Nondimensional representations for occulter design and performance evaluation

Jena-Optronik GmbH (JOP) has a strong heritage in the development of cameras for numerous space-based applications. So far, our focus has been on cameras working in the visible & near-infrared range of the spectrum. The main application case for these cameras is the use as autonomous star trackers being part of a satellite’s Guidance, Navigation & Control System. JOP has been very successful with these cameras –for a long time and is the world market leader in providing such sensors to satellite prime manufactures. Investigating the possible applications of cameras in space, one realizes that thermal or long wave infrared (IR) cameras are necessary for specific applications. One major field for several of such applications is the field of Space Situational Awareness (SSA). SSA has been attracting more and more attention over the past years especially for space objects, natural debris as well as man-made threats & disturbances such as military conflicts. Two further application fields for IR cameras are formation flying and docking. The first rendezvous and docking with a non-cooperative satellite (Intelsat 901) in geostationary orbit by Northrop Grummans MEV-1 was a key milestone for docking capabilities. Additionally, the recent years have shown that a transition from few big and multi-purpose satellites towards small, medium or even large constellations consisting of numerous small satellites is taking place. Especially for constellations, a key aspect is formation flying which usually requires relative navigation. The relative angles between the satellites can be easily provided by IR cameras as they detect the satellites reliably and independently of local lighting conditions due to their elevated temperature against the cold space background. Based on the very successful ASTRO product range of space proven cameras, ASTROtir (tir = thermal infra-red) will extend JOPs product capabilities into the thermal / long wave infrared (LWIR) wavelength range to cover all of the applications cases listed above. Following a successful ESA co-funded first evaluation, the ASTROtir development project has been kicked-off in December 2022 in cooperation with ESA. Target of this project is to demonstrate TRL8 of ASTROtir. Future applications are formation flying (relative navigation), approach and docking with a non-cooperative space object as well as detailed image generation of near satellite objects. Currently, no European solution for an IR camera covering the application cases and mission scenarios is available as off-the-shelf product, which further increases ASTROtir’s already promising market potential. As the market demand, especially in the field of SSA, is rising further in the coming years, its development will be closely followed and its market entry is eagerly awaited. Jena-Optronik will present the preliminary design and development status of ASTROtir. As ASTROtir aims primarily at applications on small and medium satellites, its target mass budget of 300g is a driving requirement. Following our intermediate / preliminary design review scheduled for August 2023, Jena-Optronik aims at presenting first results from ASTROtir’s system analyses as well as the related plans for the EM and EQM campaigns.

We carried out a set of experiments to compare three particle number concentration standards (NCSs) by calibrating the same condensation particle counter (CPC) unit (Model 3772, TSI Inc., Shoreview, MN, USA). The standards were, in the order of operation size range, the primary NCS of the National Institute of Advanced Industrial Science and Technology (AIST, Japan), the Single Charged Aerosol Reference (SCAR) (Finland), and the Inkjet Aerosol Generator (IAG) of AIST. The results obtained with the 3 standards were found to agree at all overlapping particle sizes within the uncertainty limits. The relative expanded uncertainties varied between 0.6% and 2.6%, depending on the size and standard, while the overall agreement between the standards was within 0.5%. The observed consistency of the results is an important step toward establishing internationally coherent particle NCSs. As a result, the CPC 3772 was successfully calibrated in a particularly wide size range, approximately from 10 nm to 10 μm. The re...

We developed a Digital Holographic Microscope (DHM) working with a partial coherent source specifically adapted to perform high throughput recording of holograms of plankton organisms in-flow, in a size range of 3 µm-300 µm, which is of importance for this kind of applications. This wide size range is achieved with the same flow cell and with the same microscope magnification. The DHM configuration combines a high magnification with a large field of view and provides high-resolution intensity and quantitative phase images refocusing on high sample flow rate. Specific algorithms were developed to detect and extract automatically the particles and organisms present in the samples in order to build holograms of each one that are used for holographic refocusing and quantitative phase contrast imaging. Experimental results are shown and discussed.

Spacecraft formation flying has received an enor- mous amount of attention over the past few years as a promising alternative to monolithic- and often large- space structures. Balanced optimal energy control of such distributed space systems guarantees maximum lifetime for these missions and hence is of great importance in mission feasibility studies. In this paper, an optimal control strategy for two and three spacecraft distributed space systems that are commanded to attain new relative coordinates, is proposed, guaranteeing balanced energy consumption among the spacecraft. We will delineate on the relevant mission scenarios both in deep space as well as in close proximity to a gravitational force field as in Earth's orbit. Index Terms— Formation flying, balanced energy reconfig- urations, optimal control

