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The effect of hot streaks from a gas turbine combustor on the thermodynamic load of internally air-cooled nozzle guide vanes (NGVs) and shrouds has been numerically investigated under flight conditions. The study follows two steps: one for the high-fidelity 60° combustor sector with simplified ten NGVs and three thermocouples attached; and the other for the NGV sectors where each sector consists of one high-fidelity NGV (probe NGV) and nine dummy NGVs. The first step identifies which NGV has the highest thermal load and provides the inlet flow boundary conditions for the second step. In the second step, the flow fields and thermal loads of the probe NGVs are resolved in detail.
With the systematically validated physical models, the two-phase flowfield of the combustor-NGVs sector has been successfully simulated. The predicted mean and maximum temperature at the combustor sector exit are in excellent agreement with the experimental data, which provides a solid basis for the hot-streak effect investigation. The results indicate that the second NGV, looking upstream from left, has the highest thermal load. Its maximum surface temperature is 8.4% higher than that for the same NGV but with the mean inlet boundary conditions, and 14.1% higher than the ninth NGV. The finding is consistent with the field-observed NGV damage pattern. To extend the service life of these vulnerable NGVs, some protection methods should be considered.
Bipolar disorder (BD) is a highly heritable mood disorder with complex genetic architecture and poorly understood etiology. Previous transcriptomic BD studies have had inconsistent findings due to issues such as small sample sizes and difficulty in adequately accounting for confounders like medication use.
We performed a differential expression analysis in a well-characterized BD case-control sample (Nsubjects = 480) by RNA sequencing of whole blood. We further performed co-expression network analysis, functional enrichment, and cell type decomposition, and integrated differentially expressed genes with genetic risk.
While we observed widespread differential gene expression patterns between affected and unaffected individuals, these effects were largely linked to lithium treatment at the time of blood draw (FDR < 0.05, Ngenes = 976) rather than BD diagnosis itself (FDR < 0.05, Ngenes = 6). These lithium-associated genes were enriched for cell signaling and immune response functional annotations, among others, and were associated with neutrophil cell-type proportions, which were elevated in lithium users. Neither genes with altered expression in cases nor in lithium users were enriched for BD, schizophrenia, and depression genetic risk based on information from genome-wide association studies, nor was gene expression associated with polygenic risk scores for BD.
These findings suggest that BD is associated with minimal changes in whole blood gene expression independent of medication use but emphasize the importance of accounting for medication use and cell type heterogeneity in psychiatric transcriptomic studies. The results of this study add to mounting evidence of lithium's cell signaling and immune-related mechanisms.
This paper presents a comprehensive analytical approach to the modelling of wall-pressure fluctuations under a turbulent boundary layer, unifying and expanding the analytical models that have been proposed over many decades. The Poisson equation governing pressure fluctuations is Fourier transformed in the wavenumber domain to obtain a modified Helmholtz equation, which is solved with a Green’s function technique. The source term of the differential equations is composed of turbulence–mean shear and turbulence–turbulence interaction terms, which are modelled separately within the hypothesis of a joint normal probability distribution of the turbulent field. The functional expression of the turbulence statistics is shown to be the most critical point for a correct representation of the wall-pressure spectrum. The effect of various assumptions on the shape of the longitudinal correlation function of turbulence is assessed in the first place with purely analytical considerations using an idealised flow model. Then, the effect of the hypothesis on the spectral distribution of boundary-layer turbulence on the resulting wall-pressure spectrum is compared with the results of direct numerical simulation computations and pressure measurements on a controlled-diffusion aerofoil. The boundary layer developing over the suction side of this aerofoil in test conditions is characterised by an adverse pressure gradient. The final part of the paper discusses the numerical aspect of wall-pressure spectrum computation. A Monte Carlo technique is used for a fast evaluation of the multi-dimensional integral formulation developed in the theoretical part.
