In Chains? Automotive Suppliers and Their Product Development Activities

A conceptual framework is developed and tested in which supplier downstream position in the supply chain, supplier innovation strategy and customer development commitment are seen as the antecedents of supplier product development activity. Using partial least squares (PLS), we analyze the results of a survey of 161 Swedish automotive suppliers and test a series of nested models to test our hypotheses. We demonstrate that the position of the supplier in the supply chain and its strategic focus on innovation not only have a direct impact on (actual) supplier product development activity, but that there is also an interaction effect, implying that the effects of strategy are contingent on the supplier???s supply chain position. Additionally, we find that customer development commitment does not have any significant direct effect on supplier product development activities, but that this relation is fully mediated by supplier innovation strategy. The meaning of the findings for developing a more extensive conceptual framework for understanding supplier product development activities, some managerial implications, and future research are discussed.supply chain;product development;supplier relations

In Chains? Automotive Suppliers and Their Product Development Activities

A conceptual framework is developed and tested in which supplier downstream position in the supply chain, supplier innovation strategy and customer development commitment are seen as the antecedents of supplier product development activity. Using partial least squares (PLS), we analyze the results of a survey of 161 Swedish automotive suppliers and test a series of nested models to test our hypotheses. We demonstrate that the position of the supplier in the supply chain and its strategic focus on innovation not only have a direct impact on (actual) supplier product development activity, but that there is also an interaction effect, implying that the effects of strategy are contingent on the supplier???s supply chain position. Additionally, we find that customer development commitment does not have any significant direct effect on supplier product development activities, but that this relation is fully mediated by supplier innovation strategy. The meaning of the findings for developing a more extensive conceptual framework for understanding supplier product development activities, some managerial implications, and future research are discussed

När det professionella omdömet inte överensstämmer med lagen - Kuratorers förhållningssätt till anmälningsskyldighet på ungdomsmottagningar

The purpose of this essay is to describe and analyze how counsellors in youth centres in the south of Sweden handle ethical dilemmas that might appear when they meet young clients. We interviewed six counsellors about how they handle the dilemma they are faced with when meeting someone under the age of fifteen who is sexually active even though they aren’t old enough according to Swedish law. In Sweden, it’s a crime to have sexual intercourse with a person under the age of fifteen, and the counsellors has to respect the duty to report as well as their confidentiality when they meet someone below fifteen who is sexually active. The results of our interviews where then analyzed using an ethical approach and we used the theory of professonal ethics, utilitarism and deontological ethics. We also used some reports about knowledgebased social work. The outcome of the essay was that the counsellors tend to lean on the utilitarism and their professional opinion, rather than the law, when deciding whether to report the young person or not. Their former experience of working with youth had a great impact on their actions

Non-Uniformity of Pellets Coating, Effect on the Dose Release Profile andHow to Improve the Coating Process by Reducing the Electrostatic Charging of the Pellets

The aim of this work was to study the effect of several process parameters used during pellets coating in two wurster fluid beds of different scales on: a) the uniformity of pellets coating, and b) the presence of an initial burst in the release profile caused by the existence of a significant fraction of pellets having a very thin film coating. The pellets used in this work presented high insulating properties. The pellets were coated with extended release films made mainly of ethyl cellulose and it was shown that larger pellets had a thicker coating. The choice of the process parameters had a large effect on the amount of pellets that were subtracted from the coating process due to the buildup of electrostatic charges on the pellets. Using not too high fluidizing air flows, pellets of larger size, a smaller pellets load and humidified air to fluidize the pellets resulted in more uniform coatings and, consequently, in more favorable release profiles that did not present or presented a reduced initial burst release

Non-Uniformity of Pellets Coating, Effect on the Dose Release Profile andHow to Improve the Coating Process by Reducing the Electrostatic Charging of the Pellets

