24 research outputs found
Midgut malrotation with volvulus discovered at an emergency caesarean section for placental abruption
Adult midgut malrotation with volvulus (AMMV) is an uncommon presentation which may be found incidentally during abdominal radiologic investigations or at laparotomy. We report a case of AMMV and small bowel gangrene in a 35-year-old Gravida four, Para three at 39 weeks, 4 days gestation who presented with a short history of worsening abdominal pain, repeated vomiting and abdominal wall guarding. Emergency caesarean section performed on account of a suspected placental abruption incidentally revealed a long segment of non-viable small intestine. Subsequent midline laparotomy disclosed a midgut malrotation with volvulus and bowel gangrene. This resulted in a 4.6m resection of non-viable small bowel with Laddâs procedure. The patient developed moderate symptoms of short bowel syndrome in the post-operative period which was successfully managed non-operatively. This case report represents a rare diagnosis, in the West-African sub-region, of an adult midgut malrotation with volvulus mimicking a third trimester obstetric emergency
Use of a porous membrane for gas bubble removal in microfluidic channels: physical mechanisms and design criteria
We demonstrate and explain a simple and efficient way to remove gas bubbles
from liquid-filled microchannels, by integrating a hydrophobic porous membrane
on top of the microchannel. A prototype chip is manufactured in hard,
transparent polymer with the ability to completely filter gas plugs out of a
segmented flow at rates up to 7.4 microliter/s per mm2 of membrane area. The
device involves a bubble generation section and a gas removal section. In the
bubble generation section, a T-junction is used to generate a train of gas
plugs into a water stream. These gas plugs are then transported towards the gas
removal section, where they slide along a hydrophobic membrane until complete
removal. The system has been successfully modeled and four necessary operating
criteria have been determined to achieve a complete separation of the gas from
the liquid. The first criterion is that the bubble length needs to be larger
than the channel diameter. The second criterion is that the gas plug should
stay on the membrane for a time sufficient to transport all the gas through the
membrane. The third criterion is that the gas plug travel speed should be lower
than a critical value: otherwise a stable liquid film between the bubble and
the membrane prevents mass transfer. The fourth criterion is that the pressure
difference across the membrane should not be larger than the Laplace pressure
to prevent water from leaking through the membrane
Scenario-Driven Supply Chain Charaterization Using a Multi-Dimensional Approach
Extreme disruptive events, such as the volcano eruption in Iceland, the Japanese tsunami, and the COVID-19 pandemic, as well as constant changes in customersâ needs and expectations, have forced supply chains to continuously adapt to new environments. Consequently, it is paramount to understand the supply chain characteristics for possible future scenarios, in order to know how to respond to threats and take advantage of the opportunities that the next years will bring. This chapter focuses on describing the characteristics of the supply chain in each of the six macro-scenarios presented in Sardesai et al. (2020b), as final stage of the scenario building methodology. Supply chains for each scenario are characterized in eight dimensions: Products and Services, Supply Chain Paradigm, Sourcing and Distribution, Technology Level, Supply Chain Configuration, Manufacturing Systems, Sales Channel, and Sustainability
Parameter Estimation and Sensitivity Analysis of Lumped Kinetic Models for Wet Oxidation of Concentrated Wastewaters
Examining relational digital transformation through the unfolding of local practices of the Finnish taxi industry
Abstract
Digital transformation has become a central construct in information systems (IS) research. Current conceptualizations largely attribute transformation to intentionality, focus on transformation within a single organization, or assign technology the role of a disruptive agent of change. Likewise, âdigitalâ tends to be a general category of technology, rather than a specific technology enacted in a time and place. Inspired by Schatzkian practice theory and its site ontology, we suggest a contextual viewpoint on digital transformation and call it ârelational digital transformation.â We analyzed the change dynamics in the context of taxi dispatch practice in Finland, studying the changing taxi dispatch platforms over years. We investigated five powerful industry actors: two incumbents, two entrants, and a federation of taxi entrepreneurs. We identified events of change in the material arrangements in sites and explain the changes through the process dynamics in the focal practice. We define relational digital transformation as a process through which practice-arrangement bundles of digital technologies evolve over time. This approach assumes the default nature of an industry is to be found in the changing relations between entities rather than in entities themselves. This provides a theoretical extension to the prevailing views of digital transformation in IS literature. It enables studying digital transformation in retrospect without attributing change agency to any entities or technologies a priori. We also contribute to practice-theoretical IS literature by demonstrating how the applicability of practice theoretical analysis extends beyond microphenomena to larger industry-level changes
Decidedly undecided change:producing spielraum for organizational periphery
Abstract
Extant strategy practice and process studies highlight the duality of change and stability, regarding strategic change as an accomplishment of both movement and recursiveness, which are also displayed by the observed difference in strategy-making between the organizational centre and its periphery. In this study, we examine the emergence of new strategic themes and related organizing in two research universitiesâ organizational peripheries. By adopting a systems-theoretical view and drawing on Luhmannian organizational analysis, we are able to examine the co-existence of stability and change in each communication event, aiming to reduce complexity but also giving rise to novel complexities, providing âspielraumâ for peripheral development activities. The study contributes to the SAPP-oriented stream of studies on strategic change in general and emergent strategy studies in particular by providing an alternative theoretical viewpoint on the centre-periphery dynamics in strategic change and showing how organizations un/decide on new strategic themes, and through what dynamics they might become introduced and organized in established organizations
Policy ambiguity:a problem, a tool, or an inherent part of policymaking?
