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Kaierik Peiponen - One of the best experts on this subject based on the ideXlab platform.

  • Gloss measurement in detection of Surface quality of pharmaceutical tablets: a case study of screening of genuine and counterfeit antimalaria tablets
    Journal of the European Optical Society: Rapid Publications, 2017
    Co-Authors: Bawuah, Pertti Paakkonen, Kaierik Peiponen
    Abstract:

    The Surface quality of pharmaceutical tablets plays an important role, especially in the drug release of a tablet and hence affects the bioavailability of the drug. Furthermore, important tablet’s properties such as coating uniformity and mechanical integrity that can be predicted based on the known Surface properties manifest the inevitable link between a tablet’s Surface property (e.g. Gloss, Average Surface Roughness) and its efficacy. In this article, laboratory based and handheld glossmeters as well as an optical profilometer were utilized for the detection of the Surface properties of commercially available pharmaceutical tablets. As a case study, we measured the Surface properties of authentic and counterfeit antimalarial tablets. Clear differences between authentic and fake tablets were detected based on the measured Average Surface Roughness and gloss values of the tablet samples. It is worth mentioning that this is the first time we have utilized both glossmeters for the purpose of Surface quality investigation of real pharmaceutical tablets. It is therefore suggested that the handheld glossmeter is a useful device for quick inspection of tablet’s Surface quality both in the production environments as well as for field screening of fake tablets.

  • on the correlation of effective terahertz refractive index and Average Surface Roughness of pharmaceutical tablets
    Journal of Infrared Millimeter and Terahertz Waves, 2016
    Co-Authors: Mousumi Chakraborty, Prince Bawuah, Tuomas Ervasti, Pertti Paakkonen, Axel J Zeitler, Jarkko Ketolainen, Kaierik Peiponen
    Abstract:

    In this paper, we have studied terahertz (THz) pulse time delay of porous pharmaceutical microcrystalline compacts and also pharmaceutical tablets that contain indomethacin (painkiller) as an active pharmaceutical ingredient (API) and microcrystalline cellulose as the matrix of the tablet. The porosity of a pharmaceutical tablet is important because it affects the release of drug substance. In addition, Surface Roughness of the tablet has much importance regarding dissolution of the tablet and hence the rate of drug release. Here, we show, using a training set of tablets containing API and with a priori known tablet’s quality parameters, that the effective refractive index (obtained from THz time delay data) of such porous tablets correlates with the Average Surface Roughness of a tablet. Hence, THz pulse time delay measurement in the transmission mode provides information on both porosity and the Average Surface Roughness of a compact. This is demonstrated for two different sets of pharmaceutical tablets having different porosity and Average Surface Roughness values.

Elaheh Ghassemieh - One of the best experts on this subject based on the ideXlab platform.

  • comparative study of tool life and hole quality in drilling of cfrp titanium stack using coated carbide drill
    Machining Science and Technology, 2013
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    The use of hybrid materials including carbon fiber reinforced plastics (CFRPs) and lightweight metals such as titanium are increasing particularly in aerospace applications. Multi-material stacks require a number of holes for the assembly purposes. In this research, drilling trials have been carried out in CFRP, Ti-6Al-4V and CFRP/Ti-6Al-4V stack workpieces using AlTiN coated tungsten carbide drill bit. The effects of process parameters have been investigated. The thrust force, torque, burr formation, delamination, Surface Roughness and tool wear have been analyzed at various processing condition. The experimental results have shown that the thrust force, torque, burr formation and the Average Surface Roughness increase with the increased feed rate and decrease with the increased cutting speed in drilling of Ti-6Al-4V. In drilling CFRP, delamination and the Average Surface Roughness has similar tendency with the cutting parameters however thrust force and torque rises with the increased cutting speed. The...

  • COMPARATIVE STUDY OF TOOL LIFE AND HOLE QUALITY IN DRILLING OF CFRP/TITANIUM STACK USING COATED CARBIDE DRILL
    Machining Science and Technology, 2013
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    The use of hybrid materials including carbon fiber reinforced plastics (CFRPs) and lightweight metals such as titanium are increasing particularly in aerospace applications. Multi-material stacks require a number of holes for the assembly purposes. In this research, drilling trials have been carried out in CFRP, Ti-6Al-4V and CFRP/Ti-6Al-4V stack workpieces using AlTiN coated tungsten carbide drill bit. The effects of process parameters have been investigated. The thrust force, torque, burr formation, delamination, Surface Roughness and tool wear have been analyzed at various processing condition. The experimental results have shown that the thrust force, torque, burr formation and the Average Surface Roughness increase with the increased feed rate and decrease with the increased cutting speed in drilling of Ti-6Al-4V. In drilling CFRP, delamination and the Average Surface Roughness has similar tendency with the cutting parameters however thrust force and torque rises with the increased cutting speed. The...

