DCB-specimen loaded with uneven bending moments

A double cantilever beam specimen loaded with uneven bending moments (DCB-UBM) is proposed for mixed mode fracture mechanics characterisation of adhesive joints, laminates and multilayers. A linear elastic fracture mechanics analysis gives the energy release rate and mode mixity analytically for both isotropic and orthotropic materials. By varying the ratio between the two applied moments, the crack tip stress state can be varied from pure mode I to pure mode II for the same specimen geometry. The specimen allows stable crack growth. A special test fixture is developed to create uneven bending moments. As a preliminary example, the DCB-UBM specimen was used for characterising fracture of adhesive joints between two laminates of thermoset glass fibre reinforced plastic.     

Influence of dietary fatty acids on the glycerophospholipid composition in organs of cod (gadus morhua)

Cod (mean start weight of 26 g) were fed three diets for 15 months, each based on a dry pellet coated at a level of 9g/100 g with soybean oil, capelin oil or sardine oil. The fatty acid compositions of neutral lipids and four glycerophospholipids of white muscle, liver, gills and heart were determined. The fatty acid composition of dietary lipids influenced the composition of neutral lipids in all organs. Linoleic acid (18∶2n−6) from soybean oil was selectively incorporated into phosphatidylcholine of the four tissues. Similar levels of 20∶5n−3 and 22∶6n−3 in phosphatidylcholine and phosphatidylethanolamine were found in all organs from cod fed capelin oil and sardine oil in spite of highly differentiated feed fatty acid levels. The polyunsaturated fatty acid (PUFA) composition of phosphatidylinositol was least influenced by dietary lipids. The preferred monoenic fatty acid in phospholipids of cod was 18∶1n−9, independent of dietary intake, whereas the longer chain monoenoic acids seemed to be preferentially catabolized. The results suggest that 20∶4n−6 as well as 20∶5n−3 and 22∶6n−3 fatty acids are essential for cod.     

Muscle fiber atrophy in leg muscles after botulinum toxin type A treatment of cervical dystonia

Previous electrophysiologic studies on the effects of local injections of botulinum toxin type A (BTX-A) have indicated impaired neuromuscular transmission in distant muscles. To further study possible distant effects of repeated BTX-A injections, we obtained percutaneous muscle biopsies of the vastus lateralis muscle from 11 patients with cervical dystonia. We examined the biopsies with histopathology and morphometry, and compared them with age-matched healthy controls. There was an increased frequency of angular atrophic type IIB fibers in the patient group, and the mean size of IIB fibers was significantly smaller (p < 0.05). In addition, there was a negative correlation between accumulated dose of botulinum toxin and relative size of type IIA fibers (p < 0.05). We postulate that the observed atrophy is due to distant effects of botulinum toxin causing progressive denervation-like changes in non-treated muscle. This observation calls for further, prospective studies of the long-term effects of the treatment.     

An Improved On-line Contingency Screening for Power System Transient Stability Assessment

This paper presents a contingency screening method and a framework for its on-line implementation. The proposed method carries out contingency screening and on-line stability assessment with respect to first-swing transient stability. For that purpose, it utilizes the single machine equivalent method and aims at improving the prior developed contingency screening approaches. In order to determine vulnerability of the system with respect to a particular contingency, only one time-domain simulation needs to be performed. An early stop criteria is proposed so that in a majority of the cases the simulation can be terminated after a few hundred milliseconds of simulated system response. The method’s outcome is an assessment of the system’s stability and a classification of each considered contingency. The contingencies are categorized by exploiting parameters of an equivalent one machine infinite bus system. A novel island detection approach, appropriate for an on-line application since it utilizes efficient algorithms from graph theory and enables stability assessment of individual islands, is also introduced. The New England and New York system as well as the large-scale model of the Continental-European interconnected system are used to test the proposed method with respect to assessment accuracy and computation time.     

Crack Tip Opening Displacement in atomistic modeling of fracture of silicon

We analyze the fracture of single crystal silicon simulated by atomistic modeling with ReaxFF first principles based reactive force field. The simulations are performed at three temperatures: 500 K, 800 K and 1200 K, capturing both brittle and ductile behavior for the selected crystallographic orientation with (1 0 0) as the fracture plane. Three failure mechanisms are observed: bond breaking, amorphization and emission of dislocations. We demonstrate that the Crack Tip Opening Displacement (CTOD) gives a realistic estimate of the fracture toughness of brittle fracture, linking continuum mechanics fracture theory with the direct crack tip atomistic approach. We discuss the physics based mechanisms of failure in silicon in view of the CTOD measurements.     

Effect of cattle manure on selenate and selenite retention in soil

The aim of the present investigation was to study the effect of manure on retention of selenium (Se) in soil. Addition of cattle manure in combination with selenite and selenate reduced the adsorption of both anions to a loam soil in a batch experiment. The results were explained by the content of low-molecular-weight organic acids in the manure which compete with Se for the sorption sites. In a pot experiment with loam and peat soils and with two pH levels within each soil, cattle slurry added together with selenate was found to increase the Se concentration in grain at the highest pH level (6.1 and 6.8 for the loam and peat, respectively). At a lower pH (5.4 and 6.0 for the loam and peat, respectively) there was no significant effect of slurry on Se concentration in grain. Application of slurry also increased the residual effect of Se applied to the loam soil in the preceding growing season. In the peat soil, no residual effect of Se was found either with or without the addition of slurry.     

"Superblind": Supervising a Blind Therapist With a Blind Analysand in a Community Mental Health Setting.

This article describes the 3-year psychoanalytic treatment of a blind female client by a blind female therapist supervised by a sighted man. The author focuses primarily on issues tied to each party's personal experience of blindness. Interpersonal psychoanalysis, which was the modality of supervision and therapy, is considered a cultural approach to psychoanalytic treatment. The author (the supervisor in the triad) suggests that the individuals involved treated each other, and were treated, with regard to their shared visual problems in ways that were influenced by previous relationships and the way that the culture in which the members were embedded treats disability in general. In the present, these cultural and relational expectations, influenced by the past, were played out between patient and therapist, between therapist and supervisor, and in the decisions and policies of the clinic system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Charcot-Marie-Tooth disease--muscle biopsy findings in relation to neurophysiology

Nine patients with Charcot-Marie-Tooth disease with reduced motor nerve conduction velocity (MNCV), i.e. type 1 (CMT1), demyelinating form, and nine patients with Charcot-Marie-Tooth disease with normal or near-normal MNCV, i.e. type 2 (CMT2), axonal form, were subjected to percutaneous muscle biopsy from the anterior tibial muscle in order to characterize histopathological abnormalities and evaluate differences between the two groups. Data from the biopsies were compared with those from 18 age- and sex-matched healthy controls. Muscle biopsies from the CMT1 patients exhibited angular atrophic fibres that were scattered or in small groups, findings commonly described as neuropathic. Muscle biopsies from the CMT2 patients exhibited atrophic fibres that were rounded or elongated in groups and hypertrophic fibres with central nuclei and fibre splitting. There were also increased amounts of connective tissue, 'whorled fibres', degeneration and signs of regeneration, findings commonly regarded as myopathic. In conclusion, muscle biopsies from patients with CMT1 and CMT2 showed markedly different histopathological abnormalities. Possible underlying mechanisms are discussed.