Material handling systems for the fluidized-bed combustion boiler at Rivesville, West Virginia

The 300,000 lbs/hr steam capacity multicell fluidized-bed boiler (MFB) utilizes complex material handling systems. The material handling systems can be divided into the following areas: (1) coal preparation; transfer and delivery, (2) limestone handling system, (3) fly-ash removal and (4) bed material handling system. Each of the above systems are described in detail and some of the potential problem areas are discussed. A major potential problem that exists is the coal drying system. The coal dryer is designed to use 600 F preheated combustion air as drying medium and the dryer effluent is designed to enter a hot electrostatic precipitator (730 F) after passage through a cyclone. Other problem areas to be discussed include the steam generator coal and limestone feed system which may have operating difficulties with wet coal and/or coal fines

On the geographical correlation of orbit error

The orbit accuracies needed to support the global crustal dynamics project and recent satellite altimeter missions have placed unique demands on the data analysis and orbit analysis systems. These demands include accurate and well distributed observations, improved computational techniques and substantial enhancements in the force models which represent the satellite's motion. For example, the satellite altimeter mission (TOPEX), whose objectives will be: (1) to measure the time variable ocean surface topography, and (2) to demonstrate the ability to map the general ocean circulation, requires that the radial component of the satellite's orbit be known with an rms accuracy of 13 cm for the three year mission lifetime. The primary force model uncertainty which limits the contemporary orbit computation accuracy is the inaccuracy in the values assigned to the spherical harmonic coefficients used to model the Earth's gravity field

Satellite laser ranging and gravity field modeling accuracy

Gravitational field mismodeling procedures errors in the estimated orbital motion of near Earth satellites. This effect is studied using a linear perturbation approach following the analysis of Kaula. The perturbations in the orbital position as defined by either orbital elements or Cartesian components are determined. From these perturbations it is possible to ascertain the expected signal due to gravitational mismodeling that would be present in station-to-satellite laser ranging measurements. This expected signal has been estimated for the case of the Lageos satellite and using the predicted uncertainties of the GEM-T1 and GEM-T2 gravity field models. The results indicate that observable signal still exists in the laser range residuals given the current accuracy of the range measurements and the accuracy of the gravity field models

Modeling radiation forces acting on TOPEX/Poseidon for precision orbit determination

Geodetic satellites such as GEOSAT, SPOT, ERS-1, and TOPEX/Poseidon require accurate orbital computations to support the scientific data they collect. Until recently, gravity field mismodeling was the major source of error in precise orbit definition. However, albedo and infrared re-radiation, and spacecraft thermal imbalances produce in combination no more than a 6-cm radial root-mean-square (RMS) error over a 10-day period. This requires the development of nonconservative force models that take the satellite's complex geometry, attitude, and surface properties into account. For TOPEX/Poseidon, a 'box-wing' satellite form was investigated that models the satellite as a combination of flat plates arranged in a box shape with a connected solar array. The nonconservative forces acting on each of the eight surfaces are computed independently, yielding vector accelerations which are summed to compute the total aggregate effect on the satellite center-of-mass. In order to test the validity of this concept, 'micro-models' based on finite element analysis of TOPEX/Poseidon were used to generate acceleration histories in a wide variety of orbit orientations. These profiles are then compared to the box-wing model. The results of these simulations and their implication on the ability to precisely model the TOPEX/Poseidon orbit are discussed

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Satellite Orbit Perturbations Due to the Geopotential

Satellite-borne radar altimeters have the capability of measuring the distance from the satellite platform to the ocean surface with an accuracy of five centimeters or less. To fully exploit the geophysical information contained in this data, it is necessary to have independent knowledge of the geocentric satellite distance to a comparable level of accuracy. Current altimeter satellite ephemerides fail this requirement by at least an order of magnitude. The radial errors contained in the estimated orbits are primarily a result of inadequacies in the modeling of the Earth's gravity field. To better understand the limitations this orbit error imposes on the analysis of the altimeter data, this study details the temporal and spatial characteristics of the radial orbit perturbations produced by the geopotential. The temporal description fully describes the frequency spectrum of the perturbations, and the spatial description provides a direct method for quantifying the perturbations on a geographical basis. These results are used to analyze the expected radial orbit perturbations of the altimeter satellite to be flown by the proposed TOPEX Mission. To facilitate other possible applications, the geopotential perturbations in the along-track and cross-track directions are presented also.Aerospace Engineering and Engineering Mechanic

