bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behaviour of fatigue cracks emanating from circular notches in Ti‐6Al‐4V under bending
Authors: BENEDETTI M. , BERTINI L. , FONTANARI V. 
Published: January 2004

ABSTRACTThis paper is aimed at evaluating the behaviour of small cracks emanating from notches in the Ti‐6Al‐4V alloy. Pulsating four point bending tests were performed at a nominal stress ratio of 0.1 and a frequency of 15 Hz on prismatic specimens with a central hole. The conditions of initiation and early propagation of fatigue cracks were investigated at two relatively high nominal stress levels corresponding to 56.6 and 100% of the 0.2% yield stress of the material. Microstructural effects were discussed. To this purpose a specific device based on the ‘in situ’ detection of cracks by photomicroscopy was developed. Corresponding results were analysed quantitatively considering the effect of the yielded region at the notch tip by elastic–plastic finite element modelling. Furthermore, information regarding the sites of fatigue crack initiation and propagation path were discussed on the basis of careful fractographic analysis of the specimens. The importance of the two phase α, β microstructure on the material damage was highlighted and correlated to the observed oscillations in the crack growth rate. Mechanically and microstructurally long cracks were correlated by linear‐elastic fracture mechanics.
A notch stress intensity approach to assess the multiaxial fatigue strength of welded tube‐to‐flange joints subjected to combined loadings
Authors: LAZZARIN P. , SONSINO C. M. , ZAMBARDI R. 
Published: January 2004

ABSTRACTFull penetration T butt weld joints between a tube and its flange are considered, subjected to pure bending, pure torsion and a combination of these loading modes. The model treats the weld toe like a sharp V‐notch, in which mode I and mode III stress distributions are combined to give an equivalent notch stress intensity factor (N‐SIF) and assess the high cycle fatigue strength of the welded joints. The N‐SIF‐based approach is then extended to low/medium cycle fatigue, considering fatigue curves for pure bending and pure torsion having the same slope or, alternatively, different slopes. The expression for the equivalent N‐SIF is justified on the basis of the variation of the deviatoric strain energy in a small volume of material surrounding the weld toe. The energy is averaged in a critical volume of radius RC and given in closed form as a function of the mode I and mode III N‐SIFs. The value of RC is explicitly referred to high cycle fatigue conditions, the material being modelled as isotropic and linear elastic. RC is thought of as a material property, independent in principle of the nominal load ratio. To validate the proposal, several experimental data taken from the literature are re‐analysed. Such data were obtained by testing under pure bending, pure torsion and combined bending and torsion, welded joints made of fine‐grained Fe E 460 steel and of age‐hardened AlSi1MgMn aluminium alloy. Under high cycle fatigue conditions the critical radius RC was found to be close to 0.40 mm for welded joints made of Fe E 460 steel and close to 0.10 mm for those made of AlSi1MgMn alloy. Under low/medium cycle fatigue, the expression for energy has been modified by using directly the experimental slopes of the pure bending and pure torsion fatigue curves.
Statistical approach to roughness‐induced shielding effects
Authors: POKLUDA J. , ŠANDERA P. , HORNÍKOVÁ J. 
Published: January 2004

ABSTRACTA new theoretical concept is introduced to describe the roughness‐induced shielding effects in metallic materials. This approach is based on the statistics of the local ratio between the characteristic microstuctural distance and the plastic zone size. A general equation involving both the crack branching and the crack closure phenomena is derived in the frame of linear elastic fracture mechanics under the assumption of remote mode I loading. It enables the determination of the intrinsic values of both the fracture toughness and the fatigue crack growth threshold. Moreover, the roughness‐induced component can be separated from other closure components, such as the plasticity or oxide‐induced closure. In order to estimate the total roughness‐induced shielding effect only standard materials data such as the yield stress, the mean grain size, the surface roughness and the fracture mode are necessary. Examples of applications concerning static fracture and fatigue are presented for selected metallic materials.
Gigacycle fatigue properties of 1800 MPa class spring steels
Authors: ABE T. , FURUYA Y. , MATSUOKA S. 
Published: January 2004