Technology Update Advances in drilling and reaming with casing or liners (DwC, DwL, RwC, and RwL) are yielding unprecedented capabilities in well design and construction. These innovations reflect the continued evolution of a versatile system of technologies that has grown in two decades from a tool to improve efficiency and mitigate drilling hazards to a system enabling advanced wellbore construction. Advancing the Technology Modern DwC involves a suite of capabilities for drilling and reaming with either the primary string or liner. The concept has a long history. In the 1950s, the production sections of wells were drilled using tubing that was ultimately cemented in the hole without recovering the bit. Slimhole coring technology from the mining industry was tried in the 1990s in an effort to improve exploration efficiency. Over the next decade, DwC technology and versatility grew. In addition to eliminating nonproductive time (NPT) tripping drillpipe out of the hole and the associated wellbore problems, DwC emerged as an effective means of proactively mitigating wellbore instability, lost circulation, and pressure transition issues. The introduction of an integrated casing drive system in the early 2000s enabled the safe and efficient rotation, reciprocation, and circulation of the casing, which led to other benefits such as ensuring high-integrity cementing and zonal isolation. Advances in casing bit design began to resolve the inherent challenge of durability vs. subsequent drillout. With growing wellbore complexity and challenges, DwC technology evolved from discrete hazard mitigation to a larger capability well plan optimization. Greater capability advanced the end objective from solving an immediate problem to constructing a high-integrity wellbore—as designed and to the total depth (TD). The latest innovations continue this wellbore construction advance on multiple fronts. Strengthening the Wellbore Plastering has been one of the more intriguing and elusive benefits of DwC techniques. The so-called smear effect crushes cuttings against the formation to form a barrier to circulation losses and enhance wellbore stability. But achieving it on a regular, predictable basis has been difficult. Plastering occurs in some wells but not in others. A greater understanding of this process is providing the means to produce and accelerate wellbore plastering reliably, thus substantially strengthening the wellbore. The first field application of the process is planned. Research has shown that the key to plastering is the concurrence of the formation’s permeability and fracture matrix with a wide range of particle sizes in the annulus. If these factors do not correspond, plastering does not occur. The main variables are the range of particle sizes and the speed of achieving an optimal size distribution. While grinding in the casing wellbore annulus can reduce cuttings to a wide range of size over time, the delay in achieving the appropriate distribution allows time for problems to develop. Early achievement of the optimal particle distribution is critical to success.

The static recrystallization kinetics of four steels microalloyed with Nb, Ti and Nb–Ti have been investigated, covering conventional and hot direct rolling conditions. The influence of the grain size on the recrystallization time has been studied for a wide range of grain sizes (20–1000 μm). For the same deformation conditions it has been observed that the quadratic dependence on grain size works well in the range of finergrain sizes (<160 μm). In contrast, the recrystallization times measured at coarse grain sizes are significantly lower than those predicted by this dependence. However, when the whole grain size range analysed is considered, a linear dependence on grain size gives the best fit to experimental data. The effect of strain on the recrystallization kinetics has been also analysed for different initial grain sizes. It has been observed that the time to reach a 50% recrystallized fraction (t0.5) shows a dependence on strain of the type t0.5∝ε-p, the exponent being influenced by the initial grain size. A unique equation has been proposed to describe the static recrystallization kinetics of Nb, Ti and Nb–Ti microalloyed steels. The predictions of the equations have been compared to previously published data on similar steels.

Dimension estimation of image manifolds by minimal cover approximation

To evaluate the ability of 100/Sn140 kV (Sn, tin filter) dual-energy computed tomography (CT) to differentiate urinary stone types in a patient cohort with a wide range of body sizes. Eighty human urinary stones were categorised into four groups (uric acid; cystine; struvite, oxalate and brushite together; and apatite) and imaged in 30-50-cm-wide water tanks using clinical 100/Sn140 kV protocols. The CT number ratio (CTR) between the low- and high-energy images was calculated. Thresholds for differentiating between stone groups were determined using receiver operating characteristics (ROC) analysis. Additionally, 86 stones from 66 patients were characterised using the size-adaptive CTR thresholds determined in the phantom study. In phantoms, the area under the ROC curve for differentiating between stone groups ranged from 0.71 to 1.00, depending on phantom size. In patients, body width ranged from 28.5 to 50.0 cm, and 79.1 % of stones were correctly characterised. Sensitivity and specificity for correctly identifying the stone category were 100 % and 100 % (group 1), 100 % and 95.3 % (group 2), 85.7 % and 60.9 % (group 3), and 52.6 % and 92.5 % (group 4). Dual-energy CT can provide in vivo urinary stone characterisation for patients over a wide range of body sizes. • Dual-energy CT helps assessment of urinary stone composition in vivo. • 100/Sn140 kV DECT differentiates among four stone types with 79.1 % accuracy. • In vivo diagnostic test achievable in patients with many body sizes.

