Inertia effect of textured lubricated contact on the bearing performance using CFD approach

Numerous studies reported that inertia of the lubricant has been considered as one of physical parameters which has a strong effect on the load support of textured bearing. In the present study, based on two-dimensional computational fluid dynamics (CFD) technique, the investigatation of the inertia effect on bearing performance is carried out varying the texture length. The Navier-Stokes equation coupled with the cavitation model are discretized using finite volume method and solved using the commercial software FLUENT®. The results show that the inertia increases the hydrodynamic film pressure and thus the load support. In addition, it is also found that increasing the texture length as well as Reynolds number will increase the cavitation region

CFD analysis of texture depth effect on the performance of hydrodynamic lubricated bearing

Surface modification of the lubricated bearing such texturing has proven to improve the hydrodynamic performance. The present paper examined the effect of texture depth as well as the texture length on the tribological performance using computational fluid dynamic (CFD) approach. The cavitation model was also considered to obtain more realistic characteristic of bearing. It was shown that by increasing texture depth of the surface of bearing, the enhanced hydrodynamic pressure was achieved. Moreover, other interesting result is that the length of cavitation region decreases with the increase in texture depth and the decrease in texture length

Analysis of water delivery performance of smallholder irrigation schemes in Ethiopia: Diversity and lessons across schemes, typologies and reaches

Irrigation systems consist of three interdependent components involving: the irrigation scheme, the on-farm management and the organizations. The irrigation scheme refers to the infrastructure for water acquisition and distribution (water delivery). This study focused on water delivery performance of 10 smallholders irrigation schemes in four regions of Ethiopia, representing diverse water sources, distribution systems, command areas (50–6000 ha) and number of beneficiary farmers (233–500 farm households) and across agro-ecologies as represented by elevation ranges (1500–2725 masl). Relative irrigation supply (RIS), irrigation intensity (Ii), cropping intensity (CI), farm level adequacy (FLA), sustainability of irrigated land (SIL), and equity and field application efficiency were employed as performance indicators. The study involved focus group discussions, household surveys and measurements of water flow across selected points of water delivery systems during 2014/2015 cropping season. More than 300 sample farmers were selected randomly from different reaches (head, mid and tail) of the schemes and before the analysis the 10 irrigation schemes were clustered into three typologies (modern, semi-modern and traditional schemes) using seven comprehensive and weighted indicators. The result showed that irrigation typology developed in this study enabled to identify three relatively homogeneous irrigation schemes typologies: modern, semi-modern and traditional. There was apparent diversity of the study schemes in terms of indicators used. At typology level, as illustrated by the RIS, the highest amount of water was diverted for semi-modern schemes (RIS of 3.84); while the highest water delivery at farm relative delivery (FRD) was recorded for the modern schemes (FRD 2.21). Traditional schemes consistently showed lower value for both RIS and FRD. Regardless of their typologies, all study schemes suffer from mismatch of water demand and supply. The lower the RIS and FRD values, the stronger was the water supply disparities between irrigation reaches. Assessment of farmers’ perception on fairness of irrigation water delivery substantiate these arguments. Implicitly, it is important to track the fate of diverted excess water. Field observation and empirical evidences show divergent points of losses of excess water indicating focus areas of improved water conservation on smallholder irrigation schemes. For example the largest proportion of over supplied water (~100%) in the semimodern schemes and in traditional schemes was lost in the conveyance and distribution systems. For modern schemes water losses in the processes of conveyance was low (26%), while the significant proportion of water (76%) was lost on farm. In view of this evidence, we concluded that irrigation schemes in Ethiopia, regardless of their typology, have low water delivery performance. As every scheme has shown its own strength and weakness, concluding sustainability in terms of typology is misleading and this suggests that policy directions should be based on composite sustainability indices

The relationship between the systemic inflammatory response, tumour proliferative activity, T-lymphocytic and macrophage infiltration, microvessel density and survival in patients with primary operable breast cancer

The significance of the inter-relationship between tumour and host local/systemic inflammatory responses in primary operable invasive breast cancer is limited. The inter-relationship between the systemic inflammatory response (pre-operative white cell count, C-reactive protein and albumin concentrations), standard clinicopathological factors, tumour T-lymphocytic (CD4+ and CD8+) and macrophage (CD68+) infiltration, proliferative (Ki-67) index and microvessel density (CD34+) was examined using immunohistochemistry and slide-counting techniques, and their prognostic values were examined in 168 patients with potentially curative resection of early-stage invasive breast cancer. Increased tumour grade and proliferative activity were associated with greater tumour T-lymphocyte (P<0.05) and macrophage (P<0.05) infiltration and microvessel density (P<0.01). The median follow-up of survivors was 72 months. During this period, 31 patients died; 18 died of their cancer. On univariate analysis, increased lymph-node involvement (P<0.01), negative hormonal receptor (P<0.10), lower albumin concentrations (P<0.01), increased tumour proliferation (P<0.05), increased tumour microvessel density (P<0.05), the extent of locoregional control (P<0.0001) and limited systemic treatment (Pless than or equal to0.01) were associated with cancer-specific survival. On multivariate analysis of these significant covariates, albumin (HR 4.77, 95% CI 1.35–16.85, P=0.015), locoregional treatment (HR 3.64, 95% CI 1.04–12.72, P=0.043) and systemic treatment (HR 2.29, 95% CI 1.23–4.27, P=0.009) were significant independent predictors of cancer-specific survival. Among tumour-based inflammatory factors, only tumour microvessel density (P<0.05) was independently associated with poorer cancer-specific survival. The host inflammatory responses are closely associated with poor tumour differentiation, proliferation and malignant disease progression in breast cancer

