Assessment of the Possibility of Using Fractal Analysis to Describe the Surface Aluminum Composites After Turning

The description of the characteristics of the surface using standardized roughness parameters can not fully predict its performance properties. One of the tools supporting the assessment of the surface layer of the treated surface may be fractal analysis. This applies both to surfaces with machining traces, which are created under conditions of high randomness and variability of process conditions, and to surfaces with directional traces and their distinct periodicity. The paper presents the results of surface roughness measurements of turned aluminium matrix composites reinforced with ceramic fibers. Carbide and diamond tools were used for turning the tested material. The trials were carried out under dry machining conditions and with minimal lubrication in the cutting zone. Surfaces were measured by the contact method, and surface roughness parameters were calculated by Gaussian filtration. Then, the values of the fractal dimension were calculated using the enclosing box method. On the basis of these calculations, the influence of machining conditions on the values of selected roughness parameters and the box fractal dimension was determined. It was found that the fractal dimension, i.e. the irregularity of the geometric structure of the surface after turning of composites, changes with the change of cutting parameters, the tool and the method of lubricating the cutting zone. Of these factors, the feed has the greatest influence. As it grows, the irregularity of the machined surface structure decreases. In addition, the correlation coefficients between the fractal dimension and the measured roughness parameters were determined. It was noticed that the fractal dimension, in the case of turning aluminum composites, best correlates with the roughness parameters Sa and Ssk and thus describes features similar to these parameters. Therefore, it was assumed that it is possible to use fractal analysis as a supplementary tool for the description of the surface condition of aluminum composites after turning in various machining conditions. On the other hand, the fractal dimension can be treated as an additional tool to describe the surface condition, especially its irregularity, which is not described by other standard roughness parameters

Consequences du traitement des neoplasies intraepitheliales cervicales par laser CO2 sur l'integrite anatomique et fonctionnelle du col uterin. [Consequences of laser CO2 treatment of cervical intraepithelial neoplasias on the anatomic and functional integrity of the cervix]

OBJECTIVES. Retrospective study to analyse objectively the effectiveness and anatomic and functional consequences for the cervix of conservative CO2 laser treatment for cervical intraepithelial neoplasia. PATIENTS AND METHODS. Analysis of therapeutic effectiveness and anatomic consequences of 1,114 treated patients followed at our colpolaparotomy surgery clinic for cervical dysplasia since 1987. Evaluation of function consequences by comparison with a group of patients who delivered after laser CO2 therapy for dysplasia (n = 56) and a group of control patients (n = 95) with a similar type of dysplasia after delivery and no treatment. The clinical course of the pregnancy and delivery were compared between the groups in search for risk of prematurity. RESULTS. Good preservation of cervical anatomy was achieved after a rigorous treatment protocol only applicable with CO2 laser. The preservation of the junctional zone facilitated diagnosis of recurrence. The risk of prematurity was low. Therapy was successful in 93.4% of the cases. CONCLUSION. The choice of conservative therapy is essential, not only when the patient desires a pregnancy but also in others since preserved anatomy facilitates diagnosis of recurrence. This findings implicate the need for an unagressive energy source and also accepting the early diagnosis and treatment

Efekt działania produktów ropopochodnych na chrząszcza Harpalus rufipes

The effects of soil contamination of petroleum products: unleaded petrol, diesel oil and used engine oil on ground beetle Harpalus rufipes De Geer were investigated. We measured development parameters (the survival and growth rate) and biochemical defense system parameters (the activity of the cytosolic fraction enzymes: superoxide dismutase, catalase, glutathione transferase, heat shock proteins HSP70, carboxyloesterase and acetylcholinesterase and microsomal fraction enzymes: cytochrome c (P450) reductase and ethoxyresorufin-O-deethylase) in the ground beetle H. rufipes. Animals were reared on contaminated soil (6 g of each petroleum product per kg of dry soil weight) through four week. There was no difference in growth rate among animals from different experimental groups. The negative impact was revealed on survival rate of the ground beetles exposed to diesel oil (ca 30 % lower) at the end of the rearing in comparison with animals from control group. In turn, for animals exposed to other petroleum products, the inhibition of some examined enzymes was measured. The effects of each petroleum product were specific. The animals kept through four weeks on soil contaminated with diesel oil had only higher glutathione transferase activity than control ones. The decrease of catalase activity, HSP70 protein in animals exposed to used engine oil and the decrease of acetylcholinesterase, glutathione transferase activity in animals exposed to unleaded petrol were noted.W badaniach porównywano wpływ produktów naftowych (benzyna bezołowiowa, olej napędowy i zużyty olej silnikowy) na chrząszcza Harpalus rufipes De Geer. Mierzono parametry: rozwojowe (przeżywalność i tempo wzrostu) i parametry biochemiczne związane z funkcjonowaniem systemu obronnego (aktywność enzymów frakcji cytozolowej: dysmutazy ponadtlenkowej, katalazy, transferazy glutationowej, białek szoku cieplnego HSP70, karboksylśsterazy i acetylocholin esterazy oraz aktywność enzymów frakcji mikrosomalnej: reduktazy cytochromu c (P450) i deetylazy etoksy-rezorufiny) w ciele chrząszczy. Do badań wykorzystano zwierzęta hodowane na glebie skażonej dawką 6 g każdego produktu ropopochodnego na kg suchej masy gleby przez okres czterech tygodni. Nie wykazano istotnych zmian w tempie wzrostu między zwierzętami z różnych grup eksperymentalnych. Ujawniono negatywny wpływ na przeżywalność chrząszczy eksponowanych na olej napędowy (ok. 30 %) pod koniec okresu doświadczalnego, w porównaniu ze zwierzętami z grupy kontrolnej. Z kolei u zwierząt eksponowanych na pozostałe produkty ropopochodne stwierdzono zahamowanie aktywności niektórych badanych enzymów. Efekty działania produktów ropopochodnych były specyficzne. Zwierzęta przetrzymywane na glebie skażonej olejem napędowym cechowała wyższa aktywność transferazy glutationowej w porównaniu do kontroli. Obniżenie aktywności katalazy i poziomu białek szoku cieplnego HSP70 zarejestrowano u zwierząt poddanych działaniu zużytego oleju silnikowego, natomiast obniżenie aktywności acetylocholinesterazy i transferazy glutationowej stwierdzono u zwierząt eksponowanych na działanie zanieczyszczeń benzyny bezołowiowej