| 1. |
- Alexander, James N.
(författare)
-
Novel detection schemes and high resolution separations in microcolumn liquid separations
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Three micro detectors were developed and studied using micro-liquidchromatography (micro-LC). An evaporative light scattering detector (ELSD) nebulizer was developed for use with flow rates ranging from 0.5 to 10 µL/min. The parameters that affect analyte response were investigated and the most influential were capillary tip position and nebulization gas flow rate. One unique advantage of thismicro detector is that it can be operated at ambient conditions which allows for the analysis of semi-volatile compounds.A radio activity monitor (RAM) flow cell was developed for use at 3 µL/min and was designed for coupling to mass spectrometry (MS). The parameters that affect analyte response and band broadening were studied. Reducing the solid scintillant particle size to 9 µm and efficiently packing the solid cells allowed for direct coupling to MS without compromising the chromatographic separation.A nano-electrospray ionization (BSI) source for MS was developed and coupled to nano-LC and capillary electrophoresis (CE). This source incorporated a 50 µm i.d. stainless steel tip that was coupled to the separation capillary. At flow rates of 100 nL/min a stable electrospray was achieved.A multi-use separations system was developed for isocratic and gradient elution micro-LC, capillary electrochromatography (CEC), and pressure CEC (PEC). The details of the system and studies on peak area and retention time repeatability are reported. Comparisons are made between nano-LC and CEC. On average, column efficiency is 57% greater for CEC compared to nano-LC using the same nanocolumn.
|
|
| 2. |
- Gorgijevski, Alexander N., 1991-
(författare)
-
Enter the Dragon : Toward a Micro-political View on Subsidiary Initiatives
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Subsidiary initiatives are proactive, entrepreneurial activities that arise locally without central directives or planning from headquarters. Prior research suggests that subsidiary initiatives are crucial to multinational corporations’ (MNCs) success in foreign locations as they hold the potential to enhance local responsiveness, worldwide learning, and global integration by the leveraging of new knowledge. However, subsidiary-driven initiatives are often met with resistance in the corporate structure, by virtue of headquarters’ limited capacity to pay attention to all stimuli, initiative misalignment to the MNC, or overall self-interest-seeking behavior. Against this background, the MNC is conceptualized as a ‘politicized forum’ where subsidiary managers strategize initiatives upwards. Consequently, a micro-political process emerges from subsidiary managers’ proactive activities. The purpose of this thesis is to investigate the role of micro-politics play in earning headquarters approval of subsidiary initiatives and how these actions may lead to increased subsidiary influence in the MNC.The empirical material consists of proprietary survey and interview data on MNC subsidiaries in Sweden. The primary respondents and informants have been top subsidiary managers, seen as the senior directors of the subsidiary and the MNCs’ top representatives in the local environment. The empirical findings, triangulated through different methodological approaches, illustrate subsidiary initiatives as complex phenomenon. The study implies that headquarters’ approval of subsidiary initiatives is contingent on several key managerial activities, as well as relational- and contextual conditions. Overall, the results lend support for the value of attracting headquarters’ attention in order for initiatives to gain traction and eventually become accepted in the MNC. Attention to initiatives is captivated by the socio-political navigation of subsidiary managers, such as their engagement in initiative-selling. Establishing credibility at headquarters through attention-building activities may also result in increased subsidiary strategic influence.This thesis shows that initiatives that challenge the status quo of the MNC may initially be rejected, but are able to ‘survive’ due to a variety of micro-political behaviors of individual managers. Furthermore, the thesis also explicates different combinatory effects on the pathways to initiative acceptance. The thesis extends the subsidiary management literature by providing nuance to the theoretical understanding of key underlying mechanisms and their effects on subsidiary-focused outcomes. Establishing subsidiary managers as ‘strategizers’ and conceptualizing the subsidiary initiative process from a micro-political view contributes to the theoretical understanding of subsidiary initiatives in the MNC by complementing traditional evolutionary perspectives.
|
|
| 3. |
|
|
| 4. |
- Vastesson, Alexander
(författare)
-
Thiol-ene and Thiol-ene-epoxy Based Polymers for Biomedical Microdevices
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Within healthcare there is a market pull for biomedical devices that can rapidly perform laboratory processes, such as diagnostic testing, in a hand-held format. For this reason, biomedical devices must become smaller, more sophisticated, and easier to use for a reasonable cost. However, despite the accelerating academic research on biomedical microdevices, and especially plastic-based microfluidic chips, there is still a gap between the inventions in academia and their benefit to society. To bridge this gap there is a need for new materials which both exhibit similar properties as industrial thermoplastics, and that enable rapid prototyping in academia.In this thesis, thiol-ene and thiol-ene-epoxy thermosets are evaluated both in terms of their suitability for rapid prototyping of biomedical microdevices and their potential for industrial manufacturing of “lab-on-chips”.The first part of the thesis focuses on material development of thiol-ene and thiol-ene-epoxy thermosets. Chemical and mechanical properties are studied, as well as in vitro biocompatibility with cells.The second part of the thesis focuses on microfabrication methods for both thermosets. This includes reaction injection molding, photostructuring, and surface modification. It is demonstrated how thiol-ene and thiol-ene-epoxy both provide advantageous thermo-mechanical properties and versatile surface modifications via “thiol-click chemistry”.In the end of the thesis, two applications for both polymer platforms are demonstrated. Firstly, thiol-ene is used for constructing nanoliter well arrays for liquid storage and on-demand electrochemical release. Secondly, thiol-ene-epoxy is used to enhance the biocompatibility of neural probes by tuning their flexibility.It is concluded that both thiol-ene and thiol-ene-epoxy thermosets exhibit several properties that are highly suitable for rapid prototyping as well as for scalable manufacturing of biomedical microdevices.
|
|