The relationship between the systemic inflammatory response, tumour proliferative activity, T-lymphocytic infiltration and COX-2 expression and survival in patients with transitional cell carcinoma of the urinary bladder

The relationship between the systemic inflammatory response, tumour proliferative activity, T-lymphocytic infiltration, and COX-2 expression and survival was examined in patients with transitional cell carcinoma of the urinary bladder (n=103). Sixty-one patients had superficial disease and 42 patients had invasive disease. Cancer-specific survival was shorter in those patients with invasive compared with superficial bladder cancer (P<0.001). On univariate analysis, stratified by stage, increased Ki-67 labelling index (P<0.05), increased COX-2 expression (P<0.05), C-reactive protein (P<0.05) and adjuvant therapy (P<0.01) were associated with poorer cancer-specific survival. On multivariate analysis of these significant factors, stratified by stage, only C-reactive protein (HR 2.89, 95% CI 1.42–5.91, P=0.004) and adjuvant therapy (HR 0.29, 95% CI 0.14–0.62, P=0.001) were independently associated with poorer cancer-specific survival. These results would suggest that tumour-based factors such as grade, COX-2 expression or T-lymphocytic infiltration are subordinate to systemic factors such as C-reactive protein in determining survival in patients with transitional cell carcinoma of the urinary bladder

The relationship between the systemic inflammatory response and survival in patients with transitional cell carcinoma of the urinary bladder

The relationship between tumour stage, grade, elevated C-reactive protein concentration (<10/>10 mg l−1), adjuvant therapy and survival was examined in patients with biopsy proven bladder cancer (n=105). On multivariate analysis stage (HR 3.37, 95% CI 1.37–8.29, P=0.008), grade (HR 2.01, 95% CI 1.14–3.57, P=0.017) and preoperative C-reactive protein (HR 3.31, 95% CI 1.09–10.09, P=0.035) were independently associated with cancer-specific survival

An elevated C-reactive protein concentration, prior to surgery, predicts poor cancer-specific survival in patients undergoing resection for gastro-oesophageal cancer

There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients undergoing resection for a variety of tumours. The aim of the present study was to examine the relationship between clinico-pathological status, preoperative C-reactive protein concentration and cancer-specific survival in patients undergoing resection for gastro-oesophageal cancer. One hundred and twenty patients attending the upper gastrointestinal surgical unit in the Royal Infirmary, Glasgow, who were selected for potentially curative surgery, were included in the study. Laboratory measurements of haemoglobin, white cell, lymphocyte and platelet counts, albumin and C-reactive protein were carried out at the time of diagnosis. All patients underwent en-bloc resection with lymphadenectomy and survived at least 30 days following surgery. On multivariate analysis, only the positive to total lymph node ratio (hazard ratio (HR) 2.02, 95% confidence interval (CI) 1.44–2.84, P<0.001) and preoperative C-reactive protein concentration (HR 3.53, 95% CI 1.88–6.64, P<0.001) were independent predictors of cancer-specific survival. The patient group with no evidence of a preoperative systemic inflammatory response (C-reactive protein ⩽10 mg l−1) had a median survival of 79 months compared with 19 months in the elevated systemic inflammatory response group (P<0.001). The results of the present study indicate that in patients selected to undergo potentially curative resection for gastro-oesophageal cancer, the presence of an elevated preoperative C-reactive protein concentration is an independent predictor of poor cancer-specific survival

The relationship between the preoperative systemic inflammatory response and cancer-specific survival in patients undergoing potentially curative resection for renal clear cell cancer

The relationship between tumour stage, grade (Fuhrman), performance status (ECOG), a combined score (UCLA Integrated Staging System, UISS), systemic inflammatory response (elevated C-reactive protein concentration), and cancer-specific survival was examined in patients undergoing potentially curative resection for renal clear cell cancer (n=100). On univariate survival analysis, sex (P=0.050), tumour stage (P=0.001), Fuhrman grade (P<0.001), UISS (P<0.001), C-reactive protein (P=0.002) were significant predictors of survival. On multivariate analysis with sex, UISS and C-reactive protein entered as covariates, only UISS (HR 2.70, 95% CI 1.00–7.30, P=0.050) and C-reactive protein (HR 4.00, 95% CI 1.21–13.31, P=0.024) were significant independent predictors of survival. The presence of a preoperative systemic inflammatory response predicts poor cancer-specific survival in patients who have undergone potentially curative resection for renal clear cell cancer