Maternal systemic inflammation during pregnancy may restrict embryo−fetal growth, but the extent of this effect remains poorly established in undernourished populations. In a cohort of 653 maternal−newborn dyads participating in a multi-armed, micronutrient supplementation trial in southern Nepal, we investigated associations between maternal inflammation, assessed by serum α1-acid glycoprotein and C-reactive protein, in the first and third trimesters of pregnancy, and newborn weight, length and head and chest circumferences. Median (IQR) maternal concentrations in α1-acid glycoprotein and C-reactive protein in the first and third trimesters were 0.65 (0.53–0.76) and 0.40 (0.33–0.50) g/l, and 0.56 (0.25–1.54) and 1.07 (0.43–2.32) mg/l, respectively. α1-acid glycoprotein was inversely associated with birth size: weight, length, head circumference and chest circumference were lower by 116 g (P = 2.3 × 10−6), and 0.45 (P = 3.1 × 10−5), 0.18 (P = 0.0191) and 0.48 (P = 1.7 × 10−7) cm, respectively, per 50% increase in α1-acid glycoprotein averaged across both trimesters. Adjustment for maternal age, parity, gestational age, nutritional and socio-economic status and daily micronutrient supplementation failed to alter any association. Serum C-reactive protein concentration was largely unassociated with newborn size. In rural Nepal, birth size was inversely associated with low-grade, chronic inflammation during pregnancy as indicated by serum α1-acid glycoprotein.
A compact transition between conductor-backed coplanar waveguide (CBCPW) and substrate integrated suspended line (SISL) is presented. Compared to the reported transitions from CBCPW to SISL, performance and compactness are improved. For demonstration purpose, a multilayer transition is designed and fabricated for operation up to 46 GHz. Experimental results, based on an electronic calibration and thru–reflect–line calibration allowing measurement in the 0.01–50 GHz frequency range, demonstrate an insertion loss of 0.59 ± 0.51 dB with a return loss of better than 10 dB in the 10 MHz to 46 GHz frequency range.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
Capillary rise of a liquid displacing gas is analysed for both open and closed capillaries. We include menisci mass and hysteresis, and show that oscillations due to inertia are muted by friction at the advancing meniscus. From single-phase numerical computations in a no-slip/slip capillary, we quantify losses due to entry, flow development, meniscus slip, exit and acceleration of fluid within the reservoir. For closed capillaries, determining viscous drag due to gas requires inclusion of compressibility, and solving a moving boundary problem. This solution is derived through perturbation expansion with respect to two different small parameters for obtaining pressure above the liquid meniscus. Our rise predictions spanning a large range of experimental conditions and fluids for both open and closed capillaries match the data. The experimental data confirm the adequacy of the theoretically constructed dimensionless groups for predicting oscillatory behaviour.
Article 6 of the SPS Agreement presents a series of interlinked obligations for importing and exporting countries of diseased agricultural products. The Russia–Pigs dispute raises the question of when an importing country is justified in imposing a ban on products from exporting countries unaffected by the disease, on the basis of the fact that the country is part of the same customs union as another country inflicted with the disease. This Article contends that four distinct classes of cross-border and cross-product externalities ought to play an important role when assessing this question in the future. It discusses the possible roles to be played by bilateral, sequential, pass-through, and supply chain externalities in propagating the transmission of agricultural disease across borders through trade.
The seasonality of individual influenza subtypes/lineages and the association of influenza epidemics with meteorological factors in the tropics/subtropics have not been well understood. The impact of the 2009 H1N1 pandemic on the prevalence of seasonal influenza virus remains to be explored. Using wavelet analysis, the periodicities of A/H3N2, seasonal A/H1N1, A/H1N1pdm09, Victoria and Yamagata were identified, respectively, in Panzhihua during 2006–2015. As a subtropical city in southwestern China, Panzhihua is the first industrial city in the upper reaches of the Yangtze River. The relationship between influenza epidemics and local climatic variables was examined based on regression models. The temporal distribution of influenza subtypes/lineages during the pre-pandemic (2006–2009), pandemic (2009) and post-pandemic (2010–2015) years was described and compared. A total of 6892 respiratory specimens were collected and 737 influenza viruses were isolated. A/H3N2 showed an annual cycle with a peak in summer–autumn, while A/H1N1pdm09, Victoria and Yamagata exhibited an annual cycle with a peak in winter–spring. Regression analyses demonstrated that relative humidity was positively associated with A/H3N2 activity while negatively associated with Victoria activity. Higher prevalence of A/H1N1pdm09 and Yamagata was driven by lower absolute humidity. The role of weather conditions in regulating influenza epidemics could be complicated since the diverse viral transmission modes and mechanism. Differences in seasonality and different associations with meteorological factors by influenza subtypes/lineages should be considered in epidemiological studies in the tropics/subtropics. The development of subtype- and lineage-specific prevention and control measures is of significant importance.
