Series Of Maneuvers Research Articles

Diving within Saturn's rings.

![Figure][1] A diagram of Cassini's final orbits (blue curves), showing the last ring-grazing orbit and the 22 Grand Finale orbits. IMAGE: NASA JET PROPULSION LABORATORY Launched in 1997, the Cassini spacecraft arrived at Saturn in 2004 and spent the following 12 years orbiting far outside the planet's rings. Among the mission's many discoveries were potentially habitable environments on Saturn's moons, including a subsurface ocean of water on Enceladus. To avoid accidental contamination of the moons with any Earth bacteria that might have hitched a ride on the spacecraft, mission planners decided that when Cassini ran out of fuel it would be deliberately crashed into Saturn. As fuel reserves ran low, the spacecraft embarked on a series of maneuvers that took it through previously unexplored regions and ended with its destruction. The first phase was a series of 20 “ring-grazing” orbits in which Cassini passed near the outer edge of the rings. Then the trajectory was shifted to fly through the gap between the planet and the inner edge of the rings, a phase dubbed the “Grand Finale.” Cassini flew through this region 22 times, in various orientations designed to optimize the scientific measurements made by its numerous instruments. Finally, in 2017 Cassini dove into the planet itself at 35 km s−1, leading to the spacecraft's fiery disintegration in the upper atmosphere. The papers in this section present results from those final phases of the mission. They include studies of Saturn's puzzling magnetic field, an isolated inner radiation belt, auroral radio emission, the mass and composition of solid grains falling from the rings toward the planet, and the composition of Saturn's atmosphere. Many more results will follow from Cassini's last period of exploration in the Saturn system. [1]: pending:yes

Swirl mission concept: Unraveling the enigma

During the Apollo era of lunar exploration, mysterious albedo patterns, called swirls, captured the imagination of the scientific community. A key aspect of this interest was due to the discovery that the swirls are associated with localized relatively strong remnant magnetic fields. Analysis of returned soil samples revealed that solar wind, galactic cosmic rays, and micrometeorite impacts change the albedo of surface soil grains, a process known as space weathering that reduces regolith reflectance over time. Thus it was natural to invoke local magnetic structures as shields that retard space weathering resulting in relatively less space weathering of the regolith in regions with the strongest localized magnetic fields. However, the origins of the magnetic anomalies and associated swirls remain enigmatic to this day.We designed the Swirl CubeSat to determine the nature of remnant lunar magnetic fields and investigate their role in moderating space weathering of the regolith and assess their suitability for radiation protection of surface assets. Swirl has one focused observational objective: characterize the magnetic field associated with the Reiner Gamma Swirl (RGS) at sub-kilometer spatial sampling, with 0.5 nTesla accuracy and 100 m spatial precision. In the Swirl mission concept, the Swirl spacecraft, a 6U CubeSat, would deploy as a secondary payload from a vehicle on a deep space trajectory. A series of maneuvers would then place the spacecraft in a low orbit that would then be modified to have a periapse of 5–10 km for thirty orbits passing over RGS. Prime Swirl observations were designed during these low-altitude passes and consist of high-resolution vector magnetic field measurements and monochrome navigation imaging.

Plethysmographic Waveform Devices

Plethysmography is a noninvasive technique which measures volume changes. Common instruments include pneumatic or air plethysmographs and photoplethysmographs. These are used in the vascular laboratory to examine both arterial and venous blood flow. The pulse volume recorder (PVR) is a type of pneumatic plethysmograph which provides estimates of arterial blood flow to a limb or digit. The PVR measures pressures changes in a cuff that are the result of volume changes due to arterial blood flow within a segment of a limb or digit enclosed by the cuff. Another type of air plethysmograph is used to measure volume changes within the entire calf after a series of maneuvers. These changes are impacted by status of the venous system and the venous valves. Photoplethysmography measures reflected infrared light in a small sensor applied to a limb or digit. The amount of light reflected is dependent on the volume of blood present. By alternating the display of these changes in the reflected light signals both arterial inflow and venous refilling can be determined. Plethysmography provides qualitative and quantitative data which can be used to estimate global arterial and venous status.

