The sonochemical reaction between Zn(NO3)2 and hexamethylenetetramine (HMT) resulted in different products depending on amounts of Zn(II) cations in the aqueous solution. Crystalline phase pure ZnO nanoparticles were obtained by using 0.05 M Zn(NO3)2-HMT. This single phase was formed by low power sonication for 20 min in an ultrasonic bath at ambient conditions and its morphology did not change for the next 60 min. Higher concentrations of precursors (0.1 and 0.5 M) led to a mixture of zinc compounds including plate-like Zn5(OH)8(NO3)2(H2O). In contrast, a mixed phase ZnO/Zn5(OH)6(CO3)2 and a single phase Zn5(OH)6(CO3)2 were formed when the precursor concentrations were decreased to 0.01 and 0.005 M, respectively. The resulting infrared absorption and ultraviolet/visible emission were dependent on the phases and defects in these zinc compounds.

Multilevel image segmentation is demonstrated as a rapid and accurate method of quantitative analysis for nanoparticle assembly in TEM images. The procedure incorporating K‐means clustering algorithm and watershed transform is tested on transmission electron microscope (TEM) images of FePt‐based nanoparticles whose diameters are less than 5 nm. By solving the nanoparticle segmentation and separation problems, this unsupervised method is useful not only in the nonoverlapping case but also for agglomerated nanoparticles. Furthermore, the method exhibits scale invariance based on comparable results from images of different magnifications.

Soil color serves as a critical indicator of its properties and conditions. It is shaped by a complex interplay of mineral and organic matter content, moisture levels, and other environmental variables. Additionally, human activities such as land-use changes and intensive agricultural practices can profoundly alter soil color. Soil color, driven by the presence of organic matter, plays a crucial role in understanding soil fertility. Its strong correlation with soil organic carbon content makes it a valuable parameter for assessing soil quality in agricultural practices. A variety of techniques have been developed to measure soil color, ranging from traditional Munsell color matching to modern color meters. Digital image colorimetry enables rapid on-site assessments of soil color, but environmental conditions such as soil water content and lighting conditions should be considered. Spectroscopic methods, particularly diffuse reflectance spectroscopy, pave the way for a more reliable and accurate composition analysis. Advances in remote sensing and computational methods are combined to explore the intricate relationships between soil color and environmental factors. Such an integrated approach not only enhances scalability but also leads to more insights and actionable strategies for environmental management and sustainable agriculture.

Motions of falling objects through air and liquid media were captured by a conventional digital camera and analyzed by a video analysis open source called Tracker. The position of the moving objects at every 33 ms was evaluated from series of images and the velocity was averaged from the change in position during each interval. For the falling in air experiment, the displacement of a ball was proportional to the time squared and the agreement with the theory was indicated by the derivation of the acceleration due to the gravity with an acceptable level of accuracy. In additions, the effects of the height of falling, the camera distance as well as the color of ball and background were investigated. In the case of falling in glycerol, the average velocity of a metal bead was initially increased with the time of falling until reaching a constant value of the terminal velocity.

The potential of microwave drying in the production of rehydrated foods is demonstrated with stink beans (Parkia speciosa), smelly legumes of Africa and Asia. Compared to stink beans dehydrated by convective drying and freeze drying, the microwave products exhibit higher moisture contents, but the distribution of microscopic pores leads to good rehydration characteristics. Dehydration by microwave drying is also achieved within a much shorter period than that commonly used in freeze drying. The dehydration time can be further reduced to 6 h comparable to convective drying, and the moisture content is dropped to 11% by decreasing the pressure during microwave drying. However, the rehydration time remains around 65 min for products from both ambient and low-pressure (400 Pa) microwave drying. In rehydration, the period is successfully reduced to 30 min by increasing the water temperature to 70 °C. The results indicate that microwave drying does not affect the value of crude protein and rehydrated products are comparable to fresh stink beans. From these findings, the microwave drying technique is an applicable technology for both manufacturers and consumers, with acceptable drying time and rehydration characteristics.