Residual Stresses in Machining of AISI 52100 Steel under Dry and Cryogenic Conditions: A Brief Summary

17th Conference on Material Forming (ESAFORM) - FinlandResidual stress is one of the most important surface integrity parameter that can significantly affect the service performance of a mechanical component, such as: contact fatigue, corrosion resistance and part distortion. For this reason the mechanical state of both the machined surface and subsurface needs to be investigated. Residual stress induced by dry and cryogenic machining of hardened AISI 52100 steel was determined by using the X-ray diffraction technique. The objective was to evaluate the influence of the tool cutting edge geometry, workpiece hardness, cutting speed, microstructural changes and cooling conditions on the distribution of the residual stresses in the machined surface layers. The results are analysed in function of the thermal and mechanical phenomena generated during machining and their consequences on the white layer formation

Resistance to frost and tuber soft rot in near-pentaploid Solanum tuberosum - S. commersonii hybrids

The objectives of the present study were to evaluate the tolerance to low temperatures and tuber soft rot in sexual near-pentaploid hybrids between incongruent 2x (1EBN) Solanum commersonii (CMM) and 4x (4EBN) S. tuberosum (TBR). For freezing resistance, killing temperatures both under non-acclimated and un- der acclimated conditions were determined using the ion leakage procedure. Values for the hybrids were dis- tributed between the wild and cultivated parental values. Some hybrids displayed an acclimation capacity close to 2.5°C, typical of hardy species. Artificial inoculation of tubers with Pectobacterium carotovorum ssp. carotovorum (formerly Erwinia carotovora ssp. carotovora) provided evidence of variability in disease response. Highly resistant hybrids were identified. After conventional phenotypic selection, wild genome content was estimated based on the presence of CMM-specific AFLP fragments. Seven primer combinations were used (Eco-AGG/Mse-CAA; Eco-ACC/Mse-CAT; Eco-ACT/Mse-CAC; Eco-ACT/Mse-CAG; Eco- ACT/Mse-CAA; Eco-ACT/Mse-CAT; Eco-AGG/Mse-CAG). The percentages of CMM-specific AFLPs ranged from 4.3% to 56.7%, with an average value of 28.1%. AFLP analysis was employed for the selection of the hybrids to be used for further breeding objectives

Interspecific somatic hybrids between Solanum bulbocastanum and S. tuberosum and their haploidization for potato breeding.

Protoplast fusion between incongruent Solanum bulbocastanum and S. tuberosum haploids was accomplished to produce hybrids combining elite traits from both parents. We identified 11 somatic hybrids out of 42 regenerants analyzed through ISSR markers. Some hybrids had loss or gain of fragments compared to the parents, likely due to rearrangements and deletions of chromosome segments after fusion, and/or to somaclonal variation during hybrid regeneration. Increased heterotic vigor for some traits as well as high diversity was observed as the effect of both ploidy and fusion combination. Microsporogenesis analysis indicated the occurrence of multivalent configurations and several meiotic abnormalities, such as chromosomes bridges and various spindle orientations. Since all hybrids were sterile, in vitro anther culture was employed for haploidization as a possible strategy to overcome barriers to hybridizations. Haploids were obtained from all the tetraploid S. bulbocastanum (+) S. tuberosum somatic hybrids tested, although with differences in both the number of embryos per 100 anthers cultured and the number of differentiated green plantlets. This is the first report on the successful production of haploid plants from S. bulbocastanum (+) S. tuberosum hybrids

Lean body weight-tailored Iodinated contrast Injection in obese patient. boer versus James Formula

Purpose. To prospectively compare the performance of James and Boer formula in contrast media (CM) administration, in terms of image quality and parenchymal enhancement in obese patients undergoing CT of the abdomen. Materials and Methods. Fifty-five patients with a body mass index (BMI) greater than 35 kg/m2were prospectively included in the study. All patients underwent 64-row CT examination and were randomly divided in two groups: 26 patients in Group A and 29 patients in Group B. The amount of injected CM was computed according to the patient's lean body weight (LBW), estimated using either Boer formula (Group A) or James formula (Group B). Patient's characteristics, CM volume, contrast-to-noise ratio (CNR) of liver, aorta and portal vein, and liver contrast enhancement index (CEI) were compared between the two groups. For subjective image analysis readers were asked to rate the enhancement of liver, kidneys, and pancreas based on a 5-point Likert scale. Results. Liver CNR, aortic CNR, and portal vein CNR showed no significant difference between Group A and Group B (all P ≥ 0.177). Group A provided significantly higher CEI compared to Group B (P = 0.007). Group A and Group B returned comparable overall subjective enhancement values (3.54 and vs 3.20, all P ≥ 0.199). Conclusions. Boer formula should be the method of choice for LBW estimation in obese patients, leading to an accurate CM amount calculation and an optimal liver contrast enhancement in CT

Effect of mulching and plant density on out of season organic potato growth, yield and quality.