ABSTRACTFatigue tests up to 108 cycles were carried out for two spring steels (Heats A and D1) and one valve spring steel (Heat F) with tensile strength, σB, of 1720, 1725 and 1764 MPa, respectively. The size and composition of inclusions in Heats Dl and F were controlled. The surface‐type fracture occurred at shorter lives below 106 cycles, while the fish‐eye‐type fracture occurred at longer lives. The fatigue limit, σW, at 108 cycles was 640 MPa for Heats A and D1 and 700 MPa for Heat F. Al2O3 inclusions for Heat A and both TiN inclusions and matrix cracks, i.e. internal facets, for Heat F were observed at the fish‐eye‐type fracture sites, while only matrix cracks were observed for Heat Dl. ODA, i.e. optically dark area, which is considered to be related to hydrogen effects, were formed around Al2O3 and TiN inclusions. Fatigue tests were also conducted after specimens were heated up to 573 K in high vacuum of 2 × 10–6 Pa. The heat treatment eliminated matrix cracks for Heat D1 and the fatigue limit at 108 cycles recovered to the estimated value of 920 MPa from the equation σw= 0.53 σB for the surface fracture. These results suggest that inclusions control and hydrogen influence the gigacycle fatigue properties for these high strength steels. In addition, it is expected that the creation of a martensite structure with a high resistance to hydrogen effects in the inclusion‐controlled steel could achieve the higher fatigue limit estimated for the surface‐type fracture.
Policy Reform and Foreign Direct Investment in Africa: Absolute Progress but Relative Decline
Authors: Asiedu Elizabeth 
Published: January 2004

AbstractDespite improvements in the policy environment, sub‐Saharan Africa's share of foreign direct investment (FDI) in developing countries continues to decline. This article provides an explanation for the deterioration in SSA's FDI global position. It argues that, although SSA has reformed its institutions, improved its infrastructure and liberalised its FDI regulatory framework, the degree of reform has been mediocre compared with the reform implemented in other developing countries. As a consequence, relative to other regions, SSA has become less attractive for FDI. An important implication of these results is that in a competitive global economy, it is not enough just to improve one's policy environment: improvements need to be made both in absolute and relative terms.
Tanzania's Cotton Sector: Reforms, Constraints and Challenges
Authors: Baffes John 
Published: January 2004

AbstractThis article contributes to the liberalisation debate in Africa by assessing the policy reforms in the Tanzanian cotton sector, the outcome of which has been mixed. The grower's share in the fob price has increased; the growers receive payments promptly; the ginning capacity has increased considerably. However, supply response did not take place; the input distribution system collapsed, while the mixing of cotton varieties constitutes a threat to the viability of the sector. The co‐operative unions figure prominently in the sector, although for all practical purposes they are bankrupt enterprises. Taxation is excessive, the tax code is complicated and tax evasion is pervasive. The cotton board and the ministries still overregulate the sector. The quality of statistics remains poor.
Social Sector Priorities: An Analysis of Budgets and Expenditures in India in the 1990s
Authors: Mooij Jos , Dev S. Mahendra 
Published: January 2004

AbstractMany policies in India, including economic reform policies, are officially intended to alleviate poverty. But how committed is the Indian government? And to what? This article addresses India's social spending priorities over the past decade. Looking at the rhetoric in budget speeches, actual expenditure patterns and the process by which budgets are formulated, it finds a widened concept of poverty and a shift away from income and employment programmes to human development. The budget‐making process is not very participatory, and the role of the Finance Ministry has increased. Although the widening of the concept of poverty has positive aspects, within the overall context of structural adjustment it has facilitated the politically convenient neglect of other dimensions (income and employment).
Swedish pre‐school children's UVR exposure – a comparison between two outdoor environments
Authors: Boldeman C. , Dal H. , Wester U. 
Published: January 2004

