Experimental study on the reduction effect of pit texture on disassembly damage for interference fit

After remanufacturing disassembly, several kinds of friction damages can be found on the mating surface of interference fit. These damages should be repaired and the cost is closely related to the severity of damages. Inspired by the excellent performance of surface texture in wear reduction, 5 shapes of pit array textures are added to the specimens’ surface to study their reduction effect of disassembly damage for interference fit. The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows: equivalent circle diameter of single texture，texture shape and texture surface density. The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density. The circular texture with a surface density of 30% and a diameter of 100μm shows an excellent disassembly damage reduction effect. The load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments. The results show that the load-carrying capacity of the excellent texture surface is increased about 40% compared with that of without texture.

Study on the morphology of Mature ovarian follicles using Image Processing Toolbox

Objective: This study aims to investigate the morphological characteristics of mature follicles with clinical value. Study Design:a retrospective studyMethods: The five morphological indexes of follicles in 72 natural ovulation cycles were measured. The shoot time of follicle photos was the day before ovulation. Measurement software was the MATLAB Image Processing Toolbox. Results: The measured average area, perimeter, equivalent circle diameter and roundness were 301.29 ± 8.52 mm2, 62.23 ± 6.82 mm, 20.21 ± 3.08 mm and 0.89 ± 0.05, respectively; and the maximal diameter was 23.12 ± 3.06 mm. Conclusion: Image Processing Toolbox is a simple and convenient measurement software. The standardization of the reference indexes of follicular morphology has an important clinical application value in reproductive medicine.Research Highlights and Graphical Abstract: In the present study, the morphological characteristics of these folliclesinclude the area, perimeter, maximal diameter, equivalent circle diameter and roundness were preliminarily studied using the related measurement software.

Influences of Processing Factors on Pore Structure of Aluminum Foams

Orthogonal experiments were employed to confirm the interactive effect of the addition of magnesium powder, milling time of aluminum powder, oxidization time of TiH2 on the pore structure of Aluminum foam, which prepared by PCM method. The results show that the three factors arragned in important order as the follows: oxidization time, milling time, and the quantity of magnesium powder. The high quality aluminum foam samples, with average porosity of 84.2%, average equivalent circle diameter of 1.9 mm and average circularity of 0.754, was made on the condition of milling time as 85 minutes, oxidization time as 10 minutes and magnesium powder content as 0.5 wt%.

309 MORPHOMETRICAL ANALYSIS OF THE LAMA GLAMA SPERM HEAD

During the last decades, the interest in breeding South American Camelids has increased, not only as companion animals but also for their high- quality fiber. Although several studies have been carried out on artificial insemination in Lama glama, this technique has not been widely applied in reproductive programs, principally due to the difficulty in collecting raw semen from males and the lack of knowledge about freezing/thawing techniques and semen characteristics. The aim of the present study was to objectively characterize llama sperm morphometry by a computer-assisted system, thereby increasing the knowledge on male llama physiology, leading to further developement of reproductive biotechnologies such as artificial insemination. Five semen samples were obtained by electroejaculation from each of 8 males, 6- to 10-year-old llamas of proven fertility. Smears were prepared from each sample and stained with Tinción 15® (Biopur S.R.L., Rosario, Argentina) and observed at x 1000 magnification. Images of sperm heads were captured by a Leica DC180 camera (Leica Microsystems Co., Wetzlar, Germany), obtaining 200 images from each sample. Binary images were obtained and area, length, width, equivalent circle diameter, curve length, curve width, perimeter, convex perimeter, roundness, and elongation were measured using QWin Plus (Leica Microsystems Co.). A total of 8005 sperm heads were measured. Descriptive statistics of the complete population was performed, with the following results obtained (mean ± SD): area (μm2) 20.09 ± 0.6, length (μm) 6.6 ± 0.3, width (μm) 4.14 ± 0.1, equivalent diameter ((μm) 5.06 ± 0.1, curve length (μm) 5.8 ± 0.3, curve width (μm) 3.48 ± 0.3, perimeter (μm) 18.54 ± 0.1, convex perimeter (μm) 17.34 ± 0.3, roundness 1.28 ± 0.04, and elongation 1.6 ± 0.01. Coefficients of variation were between 0.47 and 8.72%. A design considering the male as a fixed factor and the ejaculate as a nested factor was used for the purpose of identifying differences in morphometry between ejaculates of the same male and/or between males. Normality was tested using the Kolmogorov test. Significant differences between ejaculates of some males were found for curve length, curve width, perimeter, roundness, and elongation (P < 0.05). There were no intra-male differences for sperm head area, length, width, equivalent circle diameter, and convex perimeter. Of the parameters, there were significant differences between males for sperm area, length, equivalent circle diameter, and convex perimeter (P < 0.05). The differences found in sperm morphometry confirm the great polymorphism observed when subjectively evaluating llama semen morphology and make the establishment of a single pattern of normal llama sperm morphometry impossible.

Naldrettite, Pd2Sb, a new intermetallic mineral from the Mesamax Northwest deposit, Ungava region, Québec, Canada

Naldrettite, Pd2Sb, is a new intermetallic mineral discovered in the Mesamax Northwest deposit, Cape Smith fold belt, Ungava region, northern Québec. It is associated with monoclinic pyrrhotite, pentlandite, chalcopyrite, galena, sphalerite, cobaltite, clinochlore, magnetite, sudburyite (PdSb), electrum and altaite. Other rarer associated minerals include a second new mineral (ungavaite, Pd4Sb3), sperrylite (PtAs2), michenerite (PdBiTe), petzite (Ag3AuTe4) and hessite (Ag2Te). Naldrettite occurs as anhedral grains, which are commonly attached or moulded to sulphide minerals, and also associated with clinochlore. Grains of naldrettite vary in size (equivalent circle diameter) from ~10 to 239 μm, with an average of 74.4 mm (n = 632). Cleavage was not observed and fracture is irregular. The mineral has a mean micro-indentation hardness of 393 kg/mm2. It is distinctly anisotropic, non-pleochroic, has weak bireflectance, and does not exhibit discernible internal reflections. Some grains display evidence of strain-induced polysynthetic twinning. Naldrettite appears bright creamy white in association with pentlandite, pyrrhotite, clinochlore and chalcopyrite. Reflectance values in air (and in oil) for R1 and R2 are: 49.0, 50.9 (35.9, 37.6) at 470 nm, 53.2, 55.1 (40.3, 42.1) at 546 nm, 55.4, 57.5 (42.5, 44.3) at 589 nm and 58.5, 60.1 (45.4, 47.2) at 650 nm. The average of 69 electron-microprobe analyses on 19 particles gives: Pd 63.49, Fe 0.11, Sb 35.75, As 0.31, and S 0.02, total 99.68 wt.%, corresponding to (Pd1.995Fe0.007)2.002(Sb0.982AS0.014S0.002)0.998. The mineral is orthorhombic, space group Cmc21, a 3.3906(1), b 17.5551(5), c 6.957(2) Å , V 414.097(3) Å3, Z = 8. Dcalc is 10.694(1) g/cm3. The six strongest lines in the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 2.2454(100)(132), 2.0567(52)(043), 2.0009(40)(152), 1.2842(42)(115), 1.2122(50)(204) and 0.8584(56)(1.17.4).