harnessing the full potential of biodiesel and advancing its integration into the transportation sector

Tropical Intraseasonal Variability in the MRI-20km60L AGCM

This study documents the detailed characteristics of the tropical intraseasonal variability (TISV) in the MRI-20km60L AGCM that uses a variant of the Arakawa-Schubert cumulus parameterization. Mean states, power spectra, propagation features, leading EOF modes, horizontal and vertical structures, and seasonality associated with the TISV are analyzed. Results show that the model reproduces the mean states in winds realistically and in convection comparable to that of the observations. However, the simulated TISV is less realistic. It shows low amplitudes in convection and low-level winds in the 30-60-day band. Filtered anomalies have standing structures. Power spectra and lag correlation of the signals do not propagate dominantly either in the eastward direction during boreal winter or in the northward direction during boreal summer. A combined EOF (CEOF) analysis shows that winds and convection have a loose coupling that cannot sustain the simulated TISV as realistically as that observed. In the composited mature phase of the simulated MJO, the low-level convergence does not lead convection clearly so that the moisture anomalies do not tilt westward in the vertical, indicating that the low-level convergence does not favor the eastward propagation. The less realistic TISV suggests that the representation of cumulus convection needs to be improved in this model.Y

Challenges in rescuing snakes to protect human lives and promote snake conservation in Tamil Nadu, India

Background: Human-snake conflicts are common worldwide, often resulting in snakebites. Snakebite envenoming causes over 125,000 deaths and 400,000 permanent disabilities worldwide every year. India alone accounts for an average of ~58,000 annual snakebite-induced deaths. As human developments rapidly expand into suburban and rural areas, snakes are being displaced and incidences of residents finding snakes within their dwellings are increasing. Most people have an innate fear of snakes, compounded by centuries of negative influence from culture and mythology manifesting in people often attempting to kill snakes. Snake rescuers are volunteers who remove and relocate snakes to safe areas. This is a risky job that poses potentially fatal implications if bitten. These volunteers mostly receive no financial compensation for their time or transportation costs, but they choose to do it for their love of snakes, conservation, and for the altruistic nature of helping others. Snake rescuers often receive no formal training and are unfunded resulting in removing snakes improperly without adequate safety equipment or the required skill set to safely complete the task. Therefore, it is critical to determine their challenges and requirements to promote the safe rescue of snakes while protecting human lives. Methodology/principal findings: In this study, we developed an online questionnaire and interviewed 152 snake rescuers in Tamil Nadu, India following written informed consent to determine their challenges and needs for rescuing snakes safely. The results demonstrate that most rescuers are males, and they conduct snake rescues for varying lengths of time. They mostly receive no formal training and are bitten by snakes. They spend their own money on the purchase of snake-handling equipment and on treatments if bitten or injured during a rescue. Conclusions/significance: The rescuers highlighted the urgent need for formal training, safety equipment and standard protocols for rescuing snakes in Tamil Nadu. Overall, this study demonstrates that snake rescuing should be appropriately regulated by the authorities, in particular the Wildlife Division of State Forest Departments in India, and formal training along with necessary equipment, medical insurance and appropriate recognition should be provided to them to safely remove snakes from human dwellings and manage the safety of both snakes and humans. They can also act as educators to disseminate information about the preventive and first aid measures for snakebites as well as the ecological importance of snakes