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Biochar has been shown to improve soil properties and plant productivity in soils with inherently low fertility. However, little has been reported for upland corns under dry and wet precipitation regimes. This study investigates the effect of biochar addition on a range of soil physicochemical, biological, and hydrological properties, and corn growth and productivity under agrometeorological drought and wet conditions. Here, experiments were laid out in a randomized complete block design with three replications at two sites during 2017 and 2018 in South Korea. Treatments included (i) CN: control (ii) IF: inorganic fertilizer (N–P–K) at 145–30–60 kg ha−1; (iii) BS: barley straw at 5 t ha−1; (iv) CWBC: corn waste biochar at 5 t ha−1; (v) CWBC + IF: corn waste biochar + inorganic fertilizer; (vi) CWBC + BS: corn waste biochar + barley straw. The year 2017 was relatively dry, whereas the year 2018 was wet. Despite drought conditions in the year 2017, biochar facilitated soil water conservation. However, higher precipitation in 2018 increased the quantity and distribution of soil water and nutrients in the top 15 cm. Biochar reduced soil bulk density, and increased porosity, cation exchange capacity and total organic carbon in both years but increased total bacterial counts during the dry year only. Bacterial population was generally higher under wet conditions. Similarly, more soil CO2 was emitted in the wet year than in the dry year. Results further indicated that biochar can enhance corn biomass and grain yield regardless of precipitation conditions. The grain index was, however, affected by rainfall and was significantly different across treatments in the year 2018 only. All biomass, grain yield, and grain index were highest in CWBC + IF treatment and lowest under CN treatment. Indeed, biochar addition appeared to improve soil quality and soil conditioning effects in the drought and wet years, ameliorating soil and plant properties. Overall, biochar can improve water and nutrients storage, availability, and uptake, and therefore corn productivity during hydrological extremes. Highlights: Biochar application consistently increased soil water content. Biochar improved soil physicochemical characteristics in the drought and wet year. Biochar increased bacterial population during the drought year. Grain yield was higher in the wet year than in the drought year. Grain yield and grain index was highest under CWBC + IF and lowest under CN treatment. [ABSTRACT FROM AUTHOR]

Developments in vehicle technology and accompanying improvements in NVH performance have led to increased consumer demand for high sound quality, such as a "sporty" engine sound. As sporty sound is subjective, this study sought to express its meaning quantitatively and to develop a model that accommodates the differences in individuals' tastes. Engine sounds of four vehicles at wide-open throttle were recorded and the signal was modulated via filtering. Acoustic and psychoacoustic parameters of the samples produced were calculated, and the preferences for sportiness were identified through jury testing. Using K-means clustering, factor analysis, and multiple linear regression, a sound quality index and a model reflecting differences in evaluators' tastes were developed. The index was retested using new evaluators and new samples, demonstrating its reliability by high correlation. This sound quality evaluation index is useful for producing highly accurate results and reflecting the opinions of groups expressing a variety of commonalities. [ABSTRACT FROM AUTHOR]

For those who enjoy driving, the "sportiness" the engine sound is an important point to consider. However, owing to its abstractness, there is no absolute definition of what sportiness sounds like. Therefore, this study aimed to develop a sound quality index capable of objectively evaluating the sportiness of engine sound based on sound quality research. Objective measurements included the process of recording the sound in the car interior under wide-open-throttle acceleration conditions for 4 vehicles, producing 13 evaluation samples by using various filters based on the recorded data, and calculating the sound metrics of each sample. Subjective evaluation was jointly carried out by 23 evaluators and a semantic differential method was used to find adjectives that could explain the concept and preference for sportiness. The developed index was validated by examining the correlation coefficient through a new sample group. Furthermore, the necessity of factor analysis was also determined. [ABSTRACT FROM AUTHOR]

High energy ball-milled iron sulfides with thin carbon layer coating (BM-FeS/C composites) were prepared by the simple and economical process. Ball-milled process, followed by carbon coating, reduced the particle size and increased the electrical conductivity. When employed as sodium-ion battery anodes, BM-FeS/C composites showed extremely high electrochemical performance with reversible specific capacity of 589.8 mAh·g−1 after 100 cycles at a current density of 100 mA·g−1. They also exhibited superior rate capabilities of 375.9 mAh·g−1 even at 3.2 A·g−1 and 423.6 mAh·g−1 at 1.5 A·g−1. X-ray absorption near edge structure analysis confirmed the electrochemical pathway for conversion reaction of BM-FeS/C composites. [ABSTRACT FROM AUTHOR]