the parasitoid trichogramma brassicae bezdenko is used for inundative releases in biological control programs against lepidopteran pests in agro-ecosystems. age-specific functional responses of t. brassicae to different egg densities (5, 10, 20, 30, 40, 60, and 80) of sterilized eggs of ephestia kuehniella at 23±1°c, 60±5% rh, and 16:8 h (l:d photoperiod ) were studied. e. kuehniella densities ...

The fast monitoring of tool wears by using various Cutting signals and the prediction models developed rapidly in recent years. Comparatively, various wear forecast models based on artificial neural networks (ANN) perform much better in accuracy and speediness than the conventional prediction models. Combining the prominent dynamic properties of back propagation neural network (BPNN) with the e...

This multicentre study analysed 12 alumina ceramic-on-ceramic components retrieved from squeaking total hip replacements after a mean of 23 months in situ (11 to 61). The rates and patterns of wear seen in these squeaking hips were compared with those seen in matched controls using retrieval data from 33 'silent' hip replacements with similar ceramic bearings. All 12 bearings showed evidence ch...

The African apes possess thinner enamel than do other hominoids, and a certain amount of dentin exposure may be advantageous in the processing of tough diets eaten by Gorilla. Dental wear (attrition plus abrasion) that erodes the enamel exposes the underlying dentin and creates additional cutting edges at the dentin-enamel junction. Hypothetically, efficiency of food processing increases with j...

We retrieved 159 femoral heads at revision surgery to determine changes in surface configuration. Macroscopic wear of the head was observed in three bipolar hip prostheses as a result of three-body wear. There was a considerable change in surface roughness in the internal articulation of bipolar hip prostheses. Roughness in alumina heads was almost the same as that in new cobalt-chromium heads....

Laboratory wear testing of ultra high molecular weight polyethylene from 12 Charnley acetabular cups, removed after periods of up to 17.5 years showed that the large patient-to-patient variations in clinical penetration rate cannot be explained by batch-to-batch variation in the wear resistance of the material. Nor was there any evidence of a time-dependent degradation in wear resistance of the...

Cr-Ni coatings with the mass ratios of 17% Cr-83% Ni, 20% Cr-80% Ni and 24% Cr-76% Ni were fabricated on H13 hot work mould steel using a laser cladding (LC). The surface-interface morphologies, chemical elements, surface roughness and phase composition of the obtained Cr-Ni coatings were analysed using a scanning electron microscope (SEM), energy disperse spectroscopy (EDS), atomic force micro...

Measurement uncertainties are vital to discussions of differences in measured values, yet they scarcely accompany discussions of wear and wear rates in the tribology literature. In this methods article, approaches to calculate uncertainties in single-point and steady-state wear rates are presented. The analysis includes analytical treatments of uncertainties for typical macroscopic tribology in...

• GNP incorporated in alumina matrix to deposit composite coatings via SPS. Raman analysis confirmed retention of as-processed coatings. Improved mechanical and tribological properties achieved for Wear mechanisms monolithic coating were revealed. Graphene possesses high fracture toughness excellent lubrication properties, which can be exploited enhance performance systems utilized combat wear....

Introduction: Wear of ultra-high molecular weight polyethylene (UHMWPE) is a major factor that affects longevity of the total joint replacement. In total hips (THR), cross-linking of polyethylene has been shown to be highly effective in reducing wear both clinically and experimentally [1-3]. Also, in TKR, Schmidig et al. [4] showed a 90% reduction of wear rate in 10 Mrad compared to 3 Mrad tibi...