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This work examines the influence of body porosity on the wake past nominally two-dimensional rectangular plates of fixed width $D$ in the moderate range of Reynolds numbers $Re = UD/\nu$ (with $U$ the incoming velocity and $\nu$ the kinematic viscosity) between 15 000 and 70 000. With porosity $\beta$ defined as the ratio of open to total area of the plate, it is well established that as porosity increases, the wake shifts from the periodic von Kármán shedding behaviour to a regime where this vortex shedding is absent. This change impacts the fluid forces acting on the plate, especially the drag, which is significantly lower for a wake without vortex shedding. We analyse experimentally the transition between these two regimes using hot-wire anemometry, particle-image velocimetry and force measurements. Coherence and phase measurements are used to determine the existence of regular, periodic vortex shedding based on the velocity fluctuations in the two main shear layers on either side of the wake. Results show that, independent of $Re$, the wake exhibits the classical Kármán vortex shedding pattern for $\beta <0.2$ but this is absent for $\beta >0.3$. In the intermediate range, $0.2<\beta <0.3$, there is a transitional regime that has not previously been identified; it is characterised by intermittent shedding. The flow alternates randomly between a vortex shedding and a non-shedding pattern and the total proportion of time during which vortex shedding is observed (the intermittency) decreases with increasing porosity.
The impact of temperature on the migration of cations within layers of clay minerals is of profound significance for the design and practical application of materials derived from clay minerals. This study focuses on Li+ and Na+ as representative cations, together with illite (Ilt) and montmorillonite (Mnt) as representative clay minerals. The study investigates the behaviour of cation migration and occupation within clay minerals across varying temperatures. A series of samples were prepared meticulously by immersing illite and montmorillonite in Li+ and Na+ solutions, subsequently subjecting them to different temperatures (unheated, 100, 150, 200, 250 and 300°C) for 24 h. Through the use of techniques such as X-ray diffraction (XRD), cation exchange capacity (CEC), Fourier-transform infrared spectroscopy (FTIR), magic angle rotating solid nuclear magnetic resonance spectroscopy (MAS NMR), and X-ray photoelectron spectroscopy (XPS), the study discerns structural transformations in illite and montmorillonite, and tracks the migration and occupation of Li+ and Na+. The findings reveal that following heating, Na+ and Li+ do not infiltrate the lattice of illite. For montmorillonite, Na+ also does not migrate into the montmorillonite lattice, however, in contrast, Li+ does exhibit migration into this lattice. Notably, the migration and occupation of interlayer Li+ within montmorillonite exhibit discernible temperature dependence. Specifically, upon reaching 150°C, interlayer Li+ migrate to ditrigonal cavities within the tetrahedral layers. As the temperature elevates to 200°C, Li+ further permeate vacant octahedral sites through the ditrigonal cavities, culminating in the formation of a localised trioctahedral structure.
Depression is a significant mental health concern affecting the overall well-being of adolescents and young adults. Recently, the prevalence of depression has increased among young people. Nonetheless, there is little research delving into the longitudinal epidemiology of adolescent depression over time.
Aims
To investigate the longitudinal epidemiology of depression among adolescents and young adults aged 10–24 years.
Method
Our research focused on young people (aged 10–24 years) with depression, using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. We explored the age-standardised prevalence, incidence and disability-adjusted life-years (DALYs) of depression in different groups, including various regions, ages, genders and sociodemographic indices, from 1990 to 2019.
Results
The prevalence, incidence and DALYs of depression in young people increased globally between 1990 and 2019. Regionally, higher-income regions like High-Income North America and Australasia recorded rising age-standardised prevalence and incidence rates, whereas low- or middle-income regions mostly saw reductions. Nationally, countries such as Greenland, the USA and Palestine reported the highest age-standardised prevalence and incidence rates in 2019, whereas Qatar witnessed the largest growth over time. The burden disproportionately affected females across age groups and world regions. The most prominent age effect on incidence and prevalence rates was in those aged 20–24 years. The depression burden showed an unfavourable trend in younger cohorts born after 1980, with females reporting a higher cohort risk than males.
Conclusions
Between 1990 and 2019, the general pattern of depression among adolescents varied according to age, gender, time period and generational cohort, across regions and nations.
