The consumption of tea, particularly green tea, can indeed help reduce stress, largely due to its amino acid content, specifically L-theanine. L-theanine is a unique amino acid found almost exclusively in tea plants (Camellia sinensis). When ingested, it crosses the blood-brain barrier and affects the activity of neurotransmitters like dopamine and serotonin. This leads to a calming effect without causing drowsiness. Studies have shown that L-theanine can decrease anxiety and improve focus and concentration, making it beneficial for managing stress. However, it's important to note that while tea can be a helpful component in stress management, it should be part of a holistic approach that includes proper diet, exercise, and adequate sleep.

Wood and grass significantly differ in cellulose content due to their structural variations and biological purposes. Wood, which forms the structure of trees, has a cellulose content that can vary widely, commonly around 40-50%. This cellulose, combined with lignin, gives wood its strength and rigidity, necessary for trees to reach considerable heights and live for many years. Grass, on the other hand, has a slightly higher proportion of cellulose, usually around 25-40%, but this is accompanied by higher levels of other compounds like hemicellulose and silica. Despite grass having a high cellulose percentage, the overall density and compactness of cellulose in wood make it a more cellulose-rich material by volume. The difference in composition reflects the evolutionary adaptations of these plants to their environments and roles in ecosystems. In summary, while grass may have a high cellulose percentage, wood generally contains more cellulose by volume due to its denser structure.

Purchasing bulk urethane resin can be done through various online retailers, industrial supply companies, or specialty chemical suppliers. Websites like Alibaba, eBay, or Amazon supply urethane resins in various quantities, suitable for both small-scale hobbyists and large industrial needs. For professional applications, companies such as Smooth-On, Reynolds Advanced Materials, or Polytek Development Corp. specialize in high-quality urethane products and offer bulk purchasing options. It's essential to consider the resin's specifications, such as viscosity, pot life, and cure time, to match your project needs. Additionally, buying in bulk often provides cost savings but ensure proper storage as urethane resins can have limited shelf lives.