The evolution of cutting forces during slot milling of unidirectional carbon fiber reinforced polymer (UD-CFRP) composites

Cutting forces generated during traditional machining of fiber reinforced polymer composites play an important role in determining machined surface quality. The cutting force signals also provide a live indicator of the dynamic behavior of the chip formation process. Cutting forces in machining FRPs are dependent primarily on the instantaneous fiber cutting angle, chip thickness, cutting edge geometry and the current state of cutting edge wear. In this study, effects of the cutting edge rake angle and tool wear on cutting force evolution during slot milling of unidirectional carbon fiber reinforced polymer (UD-CFRP) composite was investigated. The cutting forces were measured in the feed and normal directions and then transformed to the tangential and radial directions of the tool path. A simplified cutting force model consisting of a shearing region and a pressing was used to determine the shearing and friction force components. This allowed determination of the friction coefficient on the clearance face of the tool. It was found that the friction coefficient varied significantly with rake angle and fiber cutting angle. The effect of rake angle on cutting forces is more discernable in the shearing region with positive rake angle tool providing the most efficient cutting. Furthermore, correlations were found between machining damage and the magnitude and orientation of the resultant shearing force

Analysis of Process Parameters for Different Material Pairs of Mechanically Lined CRA Pipes Manufactured by Thermal-Hydraulic Expansion Process

Mechanically lined corrosion resistant pipes are produced by establishing a sufficiently high residual contact pressure (gripping force) between a corrosion resistant liner and a steel outer pipe. The most effective way to achieve such high contact pressure is by the thermal-hydraulic expansion manufacturing process. In this study, simulation of the thermal-hydraulic expansion process of mechanically lined corrosion resistant pipes is performed using the finite element method. The effects of process parameters such as process temperature, hydraulic pressure, and cooling rates for different material pairs of mechanically lined corrosion resistant pipes are investigated. Results reveal that both the water- and air-cooling rates have negligible influence on the magnitude of residual contact pressure. The furnace temperature is proved to be the governing factor to obtain high residual contact pressure for the material pairs N08825/X65 and N08031/X65. However, for the material pair 304/X65, increasing the temperature difference by reducing the hydraulic loading and unloading time durations as much as possible is the most effective way to increase the residual contact pressure

Effects of oral creatine supplementation on body composition and objective physical function in rheumatoid arthritis patients. A randomised controlled trial

Objective: Muscle wasting (‘rheumatoid cachexia’) is evident in most rheumatoid arthritis (RA) patients, including those with well-controlled disease, and contributes substantially to the reductions in strength and physical function that are characteristic of this disease. The aim of this randomized controlled trial was to investigate the efficacy of oral creatine (Cr) supplementation on improving muscle mass, strength and function in stable RA patients. Method: Forty RA patients were randomized to 12 weeks supplementation of Cr or placebo, in a double-blind fashion. Body composition (by whole-body dual-energy X-ray absorptiometry, DXA, and bioelectrical impedance spectroscopy, BIS), strength and objectively-assessed physical function measures were taken at baseline, week 12, and week 24 (i.e. after 12 weeks of treatment withdrawal). Data was analyzed by ANCOVA. Results: Cr supplementation increased appendicular lean mass (ALM; a surrogate DXA measure of muscle mass) by (mean±SE) 0.52±0.13kg (P=0.004 vs placebo), and total LM by 0.60±0.37kg (P=0.158 vs placebo). The increment in LM by DXA corresponded with the elevation in intracellular water (ICW) estimated by BIS (0.64±0.22 L, P=0.035 vs placebo). However, the observed increases in ALM, total LM and ICW were not accompanied by improvements in isometric knee extensor strength (P=0.408), hand-grip strength (P=0.833), or objectively assessed function (30s sit-to-stand, 50’ walk, 8’ up-&-go, estimated VO2max; P’s=0.335-0.764) Conclusion: Twelve weeks of Cr supplementation improved muscle mass, but not strength or objectively-measured physical function in RA patients. As no adverse treatment-related effects occurred, Cr supplementation appears to be a safe and acceptable adjunct treatment for attenuating muscle loss in RA patients. This treatment may be especially suitable for patients with severe rheumatoid cachexia

2-Benzyloxynaphthalene aminoalkylated chalcone designed as acetylcholinesterase inhibitor: Structural characterisation, in vitro biological activity and molecular docking studies

