Sabine Otten

This chapter gives biographical information, and, more importantly, summarizes Sabine Otten's mein areas of research interests and -findings

Modeling soil system:complexity under your feet

This is an introductory articl

Challenges in imaging and predictive modeling of rhizosphere processes

Background Plant-soil interaction is central to human food production and ecosystem function. Thus, it is essential to not only understand, but also to develop predictive mathematical models which can be used to assess how climate and soil management practices will affect these interactions. Scope In this paper we review the current developments in structural and chemical imaging of rhizosphere processes within the context of multiscale mathematical image based modeling. We outline areas that need more research and areas which would benefit from more detailed understanding. Conclusions We conclude that the combination of structural and chemical imaging with modeling is an incredibly powerful tool which is fundamental for understanding how plant roots interact with soil. We emphasize the need for more researchers to be attracted to this area that is so fertile for future discoveries. Finally, model building must go hand in hand with experiments. In particular, there is a real need to integrate rhizosphere structural and chemical imaging with modeling for better understanding of the rhizosphere processes leading to models which explicitly account for pore scale processes

Design of a gas force simulator for the MIT Electromechanical Valve Drive project

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaf 29).The MIT electromechanical Valve Drive (EMVD) is a continuously variable valve actuation device for an automotive internal combustion engine. Current experimentation of the EMVD has been limited to intake valve events. When the exhaust valve opens into the cylinder it must do so against gas forces arising from high pressure in the engine cylinder. This gas force causes power losses in the EMVD. A gas force simulator has been designed to simulate the pressure acting against the exhaust valve in the engine cylinder. This allows the power loss as a result of the gas force to be measured for the EMVD.by James S. Otten.S.B

System optimization of gasdynamic lasers, computer program user's manual

The user's manual for a computer program that performs system optimization of gasdynamic lasers is provided. Detailed input/output formats are CDC 7600/6600 computers using a dialect of FORTRAN. Sample input/output data are provided to verify correct program operation along with a program listing

The Effect of Gender Equality on International Soccer Performance

In this article, we propose a new estimation strategy that draws on the variation in the performance between the male and the female national soccer team within a country to identify the effect of gender equality on women’s soccer success. For this, country year fixed effects are used to control for both time-constant and time-variant country specific factors. Our results reveal that within-country differences in our proxies for gender equality explain the international soccer performance of female teams, but have no notable explanatory power for the success of male teams. This suggests that gender equality is an important determinant of female sport success

The efforts of direct support professionals to facilitate inclusion:The role of psychological determinants and work setting

BackgroundVarious studies have found that direct support professionals (DSPs) play an important role in determining the degree to which people with intellectual disabilities (ID) are included in society. However, less research has been conducted on the psychological processes that may influence the behavioural intentions of DSPs to actually engage with and invest effort in supporting their clients' inclusion. Five possible psychological variables are identified in the literature: attitudes, social norms, experienced competencies, identity and meta‐evaluation. In our research, we tested whether these processes influence the (intended) efforts DSPs make to facilitate their clients' inclusion.MethodA structured questionnaire was sent to 927 DSPs working in one of three different locations (an ordinary non‐segregated setting, a reversed non‐segregated setting and a residential facility). Of these, 336 DSPs completed the questionnaire.ResultsSeveral variables revealed differences between the three locations, specifically in efforts to facilitate inclusion, attitudes, social norms, experienced competencies and professional identity. Looking at the overall means, we found (relatively) high scores for the experienced competencies, role identity and meta‐evaluation. In contrast, the means were relatively negative regarding the DSPs' attitudes to inclusion and their assumed social norms.ConclusionsDirect support professionals' efforts to facilitate inclusion depend on their attitude towards inclusion, the experienced competencies, their role identity, the DSPs' meta‐evaluation and, indirectly through attitudes, also on the assumed social norms of the relevant stakeholders. Organizations responsible for supporting people with ID and which may want their DSPs to make greater efforts to facilitate inclusion should pay attention to these psychological variables

Exploring the extended density-dependent Skyrme effective forces for normal and isospin-rich nuclei to neutron stars

We parameterize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resulting Skyrme parameters can be suitably used to model the neutron star with the "canonical" mass ($\sim 1.4 M_\odot$). For the appropriate comparison we generate a parameter set for the standard Skyrme effective force (SSEF) using exactly the same set of the data as employed to determine the parameters of the GSEF. We find that the GSEF yields larger values for the neutron skin thickness which are closer to the recent predictions based on the isospin diffusion data. The Skyrme parameters so obtained are employed to compute the strength function for the isoscalar giant monopole, dipole and quadrupole resonances. It is found that in the case of GSEF, due to the the larger value of the nucleon effective mass the values of centroid energies for the isoscalar giant resonances are in better agreement with the corresponding experimental data in comparison to those obtained using the SSEF. We also present results for some of the key properties associated with the neutron star of "canonical" mass and for the one with the maximum mass.Comment: 45pages, 16 figure

Electromechanical tuning of vertically-coupled photonic crystal nanobeams

We present the design, the fabrication and the characterization of a tunable one-dimensional (1D) photonic crystal cavity (PCC) etched on two vertically-coupled GaAs nanobeams. A novel fabrication method which prevents their adhesion under capillary forces is introduced. We discuss a design to increase the flexibility of the structure and we demonstrate a large reversible and controllable electromechanical wavelength tuning (> 15 nm) of the cavity modes.Comment: 11 pages, 4 figure