Behavior of Stressed and Unstressed 304L Specimens in Tuff Repository Environmental Conditions

Abstract This paper presents preliminary results of an investigation nf the behavior of candidate barrier material for high level nuclear waste storage, Type 304L stainless steel, in tuff repository environmental conditions. Tuff is a densely welded., devitrified, igneous rock common to the proposed repository site at Yucca Mountain, Nevada. The results discussed include: irradiation corrosion tests, U-bend irradiation corrosion tests, slow strain rate tests, and bent beam stress corrosion tests. Results indicate that Type 304L stainless steel shows excellent resistance to qeneral, localized, and stress corrosion under tne environmental and microstructural conditions tested so far. The environmental test conditions are 50-100°C J-13 well water (non-saline, near neutral pH, and oxic in nature) and saturated steam at 100°C. Microstructural conditions include solution annealed and long furnace heat treatments to provoke a sensitized structure. However, this particular type of stainless steel may be susceptible to long-term, low-temperature sensitization because of the combination of expected time at elevated temperature and residual stress in the container after emplacement in the repository. Other grades of austenitic stainless steels are reported to be more resistant to low-temperature sensitization. Future work will therefore include more extensive testing of these grades

Productivity and Nutritive Value of Black Soldier Fly (Hermetia illucens) Larvae Fed with Different Waste Substrates

Due to the unavailability and rising market price of fishmeal and soybean meal, insect larvae, such as black soldier fly larvae (BSFL: Hermetia illucens), are currently being investigated as an alternate source of protein for swine and poultry. The productivity and nutritional value of BSFL were examined in this study together with the effects of various waste substrates. There were two experimental containers for every treatment and were replicated three times and laid out using a Completely Randomized Design (CRD). A total of twenty-four (24) plastic containers (12 x 8.5 x 3 inches) were used which per container contained 100 grams/1000 of 4 days old BSF larvae. The results showed that BSF larvae fed with T2-Fruit remains and T3 -Vegetable scraps yielded the highest production of 1230-1312 grams and an early maturation period of 18-19 days. Both T2-Fruit remains and T3 -Vegetable scraps have the highest nutritional value of around 43% to 47% of crude protein content, respectively as compared to the rest of the treatments.  The nutritional profile of BSF larvae fed fruit and vegetable waste suggests that it may be used as a less expensive and more sustainable source of protein for pigs and poultry

Apicoectomy Using Er:YAG Laser in Association with Microscope: A Comparative Retrospective Investigation

This study aims to compare and validate two soil-vegetation-atmosphere-transfer (SVAT) schemes: TERRA-ML and the Community Land Model (CLM). Both SVAT schemes are run in standalone mode (decoupled from an atmospheric model) and forced with meteorological in-situ measurements obtained at several tropical African sites. Model performance is quantified by comparing simulated sensible and latent heat fluxes with eddy-covariance measurements. Our analysis indicates that the Community Land Model corresponds more closely to the micrometeorological observations, reflecting the advantages of the higher model complexity and physical realism. Deficiencies in TERRA-ML are addressed and its performance is improved: (1) adjusting input data (root depth) to region-specific values (tropical evergreen forest) resolves dry-season underestimation of evapotranspiration; (2) adjusting the leaf area index and albedo (depending on hard-coded model constants) resolves overestimations of both latent and sensible heat fluxes; and (3) an unrealistic flux partitioning caused by overestimated superficial water contents is reduced by adjusting the hydraulic conductivity parameterization. CLM is by default more versatile in its global application on different vegetation types and climates. On the other hand, with its lower degree of complexity, TERRA-ML is much less computationally demanding, which leads to faster calculation times in a coupled climate simulation