88 research outputs found

    Notched multiaxial fatigue of Al7050-T7451: on the need for an equivalent process zone size

    Get PDF
    The aim of this work is to investigate stress gradient effects on the fatigue life estimation of notched Al 7050-T7451 specimens under combined torsion and push-pull loading conditions. Initially, simple push-pull and torsion fatigue tests in plain and notched specimens were independently conducted not only to obtain the material properties necessary to calibrate a standard multiaxial critical plane based model, but also to raise the critical distance versus life curves in tension (L – Nf) and in torsion (L – Nf). This latter step also required a Finite Element Elastic Stress Analysis of the notched specimens tested in the medium high-cycle fatigue regime. Then, proportional multiaxial fatigue tests were carried out using this same notched geometry. The combination of a multiaxial model with the theory of critical distance (TCD) was applied to estimate fatigue lives. For this aluminium alloy, neither the use of the L – Nf nor L – Nf combined with the predictive multiaxial model was able to estimate lives in an accurate way

    Notched multiaxial fatigue of Al7050-T7451: on the need for an equivalent process zone size

    Get PDF
    The aim of this work is to investigate stress gradient effects on the fatigue life estimation of notched Al 7050-T7451 specimens under combined torsion and push-pull loading conditions. Initially, simple push-pull and torsion fatigue tests in plain and notched specimens were independently conducted not only to obtain the material properties necessary to calibrate a standard multiaxial critical plane based model, but also to raise the critical distance versus life curves in tension (L? – Nf) and in torsion (L? – Nf). This latter step also required a Finite Element Elastic Stress Analysis of the notched specimens tested in the medium high-cycle fatigue regime. Then, proportional multiaxial fatigue tests were carried out using this same notched geometry. The combination of a multiaxial model with the theory of critical distance (TCD) was applied to estimate fatigue lives. For this aluminium alloy, neither the use of the L? – Nf nor L? – Nf combined with the predictive multiaxial model was able to estimate lives in an accurate way

    "high Doses Of Riboflavin And The Elimination Of Dietary Red Meat Promote The Recovery Of Some Motor Functions In Parkinson's Disease Patients. C.g. Coimbra And V.b.c. Junqueira. Brazilian Journal Of Medical And Biological Research, 36: 1409-1417, 2003"

    Get PDF
    [No abstract available]37912971299Coimbra, C.G., Junqueira, V.B.C., High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients (2003) Brazilian Journal of Medical and Biological Research, 36, pp. 1409-1417Pare, S., Burr, S.I., Ross, S.E., Effect of day-time protein restriction on nutrient intakes of free-living Parkinson's disease patients (1992) American Journal of Clinical Nutrition, 55, pp. 701-707Simon, N., Gantcheva, R., Bruguerolle, B., Viallet, F., The effects of a normal protein diet on levodopa plasma kinetics in advanced Parkinson's disease (2004) Parkinsonism and Related Disorders, 10, pp. 137-142Fahn, S., Elton, R.L., Unified Parkinson's Disease Rating Scale (1987) Recent Developments in Parkinson's Disease, 2, pp. 153-164. , Members of the UPDRS Development Committee Fahn S, Marsden CD, Calne DB & Goldstein M (Editors), MacMillan Health Care Information, Florham Park, NJ, USABaldereschi, M., DiCarlo, A., Vanni, P., Ghetti, A., Carbonin, P., Amaducci, L., Inzitani, D., Italian longitudinal study on aging working group. Lifestyle related risk factors for Parkinson's disease: A populational study (2003) Acta Neurologica Scandinavica, 108, pp. 239-244Tsai, C.H., Lo, S.K., See, L.C., Chen, H.Z., Chen, R.S., Weng, Y.H., Chang, F.C., Lu, C.S., Environmental risk factors of young onset Parkinson's disease (2002) Clinical Neurology and Neurosurgery, 104, pp. 328-333Tanner, C.M., Epidemiological clues to the cause of Parkinson's disease (1994) Movement Disorders 3, pp. 124-146. , Marsden CD & Fahn S (Editors) Butterworth-Heinemann, Oxford, UKGolbe, L.I., Farrel, T.M., Davis, P.H., Case-control study of early life dietary factors in Parkinson's disease (1988) Archives of Neurology, 45, pp. 350-353Abbot, R.D., Ross, G.W., White, C.R., Sanderson, W.T., Burchfiel, C.M., Kashon, M., Sharp, D.S., Petrovitch, H., Environment, lifestyle, and physical precursors of clinical Parkinson's disease: Recent findings from the Honolulu-Asia aging study (2003) Journal of Neurology, 250 (SUPPL. 3), pp. III30-III3

    Controlled deterioration test and use of the Seed Vigor Imaging System (SVIS ® ) to evaluate the physiological potential of crambe seeds

    Full text link
    Vigor tests are important tools for verifying the physiological potential of seed lots; however, various aspects can interfere in the consistency of the test results. The search for less subjective procedures has drawn the interest of researchers. The aim of this study was to adapt the methodology of the controlled deterioration test and verify the efficiency of the Seed Vigor Imaging System (SVIS®) to evaluate the vigor of crambe seeds. Initially, seed moisture content was determined and germination and vigor were evaluated in five seed lots. For the controlled deterioration test, the seed moisture content was adjusted to 18%, 20%, and 22%, and the results were interpreted at four and five days after sowing. The controlled deterioration test should be performed with initial adjustment of seed moisture content to 18%, and the germination test should be evaluated on the fifth day after sowing. SVIS® provided information on the vigor index and the length and uniformity of seedling development. Computerized image analysis is effective in evaluating the vigor of crambe seeds, and the uniformity of seedling development parameter offers the most consistent data

    Use of Curcuma longa in cosmetics: extraction of curcuminoid pigments, development of formulations, and in vitro skin permeation studies

    Get PDF
    Curcuma longais a ginger family aromatic herb (Zingiberaceae) whose rhizomes contain curcuminoid pigments, including curcumin, a compound known for its anti-inflammatory effects. The objective of this study was to obtain curcuminoid-rich extracts, develop topical formulations thereof, and assess the stability and skin permeation of these formulations. Curcuma longa extracts were obtained and used to develop formulations. Skin permeation studies were conducted in a modified Franz diffusion cell system, and skin retention of curcuminoid pigments was quantified in pig ear membrane. Prepared urea-containing gel-cream formulations were unstable, whereas all others had satisfactory stability and pseudoplastic rheological behavior. The amount of curcuminoid pigments recovered from the receptor solution was negligible. The skin concentration of curcuminoid pigments retained was positive (>20 µg/g of skin, mostly in the stratum corneum), considering the low skin permeability of curcumin. We conclude that development of topical formulations containing curcumin or Curcuma longaextract is feasible, as long as adjuvants are added to improve preservation and durability. The formulations developed in this study enabled penetration of curcumin limited to the superficial layers of the skin and then possibly without a risk of systemic action, thus permitting local use as a topical anti-inflammatory
    corecore