This study documents three chapel furnishings dating from around 1500 belonging to the Edgcumbe family at Cotehele, Cornwall, south-west England, and discusses their survival during the Protestant Reformation and beyond. The textiles were exhibited to the Society of Antiquaries of London by W H St John Hope, FSA and the text of his presentation was published in the Proceedings of the Society in 1912–13. The present article brings together the numerous other historic writings concerning the textiles. Their possible origins are explored and assessed in context with pieces of similar date. Observations of their original making and later changes are recorded, while interpretations by historians of this period are put forward for consideration. The rarity of survival of the textiles and their documented history is acknowledged.
Worldwide adoption of 5G mobile devices has been one of the main driving engines behind semiconductor industry. Since the initial release in 2020, 5G-enabled devices have surpassed the market penetration of 3G/4G smartphones. 5G brings higher data capacity, low latency, and new applications. These are possible due to lower feature nodes such as FinFET 3 nm/5 nm but also due to improvements of the 5G radio frequency (RF)front-end circuitry. This paper presents 5G RF front-end architectures with novel circuits and measurement details which will be part of future 5G advanced and 6G mobile devices and are easier to be controlled using digital circuitry. The paper presents an envelope-controlled power amplifier (PA) principle, along with a novel simplified calibration architecture designed for 5G/5G+ operating under 6 GHz, as well as for frequency range 2 millimeter-wave PAs. An earlier version of this paper was presented at the 2023 53rd European Microwave Conference and was published in the Proceedings [Balteanu F, Thoomu K, Pingale A, Venimadhavan S, Sarkar S, Choi Y, Modi H, Drogi S, Lee J and Agarwal B (2023) Enabling RF circuit techniques for 5G and beyond In 53rd European Microwave Conference (EuMC), Berlin, Germany, 22–25].
The larynx is the second most prevalent subsite for head and neck cancer. Over half of head and neck cancer patients present with advanced disease. We report our regional practices for palliative intent laryngeal squamous cell cancer (SCC).
Methods
Retrospective analysis of patients with laryngeal SCC treated with palliative intent, discussed at the regional head and neck multidisciplinary team meeting from July 2010 to June 2016.
Results
A total of 65 patients were included, of whom 45 per cent had potentially curable disease but were not fit for curative treatment. Nine patients (14 per cent) underwent tracheostomy, with mean survival and hospital stay of 278 and 48 days, respectively. Four patients (6 per cent) underwent debulking surgery with mean survival and hospital stay of 214 and 1 days, respectively.
Conclusion
All palliative treatment measures offered to patients can have an impact on survival and quality of life. Patients should be at the centre of the decision-making process and counselled on the potential impact of interventions.
This field report presents the planning and execution of a large-scale aeromedical refugee retrieval operation amid the on-going Russia-Ukraine crisis. The retrieval was coordinated by the Italian Department of Civil Protection and led by the Centrale Remota Operazioni Soccorso Sanitario (CROSS), a governmental facility overseeing medical assistance. An Airbus A320 was chosen for its capacity of 165 passengers, with one emergency stretcher maintaining maximum seating. The aircraft was equipped with an Advanced Life Support kit, and specific considerations for medical equipment compliance were made. Special cases, including patients with on-going chemotherapy and end-stage kidney disease, underwent fit-to-fly screening. The boarding process in Lublin, Poland involved triage and arrangements for passengers with gastroenteric symptoms. Notably, 22 passengers with recent episodes of illness were isolated. The successful operation, demonstrating the viability of evacuating vulnerable individuals via commercial airlines, underscores the importance of precise planning and coordination in crisis situations.
Gas turbines play a vital role in various industries. Timely and accurately predicting their degradation is essential for efficient operation and optimal maintenance planning. Diagnostic and prognostic outcomes aid in determining the optimal compressor washing intervals. Diagnostics detects compressor fouling and estimates the trend up to the current time. If the forecast indicates fast progress in the fouling trend, scheduling offline washing during the next inspection event or earlier may be crucial to address the fouling deposit comprehensively. This approach ensures that compressor cleaning is performed based on its actual health status, leading to improved operation and maintenance costs. This paper presents a novel prognostic method for gas turbine degradation forecasting through a time-series analysis. The proposed approach uses the Temporal Fusion Transformer model capable of capturing time-series relationships at different scales. It combines encoder and decoder layers to capture temporal dependencies and temporal-attention layers to capture long-range dependencies across the encoded degradation trends. Temporal attention is a self-attention mechanism that enables the model to consider the importance of each time step degradation in the context of the entire degradation profile of the given health parameter. Performance data from multiple two-spool turbofan engines is employed to train and test the method. The test results show promising forecasting ability of the proposed method multiple flight cycles into the future. By leveraging the insights provided by the method, maintenance events and activities can be scheduled in a proactive manner. Future work is to extend the method to estimate remaining useful life.