The aim of this work was to study the effect of several process parameters used during pellets coating in two wurster fluid beds of different scales on: a) the uniformity of pellets coating, and b) the presence of an initial burst in the release profile caused by the existence of a significant fraction of pellets having a very thin film coating. The pellets used in this work presented high insulating properties. The pellets were coated with extended release films made mainly of ethyl cellulose and it was shown that larger pellets had a thicker coating. The choice of the process parameters had a large effect on the amount of pellets that were subtracted from the coating process due to the buildup of electrostatic charges on the pellets. Using not too high fluidizing air flows, pellets of larger size, a smaller pellets load and humidified air to fluidize the pellets resulted in more uniform coatings and, consequently, in more favorable release profiles that did not present or presented a reduced initial burst release

Cross-sectional structure evolution of phase-separated spin-coated ethylcellulose/hydroxypropylcellulose films during solvent quenching

Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. The films are applied on the pellets using fluidized bed spraying. The drug transport rate is determined by the structure of the porous films that are formed as the water-soluble HPC leaches out. However, a detailed understanding of the evolution of the phase-separated structure during production is lacking. Here, we have investigated EC/HPC films produced by spin-coating, which mimics the industrial manufacturing process. This work aimed to understand the structure formation and film shrinkage during solvent evaporation. The cross-sectional structure evolution was characterized using confocal laser scanning microscopy (CLSM), profilometry and image analysis. The effect of the EC/HPC ratio on the cross-sectional structure evolution was investigated. During shrinkage of the film, the phase-separated structure undergoes a transition from 3D to nearly 2D structure evolution along the surface. This transition appears when the typical length scale of the phase-separated structure is on the order of the thickness of the film. This was particularly pronounced for the bicontinuous systems. The shrinkage rate was found to be independent of the EC/HPC ratio, while the initial and final film thickness increased with increasing HPC fraction. A new method to estimate part of the binodal curve in the ternary phase diagram for EC/HPC in ethanol has been developed. The findings of this work provide a good understanding of the mechanisms responsible for the morphology development and allow tailoring of thin EC/HPC films structure for controlled drug release

Three-dimensional reconstruction of porous polymer films from FIB-SEM nanotomography data using random forests

Combined focused ion beam and scanning electron microscope (FIB-SEM) tomography is a well-established technique for high resolution imaging and reconstruction of the microstructure of a wide range of materials. Segmentation of FIB-SEM data is complicated due to a number of factors; the most prominent is that for porous materials, the scanning electron microscope image slices contain information not only from the planar cross-section of the material but also from underlying, exposed subsurface pores. In this work, we develop a segmentation method for FIB-SEM data from ethyl cellulose porous films made from ethyl cellulose and hydroxypropyl cellulose (EC/HPC) polymer blends. These materials are used for coating pharmaceutical oral dosage forms (tablets or pellets) to control drug release. We study three samples of ethyl cellulose and hydroxypropyl cellulose with different volume fractions where the hydroxypropyl cellulose phase has been leached out, resulting in a porous material. The data are segmented using scale-space features and a random forest classifier. We demonstrate good agreement with manual segmentations. The method enables quantitative characterization and subsequent optimization of material structure for controlled release applications. Although the methodology is demonstrated on porous polymer films, it is applicable to other soft porous materials imaged by FIB-SEM. We make the data and software used publicly available to facilitate further development of FIB-SEM segmentation methods. Lay Description For imaging of very fine structures in materials, the resolution limits of, e.g. X-ray computed tomography quickly become a bottleneck. Scanning electron microscopy (SEM) provides a way out, but it is essentially a two-dimensional imaging technique. One manner in which to extend it to three dimensions is to use a focused ion beam (FIB) combined with a scanning electron microscopy and acquire tomography data. In FIB-SEM tomography, ions are used to perform serial sectioning and the electron beam is used to image the cross section surface. This is a well-established method for a wide range of materials. However, image analysis of FIB-SEM data is complicated for a variety of reasons, in particular for porous media. In this work, we analyse FIB-SEM data from ethyl cellulose porous films made from ethyl cellulose and hydroxypropyl cellulose (EC/HPC) polymer blends. These films are used as coatings for controlled drug release. The aim is to perform image segmentation, i.e. to identify which parts of the image data constitute the pores and the solid, respectively. Manual segmentation, i.e. when a trained operator manually identifies areas constituting pores and solid, is too time-consuming to do in full for our very large data sets. However, by performing manual segmentation on a set of small, random regions of the data, we can train a machine learning algorithm to perform automatic segmentation on the entire data sets. The method yields good agreement with the manual segmentations and yields porosities of the entire data sets in very good agreement with expected values. The method facilitates understanding and quantitative characterization of the geometrical structure of the materials, and ultimately understanding of how to tailor the drug release