Background: Overexposure to ultraviolet radiation (UVR) in childhood is a major risk factor for skin cancer. Shady environments are recommended as one method of protection.Methods: Environmental exposure to UVR and environmental protection were assessed by dosimeter measurements on 64 children aged 1–6 years at two geographically close and topographically similar pre‐schools outside Stockholm. Outdoor play constructions of site 1 (34 children) were mainly exposed to the sun, and those of site 2 (30 children) were mainly shaded. Dosimetry was carried out during 11 work days in May–June 2002 under clear weather conditions. The reliability of dosimeters was tested with meteorologically modelled data from SMHI, and with stationary dosimeters exposed to free sky, and compared with other UV instruments. The differences between children's outdoor stays were adjusted for.Results: The children's average daily exposures were approximately 200 JCIE/m2 erythemally effective UVR. The average relative UVR exposure (% total available UVR 08:30–18:30) was 6.4% (7.0% at site 1, 5.7% at site 2). Fractions of available UVR during outdoor stay were 14.4% (both sites), 15.3% (site 1), and 13.3% (site 2). In terms of relative differences, 5–6‐year‐old children at site 2 were exposed to 41% less UVR, and 1–4‐year‐old children 6% less than those at site 1.Conclusion: The difference can be explained by the children's outdoor pre‐school environments, and the behaviors linked to these environments. It is recommended to consider the attractiveness of shady environments in the design of children's pre‐school playgrounds, particularly if these are extremely exposed to the sun.
Inter‐relation between variables determining constitutional UV sensitivity in Caucasian children
Authors: Uter W. , Pfahlberg A. , Kalina B. , Kölmel K. F. , Gefeller O. 
Published: January 2004

Background/Purpose: Sensitivity to ultraviolet (UV) light is associated with phenotypic variables like iris or hair colour or freckling, which are all strongly inter‐related. We assessed the pattern of association among these factors to construct a summary measure reflecting constitutional UV sensitivity in a simple one‐dimensional score with sufficient discriminating power.Methods: Information on iris and hair colour (3 and 4 categories, respectively), freckling (none vs. any) and the reaction to mid‐day summer sunlight as an outcome (dichotomized into ‘burn’ and ‘tan’) was collected in a cross‐sectional study among children at school enrolment in 1999 and 2000 in Göttingen, Germany (n=3765 with complete data). Chi‐squared automatic interaction detector (CHAID) analysis and log‐linear modelling was used to assess the pattern of mutual inter‐relations.Results: Hair colour turned out to be the factor most strongly associated with UV sensitivity. In case of blonde or brown hair (the most common phenotypes in our sample), the consideration of freckling further refined the classification system, whereas iris colour did not contribute additional information. The results of the CHAID and log‐linear analyses suggest a simple five‐point score capturing constitutional UV sensitivity. The discriminating power of this score was high in our sample, with the proportion of persons who burned ranging from 7.7 (lowest category) to 73% (highest category).Conclusion: The new scoring system summarized efficiently relevant information on individual constitutional UV sensitivity in our sample. Its further validation in independent studies comprising Caucasian children or adults is necessary to assess objectively its properties for future applications.
Photodynamic therapy with chlorin e6 for skin metastases of melanoma
Authors: Sheleg Sergey V. , Zhavrid Edvard A. , Khodina Tatsiana V. , Kochubeev Georgy A. , Istomin Yury P. , Chalov Vadim N. , Zhuravkin Ivan N. 
Published: January 2004

Background: Photodynamic therapy (PDT) has been successfully applied in clinical settings to destroy neoplasms, but the efficacy of such a treatment is dependent on the type of neoplasm and the photosynthesizer used. Here, we perform a clinical assessment of PDT for skin metastases of pigmented melanoma using chlorin e6.Study design/Materials and methods: PDT with chlorin e6 photosensitizer was administered to 14 patients with skin metastases from melanoma (10 females, four males, mean age 49.6 years). Chlorin e6 at a dose of 5 mg/kg of patient's weight was intravenously injected. The treatment course consisted of two courses of PDT exposure 1 h after intravenous chlorin e6 injection and 24 h post‐injection. The light energy density for each skin tumor was 80–120 J/cm2 per treatment, with a light power density of 250–300 mW/cm2.Results: All skin melanoma metastases that received PDT showed complete regression with no recurrence during the study period. The complete response of all skin metastases from melanoma occurred in eight cases after one PDT treatment. In the remaining six individuals, tumors required multiple PDT courses prior to complete regression. No cases of photodermatitis were registered. The Karnofsky performance scale score of the patients with skin metastases from melanoma showed no significant difference before and after PDT. No patients had significant changes in blood cell counts that would indicate chlorin e6 systemic toxic effect. Blood chemistry and urinalysis did not show any evidence of chlorin e6 renal and hepatic injury.Conclusions: PDT with chlorin e6 for skin metastases from melanoma is effective and well tolerated. Further clinical investigation of PDT with chlorin e6 is warranted.
Effects of repeated sunbed exposures on the human skin. In vivo measurements with confocal microscopy
Authors: Gambichler T. , Sauermann K. , Altintas M. A. , Paech V. , Kreuter A. , Altmeyer P. , Hoffmann K. 
Published: January 2004

