Adapting the Electron Beam from SEM as a Quantitative Heating Source for Nanoscale Thermal Metrology.

The electron beam (e-beam) in the scanning electron microscopy (SEM) provides an appealing mobile heating source for thermal metrology with spatial resolution of ∼1 nm, but the lack of systematic quantification of the e-beam heating power limits such application development. Here, we systemically study e-beam heating in LPCVD silicon nitride (SiNx) thin-films with thickness ranging from 200 to 500 nm from both experiments and complementary Monte Carlo simulations using the CASINO software package. There is good agreement about the thickness-dependent e-beam energy absorption of thin-film between modeling predictions and experiments. Using the absorption results, we then demonstrate adapting the e-beam as a quantitative heating source by measuring the thickness-dependent thermal conductivity of SiNx thin-films, with the results validated to within 7% by a separate Joule heating experiment. The results described here will open a new avenue for using SEM e-beams as a mobile heating source for advanced nanoscale thermal metrology development.

Measuring the Healthiness of the Packaged Food Supply in Australia.

The increasing availability of packaged foods plays a key role in nutritional transition. This study examined the healthiness of the Australian packaged food supply using a range of different metrics; 40,664 packaged products from The George Institute's FoodSwitch database were included. Median and interquartile range (IQR) were determined for each measure of nutrient composition; mean and standard deviation (SD) for the measure based upon Health Star Rating (HSR); and proportions (%) for the measures based upon products with a higher HSR, classification of foods as either core or discretionary, extent of processing and proportions of foods that met reformulation targets for sodium, saturated fat and total sugars. Overall median (IQR) values were 1093 (1256) kJ/100 g for energy, 1.7 (6.3) g/100 g for saturated fat, 5.3 (21.4) g/100 g for total sugars, 163 (423) g/100 g for sodium and 50 (100) g or mL for serving size. Overall mean (SD) HSR was 2.8 (1.4), proportion with HSR < 3.5 was 61.8%, proportion of foods defined as discretionary was 53.0% and proportion of foods defined as highly processed was 60.5%. There were sodium targets set for 21,382/40,664 (53%) foods and achieved for 14,126/40,664 (35%). Corresponding figures for saturated fat were 328/40,664 (0.8%) and 130/40,664 (0.3%). Nutrient profiling, dietary guidelines and the extent of food processing provided comparable assessments of the nutritional quality of Australia's packaged food supply. Individual measures of nutrient composition did not, but may be of value for identifying specific foods of concern.

Feasibility study of a soil-based rubberized CLSM.

The development of beneficial uses of recycled scrap tires is always in great demand around the world. The disposal of on-site surplus excavated soil and the production of standard engineering aggregates have also been facing increasing environmental and ecological challenges in congested islands, such as Taiwan. This paper presents an experimental study using recycled crumb rubber and native silty sand to produce a lightweight, soil-based, rubberized controlled low strength material (CLSM) for a bridge approach repair. To assess the technical feasibility of this material, the effects of weight ratios of cement-to-water (C/W) and water-to-solid (W/S), and of rubber content on the engineering properties for different mixtures were investigated. The presented test results include flowability, unit weight, strength, settlement potential, and bearing capacity. Based on the findings, we conclude that a soil-based rubberized CLSM with 40% sand by weight and an optimal design ratio of 0.7 for C/W and 0.35 for W/S can be used for the proposed bridge approach repair. Such a mixture has demonstrated acceptable flowability, strength, and bearing capacity. Its lower unit weight, negligible compressibility, and hydrocollapse potential also help ensure that detrimental settlement is unlikely to occur. The results illustrate a novel scheme of CLSM production, and suggest a beneficial alternative for the reduction of scrap tires as well as conservation of resources and environment.