A new 5-parameter MOS transistor mismatch model is introduced capable of predicting transistor mismatch with very high accuracy for ohmic and saturation strong inversion regions, including short channel transistors. The new model is based on splitting the contribution of the mobility degradation parameter mismatch into two components, and modulating them as the transistor transitions from ohmic to saturation regions. The model is tested for a wide range of transistor sizes (30), and shows excellent precision, never reported before for such a wide range of transistor sizes, including short channel transistors.

To verify previously reported findings for the European Medicines Agency's method for Average Bioequivalence with Expanding Limits (ABEL) for assessing highly variable drugs and to extend the assessment for other replicate designs in a wide range of sample sizes and CVs. To explore the properties of a new modified method which maintains the consumer risk ≤0.05 in all cases. Monte-Carlo simulations of three different replicate designs covering a wide range of sample sizes and intra-subject variabilities were performed. At the switching variability of CV wR 30% the consumer risk is substantially inflated to up to 9.2%, which translates into a relative increase of up to 84%. The critical region of inflated type I errors ranges approximately from CV wR 25 up to 45%. The proposed method of iteratively adjusting α maintains the consumer risk at the desired level of ≤5% independent from design, variability, and sample size. Applying the European Medicines Agency's ABEL method at the nominal level of 0.05 inflates the type I error to an unacceptable degree, especially close to a CV wR of 30%. To control the type I error nominal levels ≤0.05 should be employed. Iteratively adjusting α is suggested to find optimal levels of the test.

We present the use of microfluidic "V-junctions" as a droplet generation strategy that incorporates enhanced performance characteristics when compared to more traditional "T-junction" formats. This includes the ability to generate target-sized droplets from the very first one, efficient switching between multiple input samples, the production of a wide range of droplet sizes (and size gradients) and the facile generation of droplets with residence time gradients. Additionally, the use of V-junction droplet generators enables the suspension and subsequent resumption of droplet flows at times defined by the user. The high degree of operational flexibility allows a wide range of droplet sizes, payloads, spacings and generation frequencies to be obtained, which in turn provides for an enhanced design space for droplet-based experimentation. We show that the V-junction retains the simplicity of operation associated with T-junction formats, whilst offering functionalities normally associated with droplet-on-demand technologies.

Magnetic material in the human hippocampus

The cost of the power consumed by the spinning frame is the principal increased cost to be set against the reduced handling costs obtainable with large packages, and accurate information as to the power requirements of any new or modified ring frame is necessary in spinning room planning. A study has been made of the various processes by which power is consumed in ring spinning. There are six separately measurable components of ring frame power and each of these has been determined, or an empirical rule for its estimation evolved, over a wide range of spinning conditions and package sizes. The results are presented in such a way that the components of total power may be obtained for almost any conceivable ring frame. For ring frames of orthodox design, tables of total power are given covering a wide range of counts, speeds, and package sizes.

The EPR spectra of barium borate glasses containing 0.1, 0.25 and 0.4 wt.% nickel particles respectively have been investigated over the temperature range 77K to 300K. The magnetic susceptibility of these glasses has also been measured between 77K and 700K. Both sets of data indicate the presence of a broad range of transition temperatures below 300K. However, the mean transition temperatures as obtained by the two techniques are different. The results confirm a superparamagnetic behaviour exhibited by the fine nickel particles. The interaction energies between the particles and the transition temperatures have been calculated on the basis of the current model, and the discrepancy of the latter with experimental value is ascribed to the presence of a wide range of particle size.

Summary Geologic and tectonic processes of ophiolite obduction deduced from structural mapping, timing of deformation and metamorphism and palinspastic reconstruction of ancient ophiolite complexes compare closely with modern processes operative in the western Pacific. Many ongoing arguments about the origin of ophiolite complexes (oceanic, island arc or marginal basin) and their emplacement (subduction-related or not) are largely semantic and depend on exactly what individuals regard as island arcs, marginal basins or subduction zones. A review of tectonic processes currently active in the western Pacific region shows a wide range in size, shape and duration of arc-basin complexes and some of these show uniformitarian models similar to those proposed for emplacement of ancient ophiolites. The Tethyan ophiolites of the Semail (Oman Mountains) and Spontang (Western Himalaya of Ladakh-Zanskar) and the Ordovician western Newfoundland ophiolites are compared with recent examples of the Mariana basin, Yap trench, Banda arc, Luzon arc and Papua New Guinea. It is concluded that they are all connected in some way with marginal basins and island arcs in varying stages of development and maturity. Emplacement of these ophiolites is related to continental underthrusting of a trapped marginal basin and accretionary prism comparable to present-day examples of the N Australian margin underthrusting Timor and the Banda Sea and the SE China margin underthrusting the Luzon arc.