Behavior of Oxide-layer Adhered on Tool Surface when Machining Ca-Deoxidized Steel

Machining of Ca-Si deoxidized, Fe-Si deoxidized and conventionally deoxidized steels was investigated in order to reveal the effect and mechanism of the tool surface layer consistnig of oxides and sulfides in preventing tool wear. The tool surface layers were surveyed by the electron probe X-ray micro-analyzer, and the structural components of the layer were identified in this study. The following concludions were obtained : When machining Ca-Si deoxidized or Fe-Si deoxidized steels, the oxides and sulfides form layers on the tool surface, which avoid the direct contact of the work iron with the tool carbides, prevent the diffusion of the tool material. When cutting Ca-Si deoxidized steels, a semitransparent layer forms preferably on carbide tools which contain TiC, and it consists of 2 to 3 CaO-Al₂O₃-SiO₂. In the case of Fe-Si deoxidized steels, an ashy-grey coloured layer forms preferably on ceramic tools and it consists of CaO, Al₂O₃, SiO₂ and MnS

Influence of Process Parameters in n-PMEDM of Inconel 800 with Electrode and Coated Electrodes

By considering the unique performances, the Powder Mixed Electrical Discharge Machining (PMEDM) mostly encounter choice for machining the hard materials with job features like intricate shapes with grater accuracy and those materials are difficult to cut in conventional machining processes. This Research aimed to prepare parameter index chart for machining nickel based super alloy - Inconel 800 for various requirements. To achieve the aim, In this experimental study on machining of Inconel 800 in PMEDM with electrolyte copper electrode as well as silver coated electrolyte copper electrode is focused. Taguchi full factorial design derived from MINITAB release-16 software was used to design the experimentation. The factors like pulse off time, Current and Pulse on Time were considered. The responses like amount of Tool Wear, Quantity of material removal, surface finishes were noted against each case. In the same experimental conditions the coated electrode increased the MRR by 36.67% with minor increment of maximum surface roughness to 16.11%

Self-Assembly of Elastin–Mimetic Double Hydrophobic Polypeptides

We have constructed a novel class of “double-hydrophobic” block polypeptides based on the hydrophobic domains found in native elastin, an extracellular matrix protein responsible for the elasticity and resilience of tissues. The block polypeptides comprise proline-rich poly(VPGXG) and glycine-rich poly(VGGVG), both of which dehydrate at higher temperature but form distinct secondary structures, β-turn and β-sheet respectively. In water at 45 °C, the block polypeptides initially assemble into nanoparticles rich in β-turn structures, which further connect into long (>10 μm), beaded nanofibers along with the increase in the β-sheet content. The nanofibers obtained are well-dispersed in water, and show thermoresponsive properties. Polypeptides comprising each block component assemble into different morphologies, showing that the conjugation of poly(VPGXG) and poly(VGGVG) plays a role for beaded fiber formation. These results may provide innovative ideas for designing peptide-based materials but also opportunities for developing novel materials useful for tissue engineering and drug delivery systems

The Administration of Xultophy for Diabetic Patients on Hemodialysis

Background: Recent diabetic treatments include Insulin Degludec/ liraglutide (IDeg/Lira, Xultophy) in clinical practice. Authors have continued clinical research concerning diabetes, chronic renal failure, dialysis, and others. Subjects and Methods: Ten patients with type 2 diabetes mellitus (T2DM) undergoing hemodialysis were investigated. They showed that ages 74.5 ± 5.9 years, M/F=6/4, BMI 21.1± 3.8kg/m2, hemodialysis duration 8.1 ± 5.7 years. At the beginning, fundamental data were Cre 8.2 ± 1.9 mg/dL, HbA1c 6.5 ± 0.8%. Xultophy was started on 5-12 doses and continued for 6 months with the same or 1-4 increased doses for better glycemic variability. Results: Out of 10 subjects, the changes in HbA1c showed a decrease in 7, stable in 2, and an increase in 1. HbA1c value was 6.2 ± 0.8% in average at 6 months. There were no remarkable adverse effects by Xultophy for 6 months. Discussion and Conclusion: Xultophy was started at 5-12 doses, which were remarkably lower doses than usual doses with satisfactory efficacy. One of the reasons may be from the characteristic of the patients, who were diabetic with undergoing hemodialysis. Another factor is possibly from liraglutide, which has hepatic clearance with potential vascular protective effects. These results are expected to become reference data for future research

Sustainable cooling method for machining titanium alloy

Hard to machine materials such as Titanium Alloy TI-6AI-4V Grade 5 are notoriously known to generate high temperatures and adverse reactions between the workpiece and the tool tip materials. These conditions all contribute to an increase in the wear mechanisms, reducing tool life. Titanium Alloy, for example always requires coolant to be used during machining. However, traditional flood cooling needs to be replaced due to environmental issues, and an alternative cooling method found that has minimum impact on the environment. For true sustainable cooling of the tool it is necessary to account for all energy used in the cooling process, including the energy involved in producing the coolant. Previous research has established that efficient cooling of the tool interface improves the tool life and cutting action. The objective of this research is to determine the most appropriate sustainable cooling method that can also reduce the rate of wear at the tool interface

