Basic requirements of fuel-injection nozzles for quiescent combustion chambers

This report presents test results obtained during an investigation of the performance of a single-cylinder, high-speed, compression-ignition test engine when using multiple-orifice fuel-injection valve nozzles in which the number and the direction of the orifices were varied independently

Performance of a High-Speed Compression-Ignition Engine Using Multiple Orifice Fuel Injection Nozzles

This report presents test results obtained at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics during an investigation to determine the relative performance of a single-cylinder, high-speed, compression-ignition engine when using fuel injection valve nozzles with different numbers, sizes, and directions of round orifices. A spring-loaded, automatic injection valve was used, centrally located at the top of a vertical disk-type combustion chamber formed between horizontally opposed inlet and exhaust valves of a 5 inch by 7 inch engine

Congenital imperforate hymen with hydrocolpos and hydronephrosis associated with severe hydramnios and increase of maternal ovarian steroidogenic enzymes

This is a clinical research paperStudy Objective: To study clinical features of patient presented with severe hydramnios, associated with hydronephrosis, that was antenatally diagnosed and has been successfully treated immediately after birth. At a molecular level, we investigated the gene expression of key steroidogenic enzymes from the maternal ovary. Design: Ultrasound scan,MRI, semi-quantitativeRT-PCR Setting: The patient was admitted to the University Hospital, University of Crete, Medical School, Greece, where all clinical data has been obtained. Gene expression studies took place at Biosciences, Brunel University, UK. Results: Semi-quantitative RT-PCR analyses revealed that there is upregulation of key steroidogenic genes in the maternal ovary, including steroidogenic acute regulatory protein, and the cytochrome P450 heme-containing proteins CYP11A, CYP17 and CYP19. From a clinical perspective, the prenatal ultrasound scan and MRI findings showed a multicystic pelvic mass, bilateral hydronephrosis and prior to delivery severe polyhydramnios. Conclusion: This clinical case is the only one that we have found in the current literature where congenital imperforate hymen accompanied with hematocolpos is associated with renal obstruction in combination with polyhydramnios and increase in maternal steroidogenic enzymes

Solid-propellant rocket motor internal ballistic performance variation analysis, phase 2

The Monte Carlo method was used to investigate thrust imbalance and its first time derivative throughtout the burning time of pairs of solid rocket motors firing in parallel. Results obtained compare favorably with Titan 3 C flight performance data. Statistical correlations of the thrust imbalance at various times with corresponding nominal trace slopes suggest several alternative methods of predicting thrust imbalance. The effect of circular-perforated grain deformation on internal ballistics is discussed, and a modified design analysis computer program which permits such an evaluation is presented. Comparisons with SRM firings indicate that grain deformation may account for a portion of the so-called scale factor on burning rate between large motors and strand burners or small ballistic test motors. Thermoelastic effects on burning rate are also investigated. Burning surface temperature is calculated by coupling the solid phase energy equation containing a strain rate term with a model of gas phase combustion zone using the Zeldovich-Novozhilov technique. Comparisons of solutions with and without the strain rate term indicate a small but possibly significant effect of the thermoelastic coupling

Universality of collapsing two-dimensional self-avoiding trails

Results of a numerically exact transfer matrix calculation for the model of Interacting Self-Avoiding Trails are presented. The results lead to the conclusion that, at the collapse transition, Self-Avoiding Trails are in the same universality class as the O(n=0) model of Blote and Nienhuis (or vertex-interacting self-avoiding walk), which has thermal exponent $\nu=12/23$, contrary to previous conjectures.Comment: Final version, accepted for publication in Journal of Physics A; 9 pages; 3 figure

Observer based feedback control of 3rd order LCC resonant converters

The paper considers specific issues related to the design and realisation of observer-based feedback of isolated output voltage for resonant power converters. To provide a focus to the study, a 3rd order LCC converter is employed as a candidate topology. It is shown that whilst resonant converters nominally operate at high switching frequencies to facilitate the use of small reactive components, by appropriate pre-conditioning of non-isolated resonant-tank voltages and currents, the resulting observer can be implemented at relatively low sampling frequencies, and hence, take advantage of low-cost digital hardware. Experimental results are used to demonstrate the accuracy of observer estimates under both transient and steady-state operating conditions, and to show operation of the observer as part of a closed-loop feedback system where the LCC resonant converter is used as a regulated power supply

Prevalence and causes of blindness and visual impairment in Muyuka: a rural health district in South West Province, Cameroon.