Military History at the Operational Level: An Interview with Robert M. Citino

Military History at the Operational Level: An Interview with Robert M. Citino Donald A. Yerxa ROBERT CITINO, WHOSE ESSAY ON THE GERMAN WAY OF war appeared in the November 2010 issue of Historically Speaking, is one of the most perceptive military historians writing today. In the last decade he has a written a number of important books on modern military history, particularly the German military experience. These include: Quest for Decisive Victory: From Stalemate to Blitzkrieg in Europe, 1899–1940 (University Press of Kansas, 2002); Blitzkrieg to Desert Storm: The Evolution of Operational Warfare (University Press of Kansas, 2004), winner of both the American Historical Association’s Paul Birdsall Prize in European Military and Strategic History and the Society for Military History’s Distinguished Book Award; The German Way of War: From the Thirty Years’ War to the Third Reich (University Press of Kansas, 2005); and Death of the Wehrmacht: The German Campaigns of 1942 (University Press of Kansas, 2007). In 2007 Citino was named the best university teacher in the U.S. in a RateMyProfessors.com poll. After reading all the books listed above, senior editor Donald Yerxa interviewed Citino in March 2011. Donald A. Yerxa : What prompted you to become a military historian? Robert M. Citino : I always like to answer this question by saying that my father fought in World War II. Of course, that’s no answer at all, because in the time and place I grew up (born on the West Side of Cleveland in 1958), everybody’s father had fought in World War II. When we played in the neighborhood, we played “army,” and the war we fought out was World War II. I guess I just took it a little farther than most of my friends—and for that I blame my parents, who gave all of their children a love of reading. I started reading books on World War II as a child and I have never stopped. So parents, if your child is reading too much, beware! Yerxa : Why did you focus on German military history? Citino : I didn’t go to college to be a military historian. I wanted to be a historian of the Weimar Republic, and was especially enthralled by its culture—Brecht and Zuckmayer and the great filmmakers and musicians. That’s why I decided to learn German. As my scholarly interest in military questions grew, I found myself turning more and more toward German military history, and realized that there was a vast literature auf deutsch that most military historians were not using at all. It seemed like a natural fit. Yerxa : Would it be fair to say that the single most important theme common to all your recent books is the value of appreciating military history at the operational level? And if so, how is operational military history distinguished from other genres of analysis? Citino : Yes, that’s a fair statement. The middle ground between low-level tactics and high-level strategy, what we call the operational level of war, is what my books emphasize. If “tactics” discusses battles, and “strategy” analyzes the war, “operations” refers to the campaign, a series of maneuvers and battles involving big units: divisions, corps, and armies. Click for larger view View full resolution From Friedrich August Dressler, Moltke in his Home (John Murray, 1907). Yerxa : What insights emerge when you look at military history at the operational level? Citino : I don’t make any special claim for operational-level analysis. It isn’t a magic key to understanding warfare, but it has traditionally been underserved in the literature, especially the English-language literature. The Wehrmacht’s signal victory in France in 1940, Case Yellow, for example, is pretty hard to understand if you just look at tactics. French tanks and British aircraft were for the most part superior to the German machines they were facing. Strategically, Germany was in a nearly hopeless situation; without a fleet, Germany had embarked on a long war against the world’s great naval powers. In that middle “operational” ground, however, the Germans came up with a daring campaign plan (sending their panzers though the Ardennes forest) that completely flustered their enemies, a victory...

Real time monitoring the orbit insertion of Chang'E-1 lunar mission

深空探测任务中的轨道机动是保证探测器进入预定轨道的关键环节, 也是实际测控 任务中的重点和难点. 在轨道机动过程中, 探测器通过点火产生自身加速度, 此过程会造成飞行状态不稳定, 使得对卫星机动过程的预测和判定变得更加复杂. 针对这些问题, 结合中国第一个深空探测任务嫦娥一号(CE-1)卫星, 对其轨道机动段, 特别是近月点入轨制动这一关键弧段, 提出了基于视向速度对探测器飞行状态进行实时监测估计的原理和方法, 进一步建立了相应的实时监测系统, 并应用于实际工程任务, 同时对该系统的表现进行评估, 为未来深空探测中的类似问题提供了一种有效的解决方法.

