High area-to-mass ratio hybrid propulsion Earth to Moon transfers

This paper examines the design of transfers that are useful to micro or nano spacecraft with high area-to-mass ratio, propelled by a simple propulsion engine (such as chemical with a specifc impulse ca. 100 to 300 s or arcjet/resistojet), and possessing relatively small solar reflective panels to provide power and a small thrust due to solar radiation pressure. This type of transfer is becoming of greater interest as advances in structures, materials, and small spacecraft design & propulsion are made. Such a hybrid design especially offers possibilities of cheaply exploring the Moon using multiple vehicles. With this small hybrid design, interior transfers in the circular restricted 3-body problem between the pair of primary and secondary masses (e.g. the Earth and Moon) are attempted using solar radiation pressure and multiple small impulses. The source of the outside solar radiation pressure is modeled using an external source rotating about – and in the plane of – the co-rotating set of primary and secondary masses. Starting from a GTO about the primary mass a basic optimization method of sequences of manoeuvres is used to achieve the transfer, where the segments are patched together using ideally small maneuvers. The spacecraft coasting arc is controlled by a number of locally optimal control laws to optimize performance while minimizing computational cost. The spacecraft hops onto a stable invariant manifold leading to the system’s Lagrange L1 point after successive small maneuvers and coasting arcs. Following connection with a manifold and subsequent arrival at a periodic orbit at L1, temporary or permanent capture around the Moon can be performed using the remaining resources at hand

Electrocardiographic prediction of lateral involvement in acute non-anterior wall myocardial infarction

AbstractPurposeRecent research has established that a tall R-wave in V1 indicates lateral wall involvement in non-anterior wall myocardial infarction (MI). The objective of this study was to assess the value of the admission electrocardiogram (ECG) to predict R-waves and consequently lateral wall damage in the late phase of non-anterior MI.MethodsECGs of 69 patients were analyzed. ST-segment changes in representative leads for lateral wall infarction such as V1, V2, V6 and I were correlated with the extent of QRS-wave changes in V1 and V6.ResultsST-segment elevation in V6 showed correlations with R/S ratio in V1 (r=0.802, B=0.440, P=<0.001) and with the depth of Q-waves in V6 (r=0.671, B=0.441, P=0.007). This correlation was higher in a small subgroup where the left circumflex branch (Cx) was the culprit vessel (r=0.888, B=1.469 and P=0.018). ST-segment depression in lead I correlated with the height of R and the surface of R in V1 (height times width of R) (r=0.542, B=−0.150, P=0.005 and r=0.538, B=−0.153, P=0.005 respectively), especially in the subgroup without proximal occlusions of RCA (r=0.711 and r=0.699). ST-segment depression in lead I also predicted Q-waves in V6 (r=0.538, B=0.114, P=0.006). ST-segment changes in V2 showed no significant correlation with either R- or Q-wave measurements.ConclusionsST-segment elevation in V6 in the acute phase of non-anterior MI predicts lateral involvement as expressed by the R/S ratio in V1 in the post reperfusion phase. A subgroup with Cx occlusion showed especially strong correlations, although the size of the group was small. In lead I ST-segment depression is correlated to height and surface of R in V1 and Q-waves in V6

The Dutch disease revisited : absorption constraint and learning by doing

This paper revisits the Dutch disease by analyzing the general equilibrium effects of a resource shock on a dependent economy, both in a static and dynamic set- ting. The novel aspect of this study is to incorporate in one coherent framework two distinct features of the Dutch disease literature that have previously been analyzed in isolation: capital accumulation with absorption constraint, and productivity growth induced by learning-by-doing. The result of long run exchange rate appreciation is maintained in line with part of the Dutch Disease literature. In addition, a permanent change in the employment shares occurs after the resource windfall, in favor of the non-traded sector and away from the traded sector growth engine of the economy. In other words, in the long run both of the classic symptoms of the Dutch Disease remain in place.info:eu-repo/semantics/publishedVersio

Gravity-driven instabilities in fibrillar colloidal gels containing a second disperse phase

Fibrillar networks are of great importance for biological systems and many industrial applications. We investigate gravity-driven instabilities in fibrilalr colloidal gels containing a second disperse phase. We use a model system containing a surfactant-stabilized oil-in-water emulsion dispersed in a gel of cellulose microfibrils in the presence of carboxymethyl cellulose. Optical scanning of the creaming emulsion containing gels along the height was used to quantify the network evolution over time. We find a remarkable correlation between the concentration of microfibrils and creaming behaviour such as initial creaming speed and final gel height. We compare this behaviour to the theoretical model of gravitational stability of poroelastic gels, which was extended to account for particle shape anisotropy and the presence of a second disperse phase. Please click Additional Files below to see the full abstract

Levels of cafestol, kahweol, and related diterpenoids in wild species of the coffee plant coffea

Abstract Specific fatty acids and sterols in food composites from seven countries were analyzed. In the 1960s, groups of 8 to 49 men from 16 cohorts, ages 40–59 years and living in the United States, Finland, the Netherlands, Italy, Greece, the former Yugoslavia, or Japan recorded their food intake. In 1987, we collected food composites representing the average food intake per cohort sample in the 1960s. The foods were transported to the Netherlands, pooled, and centrally analyzed for energy, total fat, 42 fatty acids, cholesterol, and four plant sterols. The fat content ranged from 12% of total daily energy in the Tanushimaru, Japan, cohort to 50% in the U.S. cohort sample, and the polyunsaturated to saturated fat ratio ranged from 0.17 in the east Finland cohort to 1.2 in Tanushimaru. The amount oftransfatty acids with 16 or 18 carbon atoms varied between 0.2 g/day in Corfu, Greece, and 8.6 g/day in Zutphen, Netherlands, and that of -linolenic acid between 0.8 g/day in Rome and 2.5 g/day in east Finland. The sum of eicosapentaenoic and docosahexanoic acid ranged from 0.1 (U.S. railroad) to 2.0 g/day (Ushibuka, Japan), and phytosterols from 170 (U.S. railroad) to 358 mg/day (Corfu, Greece). Thus the intake of various fatty acids and sterols with potential relevance for coronary heart disease occurrence varied 10-fold or more between cohorts. Our data can be used to generate new hypotheses about the causes of differences in incidence of diseases between countries