Transverse Compaction Analysis of 2.5D Preform Composite

Transverse compaction is an important pattern of deformation during the composite resin transfer molding (RTM) process. Reasonable compaction rate is related to both the composite mould design and the fiber volume fraction of the final composite. In this paper, a mesoscopic geometry model based on CT scanning of 2.5D preform reinforcements is presented. Applying this model to the FEM simulation of transverse compaction, we prove the validation on simulating transverse compaction property of 2.5D preform by comparing to results of compaction test. Orientation angle during the progressive compaction is studied. Using this geometry structure, we build internal and surface RUC respectively then combining together to predict the in-plane mechanical property of 2.5D preform composite. Prediction result is acceptable corresponding to the mechanical properties calculated by homogenized method and compressive stiffness tested by combined loading compression (CLC) experiment.

How do gloves affect cutaneous sensibility in medical practice? Two new applied tests

In order to quantify the effect of medical gloves on tactile performance, two new Simulated Medical Examination Tactile Tests (SMETT) have been developed to replicate the tactile and haptic ability required in medical examinations: the ‘Bumps’ test and the ‘Princess and the Pea’ (P&P) test. A pilot study was carried out using 30–40 subjects for each test in order to investigate the suitability of the tests for medical glove evaluation. Tests were performed with latex and nitrile examination gloves and without gloves. Following the tests, small-scale studies were carried out to investigate the effect of various design parameters, such as material stiffness and tactile exploration method. In the ‘Bumps’ test, subjects performed significantly better in the ungloved condition, and there were ‘almost significant’ differences between the gloves, with the thinner latex gloves performing better than the thicker nitrile gloves. Both finger orientation and surface lubrication were found to have a significant effect on results, indicating that these need to be clearly defined in the test procedure. In the ‘P&P’ test, no significant effect of hand condition was found, suggesting that haptic sensing is less affected by medical gloves than cutaneous sensibility. Other factors such as material stiffness, technique and test orientation had a more significant effect. The SMETT ‘Bumps’ test has potential as a clinical manual performance evaluation tool and may be used to evaluate the relative effects of different gloves. The SMETT ‘P&P’ test is a valid measure of haptic or tactile performance, but should not be used in glove evaluation. Both tests could have further applications, such as in the assessment of neurological impairment or aptitude testing for potential surgeons.

Rearing in a distorted magnetic field disrupts the ‘map sense’ of juvenile steelhead trout

We used simulated magnetic displacements to test orientation preferences of juvenile steelhead trout ( Oncorhynchus mykiss ) exposed to magnetic fields existing at the northernmost and southernmost boundaries of their oceanic range. Fish reared in natural magnetic conditions distinguished between these two fields by orienting in opposite directions, with headings that would lead fish towards marine foraging grounds. However, fish reared in a spatially distorted magnetic field failed to distinguish between the experimental fields and were randomly oriented. The non-uniform field in which fish were reared is probably typical of fields that many hatchery fish encounter due to magnetic distortions associated with the infrastructure of aquaculture. Given that the reduced navigational abilities we observed could negatively influence marine survival, homing ability and hatchery efficiency, we recommend further study on the implications of rearing salmonids in unnatural magnetic fields.

NiCr Electrically Conductive Coatings on Cotton Fabric by Electron Beam Evaporated Deposition

The 80Ni20Cr coatings on cotton fabric substrates using the electron beam evaporated deposition are reported to improve the electrical conductivity of fabric substrates. The cotton fabrics are coated twice for single-faced NiCr film and one time per face for double-faced NiCr film, respectively. The morphology of coatings is characterized by an optical microscopy. The effect of sample length and test orientation of warp-wise and weft-wise on electrical conductivity is measured. It is found that the NiCr coatings dramatically increase the electrical conductivity of cotton fabrics. For warp-wise orientation with lengthwidth (4 cm1 cm) of test sample, the surface resistance is about 0.7 MΩ for single-faced coating and 0.89 MΩ for double-faced coating, while the surface resistance of raw cotton fabric is above 104 MΩ. The results tested from warp-wise and weft-wise are uniform, which is mainly because of the structure balance of the plain fabrics. The microstructure observation indicates that the single-faced coatings are uniform and dense, and the present double-faced coating processes are not enough to completely cover the fabric substrates. The uniform and dense coatings of single-faced NiCr coatings could be the reason that the electrical conductivity is better than that of the present double-faced NiCr coating.

Stereoscopic Tilt and Size Aftereffects

Adaptation to a random-dot stereograting with no monocularly visible contours produces a tilt aftereffect in a briefly-viewed test stereograting. The effect is maximal for adapting orientation at ±20–30° from the test orientation. Similarly, the perceived spatial frequency of a stereograting is altered by adaptation to a stereograting of adjacent spatial frequencies.