AIM: To estimate the prevalence and causes of blindness and visual impairment in the population aged 40 years and over in Muyuka, a rural district in the South West Province of Cameroon. METHODS: A multistage cluster random sampling methodology was used to select 20 clusters of 100 people each. In each cluster households were randomly selected and all eligible people had their visual acuity (VA) measured by an ophthalmic nurse. Those with VA <6/18 were examined by an ophthalmologist. RESULTS: 1787 people were examined (response rate 89.3%). The prevalence of binocular blindness was 1.6% (95% CI: 0.8% to 2.4%), 2.2% (1.% to 3.1%) for binocular severe visual impairment, and 6.4% (5.0% to 7.8%) for binocular visual impairment. Cataract was the main cause of blindness (62.1%), severe visual impairment (65.0%), and visual impairment (40.0%). Refractive error was an important cause of severe visual impairment (15.0%) and visual impairment (22.5%). The cataract surgical coverage for people was 55% at the <3/60 level and 33% at the <6/60 level. 64.3% of eyes operated for cataract had poor visual outcome (presenting VA<6/60). CONCLUSIONS: Strategies should be developed to make cataract services affordable and accessible to the population in the rural areas. There is an urgent need to improve the outcome of cataract surgery. Refractive error services should be provided at the community level

MEASURING AN ALMOST IDEAL DEMAND SYSTEM WITH GENERALIZED FLEXIBLE LEAST SQUARES

Structural change in meat consumption has been the focus of many researchers during the last two decades. In this paper we develop a dynamic linear Almost Ideal Demand System (AIDS) model from a cost function that allows for time varying parameters. This model is consistent with inertia in the parameters of the cost and indirect utility functions. It allows for persistent preferences which may arise from cultural biases, lifestyles, peer pressure, etc. An empirical application is conducted with US meat consumption and price data using a generalized system of flexible least squares, Generalized Flexible Least Squares (GFLS). GFLS allows parameters to evolve slowly over time through incorporating of penalties in fluctuations. Estimated quarterly elasticities were subjected to additional analysis to determine how highly they were related to the Brown and Schrader Cholesterol Index and relative prices. The combined results support that the movements of elasticities over time are related to both.Demand and Price Analysis, Institutional and Behavioral Economics,

Expression of mTOR and downstream signalling components in the JEG-3 and BeWo human placental choriocarcinoma cell lines

This article has been made available through the Brunel Open Access Publishing Fund.Emerging data suggest that nutritional status and body weight are related to reproductive function, and nutrient imbalances during pregnancy lead to changes in the expression of fetal genes. Recent studies show that the mTOR acts as a placental growth signalling sensor and its expression is down-regulated in intrauterine growth restriction. To date, very little is known about the expression of this signalling pathway in choriocarcinoma, one of the most lethal germ cell cancers. In this study, cultures of fusigenic (BeWo) and non-fusigenic (JEG-3) human choriocarcinoma cell lines were used to investigate the expression of mTOR and its downstream signalling components. The effects of an inducer of syncytialisation (forskolin) on mTOR, eIF4E binding proteins (4EBPs) and ribosomal protein S6 kinases (S6Ks) in BeWo cells were also assessed. RT-PCR studies revealed that mTOR, 4EBP and S6Ks are expressed at mRNA level in both JEG-3 and BeWo cells. Semi-quantitative RT-PCR analysis revealed that in early stages of syncytialisation (50 µM forskolin for 48 h), the expression of mTOR and 4EBP was down-regulated when compared to unstimulated cells. In fully syncytialised cells (50 µM forskolin for 72 h) the expression of both genes was similar to basal levels. Interestingly, the phosphorylation (Ser371, Thr389) status of p70S6K remained unaltered upon forskolin treatment. These data validate BeWo cells as an experimental model to study the effects of forskolin-induced syncytialisation on mTOR signalling.This article is available through the Brunel Open Access Publishing Fun

Internalisation of membrane progesterone receptor-α after treatment with progesterone: Potential involvement of a clathrin-dependent pathway

This article has been made available through the Brunel Open Access Publishing Fund.Internalisation and recycling of seven trans-membrane domain receptors is a critical regulatory event for their signalling. The mechanism(s) by which membrane progesterone receptor-α (mPRα) number is regulated on the cell surface is unclear. In this study, we investigated the cellular distribution of mPRα and mechanisms of mPRα trafficking using a cell line derived from a primary culture of human myometrial cells (M11) as an experimental model. RT-PCR and immunofluorescent analysis demonstrated expression of mPRα in M11 cells with mPRα primarily distributed on the cell surface under basal conditions. For the first time, plasma membrane localisation of mPRα was confirmed using immuno-gold transmission electron microscopy. Stimulation of M11 cells with progesterone (P4, 100 nM) resulted in internalisation of mPRα from the plasma membrane to the cytoplasm (10 min) and subsequent partial translocation back to the cell surface (20 min). We investigated potential endocytotic pathways involved in trafficking of mPRα after its internalisation. Partial co-localisation of clathrin with mPRα was obvious after 10 min of P4 treatment. Of note, chlorpromazine (inhibitor of clathrin-mediated pathway) inhibited the endocytosis of mPRα, whereas treatment with nystatin (inhibitor of caveolae-mediated pathway) did not affect internalisation. Collectively, these data suggest that mPRα is expressed on the cell surface of M11 cells and undergoes endocytosis after P4 stimulation primarily via a clathrin-mediated pathway.This article is available through the Brunel Open Access Publishing Fun