Analysis and implementation of in-plane stationkeeping of continuously perturbed Walker constellations

The stationkeeping of symmetric Walker constellations is analyzed by considering the perturbations arising from a high order and degree Earth gravity field and the solar radiation pressure. These perturbations act differently on each group of spacecraft flying in a given orbital plane, causing a differential drift effect that would disrupt the initial symmetry of the constellation. The analysis is based on the consideration of a fictitious set of rotating reference frames that move with the spacecraft in the mean sense, but drift at a rate equal to the average drift rate experienced by all the vehicles over an extended period. The frames are also allowed to experience the J 2 -precession such that each vehicle is allowed to drift in 3D relative to its frame. A two-impulse rendezvous maneuver is then constructed to bring each vehicle to the center of its frame as soon as a given tolerance deadband is about to be violated. This paper illustrates the computations associated with the stationkeeping of a generic Walker constellation by maneuvering each leading spacecraft within an orbit plane and calculating the associated velocity changes required for controlling the in-plane motions in an exacting sense, at least for the first series of maneuvers. The analysis can be easily extended to lower flying constellations, which experience additional perturbations due to drag.

Modeling and Control of an Aeroelastic Morphing Vehicle

Morphing aircraft are conceived as multirole platforms that modify their external shape substantially to adapt to a changing mission environment The dynamic response of the unmanned aerial vehicle will be governed by the time-varying aerodynamic forces and moments which will be a function of the wing's shape changes by the morphing command. Here, it is assumed that the morphing unmanned aerial vehicle behaves as a variable geometry rigid body, but with dynamic coefficients corrected to include quasi-steady aeroelastic effects. A multiloop controller for the aeroelastic morphing unmanned aerial vehicle concept is formulated to provide both proven structural and self-scheduled characteristics. The proposed controller uses a set of inner-loop gains to provide stability using classical techniques, whereas a linear parameter-varying outer-loop controller is devised to guarantee a specific level of robust stability and performance for the time-varying dynamics. Reduced-order controllers are synthesized using a robust control reduction technique. A series of maneuvers are devised to exhaustively evaluate the performance of the synthesized multiloop controller subject to large-scale geometrical shape changes. The underlying multiloop approach successfully enables in-flight transformation between vehicle states in less than one minute, while maintaining the overall vehicle stability and control.

Corrective Hair Restoration Techniques for the Aesthetic Problems of Temperoparietal Flaps

Temperoparieto-occipital flaps (Juri flap) and temperoparietal flaps (Elliott) were commonly performed in the previous decades but have fallen out of favor for the most part with the development of follicular unit hair transplantation. Besides high complication rates, these procedures created straight abrupt hairlines in many cases, posterior hair direction, hair density that was disproportionately thick, and blunt temperofrontal angles. Because there are many patients who live with cosmetic deformities created by previous flap procedures, the objective of this article is to present a series of techniques that will restore these patients to normal cosmesis. The techniques for amelioration of poor cosmesis secondary to flap procedures are (1) undulating follicular unit grafting anterior to the hairline, (2) removal of 2- to 3-mm cylinders of hair-bearing scalp at the anterior hairline, (3) removal of 2- to 3-mm cylinders of hair-bearing scalp from within the flap itself, and (4) appropriate fusiform excision techniques to create a normal temperofrontal angle. The combination of the aforementioned techniques has restored a very natural cosmesis in patients who have poor aesthetics after flap surgery. Many patients exist who have had Juri and Elliott flaps. Although the cosmetic deformities that are created from these flaps are difficult to improve, they can be ameliorated effectively through a series of maneuvers that are described in this article.

Anterior cruciate ligament reconstruction affects proprioception in the cat's knee.

