Introduction Gears are highly engineered machine elements that must be designed not only to meet the torque, speed, life and noise requirements under nominal conditions, but also to compensate for adverse effects due to manufacturing errors, variations and elastic deformations of the support structures. In addition to the elastic deformation of the support and structures, manufacturing errors i...

the research was conducted in order to determine the bending stress, young’s modulus, shearing stress, and shearing energy of safflower stalk as a function of moisture content and stalk region. the bending forces were measured at different moisture contents and the bending stress and the young’s modulus were calculated from these data. for measuring the shear forces, the stalk specimens were se...

Sixteen lipophilic N-(X)sulfonyl carbamoyl lariat ethers with polyether ring sizes of 12-crown-4, 14-crown-4, 15-crown-5, and 18-crown-6 are utilized for competitive alkali metal cation extractions from aqueous solutions into chloroform. Variation of the electron-withdrawing properties of X in the series of methyl, phenyl, 4-nitrophenyl, and trifluoromethyl allows the influence of the acidity o...

one of the most prominent industries is bending, while using rotary draw bending method is known to be the most conventional approach for thin wall tube bending. pressure die is one effective tool which boosts the tube during the process and eventually improves the bending quality. other effective parameters are mandrel and the amount of clearance between tube and mandrel. in the present study,...

BACKGROUND/AIM Few studies have assessed the incidence and risk factors to crown fractures in preschool children. The aim of this study was to estimate the incidence of crown fracture in the primary dentition over a 1-year follow-up period, identify risk factors, and test the hypothesis that children with previous crown fracture are more prone to experience further cases of crown fracture indep...

Abstract We report on the experimental studies of interaction electromagnetic radiation with borosilicate crown glass K108 in ultrawide frequency range from 0.002 to 1500 THz. Four different types spectrometers are used measure reflectivity and/or transmittance spectra. Spectral dependences complex dielectric permittivity, refractive index and extinction coefficient extracted measured The optic...

sheet metal components design and manufacture need a great deal of experience and know-how. strip layout design is usually done with trial and error until best design for strip layout is finally achieved. knowledge for the system is formulated from plasticity theories, experimental results, and the empirical knowledge of field experts. in this paper, an algorithm which can automatically design ...

Crown-ethers have recently been used to assemble porous liquids (PLs), which are liquids with permanent porosity formed by mixing bulky solvent molecules (e.g., 15-crown-5 ether) with solvent-inaccessible organic cages. PLs and crown-ethers belong to a novel class of materials, which can potentially be used for gas separation and storage, but their performance for this purpose needs to be asses...

To analyze the main variables affecting crown biomass, we measured crown biomass and a number of variables describing tree size, such as stem diameter at breast height (D), tree height (H), crown width (Cw) and crown length (Cl), from 754 sample trees of four pine species in China, specifically, Pinus massoniana, P. yunnanensis, P. tabulaeformis and P. elliottii. In addition, we developed indiv...

PURPOSE The purpose of this study was to analyze the retention force changes and wear behaviours of double-crown systems over long-term use. MATERIALS AND METHODS Ten groups, each consisting of six samples, were evaluated. Specifically, casting gold alloy primary crown - casting gold alloy secondary crown (AA), laser sintering primary crown - laser sintering secondary crown (LL), casting Cr a...