Experimental investigation and force modeling of orthogonal cutting with the effect of third deformation zone

Metal cutting is the most common manufacturing method used in various industries. There have been many investigations on the interaction between the cutting edge and the material in the first and the second deformation zones in order to understand the mechanics of the process. Investigations on the third deformation zone, on the other hand, have been limited although it may have significant effects on the process and the machined part. Especially in finishing operations where slow feed rates are used, the contributions of the edge and flank contacts on the total cutting force can be substantial. Furthermore, the third zone determines the surface quality and the integrity due to its direct contact with the finished surface. Despite of these important effects of the third zone, there is lack of analytical and practical methods for modeling and predictions of the third deformation zone in metal cutting which is the focus of the thesis. In this study, an experimental analysis of cutting forces along with the thermal investigation of third deformation zone is presented. An orthogonal cutting model including a thermo-mechanical model with sticking and sliding contact zones is developed in order to determine the effects of hone radius and flank contact on cutting forces. Different approaches such as full and elastic recovery of the material are considered for contact length calculations. Predictions of the proposed model are compared with the measurements and. it is shown that the model predictions are reasonably comparable to the experimental data with close trends

Serum vascular cell adhesion molecule-1 (VCAM1) level is elevated in colorectal cancer regardless of the tumor stage

Purpose: Vascular cell adhesion molecule-1 (VCAM1) is a transmembrane glycoprotein, which is expressed on endothelium and plays role in inflammation. It is over-expressed on colorectal cancer (CRC) cells and plays role in metastasis development and angiogenesis. We aimed to compare serum VCAM1 levels of CRC patients with heathy controls and evaluate its relationship with clinicopathological parameters, treatment response and overall survival (OS).Methods: The study enrolled 111 patients with histopathologically confirmed CRC followed-up in our clinic and 30 sex- and age-matched healthy controls. Pre-treatment serum VCAM1 levels were determined by the solid-phase sandwich ELISA method.Results: Metastatic disease was present in 57 patients. Forty percent of 40 metastatic patients receiving systemic therapy had partial or complete response. The median serum VCAM1 level was significantly higher in CRC patients than controls (p<0.001). In addition, serum VCAM1 level was significantly higher in diabetic CRC patients than those without diabetes (p = 0.03). There was no significant relationship between VCAM1 and other clinicopathological parameters including stage and response to systemic therapy. The median follow-up period was 12 (±8.2) months. Twenty patients were dead at the time of analysis. The presence of metastasis (p < 0.001) and elevated CEA level (p < 0.001) were factors affecting OS significantly. However, serum VCAM1 did not have a significant impact on OS (p = 0.55).Conclusion: Serum VCAM1 level is significantly elevated in CRC patients regardless of the tumor stage. However, it has no prognostic or predictive role for response to systemic therapy

Modeling and experimental investigation of edge hone and flank contact effects in metal cutting

In this study, a process model for orthogonal cutting is developed in order to determine the effect of the hone radius and flank contact on cutting forces. A thermo-mechanical model at primary shear zone with sticking and sliding contact zones on the rake face is used for cutting forces and these contact zones are implemented in the third deformation zone. The model predictions are verified by experiments using carbide inserts with various hone radii at different speeds and feeds

Experimental and analytical investigation of third deformation zone in orthogonal cutting

In this study, an analytical investigation of cutting forces of third deformation zone is presented. An orthogonal cutting model including a thermo-mechanical model with dual zone friction behaviour is proposed in order to determine the effects of hone radius and flank contact on cutting forces. Furthermore different approaches for friction and material behavior are considered for precise modeling. Also full and elastic recovery of the material are considered for contact length calculations for the same reasons. Predictions of the proposed model are compared with the force and thermal measurements and it is shown that the model predictions are reasonably comparable with the experimental data

Silencing of Wwox Increases Nuclear Import of Dvl proteins in Head and Neck Cancer

Background: Wnt signaling pathway is associated with a variety of human cancers, including HNSCC. Wnt proteins control cellular events such as proliferation, fate specification, polarity, and migration by transducing signals to the nucleus through several cytoplasmic relay proteins. Although activation of the Wnt/beta-catenin pathway is a frequent event in various cancers, there is limited knowledge on the contribution of this signaling mechanism in HNSCC. The Wwox tumor suppressor protein participates in the regulation of Wnt signaling by interacting with Dvl proteins

Serum vascular cell adhesion molecule-1 (VCAM1) level is elevated in colorectal cancer regardless of the tumor stage

Purpose: Vascular cell adhesion molecule-1 (VCAM1) is a transmembrane glycoprotein, which is expressed on endothelium and plays role in inflammation. It is over-expressed on colorectal cancer (CRC) cells and plays role in metastasis development and angiogenesis. We aimed to compare serum VCAM1 levels of CRC patients with heathy controls and evaluate its relationship with clinicopathological parameters, treatment response and overall survival (OS).Methods: The study enrolled 111 patients with histopathologically confirmed CRC followed-up in our clinic and 30 sex- and age-matched healthy controls. Pre-treatment serum VCAM1 levels were determined by the solid-phase sandwich ELISA method.Results: Metastatic disease was present in 57 patients. Forty percent of 40 metastatic patients receiving systemic therapy had partial or complete response. The median serum VCAM1 level was significantly higher in CRC patients than controls (p&lt;0.001). In addition, serum VCAM1 level was significantly higher in diabetic CRC patients than those without diabetes (p = 0.03). There was no significant relationship between VCAM1 and other clinicopathological parameters including stage and response to systemic therapy. The median follow-up period was 12 (±8.2) months. Twenty patients were dead at the time of analysis. The presence of metastasis (p &lt; 0.001) and elevated CEA level (p &lt; 0.001) were factors affecting OS significantly. However, serum VCAM1 did not have a significant impact on OS (p = 0.55).Conclusion: Serum VCAM1 level is significantly elevated in CRC patients regardless of the tumor stage. However, it has no prognostic or predictive role for response to systemic therapy.</p

Turkish Guideline for Diagnosis and Treatment of Allergic Rhinitis (ART)

Object: To prepare a national guideline for Oto-rhinolaryngologist who treat allergic rhinitis patient