Evaluation of Wear Resistance in Tungsten-Doped Diamond-like Carbon Coatings (WC/C) on Coated and Uncoated Surfaces Under Starved Oil Lubrication with R452A Refrigerant.

This article assesses the potential of using a diamond-like carbon coating doped with tungsten, a-C:H:W (WC/C), on the sliding pairs of refrigeration compressors. The ability of WC/C coating to provide low wear and a low coefficient of friction was experimentally verified in a specific refrigeration compressor operating environment (lubrication with oil diluted with refrigerant) and under extreme operating conditions (starved lubrication with a small amount of oil). Conditions of starved lubrication with a substance of reduced lubricity promote a temperature increase and high mechanical (friction) stresses on the surface of the sliding pairs.

Effect of a Cat's Permanent Presence on the Health and Social Network of Older Adults With Alzheimer's Disease or Disabilities in a Nursing Home.

Our study analyzes the effects of the permanent presence of cats on the health and social network of residents with pathologies in nursing home. Fifty-three residents, thirty-six caregivers, and four cats in three Alzheimer's Disease units ("ADU") and one Disability unit ("DISU") were observed for 180 hours. Social networks were created via instantaneous sampling of physical proximities and social exchanges between residents, caregivers, and the cats.

Inspection of Spot Welded Joints with the Use of the Ultrasonic Surface Wave.

Spot welded joints play a crucial role in the construction of modern automobiles, serving as a vital method for enhancing the structural integrity, strength, and durability of the vehicle body. Taking into account spot welding process in automotive bodies, numerous defects can arise, such as insufficient weld nugget diameter. It may have evident influence on vehicle operation or even contribute to accidents on the road.

Mixtures of Lubricants and Ecological Refrigerants under Starved Lubrication Conditions.

The presented results show that the presence of refrigerant significantly deteriorates the lubricating properties of compressor oil under starved lubrication conditions (with a small amount of oil). The change can be 40-120% compared to the properties of the oil alone. Additionally, in the group of oils that are substitutes (operational alternatives) compatible with a given refrigerant, the effect of the refrigerant on the lubricating properties varies.

The Influence of Aminoalcohols on ZnO Films' Structure.

Preparing structures with the sol-gel method often requires control of the basal plane of crystallites, crystallite structures, or the appearance of the voids. One of the critical factors in the formation of a layer are additives, such as aminoalcohols, which increase the control of the sol formation reaction. Since aminoalcohols differ in boiling points and alkalinity, their selection may play a significant role in the dynamics of structure formation.