Abstract
It has been acknowledged that the Information Systems (IS) discipline needs to pay attention to policymaking. However, the IS field has not yet sufficiently acknowledged complexities of policymaking and the resulting ambiguity. We present two worldviews that underlie how IS research has approached policymaking and, indirectly, policy ambiguity. In the dominant ârepresentationalistâ view, a policy is planned and implemented in a linear manner, and ambiguity is seen as problematic. The âenactivistâ view sees a policy and its implementation as mutually constitutive: a policy does not exist without its implementation but it also guides the implementation. This can result in unresolvable paradoxes that manifest as ambiguities. Based on our review of the extant IS research we present existing perspectives to policy(making) and ambiguity. We call for IS researchers invested in policy/regulation-related research to be aware of and explicit about the views to policy(making) and ambiguity guiding their research
Process modelling and feasibility study of sorption-enhanced methanol synthesis
Abstract
A sorption-enhanced process for hydrogenation of COâ to methanol was designed and investigated by mathematical modelling and techno-economic analysis. The modelling methodology combined dynamic modelling of the cyclic reactor operation with pseudo-steady state modelling of the overall process. With continuous adsorption of water in the sorption-enhanced process, highly pure methanol (>99%) was produced without downstream distillation. The dynamic reactor cycle was designed and optimized to maximize the methanol production rate. The cycle and the process were modelled in two reactor configurations: adiabatic and isothermal. Under the default cost assumptions for the raw materials (COâ 50 âŹ/t, hydrogen 3000 âŹ/t) the adiabatic configuration was found more competitive in terms of the overall methanol production cost, at 1085 âŹ/t compared to 1255 âŹ/t for the isothermal case. The cost estimate for the adiabatic case was found comparable to a reference process representing conventional COâ hydrogenation to methanol (1089 âŹ/t). In addition to the methanol process, the developed modeling method has potential in the design of other sorption-enhanced processes
Is a taximeter a guarantee of honesty or a barrier to entry?:exploring technology discourses as consequences of policy ambiguity
Abstract
Information Systems (IS) researchers have become increasingly interested in policy. Government policy enables and constrains the range of technologies operating on the market. In the spirit of enabling innovation, governments around the world have moved to the principle of technological neutrality: regulating goals instead of specific technologies. In this paper, we focus on the legislative context of the Finnish taxi industry. Finlandâs previous legislation mandated all taxicabs to be equipped with a taximeter, while prohibiting other vehicle classes from using it. Finlandâs recent deregulation reform The Act on Transport Services adopted the principle of technology neutrality and thus introduced deliberate ambiguity into legal text. This ambiguity leaves room for different stakeholders to construct their own interpretations. For this paper, we conducted 19 interviews with five stakeholder types in the Finnish taxi industry and related regulatory bodies: legislators, legislation implementers, new entrants, incumbent taxi industry, and incumbent technology providers. We found how policy ambiguity opened a plethora of contesting discourses about what this seemingly mundane technology is for. We depart from the mainstream conception of policy, which views policy as a âbest practiceâ that can be easily transferred across contexts. Instead, we call for more attention to policy ambiguity, multi-stakeholder policy contexts, and conflicting power interests