density, viscosity and refractive index of pure, binary and ternary mixtures of diethanolamine (dea) and methyl diethanolamine (mdea) with water have been measured at different temperatures from 288.15 k to 323.15 k at atmospheric pressure. also, this study presents the effects of mixture composition and temperature upon these thermo- physical properties. to measure the density and refractive i...

Today, the relationship between health-related quality of life at school (general satisfaction, relationships with teachers, negative emotions), body mass index with stress is challenging issues in domain of health and psychology. This study aimed to determine the perceived stress and its relationship with body mass index, general satisfaction, relationship with teachers, negative emotions. Dur...

Conspecific negative density-dependent establishment, in which local abundance negatively affects establishment of conspecific seedlings through host-specific enemies, can influence species diversity of plant communities, but the generality of this process is not well understood. We tested the strength of density dependence using the United States Forest Service's Forest Inventory and Analysis ...

One main feature of metamaterials is the occurrence of a negative dynamic mass density that is produced when an inner local resonance is present. The inner resonance can be obtained in composite materials containing composite inclusions. For suitable ratios of the physical properties of the constituting materials, the composite inclusions act as spring-mass systems. The scaling of physical prop...

as a first step towards mechanization related to any product, including date fruit, it is necessary to have comprehensive information about the product. physical and mechanical properties are needed for the design of post harvest machinery and equipment. the objective of this study was to determine and compare some physical properties such as dimension, mass and volume, particulate density, pit...

the effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope ( 20%.) the results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slope...

We show that a large class of supersymmetric compactifications, including all simply connected Calabi-Yau and G2 manifolds, have classical configurations with negative energy density as seen from four dimensions. In fact, the energy density can be arbitrarily negative – it is unbounded from below. Nevertheless, positive energy theorems show that the total ADM energy remains positive. Physical c...