To study the cat's knee after anterior cruciate ligament reconstruction, we compared its neural and muscular activity with that in the normal and the unstable knee. We recorded the electric activity in the articular nerves (posterior -PAN and medial -MAN) and periarticular muscles (quadriceps and hamstring) while performing passive flexion, extension, external and internal rotation, and also anterior translation of the tibia at 30 degrees and 90 degrees of flexion. The same series of maneuvers was performed in the same knees after surgical section of the anterior cruciate ligament and then after anterior cruciate reconstruction. The electric activity recorded in the reconstructed knee was compared to that in the same knee before surgery and in the same unstable knee after anterior cruciate section. We observed that the reconstructed knee, compared to the injured knee, showed a decrease in articular nerves and quadriceps activity while it regained stability. This decrease converged to the recordings in the normal knee. However, differences in MAN, PAN and hamstring activity were still present in the reconstructed knee. This suggests that, although anterior cruciate reconstruction seems beneficial for restoring articular nerve and periarticular muscle activities to a certain degree, proprioception in the reconstructed knee does not match that in the normal knee.

The treatment of stimulant dependence

Rehabilitation efforts offered to individuals with stimulant dependence incorporate a series of maneuvers to accomplish three major goals. Following active detoxification, most clinicians attempt to: (1) increase motivation for abstinence and maintain a high level of commitment to this goal; (2) help individuals to rebuild a stable life-style without substances; and (3) actively work toward ways of decreasing the probability of relapse (relapse prevention). While these activities incorporate education, counseling, outreach to families and exposure to self-help groups (e.g. Cocaine Anonymous), numerous pharmacological approaches have been tested. Each mode of drug therapy is based on a reasonable hypothesis, but appropriately controlled and structured clinical trials have not yet revealed any pharmacological approach for rehabilitation of stimulant-dependent individuals for which the risks have been shown to outweight the assets.

Retention of nondeflating balloon in small bowel

Intubation of the upper gastrointestinal tract with balloon catheters has a role in the diagnosis, treatment, and research of many gastrointestinal conditions. A potential complication of this procedure, albeit rare, is failure of the balloon to deflate, thereby preventing removal of the intestinal tube. We describe a case where this problem arose and the series of maneuvers that were attempted to resolve it. Attempts at overdistending the balloon, reaching it via endoscopy, and ultrasound localization of the balloon all failed. The tube was successfully removed following CT-guided percutaneous needle puncture of the impacted balloon. The published experience with nondeflating catheter balloons in hollow viscera has been reviewed and the suggested methods for deflation or puncture are discussed.

Mars Observer trajectory and orbit control

The Mars Observer mission will study Mars from a low-altitude orbit. During interplanetary cruise, propulsive maneuvers are required to ensure capture, with a secondary constraint to satisfy limits on the probability of impact with Mars. After capture, the spacecraft will be brought to a near-circular mapping orbit through a series of maneuvers. Mapping orbit maneuvers will be performed in order to follow a predetermined set of ground tracks and to maintain orbit altitude. This will allow accurate spacecraft command sequence generation and aid science planning throughout the mapping phase. Specific orbit control plans for the open and close of the launch period have been developed to meet these needs. This paper describes the control capabilities and the associated expected velocity changes for the mission.

Noninvasive Evaluation of the Upper Extremity

Vascular problems of the arm and hand can be assessed by a number of noninvasive modalities that are chosen on the basis of the history and physical examination. For suspected upper-extremity ischemia, we begin with SLPs and velocity-waveform analysis. The former test will define the extent and approximate location of the disease process, and subjective assessment of the waveform will further determine the degree and location of occlusive disease. When digital ischemia is suspected, the Doppler examination combined with intermittent compression of the radial and ulnar arteries is valuable for defining the variable arterial anatomy of the hand and the patency of the common and proper digital arteries. The extent of distal ischemia can be assessed by digital pressures. Duplex scanning has been found to be of value in determining the source of upper-extremity micro-emboli, in imaging suspected aneurysmal changes, and for evaluating arteriovenous fistulae and bypass grafts. Cold testing is used to confirm the diagnosis of Raynaud's disease after excluding proximal occlusive disease. When symptoms suggest intermittent arterial obstruction, arterial compression at the thoracic outlet is assessed by monitoring the arterial waveform during a series of maneuvers that change the anatomy of the outlet. Although a combination of IPG and venous Doppler examination accurately identifies venous occlusion, we routinely use duplex scanning in this setting. In addition to providing both anatomic and hemodynamic information about the subclavian vein, the jugular vein and the junction of the innominate vein can also be studied. Because of its ability to image in a coronal plane, MRI scanning is another nonivasive study that we have found useful for evaluation of venous anatomy and patency of the subclavian, jugular, and innominate veins. Venous thrombosis, often the first manifestation of subclavian vein compression at the thoracic inlet, is best evaluated using duplex scanning.