Research was carried out on potato (Solanum tuberosum L., cv. Spunta) growing in the fi eld in the Campania region (southern Italy) in 2007 and 2008, adopting organic farming practices, in order to evaluate the effects of two mulching treatments (black biodegradable fi lm and bare soil) and six plant densities (12.5, 10.0, 8.3, 7.1, 6.2 and, as a control, 5.3 plants per m2) on growth, yield and quality of “new potato” winter-spring and summer-autumn crops. Only in the case of the summer-autumn crop cycle, mulching resulted in a higher yield, plant dry matter and leaf area compared with the bare soil control, while in both crop cycles this latter treatment induced a delay in harvest. The winter-spring cycle gave a higher production of 40-70 mm tubers, while the summer-autumn cycle resulted in a higher vitamin C content. For the winter-spring crop cycle, the plant density of 8.3 plants·m-2 resulted in the highest yield for food-use tubers, whereas the highest production of seed tubers was obtained with a density of 12.5 plants·m-2. The plant density of 8.3 plants·m-2 also resulted in the highest plant dry matter and leaf area. For the summer-autumn crop cycle, the 10 plants·m-2 density gave the highest production of 40-70 mm calibre tubers, as well as the highest plant dry matter and leaf area. In this cycle, the 6.3 plants·m-2 density resulted in the highest production of 70-80 mm calibre tubers. In terms of cost effectiveness, the choice of biodegradable mulching could save the expense of manual weed control and, in the case of the summer-autumn crop cycle, it is also associated with a higher yield. Overall, tuber yield increased with plant density but the fi nal production was also affected by the crop cycle. This may depend on the different environmental conditions and duration which characterized each cultural cycle and, therefore, affected the vegetative development of organic new potatoes

TUMOUR CASE IN KOI CARP (Cyprinus carpio)

A case study of tumour in koi carp (Cyprinus carpio) was observed in rearing periode. This tumour occurs solitary, large, pale red, fleshy masses under the lips and dental plates on the outside, and by reason of its size, may prevent closure the mouth. Moreover, this tumour goes through into the inside of the mouth. At necropsy, there were two soft, firm, small mass at inside of the mouth and the bigger mass at outside the mouth. Samples of this tumour were fixed in 10% formalin were used for histology analysis. The clinical course of the tumour is one of relatively slow but progressive growth. The proliferative stage of the neoplastic process is preceded and accompanied by a striking vascular reaction. Intensed hyperemia invariably occurs in that region of the mucosal surface which later becomes the site of neoplastic proliferation. Neoplastic cells lied around lamina propria and submucosal. These cells were joined together to make vacuolization and the other cells become pleiomorphism with hyperchromatic nucleus and N/C ratio cells are 1:1. In some area, there were many empty holes, around the holes there were debris cells, inflammation cells, and erythrocytes

Stochastic changes affect Solanum wild species following autopolyploidization

Polyploidy is very common within angiosperms, and several studies are in progress to ascertain the effects of early polyploidization at the molecular, physiological, and phenotypic level. Extensive studies are available only in synthetic allopolyploids. By contrast, less is known about the consequences of autopolyploidization. The current study aimed to assess the occurrence and extent of genetic, epigenetic, and anatomical changes occurring after oryzaline-induced polyploidization of Solanum commersonii Dunal and Solanum bulbocastanum Dunal, two diploid (2n=2×=24) potato species widely used in breeding programmes. Microsatellite analysis showed no polymorphisms between synthetic tetraploids and diploid progenitors. By contrast, analysis of DNA methylation levels indicated that subtle alterations at CG and CHG sites were present in tetraploids of both species. However, no change occurred concurrently in all tetraploids analysed with respect to their diploid parent, revealing a stochastic trend in the changes observed. The morpho-anatomical consequences of polyploidization were studied in leaf main veins and stomata. With only a few exceptions, analyses showed no clear superiority of tetraploids in terms of leaf thickness and area, vessel number, lumen size and vessel wall thickness, stomata pore length and width, guard cell width, and stomatal density com- pared with their diploid progenitors. These results are consistent with the hypothesis that there are no traits system- atically associated with autopolyploidy