Electrical Dose for Ventricular Defibrillation of Large and Small Animals Using Precordial Electrodes

Electrical ventricular defibrillation of heavy subjects (over 100 kg body weight) is uncommon for the human or any animal species. This paper reports trans-chest ventricular defibrillation of subjects ranging in weight from 2.3 to 340 kg using conventional defibrillation current (heavily damped sine wave) of 0.3-30 ms duration. It was found that a body weight-to-electrical-shock strength relationship exists and can be expressed in terms of either electrical energy or peak current. For the duration of current pulse used clinically (3-10 ms), the relationship between energy requirement and body weight is expressed by the equation U = 0.73 W(1.52), where U is the energy in W·s and W is the body weight in kilograms. The current relationship is I = 1.87 W(0.88) where I is the peak current in amperes and W is the body weight in kilograms. The energy dose is somewhat more species and weight dependent and ranges from 0.5 to 10 W·s/kg (0.23-4.5 W·s/lb). The data obtained indicate that the peak current dose is virtually species and weight independent and is therefore a better indicator than energy for electrical defibrillation with precordial electrodes. In the duration range of 3-10 ms, the electrical dose is very nearly 1 A/kg of body weight (0.45 A/lb)

Adenosine Triphosphate-Competitive mTOR Inhibitors: A New Class of Immunosuppressive Agents That Inhibit Allograft Rejection

Innledning. Trykksår er en kjent komplikasjon ved varig immobilisering av pasienter. Det finnes relativt få europeiske studier om rekonstruktiv behandling av tilstanden. Studiet undersøkte forekomst og ulike kliniske aspekter ved plastisk rekonstruksjon av pasienter med alvorlige trykksår ved Universitetssykehuset i Nord Norge. Materiale og metoder. Retrospektiv studie av trykksår grad 3 og 4, av ulik lokalisasjon, behandlet med plastisk kirurgi ved Universitetssykehuset i Nord-Norge (Tromsø og Harstad) i perioden 01.01.2011-31.12.2015 med innleggelse. Seleksjonskriterier: trykksår grad 3 og 4 og plastisk rekonstruksjon. Statistisk analyse ble gjennomført med bruk av deskriptiv statistikk, Independent samples T-test og Pearson's chi-squared test. Resultater. Det ble gjennomført en omfattende undersøkelse av pasientdata. Studiepopulasjonen består av 29 pasienter, 62 % kvinner, med 38 rekonstruktive inngrep (25 % øyeblikkelig hjelp) med 1,24 rekonstruktive inngrep per pasient. Gjennomsnittlig liggetid var 31,38 dager, med langt sykehusopphold i påvente av inngrepet. 20/29 pasienter (68,96 %) har hatt invalidiserende tilstand, 9/29 pasienter (31,03 %) med dokumentert underernæring. Kvinnelige pasienter var eldre enn mannlige pasienter (gjennomsnittsalder på 75,1 år versus 64,64 år) og hadde kortere innleggelsestid (23,17 dager versus 44,82 dager) og færre inngrep per pasient. Kun 48,28 % av pasientene fikk vurdering av ernæringsstatus, og det ble ikke funnet forbedring i løpet av studieårene. Gjennomsnittslengden per inngrep var 1,99 timer. Det ble brukt ulike lapper ved 63,89 % inngrep. 5/29 pasienter (17,24 %) måtte reopereres. Hyppighet av komplikasjoner var så høy som 41,38 %. Kun 17/29 pasienter (58,62 %) hadde fullstendig sårtilheling ved utskrivelse. Det ble ikke påvist signifikant korrelanse mellom kjønn, lang preoperativ faste, underernæring, lave hemoglobin og albuminnivåer, høyt CRP nivå, multiresistente bakterier i såret eller bein under sårområde og lengre sykehusopphold eller økt antall kirurgiske inngrep, trolig grunnet for lite studieutvalg. Konklusjon. Det ble funnet dårlig etterlevelse av Nasjonal faglig retningslinje for forebygging og behandling av underernæring og stort forbedringspotensial i dokumentføring og bruk av medisinske koder