We developed a systematic experimental method to demonstrate that damage threshold fluence (DTF) for fused silica changes with the number of femtosecond laser (800 nm,
, 10 Hz and 600 Hz) pulses. Based on the experimental data, we were able to develop a model which indicates that the change in DTF varies with the number of shots logarithmically up to a critical value. Above this value, DTF approaches an asymptotic value. Both DTF for a single shot and the asymptotic value as well as the critical value where this happens, are extrinsic parameters dependent on the configuration (repetition rate, pressure and geometry near or at the surface). These measurements indicate that the power of this dependence is an intrinsic parameter independent of the configuration.
We report a roll-to-roll dry processing for making low cost and high performance electrodes for lithium-ion batteries (LIBs). Currently, the electrodes for LIBs are made with a slurry casting procedure (wet method). The dry electrode fabrication is a three-step process including: step 1 of uniformly mixing electrode materials powders comprising an active material, a carbonaceous conductor and the soft polymer binder; step 2 of forming a free-standing, continuous electrode film by pressing the mixed powders together through the gap between two rolls of a roll-mill; and step 3 of roll-to-roll laminating the electrode film onto a substrate such as a current collector. Compared with the conventional wet slurry electrode manufacturing method, the dry manufactural procedure and infrastructure are simpler, the production cost is lower, and the process eliminates volatile organic compound emission and is more environmentally friendly, and the ability of making thick (>120µm) electrodes with high tap density results in high energy density of final energy storage device. A prototype LIBs of LiNi0.6Mn0.2Co0.2O2 (NMC622)/graphite also has 230 Wh/ kg energy density.
Heading date (HD) and flowering date (FD) are critical for yield potential and stability, so understanding their genetic foundation is of great significance in wheat breeding. Three related recombinant inbred line populations with a common female parent were developed to identify quantitative trait loci (QTL) for HD and FD in four environments. In total, 25 putative additive QTL and 20 pairwise epistatic effect QTL were detected in four environments. The additive QTL were distributed across 17 wheat chromosomes. Of these, QHd-1A, QHd-1D, QHd-2B, QHd-3B, QHd-4A, QHd-4B and QHd-6D were major and stable QTL for HD. QFd-1A, QFd-2B, QFd-4A and QFd-4B were major and stable QTL for FD. In addition, an epistatic interaction test showed that epistasis played important roles in controlling wheat HD and FD. Genetic relationships between HD/FD and five yield-related traits (YRTs) were characterized and ten QTL clusters (C1–C10) simultaneously controlling YRTs and HD/FD were identified. The present work laid a genetic foundation for improving yield potential in wheat molecular breeding programmes.
A new optical delivery system has been developed for the (scanning) transmission electron microscope. Here we describe the in situ and “rapid ex situ” photothermal heating modality of the system, which delivers >200 mW of optical power from a fiber-coupled laser diode to a 3.7 μm radius spot on the sample. Selected thermal pathways can be accessed via judicious choices of the laser power, pulse width, number of pulses, and radial position. The long optical working distance mitigates any charging artifacts and tremendous thermal stability is observed in both pulsed and continuous wave conditions, notably, no drift correction is applied in any experiment. To demonstrate the optical delivery system’s capability, we explore the recrystallization, grain growth, phase separation, and solid state dewetting of a Ag0.5Ni0.5 film. Finally, we demonstrate that the structural and chemical aspects of the resulting dewetted films was assessed.
