Measuring Urban Low-Carbon Sustainability in Four Chinese Cities

Practices and research on measuring traditionally urban sustainability abound, therefore the challenge now is related to how the urban carbon issues are included into current measuring methods, thus there is a need to develop methods for measuring urban low-carbon sustainability. In this paper, a simple method, which is based on low-carbon sustainability index, is developed. The overall urban low-carbon sustainability index is the weighted sum of 11 single indices, and each single index is defined as the indicator assessing the development level against the baseline. The baseline is often the criteria or the minimum requirement of low-carbon sustainability. Case studies in four Chinese cities have put this method into practice, and the results show that all four selected cities fail to pass the testing of sensible low-carbon sustainability rule and they are all in weakly low-carbon sustainable development. Although the four cities have made great progress in their capacity building on pollution control and their capacities on wastewater treatment, main pollutants’ removal and household and hazardous wastes treatment are enough to meet the needs of local development, they are all facing the great challenges on using of sustainable energy, offsetting of CO2 emissions and adoptions of nature-based solutions. The method developed by this research is a useful tool for decision makers identifying whether the local development is not on a low-carbon sustainable path.

DETERMINATION OF RESIDUAL RESOURCE OF MEASURING CURRENT TRANSFORMERS USING FUZZY SIMULATION

The article analyzes the damage of the main elements of current measuring transformers (CMT) and proposes a mathematical model of the residual life of CMT obtained by fuzzy modeling using Matlab software.

Arduino Mega Based Current Recorder Prototype Implementation

Current measurements in electric power systems are important aspects, both for monitoring and protection. The researchers have designed, created and tested a digital current measuring and recording prototype instrument. The current signals were sensed by the split-core current transformers, entered to the signal conditioning, to the main Arduino Mega 2560 microcontroller, and finally to the three outputs, namely a PC monitor, SD card data logger and LCD. It was tested and the results were compared to the computation results and the clamp ammeter readings, as the reference instrument. On both single and three phase systems, the absolute deviations would considerably rise and the relative deviations would slightly reduce as the load currents increased. Nevertheless, the values on both systems were not exactly same. For the single phase, the average absolute and relative deviation slopes were 0.156548 A/kW and -0.0020772 %/kW respectively. On other hand, for the three phase system, they were 0.12372 A/kW and -0.04176 %/kW respectively. The relative deviations to the computation results were under 6%, tended to be 3%, and the relative deviations to the reference instrument readings were under 3%, tended to be 1%, as the load increased.

Experimental Study on the Inverse Estimation of Horizontal Air Temperature Distribution in Built Spaces Using a Ground-Based Thermal Infrared Spectroradiometer

Air temperature is an important physical indicator for urban and architectural environments; however, it is difficult to obtain its distributive characteristics by field measurements owing to the limitations of current measuring instruments. In this context, this study was conducted to demonstrate whether a small and portable ground-based thermal infrared spectroradiometer can be used to estimate the horizontal air temperature distribution in built spaces. For this estimation, we first calculated a forward model using radiative transfer simulations, and the air temperature distribution was inversely estimated from the observed radiance using the model. To regularize the estimated air temperature, we used the maximum a posteriori method, which uses prior information. To verify this estimation method, we conducted measurement experiments in two types of built spaces that had different air temperature distributions within spaces that were approximately 20 m long. Moreover, we conducted a parametric case study on the prior information. As a result, we were able to estimate the air temperature distribution with an average root mean square error (RMSE) of 1.3 °C for all cases when the average RMSE of the prior information for all cases was 2.1 °C. This improvement in the RMSE indicates that this method is able to remotely estimate the horizontal air temperature distribution in built spaces.

Half division two-dimensional method for simple sinusoidal quantities parameters accurate measurement

Several variants of half division two-dimensional method are proposed, which is the basis of a fundamentally new approach for constructing measuring instruments for sinusoidal or periodic electrical quantities. These measuring instruments are used in the diagnosis of electric power facilities. The most general variant, called midpoint method, is considered. The proposed midpoint method allows you to measure much smaller than using widespread methods, alternating currents or voltages, especially when changing the amplitude of the measured signal in very wide ranges, by 1–2 orders of magnitude. It is shown that using the midpoint method it is possible to suppress sinusoidal or periodic interference in the measuring path, in particular, to measure small alternating current when sinusoidal or periodic interference is 1–2 orders of magnitude higher than the useful signal. Based on the results of comparative tests, it was found that the current measuring device implementing the midpoint method is an order of magnitude more sensitive than the currently used high-precision measuring instruments.