Adjuvants to immunological methods for mRNA purification. Application to the isolation of mRNA for carbonic anhydrase I from rabbit reticulocytes.

In order to generate the molecular probes needed to investigate the seemingly coordinate expression of carbonic anhydrase (CA I) and beta-globin within erythrocytes during human development, CA I-containing polyribosomes have been isolated from rabbit reticulocytes by reaction with purified antibodies to CA I followed by immunoadsorption of immune complexes with formalin-fixed protein A-bearing bacteria. In the course of such isolation, a series of maneuvers were seen to have a markedly favorable influence on the level of purity attained. These maneuvers include the use of 5 mg/ml of heparin concentrations to attenuate nonspecific binding and entrapment of unwanted polyribosomes, the addition of 200 units/ml of placental ribonuclease inhibitor to augment recovery in reactions which by test already appeared RNase-free, and the preadsorption of polyribosomes with formalin-fixed bacteria prior to immunological reaction so as to remove a subset of polyribosomes seemingly predisposed to nonspecific binding. In the absence of all of the maneuvers, attained purity was no greater than a few per cent. When all were employed, CA I-mRNA derived from immunopurified polyribosomes was recovered with more than 80% purity and 20% yield, as evident from both immunoassays and electrophoresis of its cell-free products.

Selection of optimal parameters for multipurpose controllable systems: General formulation of the problem and solution algorithms

This paper describes an approach to the selection of optimal parameters for multipurpose controllable systems intended to perform a series of maneuvers. The paper is an extension of the writer's previous papers on the subject (Refs. 1---6). It states the problem in general terms and discusses the selection of a functional. Depending on the amount of available data on the parameters of maneuver, the problem reduces to either minimization of a function of many variables or a game problem. Algorithms for the solution of the problems formulated are developed. A model problem of space flight mechanics with low-thrust engines is used for illustration purposes. Several applications of the approach developed are contained in Refs. 7---9. In addition, Refs. 8---9 suggest one more method for solving the problem of Section 3, the so-called method of optimal coverings. Another direction of research is described in Ref. 10.

Immunoglobulins (E,M,G) and complement in the connective tissues of the thyroid in Graves's disease.

Abstract When 14 thyroid glands from patients with Graves's disease were studied by immunofluorescence technic, immunofluorescence in focal areas of the stroma was found in all, as well as in the follicular basement membranes in 10. Positive staining was produced by specific antiserums to human immunoglobulins E, M, and G, and complements C1q and C3. Specificity of immunofluorescent staining was confirmed by a series of maneuvers. This includes loss of staining property from sections of thyroid upon elution with acid citrate solution before staining, but not with phosphate-buffered saline elution, and negative staining for fibrinogen (except intravascularly). No staining was found in a variety of control thyroid glands. The connective-tissue localization of complement and immunoglobulins suggests that Graves's disease may be an immune disorder, with possible links to other immune disorders such as rheumatoid arthritis, systemic lupus erythematosus, and nephrosis.

Medicare deadlock in Quebec.

The present state of deadlock between the government of the province of Quebec and the medical specialists in the province has followed a series of maneuvers that not only have been complex and difficult to follow in themselves, but also have most recently been intertwined with a serious political crisis. Yet the issues are of fundamental importance to the medical profession, and for this reason merit the attention of anyone interested in the changing interface between the profession and the government. With the passage of Bill 8 through the provincial legislature in June, 1970, the provincial government sought to establish . . .