A Study of the Impact of Methanol, Ethanol and the Miller Cycle on a Gasoline Engine

This paper focuses on the investigation and optimisation of the Miller cycle, methanol, ethanol and turbocharging when applied to a high-performance gasoline engine. These technologies have been applied both individually and concurrently to test for potential compounding effects. Improvements have been targeted with regards to both emission output and performance. Also assessed is the capability of the engine to operate when exclusively powered by biofuels. This has been carried out numerically using the 1D gas dynamics tool ‘WAVE’, a 1D Navier–Stokes equation solver. These technologies have been implemented within the McLaren M838T 3.8L twin-turbo engine. The Miller cycle early intake valve close (EIVC) improved peak efficiency by 0.17% and increased power output at low and medium loads by 11%. Reductions of 6% for both NOx and CO were also found at rated speed. The biofuels achieved NOx and CO reductions of 60% and 96% respectively, alongside an efficiency increase of 2.5%. Exclusive biofuel use was found to be feasible with a minimum 35% power penalty. Applied cooperatively, the Miller cycle and biofuels were not detrimental to each other, compounding effects of a further 0.05% efficiency and 2% NOx improvements were achieved.

Policy assessments for the carbon emission flows and sustainability of Bitcoin blockchain operation in China

The growing energy consumption and associated carbon emission of Bitcoin mining could potentially undermine global sustainable efforts. By investigating carbon emission flows of Bitcoin blockchain operation in China with a simulation-based Bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the Bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.50 million metric tons of carbon emission correspondingly. Internationally, this emission output would exceed the total annualized greenhouse gas emission output of the Czech Republic and Qatar. Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China. In this work, we show that moving away from the current punitive carbon tax policy to a site regulation policy which induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of Bitcoin blockchain operation.

Evaluation of Green Development Efficiency of the Major Cities in Gansu Province, China

Green development (GD) has become a new model of sustainable development across the world. However, our knowledge of green development efficiency (GDE) in Gansu province is poor. In remedy, this study, based on the panel data of 12 major cities in Gansu from 2010 to 2017, employed the super-efficient Slack-based measure (SBM) to analyze and evaluate GDE from the input–output perspective. Furthermore, we analyzed the input redundancy and output deficiency of identified inefficient cities in 2017 and conducted spatial autocorrelation analysis of GDE of the cities under study. Results show differences in the GDE of the major cities in Gansu, with an average value of 0.985. Green development efficiency in Lanzhou, Qingyang, Jinchang, Jiuquan, and Tianshui was relatively higher than in other cities. Green development efficiency in Zhangye, Wuwei, Jiayuguan, Baiyin, Dingxi, Longnan, and Longnan was less than one due to their redundant labor and capital input and excessive pollutant emission output. The overall GDE in Gansu depicts “high east and low west” zones. Each city in Gansu needs to formulate targeted policies and regulations to improve resource utilization, innovation capacity, reduce pollutant emission, optimize the industrial structure, and promote inter-city cooperation to construct a sustainable green economy.

Исследование микроволнового поглощения в полупроводниках для устройств умножения частоты и управления выводом излучения непрерывных и импульсных гиротронов

The results of experimental investigation into the dielectric losses in GaAs, InP:Fe, and Si semiconductor crystals in the millimeter wavelength range (80–260 GHz) using the original precise method of measuring the reflectance and dielectric-loss tangent tanδ based on open high-quality Fabry–Perot cavities are presented. It is shown that the losses in the frequency range from 100 to 260 GHz in ultrapure semiconductor single-crystal GaAs substrates are mainly determined by lattice absorption, while the main loss mechanism in single-crystal silicon is absorption by free carriers; herewith, tan δ ≈ (1–2) × 10^–4 even for a noticeable, at a level of 10^12 cm^–3, free carrier concentration. In contrast with GaAs and Si, tanδ in compensated InP:Fe crystals is almost independent of frequency in the range from 100 to 260 GHz, which is associated with the material conductivity and optimization of microwave semiconductor devices, in particular, frequency-multiplication devices and devices of the controlled emission output of continuous and pulsed gyrotrons.

Molecular logic gates based on benzo-18-crown-6 ether of styrylquinoline: a theoretical study

Absorption and emission output of 1 can be utilized to build AND, NOR, XOR, XNOR, INHIBIT, and IMPLICATION logic gates.