The design of an acetylcholinesterase inhibitor with multifunctional properties became the perspective for the development of an effective drug against Alzheimer's disease. Towards this target, 1-{4-hydroxy-3-[(piperidin-1-yl)methyl]phenyl}ethan-1-one (chalcone 3) was prepared and studied as an acetylcholinesterase inhibitor. The novel chalcone 3 was synthesised via Claisen-Schmidt condensation reaction with 84% yield and characterized using 1D and 2D NMR spectroscopy. The in vitro bioactivity studies of chalcone 3 demonstrated excellent inhibitory activity against AChE (IC50 1.0 nM) showing 33-fold better inhibition than donepezil, biometal chelating ability and moderate antioxidant activity. Chalcone 3 with these fascinating multifunctional proprieties can be a good candidate for the development of AD treatments. A molecular modelling investigation revealed that chalcone 3 showed dual binding inhibition of AChE enzyme. XRD shows short intra- and inter-molecular interactions with two chalcone 3 molecules per cell. Interesting Hirshfeld Surface Analysis (HSA) was conducted showing explicit agreement with the XRD analysis

Barriers for introducing HIV testing among tuberculosis patients in Jogjakarta, Indonesia: a qualitative study

<p>Abstract</p> <p>Background</p> <p>HIV and HIV-TB co-infection are slowly increasing in Indonesia. WHO recommends HIV testing among TB patients as a key response to the dual HIV-TB epidemic. Concerns over potential negative impacts to TB control and lack of operational clarity have hindered progress. We investigated the barriers and opportunities for introducing HIV testing perceived by TB patients and providers in Jogjakarta, Indonesia.</p> <p>Methods</p> <p>We offered Voluntary Counselling and Testing (VCT) to TB patients in parallel to a HIV prevalence survey. We conducted in-depth interviews with 33 TB patients, 3 specialist physicians and 3 disease control managers. We also conducted 4 Focus Group Discussions (FGDs) with nurses. All interviews and FGDs were recorded and data analysis was supported by the QSR N6^®software.</p> <p>Results</p> <p>Patients' and providers' knowledge regarding HIV was poor. The main barriers perceived by patients were: burden for accessing VCT and fear of knowing the test results. Stigma caused concerns among providers, but did not play much role in patients' attitude towards VCT. The main barriers perceived by providers were communication, patients feeling offended, stigmatization and additional burden.</p> <p>Conclusion</p> <p>Introduction of HIV testing among TB patients in Indonesia should be accompanied by patient and provider education as well as providing conditions for effective communication.</p

Microscale characterization of prostate biopsies tissues using optical coherence elastography and second harmonic generation imaging

© 2018 USCAP, Inc All rights reserved. Photonics, especially optical coherence elastography (OCE) and second harmonic generation (SHG) imaging are novel high-resolution imaging modalities for characterization of biological tissues. Following our preliminary experience, we hypothesized that OCE and SHG imaging would delineate the microstructure of prostate tissue and aid in distinguishing cancer from the normal benign prostatic tissue. Furthermore, these approaches may assist in characterization of the grade of cancer, as well. In this study, we confirmed a high diagnostic accuracy of OCE and SHG imaging in the detection and characterization of prostate cancer for a large set of biopsy tissues obtained from men suspected to have prostate cancer using transrectal ultrasound (TRUS). The two techniques and methods described here are complementary, one depicts the stiffness of tissues and the other illustrates the orientation of collagen structure around the cancerous lesions. The results showed that stiffness of cancer tissue was ∼57.63% higher than that of benign tissue (Young's modulus of 698.43±125.29 kPa for cancerous tissue vs 443.07±88.95 kPa for benign tissue with OCE. Using histology as a reference standard and 600 kPa as a cut-off threshold, the data analysis showed sensitivity and specificity of 89.6 and 99.8%, respectively. Corresponding positive and negative predictive values were 99.5 and 94.6%, respectively. There was a significant difference noticed in terms of Young's modulus for different Gleason scores estimated by OCE (P-value<0.05). For SHG, distinct patterns of collagen distribution were seen for different Gleason grade disease with computed quantification employing a ratio of anisotropic to isotropic (A:I ratio) and this correlated with disease aggressiveness