Medium density fiberboard (MDF) is an industrial product created from lignocellulosic fibers and resin through the combined action of pressure and heat. Have homogeneity, dimensional stability and mechanical strength similar to solid wood. Milling is a machining method widely used within furniture industries; and despite the noteworthy relevance of the subject, there are few specific works dealing with the MDF milling process using computerized numerical control machines. It is increasingly necessary a programmed machining able to generate suitable surface to coatings, allowing for minimum waste and maximum efficiency, besides the decrease of the tool wear. The irregular surface after machining reduces the quality of the final product; this characteristic is defined by measuring the roughness of MDF panel workpieces. Thus, it is possible to quantify the surface quality and improve the machining process with cutting speed, feed rate, depth cut among others. It was observed that roughness exhibited lower values in higher cutting speeds and low feed rates. The 1 mm depth of cut showed optimized surface results. It was concluded that the parameters studied here significantly influence the finishing, resulting in irregular surfaces that can reduce the quality of products.

The specific heat Cv of the ternary semiconducting compounds CuGaSe2, CuGaTe2, and CuInTe2 is determined experimentally in a temperature region within 2 and 30 K. From the results the Debye temperatures and standard entropies are calculated. By dividing Cv into a Debye and two Einstein contributions the approximate shape of the low frequency phonon modes is estimated.

The thermal expansion coefficients αa and αc of the lattice parameters a and c of CuInSe2 are measured in the temperature range from 30 to 300 K. Both αa and αc decrease with decreasing temperature below 300 K and become negative at about 60 and 80 K, respectively. The results are discussed in terms of the principal Grüneisen parameters of chalcopyrite structure crystals. It is concluded that there are low‐energy lattice vibrational modes with negative Grüneisen parameters in CuInSe2.

The thermal expansion coefficients αa and αc of the lattire parameters a and c of CuInTe2, are measured in the temperature range from 30 to 300 K using the X‐ray Bond metohod. Both αa and αc decrease with decreasing tcmperature and become negative at about 38 and 54 K, respectively. The results are discussed in terms of the principal Grüneisen parameters of chalcopyrite structure crystals. It is concluded that there are low‐energy lattice vibrational modes with negative Grüneisen parameters in CuInTe2. A comparison is mde with previous measurements for CuInTe2, and other Cu–III–VI2 compounds as well as with theoretical estimates.

Recently simple theoretical estimations of the bulk modules B of the A1B1IIClr-and AIIBIVCZ-compounds have been given by NEUMANN and OSHCHERIN, respectively.On the other hand bulk modules of the binary sphalerite compounds have been used for calculating the Debye characteristic temperatures 8B of these compounds (DEUS, SCHNEIDER). I n that paper the approximation. The constants a, and a2 depending on structure and type of substance have been choosen because of the similarity to the binary compoundsforthe ATIBIVCV 2-or AIBIIICVI 2 compounds as for the AIrlBV-or AIIBV1-compounds respectively. This means a, == 2.94 or 2.29 . 10-2 Ks kniol-l/Y and a2 = -35.5 or -9.3 K, respectively. The mass m must