Protective films on complex substrates of thermoplastic and cellular elastomers:Prospective applications to rubber, nylon and cork

Deposition of thin films is an appropriate methodology to enhance the performance of a material by modification of its surface, while keeping the properties of the bulk largely unaffected. However, a practical implementation becomes less straightforward when dealing with sensitive or complex substrates, for instance, those which cannot be subjected to harsh treatments, such as cleaning and etching, or extreme deposition conditions, like high temperatures, and ion impingement et cetera. This paper concentrates on deposition processing of complex substrates. In particular, it discusses the deposition of two types of protective coatings (diamond-like carbon (DLC) films against friction and wear, and TiO2 films against UV light) on three types of thermoplastic and cellular elastomers (rubber, nylon and cork). It is demonstrated that a successful protection of thermoplastic elastomers against wear with DLC films can be attained, after a thorough adaptation of the procedure to the characteristics of the specific substrate. In addition, the paper reports the very first depositions on a cellular elastomer like cork by vapor deposition methods, including Atomic Layer Deposition (ALD)

Locking and enrichment strategies

A short overview of different locking mechanisms is presented, in which the more recent locking phenomenon tension locking is placed. Tension locking is found during composite forming simulations and occurs when the element edges are unaligned with the fiber directions. Discontinuities in composite forming simulations show similarities with other weak discontinuities such as material interfaces and shear bands found during shear localization. Two enrichment strategies are explored to resolve tension locking in linear triangular elements

Cover crops did not improve soil health but hydroclimatology may guide decisions preventing cash crop yield loss

Introduction: Cover crop (CC) is an essential tool to improve or maintain soil health, potentially improving cash crop productivity. Several recent reports of cash crop yield reduction following cover cropping necessitated this research to guide efficient CC decisions in the season before corn (Zea mays) or soybean (Glycine max) is to be grown. Methods: Therefore, we designed this multi-year, multi-location study to include the farmers who plant CC following the harvest of a small grain crop, majorly wheat (Triticum aestivum) or oats (Avena sativa), and then grow corn or soybean cash crop in the subsequent season. We also selected the farmers who used a fall CC mix that was winter-terminated, to avoid further complexities. The major objective of this study was to document soil health changes and cash crop yields following CC in eight selected locations around SD for three consecutive CC seasons between 2017-2020. Experimental plots were laid out at the farmer-cooperators’ CC fields, where no cover (NC) ‘control’ was tested against CC in a randomized complete block design (RCBD). Soil samples were analyzed for selected soil health indicators (SHIs): potentially mineralizable nitrogen (PMN), permanganate oxidizable carbon (POXC), soil respiration (SR), soil microbial biomass (SMB), soil nitrate-nitrogen, soil organic matter (SOM), and other basic soil properties (pH, electrical conductivity, etc.); crop and residue biomass were calculated, and cash crop economic yields were measured. Results and discussion: No statistically significant (p30 g kg-1). These findings directed us to investigate hydroclimatological parameters and climatological indices such as accumulated precipitation, standardized precipitation index (SPI), and standardized precipitation-evapotranspiration index (SPEI) for their impact on CC’s influence on cash crop yields. Conclusion: Our analyses indicated that hydroclimatology, especially SPEI for the month before CC planting can be used as a tool to guide successful CC decisions, reducing the risk of cash crop yield loss. Further investigations with SPI and SPEI, along with other climatological parameters are needed to explore and design better CC management tools. Copyright © 2023 Sanyal, Mukherjee, Rahhal, Wolthuizen, Karki, Clark and Bly.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

ironXS: High-school screening for hereditary haemochromatosis is acceptable and feasible

As the results of the Human Genome Project are realised, screening for genetic mutations that predispose to preventable disease is becoming increasingly possible. How and where such screening should best be offered are critical, unanswered questions. This study aimed to assess the acceptability and feasibility of genetic screening for preventable disease, using the model of hereditary haemochromatosis, in high-school students. Screening was offered for the HFE C282Y substitution to 17 638 students. Questionnaires were administered at the time of screening (Q1) and approximately 1 month after results were communicated (Q2). Outcomes assessed were uptake of screening, change in scores of validated anxiety, affect and health perception scales from Q1 to Q2, knowledge and iron indices in C282Y homozygous individuals. A total of 5757 (32.6%) students had screening and 28 C282Y-homozygous individuals (1 in 206) were identified, and none of the 27 individuals who had iron indices measures had significant iron overload. There was no significant change in measures of anxiety, affect or health perception in C282Y homozygous or non-homozygous individuals. Over 86% of students answered each of five knowledge questions correctly at Q1. Genetic population-based screening for a preventable disease can be offered in schools in a way that results in minimal morbidity for those identified at high risk of disease. The results of this study are not only relevant for haemochromatosis, but for other genetic markers of preventable disease such as those for cardiovascular disease and cancer