LIMIT LOAD AND J-ESTIMATES FOR IDEALISED PROBLEMS OF DEEPLY CRACKED WELDED JOINTS IN PLANE-STRAIN BENDING AND TENSION

Using simple assumed deformation fields, approximate solutions have been obtained for tension and bending specimens containing welds for both limit loads and for fully plastic proportionality coefficients between the singular field amplitude J and the strain energy. The solutions allow for the degree of over or undermatch in the material tensile properties of the weld metal relative to the parent steel, and for the size of the weld region relative to the remaining ligament ahead of the crack. Detailed finite-element analyses have been performed for particular values of under/over-match and size of weld region. These refine the approximate analytical solutions for the particular cases examined, and show broad agreement with the trends predicted by the analytical models. The results have been used to provide guidance for testing weldments using standard, bend-type geometries. For small-specimen testing, cracks should be sufficiently deep for the remaining ligament ahead of a centrally located crack to be less than the total width of the weld. For large specimens, the weld region should be less than 20% of the size of the remaining ligament. If these guidelines are followed then standard relationships may be used to derive J from the area under the load-displacement curve. Common advice that the tensile properties of the weaker material in a weldment should be used in J-estimation techniques has been shown to be appropriate in many cases. However, the advice is likely to be overconservative when plastic deformation is predominantly in the weld even for overmatched weld properties, or predominantly in base metal even for undermatched weld properties. The results in the paper enable such cases to be identified.     

Accuracy of confidence ratings associated with general knowledge and eyewitness memory.

The confidence–accuracy (C–A) relation for general knowledge (GK) and eyewitness memory (EM) was compared in both within- and between-Ss analyses. Researchers in the cognitive tradition tend to use within-Ss designs and to find moderately positive C–A relations, whereas those in the forensic tradition tend to use between-Ss designs and to find no relations. 80 Ss took part in 1 of 2 conditions, EM or GK. No difference between conditions was found on the within-Ss measure of the C–A relation, but there was differentiation with a between-Ss measure. There was a strong positive C–A correlation (r?=?.58, p?r?=?–.11, ns). One source of this difference may be the differing opportunities for calibration offered by the 2 kinds of memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attachments beyond infancy.

Attachment theory is extended to pertain to developmental changes in the nature of children's attachments to parents and surrogate figures during the years beyond infancy, and to the nature of other affectional bonds throughout the life cycle. Various types of affectional bonds are examined in terms of the behavioral systems characteristic of each and the ways in which these systems interact. Specifically, the following are discussed: (a) the caregiving system that underlies parents' bonds to their children, and a comparison of these bonds with children's attachments to their parents; (b) sexual pair-bonds and their basic components entailing the reproductive, attachment, and caregiving systems; (c) friendships both in childhood and adulthood, the behavioral systems underlying them, and under what circumstances they may become enduring bonds; and (d) kinship bonds (other than those linking parents and their children) and why they may be especially enduring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult attachment classification and self-reported psychiatric symptomatology as assessed by the Minnesota Multiphasic Personality Inventory--2.

This study examined differences in self-reported psychiatric symptomatology on the Minnesota Multiphasic Personality Inventory-2 according to adult attachment status on the Adult Attachment Interview in first-time mothers from a high-risk poverty sample. Participants reported fairly high levels of symptomatology regardless of attachment status. The dismissing adult attachment group reported comparatively little psychiatric distress, emphasized independence, and scored the lowest on self-reported anxiety. The preoccupied group was highest on a range of indices of psychiatric symptoms indicative of self-perceived distress and relationship problems. The autonomous group's scores ranged between the scores of the other 2 groups on most scales. These different symptom patterns are consistent with adult attachment status as an index of self-representation and as a set of strategies for processing emotions and thoughts related to distress and to attachment relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of (2'-5') and (3'-5') phosphodiester linkages on conformational and stacking properties of cytidylyl-cytidine in aqueous solution

Conformational properties of (2'-5') and (3'-5') CpC have been determined by proton magnetic resonance spectroscopy at 220 MHz. The ribose ring structures are predominantly 3E with the exception of the ring from the 2'-phosphate fragment of C(2'-5')pC which exhibits an 2E pucker. Bases are oriented anti with respect to the ribose and the conformations about C4'-C5', C5'-O5', C3'-O3' (C2'-O2') are gg, g'g', and g+ in equilibrium g-, respectively. The dimers exist as mixtures of stacked (g+g+ and g-g- about the P-O(C) bonds) and unstacked species at 20 degrees C. Stacking is estimated to be 35% in both dimers.     

Evolutionary Scheduling: A Review

Early and seminal work which applied evolutionary computing methods to scheduling problems from 1985 onwards laid a strong and exciting foundation for the work which has been reported over the past decade or so. A survey of the current state-of-the-art was produced in 1999 for the European Network of Excellence on Evolutionary Computing EVONET—this paper provides a more up-to-date overview of the area, reporting on current trends, achievements, and suggesting the way forward.     