  • Delamination and wear in drilling of carbon-fiber reinforced plastic composites using multilayer TiAlN/TiN PVD-coated tungsten carbide tools
    Journal of Reinforced Plastics and Composites, 2012
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    This study aims to investigate drilling process in carbon-fiber reinforced plastic (CFRP) composites with multilayer TiAlN/TiN PVD-coated tungsten carbide drill. The effect of process parameters have been investigated in drilling of Hexcel M21-T700GC. Thrust force and torque were measured online throughout the drilling experiments. Delamination were observed using optical microscope and analyzed via a developed algorithm based on digital image processing technique. Surface Roughness of each hole was measured using a Surface profilometer. In addition, the progression of tool wear in various Surfaces of drill was observed using tool microscope and measured using image software. Our results indicate that the thrust force and torque increased with the increasing cutting speed and feed rate. Delamination and Average Surface Roughness that rose with the increase in feed rate, however, decreased with the increasing cutting speed. The Average Surface Roughness tended to increase with the increase in feed rate and...

  • Delamination and wear in drilling of carbon-fiber reinforced plastic composites using multilayer TiAlN/TiN PVD-coated tungsten carbide tools
    Journal of Reinforced Plastics and Composites, 2012
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    This study aims to investigate drilling process in carbon-fiber reinforced plastic (CFRP) composites with multilayer TiAlN/TiN PVD-coated tungsten carbide drill. The effect of process parameters have been investigated in drilling of Hexcel M21-T700GC. Thrust force and torque were measured online throughout the drilling experiments. Delamination were observed using optical microscope and analyzed via a developed algorithm based on digital image processing technique. Surface Roughness of each hole was measured using a Surface profilometer. In addition, the progression of tool wear in various Surfaces of drill was observed using tool microscope and measured using image software. Our results indicate that the thrust force and torque increased with the increasing cutting speed and feed rate. Delamination and Average Surface Roughness that rose with the increase in feed rate, however, decreased with the increasing cutting speed. The Average Surface Roughness tended to increase with the increase in feed rate and decrease with the increasing cutting speed in drilling of carbon-fiber reinforced plastic (CFRP). Feed rate was found as the predominant factor on the drilling outputs. Abrasive wear was observed on both flank and relief Surfaces, which created edge wear on cutting edges. No sign of chipping or plastic deformation has been observed on the Surfaces of drills.

Ozden Isbilir - One of the best experts on this subject based on the ideXlab platform.

  • comparative study of tool life and hole quality in drilling of cfrp titanium stack using coated carbide drill
    Machining Science and Technology, 2013
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    The use of hybrid materials including carbon fiber reinforced plastics (CFRPs) and lightweight metals such as titanium are increasing particularly in aerospace applications. Multi-material stacks require a number of holes for the assembly purposes. In this research, drilling trials have been carried out in CFRP, Ti-6Al-4V and CFRP/Ti-6Al-4V stack workpieces using AlTiN coated tungsten carbide drill bit. The effects of process parameters have been investigated. The thrust force, torque, burr formation, delamination, Surface Roughness and tool wear have been analyzed at various processing condition. The experimental results have shown that the thrust force, torque, burr formation and the Average Surface Roughness increase with the increased feed rate and decrease with the increased cutting speed in drilling of Ti-6Al-4V. In drilling CFRP, delamination and the Average Surface Roughness has similar tendency with the cutting parameters however thrust force and torque rises with the increased cutting speed. The...

  • COMPARATIVE STUDY OF TOOL LIFE AND HOLE QUALITY IN DRILLING OF CFRP/TITANIUM STACK USING COATED CARBIDE DRILL
    Machining Science and Technology, 2013
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    The use of hybrid materials including carbon fiber reinforced plastics (CFRPs) and lightweight metals such as titanium are increasing particularly in aerospace applications. Multi-material stacks require a number of holes for the assembly purposes. In this research, drilling trials have been carried out in CFRP, Ti-6Al-4V and CFRP/Ti-6Al-4V stack workpieces using AlTiN coated tungsten carbide drill bit. The effects of process parameters have been investigated. The thrust force, torque, burr formation, delamination, Surface Roughness and tool wear have been analyzed at various processing condition. The experimental results have shown that the thrust force, torque, burr formation and the Average Surface Roughness increase with the increased feed rate and decrease with the increased cutting speed in drilling of Ti-6Al-4V. In drilling CFRP, delamination and the Average Surface Roughness has similar tendency with the cutting parameters however thrust force and torque rises with the increased cutting speed. The...