Structure formation and coarsening kinetics of phase-separated spin-coated ethylcellulose/hydroxypropylcellulose films

Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport from pharmaceutical pellets. The drug transport rate is determined by the structure of the porous films that are formed as water-soluble HPC leaches out. However, a detailed understanding of the evolution of the phase-separated structure in the films is lacking. In this work, we have investigated EC/HPC films produced by spin-coating, mimicking the industrial fluidized bed spraying. The aim was to investigate film structure evolution and coarsening kinetics during solvent evaporation. The structure evolution was characterized using confocal laser scanning microscopy and image analysis. The effect of the EC:HPC ratio (15 to 85 wt% HPC) on the structure evolution was determined. Bicontinuous structures were found for 30 to 40 wt% HPC. The growth of the characteristic length scale followed a power law, L(t) ∼ t(n), with n ∼ 1 for bicontinuous structures, and n ∼ 0.45-0.75 for discontinuous structures. The characteristic length scale after kinetic trapping ranged between 3.0 and 6.0 μm for bicontinuous and between 0.6 and 1.6 μm for discontinuous structures. Two main coarsening mechanisms could be identified: interfacial tension-driven hydrodynamic growth for bicontinuous structures and diffusion-driven coalescence for discontinuous structures. The 2D in-plane interface curvature analysis showed that the mean curvature decreased as a function of time for bicontinuous structures, confirming that interfacial tension is driving the growth. The findings of this work provide a good understanding of the mechanisms responsible for morphology development and open for further tailoring of thin EC/HPC film structures for controlled drug release

New characterization measures of pore shape and connectivity applied to coatings used for controlled drug release

Pore geometry characterization-methods are important tools for understanding how pore structure influences properties such as transport through a porous material. Bottlenecks can have a large influence on transport and related properties. However, existing methods only catch certain types of bottleneck effects caused by variations in pore size. We here introduce a new measure, geodesic channel strength, which captures a different type of bottleneck effect caused by many paths coinciding in the same pore. We further develop new variants of pore size measures and propose a new way of visualizing 3-D characterization results using layered images. The new measures together with existing measures were used to characterize and visualize properties of 3-D FIB-SEM images of three leached ethyl-cellulose/hydroxypropyl-cellulose films. All films were shown to be anisotropic, and the strongest anisotropy was found in the film with lowest porosity. This film had very tortuous paths and strong geodesic channel-bottlenecks, while the paths through the other two films were relatively straight with well-connected pore networks. The geodesic channel strength was shown to give important new visual and quantitative insights about connectivity, and the new pore size measures provided useful information about anisotropies and inhomogeneities in the pore structures. The methods have been implemented in the freely available software MIST

Correlating 3D porous structure in polymer films with mass transport properties using FIB-SEM tomography

Porous polymer coatings are used to control drug release from pharmaceutical products. The coating covers a drug core and depending on the porous structure, different drug release rates are obtained. This work presents mass transport simulations performed on porous ethyl cellulose films with different porosities. The simulations were performed on high spatial resolution 3D data obtained using a focused ion beam scanning electron microscope. The effective diffusion coefficient of water was determined using a diffusion chamber. Lattice Boltzmann simulations were used to simulate water diffusion in the 3D data. The simulated coefficient was in good agreement with the measured coefficient. From the results it was concluded that the tortuosity and constrictivity of the porous network increase with decreasing amount of added hydroxypropyl cellulose, resulting in a sharp decrease in effective diffusion. This work shows that high spatial resolution 3D data is necessary, and that 2D data is insufficient, in order to predict diffusion through the porous structure with high accuracy