Carnitine for Body Composition in Hemodialysis Patients

Background: Authors and colleagues have continued clinical research for hemodialysis patients. Currently, a pilot study presents intervention of carnitine for changes of the body composition. Subjects and Methods: Subjects were six patients on hemodialysis with intervention of carnitine (group 1). Average data were 74.3 years, 65.4 kg, 22.6 in BMI. As levocarnitine, L-Cartin FF injection 1000 mg was administered three times a week for six months. Group 2 has six control patients for age-, sex-, body weight, BMI-matched (group 2). Body composition of muscle and fat tissues were measured by InBody 770 on 0 and 6 months. Results: In group 1, muscle volume and skeletal muscle showed increasing tendency without statistical significance. In contrast, there were significant decreases of body fat volume (22.3 kg vs 20.5 kg, 39.0% vs 35.8%) (p<0.05). No significant differences were found in hemoglobin, total protein, albumin and Cardio-Thoracic Ratio (CTR) of chest X-ray. Group 2 showed no significant changes. Discussion and Conclusion: Hemodialysis patients often have muscular reduction. Previous reports showed improved lean body mass by carnitine administration, which may support our result. These results from current pilot study would be expected to become useful reference data in the pathophysiological investigation in patients on hemodialysis

Investigation of Nerve Conduction in Patients with Diabetes and/or Hemodialysis

Diabetic peripheral neuropathy (DPN) has been clinically important, and nerve conduction studies (NCS) have been performed with rather complexity and high cost. By advances in technology, simple and useful DPN-Check device was developed obtaining NCS data as sural nerve conduction velocity (SNCV) and sural nerve action potential (SNAP). We enrolled 52 subjects classified into 4 groups according to the presence of hemodialysis (HD) and diabetes mellitus (DM) as follows: HD (+), DM (+) in group 1, HD (+), DM (-) in group 2, HD (-), DM (+) in group 3 and healthy controls in group 4. Average age was similar from 68 to 74 years in 4 groups. Median value of SNCV was 31, 48, 49, 54 m/sec, and median value of SNAP was 3, 9, 6, 22 μV, respectively, in 4 groups. These results might suggest some relationship between impaired states of HD and DM, and would become fundamental data for pathophysiological investigation of peripheral neuropathy of HD and/or DM in the future

Influence of Diabetes and Hemodialysis Against Nerve Conduction Studies

Background: Diabetic peripheral neuropathy (DPN) has been prevalent and discussed, and nerve conduction studies (NCS) has been continued. We have checked NCS using recently introduced useful DPN-Check device. Subjects and Methods: The subjects were 66 patients (pts) classified into 4 groups according to existence of diabetes mellitus (DM) and hemodialysis (HD); Group1: DM (+), HD (+) in 15 pts, group 2: DM (-), HD (+) in 15 pts, group 3: DM (+), HD (-) in 20 pts, group 4: 16 healthy controls. Methods included measurements of sural nerve conduction velocity (SNCV) and sural nerve action potential (SNAP) using HDN-1000. Results: Average age in each group was 64.4 years to 72.6 years. SNCV value of 4 group in average was 37.1 m/sec, 46.3 m/sec, 49.3 m/sec, 53.2 m/sec, respectively, and value of group 1 was significantly lower than those of group 2,3,4 (p<0.01). Similarly, average SNAP was 4.1 μV, 8.7 μV, 8.0 μV, 21.6 μV, respectively, and group 1,2,3 were significantly lower than group 4 (p<0.01). There was significant correlation between SNCV and SNAP in all subjects (p<0.01). Significant correlations were shown between DM duration and SNCV, and DM duration and SNAP (p<0.01). Discussion and Conclusion: SNCV and SNAP were measured successfully and easily by HDN-1000, indicating clinical availability. Obtained data suggested that 1) SNCV is not significantly decreased due to only uremic neuropathy, 2) SNCV is significantly decreased in patients with both HD and DM, 3) SNAP is significantly decreased in patents with DM for years and 4) SNAP would be remarkably decreased when HD is in addition to DM. These results would become the basal data of future NCS for DM and HD

Investigation of Nerve Conduction in Patients with Diabetes and/or Hemodialysis

Diabetic peripheral neuropathy (DPN) has been clinically important, and nerve conduction studies (NCS) have been performed with rather complexity and high cost. By advances in technology, simple and useful DPN-Check device was developed obtaining NCS data as sural nerve conduction velocity (SNCV) and sural nerve action potential (SNAP). We enrolled 52 subjects classified into 4 groups according to the presence of hemodialysis (HD) and diabetes mellitus (DM) as follows: HD (+), DM (+) in group 1, HD (+), DM (-) in group 2, HD (-), DM (+) in group 3 and healthy controls in group 4. Average age was similar from 68 to 74 years in 4 groups. Median value of SNCV was 31, 48, 49, 54 m/sec, and median value of SNAP was 3, 9, 6, 22 μV, respectively, in 4 groups. These results might suggest some relationship between impaired states of HD and DM, and would become fundamental data for pathophysiological investigation of peripheral neuropathy of HD and/or DM in the future