  • Delamination and wear in drilling of carbon-fiber reinforced plastic composites using multilayer TiAlN/TiN PVD-coated tungsten carbide tools
    Journal of Reinforced Plastics and Composites, 2012
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    This study aims to investigate drilling process in carbon-fiber reinforced plastic (CFRP) composites with multilayer TiAlN/TiN PVD-coated tungsten carbide drill. The effect of process parameters have been investigated in drilling of Hexcel M21-T700GC. Thrust force and torque were measured online throughout the drilling experiments. Delamination were observed using optical microscope and analyzed via a developed algorithm based on digital image processing technique. Surface Roughness of each hole was measured using a Surface profilometer. In addition, the progression of tool wear in various Surfaces of drill was observed using tool microscope and measured using image software. Our results indicate that the thrust force and torque increased with the increasing cutting speed and feed rate. Delamination and Average Surface Roughness that rose with the increase in feed rate, however, decreased with the increasing cutting speed. The Average Surface Roughness tended to increase with the increase in feed rate and...

  • Delamination and wear in drilling of carbon-fiber reinforced plastic composites using multilayer TiAlN/TiN PVD-coated tungsten carbide tools
    Journal of Reinforced Plastics and Composites, 2012
    Co-Authors: Ozden Isbilir, Elaheh Ghassemieh
    Abstract:

    This study aims to investigate drilling process in carbon-fiber reinforced plastic (CFRP) composites with multilayer TiAlN/TiN PVD-coated tungsten carbide drill. The effect of process parameters have been investigated in drilling of Hexcel M21-T700GC. Thrust force and torque were measured online throughout the drilling experiments. Delamination were observed using optical microscope and analyzed via a developed algorithm based on digital image processing technique. Surface Roughness of each hole was measured using a Surface profilometer. In addition, the progression of tool wear in various Surfaces of drill was observed using tool microscope and measured using image software. Our results indicate that the thrust force and torque increased with the increasing cutting speed and feed rate. Delamination and Average Surface Roughness that rose with the increase in feed rate, however, decreased with the increasing cutting speed. The Average Surface Roughness tended to increase with the increase in feed rate and decrease with the increasing cutting speed in drilling of carbon-fiber reinforced plastic (CFRP). Feed rate was found as the predominant factor on the drilling outputs. Abrasive wear was observed on both flank and relief Surfaces, which created edge wear on cutting edges. No sign of chipping or plastic deformation has been observed on the Surfaces of drills.

Iskender Yilgor - One of the best experts on this subject based on the ideXlab platform.

  • influence of the Average Surface Roughness on the formation of superhydrophobic polymer Surfaces through spin coating with hydrophobic fumed silica
    Polymer, 2015
    Co-Authors: Emel Yilgor, Iskender Yilgor
    Abstract:

    Abstract Formation of superhydrophobic polymer Surfaces were investigated through successive spin-coating of hydrophobic fumed silica dispersed in an organic solvent onto polymer films. Two different polymers, a hydrophobic segmented silicone-urea copolymer (TPSC) and hydrophilic poly(methyl methacrylate) (PMMA) were used as model substrates. Influence of the polymer type and structure, silica concentration and the number of silica layers applied on the topography, Average Roughness and the wetting behavior of the Surfaces were determined. Polymer Surfaces obtained were characterized by scanning electron microscopy, white light interferometry, atomic force microscopy and advancing and receding water contact angle measurements. It was possible to obtain superhydrophobic Surfaces displaying hierarchical micro/nano features both for TPSC and PMMA. A close correlation was observed between the number of silica layers applied and Average Surface Roughness obtained. It was demonstrated that an Average Surface Roughness value of 125–150 nm was necessary for the formation of superhydrophobic Surfaces, both for TPSC and PMMA. Chemical structure and nature of the polymeric substrate seem to play a significant role on the topography and Average Roughness of the silica coated Surfaces formed. Superhydrophobic Surfaces displayed static and advancing water contact angles well above 150° and fairly small contact angle hysteresis.

Mousumi Chakraborty - One of the best experts on this subject based on the ideXlab platform.

  • on the correlation of effective terahertz refractive index and Average Surface Roughness of pharmaceutical tablets
    Journal of Infrared Millimeter and Terahertz Waves, 2016
    Co-Authors: Mousumi Chakraborty, Prince Bawuah, Tuomas Ervasti, Pertti Paakkonen, Axel J Zeitler, Jarkko Ketolainen, Kaierik Peiponen
    Abstract:

    In this paper, we have studied terahertz (THz) pulse time delay of porous pharmaceutical microcrystalline compacts and also pharmaceutical tablets that contain indomethacin (painkiller) as an active pharmaceutical ingredient (API) and microcrystalline cellulose as the matrix of the tablet. The porosity of a pharmaceutical tablet is important because it affects the release of drug substance. In addition, Surface Roughness of the tablet has much importance regarding dissolution of the tablet and hence the rate of drug release. Here, we show, using a training set of tablets containing API and with a priori known tablet’s quality parameters, that the effective refractive index (obtained from THz time delay data) of such porous tablets correlates with the Average Surface Roughness of a tablet. Hence, THz pulse time delay measurement in the transmission mode provides information on both porosity and the Average Surface Roughness of a compact. This is demonstrated for two different sets of pharmaceutical tablets having different porosity and Average Surface Roughness values.