Backgound: Ultraviolet (UV) lamps used in commercial sunbeds are usually defined as UVA sources. Although it is well accepted that sunbed exposure significantly increases melanin pigmentation, its capacity to induce epidermal thickening is discussed controversially.Objectives: The aim of this study was to assess non‐invasively the effects of repeated sunbed exposures on epidermal thickness, cell size, and pigmentation by means of confocal laser‐scanning microscopy (CLSM) in vivo.Methods: Eight volunteers had sunbed exposures six times in a 3‐week period (cumulative dose: 126 J/cm2 UVA). During irradiation, a small site (2 cm×2 cm) on the lateral aspect of the inner forearm was covered with a UV‐opaque sheet (non‐exposed site). CLSM was performed with the Vivascope (Lucid, Henrietta, NY, USA) 24 h after the last UVA exposure on non‐exposed sites and UVA‐exposed sites that were on the medial aspect of the inner forearm at a distance of 2 cm to the non‐exposed measurement site. The following parameters were assessed: thickness of the horny layer (DSC), minimal thickness of the epidermis (Emin), minimal thickness of the viable epidermis (VEmin), cell size of the granular layer (Agran), and the epidermal melanin content (MI). Additionally, colorimetric measurements have been carried out on non‐exposed and UVA‐exposed sites.Results: DSC of the UVA‐exposed skin was significantly higher than the one of non‐exposed sites (mean±SD: 15±2.9 μm vs. 12.8±3 μm). Although Emin was significantly higher in UVA‐exposed sites (mean±SD: 40.4±3.6 μm vs. 39±2.9 μm), a slight but not statistically significant (P>0.05) decrease of VEmin was observed (25.5±2.1 μm vs. 26.2±2.4 μm). The median of cell size of the granular layer (Agran) significantly (P=0.008) differed between non‐exposed (752.1 μm2) and UVA‐exposed sites (600 μm2). MI was significantly (P=0.014) higher for the UVA‐exposed skin (1.12 vs. 1.34). Accordingly, colorimetry revealed significantly (P< 0.01) lower skin brightness for UVA‐exposed sites (L*=60.2±4.3) as compared with non‐exposed sites (L*=63.4±3.9).Conclusions: Sunbed exposures seem to induce photoadaption not only by skin pigmentation but also by epidermal thickening that is predominantly due to an increase in thickness of the horny layer. Moreover, our data indicate that UVA radiation has an influence on the cell size of the granular layer. CLSM is a promising tool for photobiological studies in vivo.
SEMIOTICS OF BEHAVIOR IN EARLY MODERN DIPLOMACY: POLISH EMBASSIES IN ISTANBUL AND BAHÇESARAY
Authors: Kołodziejczyk Dariusz 
Published: January 2004

AbstractCeremonial has always played a great role among European and Middle Eastern societies, reflecting the value systems cherished by their elites. Embassy instructions and envoys' reports provide valuable material concerning codes of behavior in early modern diplomacy. What was considered "proper," and how was an envoy expected to behave in order to stress his sovereign's dignity and power? Oriental courts in Istanbul and Bahçesaray developed elaborate ceremonials for foreign envoys. Forced into a deep prostration before the Muslim ruler, sometimes even threatened with physical violence, Polish envoys deeply resented their humiliation. Some of them sought comfort in alcohol, others produced fabulous reports of their imaginary altercations with Ottoman and Crimean dignitaries, and others found pleasure and revenge in contemptuous descriptions of their hosts' "barbarous" habits. Until recently, such diplomatic reports have been used in Polish historiography almost uncritically. Yet such reports often tell us more about their authors' mentalities than about the world they pretend to describe.
MIGRATION AND RELIGIOUS IDENTITY: THE PORTUGUESE OF SEVENTEENTH-CENTURY ROUEN
Authors: Brunelle Gayle 
Published: January 2004