A transcultural study on stirred strawberry yogurt: consumer acceptability versus sensory quality with trained panel

The present work was designed in order to obtain the cut off point, to be used in a shelf life study on whole stirred strawberry yogurt. The study was simultaneously carried out in Argentina, Chile and Costa Rica, assaying the same kind of product, elaborated in each one of the countries. The sensory quality parameters obtained from trained panelists and the consumers acceptability, were correlated by using the cut off point methodology through a quality evaluation by the Karlsruhe scale. According to preliminary studies, the storage at 42 degrees C produced considerable damage on parameters such as pH, acidity (volumetric assay), viscosity and sensory quality. For each sample, the cut off point was determined. This value corresponds to the threshold score for the sensory quality, where the consumer starts to perceive negative changes in the product, when comparing with the fresh product. The rejection percentage was also calculated according to the cut off point. The cut off points and the percentage of rejection obtained by the three participating countries were similar. Data obtained from Costa Rica showed changes in color, acidity and rancidity. Argentinean yogurts developed acidity that had a negative effect on texture, appearance and residual flavors. Chilean samples presented a sensory quality that remains almost without change through the studied time. The differences of the deterioration pattern amongst the three countries, demonstrates that the products are different in formulation and elaboration process, in spite of been the same kind of yogurt. This could be explained by differences specified in the regulation of each country.     

Induction of stilbenes in grapes by UV-C: Comparison of different subspecies of Vitis

Bioactive products enriched in stilbenes are considered of potential future interest, and the main sources of stilbenes in human diet are grapes. Postharvest ultraviolet C (UV-C) treatment was used to induce stilbene biosynthesis in grapes of three varieties of Vitis vinifera sylvestris, seven of Vitis vinifera sativa, and two Hybrid Direct Producers (HDPs). Stilbenes have been identified by UPLC-DAD-TQD and quantified by HPLC-DAD, and cluster analyses have been performed to classify subspecies by their stilbene profile. After UV-C treatment, the Syrah variety reached a maximum of 25 mg kg^? 1 f.w. of total stilbenes in the 2008 vintage, and in the statistical analysis, this variety stood out from the other Vitis varieties tested. In 2008, varieties belonging to the sylvestris group and Vitis vinifera sativa Merlot also presented high stilbene production; however, the expected concentration in the HDPs was not obtained.Industrial relevanceIn this study, postharvest UV-C treatment has been applied to obtain stilbene-enriched grapes from several subspecies of Vitis. The most suitable raw material for bioactive stilbene-enriched products, such as nutraceutics and wines, has been established. This is an essential prerequisite to scaling up the process. Such stilbene-enriched products are known to have added-value as a result of the confirmed positive bioactivity of these compounds, and are gaining market acceptance.     

New Pacidamycin Antibiotics Through Precursor‐Directed Biosynthesis

Pacidamycins, mureidomycins and napsamycins are structurally related uridyl peptide antibiotics that inhibit translocase I, an as yet clinically unexploited target. This potentially important bioactivity coupled to the biosynthetically intriguing structure of pacidamycin make this natural product a fascinating subject for study. A precursor‐directed biosynthesis approach was employed in order to access new pacidamycin derivatives. Strikingly, the biosynthetic machinery exhibited highly relaxed substrate specificity with the majority of the tryptophan analogues that were administered; this resulted in the production of new pacidamycin derivatives. Remarkably, 2‐methyl‐, 7‐methyl‐, 7‐chloro‐ and 7‐bromotryptophans produced their corresponding pacidamycin analogues in larger amounts than the natural pacidamycin. Low levels or no incorporation was observed for tryptophans substituted at positions 4, 5 and 6. The ability to generate bromo‐ and chloropacidamycins opens up the possibility of further functionalising these compounds through chemical cross‐coupling in order to access a much larger family of derivatives.     

Human dietary exposure to heavy metals via the consumption of greenshell mussels (Perna canaliculus Gmelin 1791) from the Bay of Islands, northern New Zealand

Cadmium (Cd), mercury (Hg), arsenic (As), lead (Pb) and tin (Sn) concentrations were determined using ICP-MS in soft tissues (wet wt.) from whole greenshell mussels (Perna canaliculus) collected from Urapukapuka-Rawhiti Island, Opua Marina, Waitangi Bridge and Opua Wharf from the Bay of Islands, northern New Zealand (NZ). All samples had metal concentrations well below the Food Standards Australia and New Zealand (FSANZ) maximum limits and were comparable to, or less than, concentrations observed in previous NZ studies. Based on the average values detected in the current study, the concentrations of heavy metals ingested in a ‘typical diet’ containing greenshell mussels are below the provisional tolerable weekly intake (PTWI). However, Māori (indigenous people of New Zealand), Pacific Islanders and Asians consume a far greater quantity of seafood (and therefore heavy metals) than the general public of New Zealand and could potentially consume enough shellfish to exceed the PTWI for Cd (but not for Hg, As, Pb or Sn). Although our results, based on the current PTWIs, indicate no significant health risk to greenshell mussel consumers in this region, PTWIs change over time; concentrations which were thought to be safe are later found to be harmful. Additionally, differences in individual human susceptibilities to various toxins could increase the risk of harm for consumers with low tolerance to heavy metals. We suggest that a survey of the frequency, amount and species consumed by groups whose diet may be largely shellfish-based is required to enable a more comprehensive risk assessment to be made.