We describe the motivation and design details of the ‘Phase II’ upgrade of the Murchison Widefield Array radio telescope. The expansion doubles to 256 the number of antenna tiles deployed in the array. The new antenna tiles enhance the capabilities of the Murchison Widefield Array in several key science areas. Seventy-two of the new tiles are deployed in a regular configuration near the existing array core. These new tiles enhance the surface brightness sensitivity of the array and will improve the ability of the Murchison Widefield Array to estimate the slope of the Epoch of Reionisation power spectrum by a factor of ∼3.5. The remaining 56 tiles are deployed on long baselines, doubling the maximum baseline of the array and improving the array u, v coverage. The improved imaging capabilities will provide an order of magnitude improvement in the noise floor of Murchison Widefield Array continuum images. The upgrade retains all of the features that have underpinned the Murchison Widefield Array’s success (large field of view, snapshot image quality, and pointing agility) and boosts the scientific potential with enhanced imaging capabilities and by enabling new calibration strategies.
Strain-mediated magnetoelectric coupling provides a powerful method for controlling nanoscale magnetism with an electric voltage. This article reviews the initial use of macroscale composites and subsequent experimental control of magnetic thin films, nanoscale heterostructures, and single domains. The discussion highlights several characteristics enabling small, fast, and energy-efficient technologies. The second section covers applications where strain-mediated magnetoelectricity has been used, with emphasis on the storage, transmission, and processing of information (i.e., memory, antenna, and logic devices). These advances are order-of-magnitude improvements over conventional technologies, and open up exciting new possibilities.
To examine the association between household food insecurity and dietary diversity in the past 24h (dietary diversity score (DDS, range: 0–9); minimum dietary diversity (MDD, consumption of three or more food groups); consumption of nine separate food groups) among pregnant and lactating women in rural Malawi.
Two rural districts in Central Malawi.
Pregnant (n 589) and lactating (n 641) women.
Of surveyed pregnant and lactating women, 66·7 and 68·6 %, respectively, experienced moderate or severe food insecurity and only 32·4 and 28·1 %, respectively, met MDD. Compared with food-secure pregnant women, those who reported severe food insecurity had a 0·36 lower DDS (P<0·05) and more than threefold higher risk (OR; 95 % CI) of not consuming meat/fish (3·19; CI 1·68, 6·03). The risk of not consuming eggs (3·77; 1·04, 13·7) was higher among moderately food-insecure pregnant women. Compared with food-secure lactating women, those who reported mild, moderate and severe food insecurity showed a 0·36, 0·44 and 0·62 lower DDS, respectively (all P<0·05). The risk of not achieving MDD was higher among moderately (1·95; 1·06, 3·59) and severely (2·82; 1·53, 5·22) food-insecure lactating women. The risk of not consuming meat/fish and eggs increased in a dose–response manner among lactating women experiencing mild (1·75; 1·01, 3·03 and 2·81; 1·09, 7·25), moderate (2·66; 1·47, 4·82 and 3·75; 1·40, 10·0) and severe (5·33; 2·63, 10·8 and 3·47; 1·19, 10·1) food insecurity.
Addressing food insecurity during and after pregnancy needs to be considered when designing nutrition programmes aiming to increase dietary diversity in rural Malawi.
Good canopy structure is essential for optimal maize (Zea mays L.) production. However, creating appropriate maize canopy structure can be difficult, because the characteristics of individual plants are altered by changes in plant age, density and interactions with neighbouring plants. The objective of the current study was to find a reliable method for building good maize canopy structure by analysing changes in canopy structure, light distribution and grain yield (GY). A modern maize cultivar (ZhengDan958) was planted at 12 densities ranging from 1.5 to 18 plants/m2 at two field locations in Xinjiang, China. At the silking stage (R1), plant and ear height increased with plant density as well as leaf area index (LAI), whereas leaf area per plant decreased logarithmically. The fraction of light intercepted by the plant (F) increased with increasing plant density, but the light extinction coefficient (K) decreased linearly from 0.61 to 0.39. Taking the optimum value of F (95%) as an example, and using measured values of K for each plant density at R1 and the equation from Beer's law, the corresponding (theoretical) LAI for each plant density was calculated and optimum plant density (9.72 plants/m2) obtained by calculating the difference between theoretical LAIs and actual observations. Further analysis showed that plant density ranging from 10.64 to 11.55 plants/m2 yielded a stable GY range. Therefore, taking into account the persistence time for maximum LAI, the plant density required to obtain an ideal GY maize canopy structure should be increased by 10–18% from 9.72 plants/m2.