AbstractIn 1633 the authorities of the city of Rouen in France arrested some of the most prominent members of the Rouennais Portuguese merchant community, whom they accused of the crime of "judaizing." This article examines that incident, and its ramifications for the Portuguese in Rouen. Most of the Portuguese merchants and their families who settled in Rouen in the sixteenth and seventeenth centuries were conversos or converted Jews, and many still secretly practiced Judaism. The arrests exposed and exacerbated a division within the Portuguese community over strategies of coexistence within Rouennais society, between those who wished to maintain their Jewish religion and those who considered themselves Christian and sought to assimilate into French society. Although royal intervention led to the release of the arrested Portuguese, the incident contributed to the dispersion of the Portuguese community in Rouen.
DID TUSCAN DIOCESES CONFESSIONALIZE IN THE SIXTEENTH AND SEVENTEENTH CENTURIES?
Authors: Comerford Kathleen 
Published: January 2004

AbstractThis article explores several dioceses in Tuscany—Arezzo, Fiesole, Lucca, Montepulciano, Siena, and Volterra—in light of the foundation of diocesan seminaries, to determine if a new corps of priests was produced and if that corps instituted major changes. Historians refer to post-Tridentine attempts to strengthen the faith and power of groups and institutions by such processes as education as the parallel trends of confessionalism and confessionalization. Since these dioceses represent different economic, educational, and demographic levels of development, the comparative study of quantitative and qualitative measures in these regions addresses the impact of educational changes in the parish clergy in a significant cross-section of late-sixteenth and seventeenth-century Tuscany. Even in dioceses which were wealthy and which supported seminaries, the institutions had little influence, and therefore the slow and spotty improvements in the parishes and dioceses did not result in the confessionalization of the region, although limited confessionalism did occur.
VESTIS VIRUM FACIT: FASHION, IDENTITY, AND ETHNOGRAPHY ON THE SEVENTEENTH-CENTURY GRAND TOUR
Authors: Stannek Antje 
Published: January 2004

AbstractA new outfit for German princes and their entourages became fashionable with the adoption of Renaissance courtly behavior after the Thirty Years' War. This article considers the role of dress in the identity-building process of young German noblemen as they learned about new and fashionable dress codes while on Grand Tour through Europe. Wearing foreign clothes became a strategy of distinction by which noble cavaliers gained access to European court societies and made themselves discernible from regional noble elites. At the same time, traveling incognito allowed a German nobleman to observe European court societies without either participating or risking the political consequences of direct involvement.
Isothermal and kinetic adsorption behaviour of Pb2 + ions on natural silicate minerals
Authors: AL-Degs Y. S. , Tutunji M. F. , Baker H. M. 
Published: January 2004

AbstractFour different types of natural clay were tested as potential adsorbents for toxic Pb2+ ions. Based on the preliminary screening studies, the adsorbents were effective at retaining Pb2+ ions from solution. A strong correlation was observed between the cation exchange capacity of clay samples and their function as adsorbents of Pb2+ ions. An adsorption isotherm of Pb ions on Petra clay was measured at 30ºC and at a concentration range of 0 –200 mg dm–3. Over the entire concentration range, the Langmuir isotherm gave a good representation of adsorption data, which confirms the formation of one molecular layer of adsorbate on the clay surface. Two variables were investigated to elucidate the rate-limiting steps of adsorption: the effect of initial concentration of Pb2+ and the effect of solution temperature. It is concluded that external diffusion was the only mechanism in operation in the adsorption process. It has been noted that adsorption of Pb2+ by natural clay is a fast process, where 80% of equilibrium capacity was established within the first minutes of interaction.
Molecular orientation of methylene blue cations adsorbed on clay surfaces
Authors: Bujdák J . , Iyi N. , Kaneko Y. , Sasai R. 
Published: January 2004

AbstractCationic dye, methylene blue (MB), was intercalated into films of expandable clay minerals with low, moderate and high layer charges (saponite, montmorillonite and synthetic expandable mica-fluorohectorite, respectively) . Tilted orientation of the dye cations on the silicate surface was observed by polarized ultraviolet-visible (UV-Vis) transmission spectroscopy. The tilting angle of the dye cations increased with the formation of high-order H-aggregates that absorb light at 525 nm. These dye species were formed only on the surface of fluorohectorite, which has the highest layer charge, and exhibited dichroism. Models for the orientation of MB cations on a clay surface were proposed based on MB orientation models previously reported, and compared with the basal spacings determined by X-ray diffraction.