Laser Rayleigh and Raman Diagnostics for Small Hydrogen/oxygen Rockets

Localized velocity, temperature, and species concentration measurements in rocket flow fields are needed to evaluate predictive computational fluid dynamics (CFD) codes and identify causes of poor rocket performance. Velocity, temperature, and total number density information have been successfully extracted from spectrally resolved Rayleigh scattering in the plume of small hydrogen/oxygen rockets. Light from a narrow band laser is scattered from the moving molecules with a Doppler shifted frequency. Two components of the velocity can be extracted by observing the scattered light from two directions. Thermal broadening of the scattered light provides a measure of the temperature, while the integrated scattering intensity is proportional to the number density. Spontaneous Raman scattering has been used to measure temperature and species concentration in similar plumes. Light from a dye laser is scattered by molecules in the rocket plume. Raman spectra scattered from major species are resolved by observing the inelastically scattered light with linear array mounted to a spectrometer. Temperature and oxygen concentrations have been extracted by fitting a model function to the measured Raman spectrum. Results of measurements on small rockets mounted inside a high altitude chamber using both diagnostic techniques are reported

Don't (fully) exclude me, it's not necessary! Identification with semi-IVs

This paper proposes a novel tool to nonparametrically identify models with a discrete endogenous variable or treatment: semi-instrumental variables (semi-IVs). A semi-IV is a variable that is relevant but only partially excluded from the potential outcomes, i.e., excluded from at least one, but not necessarily all, potential outcome equations. It follows that standard instrumental variables (IVs), which are fully excluded from all the potential outcomes, are a special (extreme) case of semi-IVs. I show that full exclusion is stronger than necessary because the same objects that are usually identified with an IV (Imbens and Angrist, 1994; Heckman and Vytlacil, 2005; Chernozhukov and Hansen, 2005) can be identified with several semi-IVs instead, provided there is (at least) one semi-IV excluded from each potential outcome. For applied work, tackling endogeneity with semi-IVs instead of IVs should be an attractive alternative, since semi-IVs are easier to find: most selection-specific costs or benefits can be valid semi-IVs, for example. The paper also provides a simple semi-IV GMM estimator for models with homogenous treatment effects and uses it to estimate the returns to education

Export and Regulatory Properties of MalE Hybrid Proteins in <i>Escherichia coli</i>

The maltose binding protein (MalE) of Escherichia coli is a secreted 370 residue polypeptide which serves as the periplasmic receptor for high-affinity membrane transport of maltose and maltodextrins. Cells tolerate synthesis and translocation across the plasma membrane of large quantities of MalE. Similarly, the outer membrane protein Omp A is not toxic when expressed in physiological amounts. Expression of an ompA-malE hybrid gene consisting of the first 274 residues of OmpA and the last 251 residues of MalE was, however, toxic, although synthesis of the OmpA part alone was not. To examine the effect of synthesis of the MalE part of the hybrid, the malE fragment was cloned into a vector where it was preceded by the gene coding for the OmpA signal peptide and was inducible by isopropy Ithiogalactoside. Upon induction, a polypeptide of the expected size was made, but expression of the truncated MalE turned out to be even more toxic than that of the OmpA-MalE hybrid. The MalE fragment was exported to the periplasm and did not interfere with the export of other secreted polypeptides. A search for suppressors of this toxicity was performed. In a chromosomal gene bank of E. coli, such a suppressor was found which coded for a 102 A-terminal residue fragment of the 217 residue protein NlpE (new outer membrane lipoprotein). NlpE is known to combat the toxicity of the cytosolic ß-galactosidase (LacZ) when artificially exported to the periplasm. This suppression is achieved by activation of the Cpx two-component signal transduction pathway controlling expression of the periplasmic protease DegP. Increased synthesis of DegP caused degradation of LacZ. The same mechanism appears to operate for the degradation of the MalE fragment. In a degP background, the NlpE fragment could not suppress toxicity. Mutants (cpxA*) exist which, without any signal, produced increased levels of DegP. In a cpxA* strain, the MalE fragment was no longer toxic. The toxicity caused by the MalE fragment can still not entirely be explained. However, several lines of evidence, such as the expression of the periplasmic spheroplast protein Y in cells producing MalE251, suggest that the most likely explanation for the lethality is a defect in the cell wall of induced cells

Evolutionary Synthesis of Cellular Automata

Synthesis of cellular automata is an important area of modeling and describing complex systems. Large amounts of combinations and candidate solutions render the usage of deterministic approaches impractical and thus nondeterministic optimization methods have to be employed. Two of the typical evolutionary approaches to synthesizing cellular automata are the evolution of a single automaton and a genetic algorithm that evolves a population of automata. The first approach, with addition of some heuristics, is known as the cellular programming algorithm. In this paper we address the second approach and develop a genetic algorithm that evolves a population of cellular automata. We test both approaches on the density classification task, which is one of the most widely studied computational problems in the context of evolving cellular automata. Comparison of the synthesized cellular automata demonstrates unexpected similarity of the evolved rules and comparable classification accuracy performance of both approaches

Community- acquired pneumonia: a case report

INTRODUCTION Community-acquired pneumonia (CAP) is an acute lower respiratory tract infection in a patient who has acquired the infection in the community. Patients typically present with fever, dyspnea, productive cough and pleuritic chest pain. On physical examination tachypnea, auscultatory rales, increased tactile fremitus and purulent sputum are present. Most common pathogens are Streptococcus pneumoniae, Haemophilus influenza and Moraxella catarrhalis. Streptococcus pneumoniae is the causative organism for up to 2/3 of all CAP. With clinical suspicion of pneumonia full blood count, urea, electrolytes and CRP should be tested. Chest x-ray typically shows lobar infiltrates. Sputum can be microbiologically tested to identify the pathogen. Supportive therapy as well as antibiotic therapy according to national guidelines is advised. CASE PRESENTATION A previously healthy 45-year old male presents to the outpatient department due to fever, cough and malaise for 2 days. On physical examination his vitals are: blood pressure 140/70 mmHg, heart rate 80/min, oxygen saturation 96%, body temperature 38 °C, breathing frequency 24/min. On auscultation rales are heard over the right lower lobe. His laboratory results show leukocytosis with elevated CRP. Chest x-ray is performed and a consolidation is seen in the right lower lobe. He is prescribed amoxicillin 500-1000 mg/8 h per os for 7-10 days. CONCLUSION CAP is one of the most common infectious diseases and is associated with considerable morbidity and mortality, particularly in elderly patients and those with significant comorbidities. The most common pathogen is Streptococcus pneumoniae. Antibiotic therapy is usually started empirically

Influence of selected environmental factors on moisture dynamics of beech wood

Bukovina sodi med najpomembnejše lesne vrste v Sloveniji. Žal uporaba bukovine zelo zaostaja za prirastkom, zato je treba nujno razviti dodatne aplikacije za rabo bukovega lesa. Ena izmed neizkoriščenih priložnosti je tudi raba za manj zahtevne konstrukcije na prostem. V primeru, da uporabljamo bukovino na prostem, moramo les na takšen ali drugačen način zaščititi. V zadnjem obdobju vedno bolj pridobiva na pomenu termična modifikacija in uporaba voskov, zato smo ti dve rešitvi uporabili tudi v tej raziskavi. Tako smo odpornost bukovine na navlaževanje spremljali v laboratorijskih razmerah in terenskih testih. Pred laboratorijskimi poizkusi smo vzorce izpostavili različnim abiotskim in biotskim dejavnikom razkroja ter določili njihov vpliv na navzemanje vode v les. Izkazalo se je, da se je najbolje obnesel termično modificiran les, impregniran s suspenzijo naravnih voskov. Po drugi strani so abiotski in biotski dejavniki razkroja močno poslabšali odpornost proti navlaževanju bukovine in termično modificirane bukovine.Beech is one of the most important tree species in Slovenia. Unfortunately, there is much more beech wood incremented annually than consumed. Thus, it is of great importance to develop new applications for use of beech wood. One of the possible solutions is use of beech in outdoor applications. However, if beech is used outdoor it has to be somehow protected. In the recent period, non-biocidal methods of wood protection such as thermal modification and use of wax emulsions are gaining more and more importance, hence we applied these two methods to beech wood in present research as well. During the research, water exclusion efficacy of wood was determined. Wood was subjected to various abiotic and biotic degradation protocols. The results exhibited that the best water performance was achieved in wax treated thermally modified beech. Water performance of wax treated wood was not affected by abiotic and biotic degradation factors. By contrast, the aging protocols applied considerably reduced water exclusion efficacy of beech and thermally modified beech wood