This study discusses the processes of increasing social malaise and an “oppositional mood” in the Cape Verdean island of Santo Antão, where growing frustration between 1975 and 1990 led to the building of massive political opposition against the single-party regime in the archipelago. Early scrutiny of the shortcomings of independent administration, anger about the installation of a new police force, resettlement schemes, a failed agrarian reform, regime violence to achieve that reform, and a generalised mood of decline in the second half of the 1980s, constitute different elements explaining the unrest in that island. Based on newly available, local archives as an innovative source, the interpretation of a remote Cape Verdean opposition island also addresses the potential of studying opposition against “winning parties” and regimes after independence in wider regional frameworks, referring to discontent and “oppositional mood” elsewhere in postcolonial (Lusophone) Africa.
The probability density function (PDF) for the free surface elevation in an irregular sea has an integral formulation when based on the cumulant generating function. To leading order, the result is Gaussian, whereas nonlinear extensions have long been limited to Gram–Charlier series approximations. As shown recently by Fuhrman et al. (J. Fluid Mech., vol. 970, 2023, A38), however, the second-order integral can be represented exactly in closed form. The present work extends this further, enabling determination of this PDF to even higher orders. Towards this end, a new ordinary differential equation (ODE) governing the PDF is first derived. Asymptotic solutions in the limit of large surface elevation are then found, utilizing the method of dominant balance. These provide new analytical forms for the positive tail of the PDF beyond second order. These likewise clarify how high-order cumulants (involving statistical moments such as the kurtosis) govern the tail, which is shown to get heavier with each successive order. The asymptotic solutions are finally utilized to generate boundary conditions, such that the governing ODE may be solved numerically, enabling novel determination of the PDF at third and higher order. Successful comparisons with challenging data sets confirm accuracy. The methodology thus enables the PDF of the surface elevation to be determined numerically, and the asymptotic tail analytically, to any desired order. Results are worked out explicitly up to fifth order. The theoretical probability of extreme surface elevations (typical of rogue waves) may thus be assessed quantitatively for highly nonlinear irregular seas, requiring only relevant statistical quantities as input.
We derive the spin Euler equation for ideal flows by applying the spherical Clebsch mapping. This equation is based on the spin vector, a unit vector field encoding vortex lines, instead of the velocity. The spin Euler equation enables a feasible Lagrangian study of fluid dynamics, as the isosurface of a spin-vector component is a vortex surface and material surface in ideal flows. We establish a non-blowup criterion for the spin Euler equation, suggesting that the Laplacian of the spin vector must diverge if the solution forms a singularity at some finite time. The direct numerical simulations (DNS) of three ideal flows – the vortex knot, the vortex link and the modified Taylor–Green flow – are conducted by solving the spin Euler equation. The evolution of the Lagrangian vortex surface illustrates that the regions with large vorticity are rapidly stretched into spiral sheets. The DNS result exhibits a pronounced double-exponential growth of the maximum norm of Laplacian of the spin vector, showing no evidence of the finite-time singularity formation if the double-exponential growth holds at later times. Moreover, the present criterion with Lagrangian nature appears to be more sensitive than the Beale–Kato–Majda criterion in detecting the flows that are incapable of producing finite-time singularities.
Derek Parfit’s view of ‘personal identity’ raises questions about whether advance decisions refusing life-saving treatment should be honored in cases where a patient loses psychological continuity; it implies that these advance decisions would not be self-determining at all. Part I of this paper argues that this assessment of personal identity undermines the distinction between suicide and homicide. However, rather than accept that an unknown metaphysical ‘further fact’ underpins agential unity, one can accept Parfit’s view but offer a different account of what it implies morally: that the social and legal bases for ascribing a persisting ‘personal identity’ maintain the distinction between homicide and suicide.
This paper raises objections to the constitution of these lines in the OCT. The lines are gnomic but they generalize based on an actual sequence of events just described and should contain an allusion to the offence that will cause the Greeks to perish, the outrage against Athena's temple. This, it is argued, stood in a lacuna best marked after 95. The article has three theses: (1) sacking ‘cities, temples, and tombs’ is implausible because the latter two are parts of the first; (2) plundering tombs refers to nothing in the play, nor was this thought of as an offence against the gods; (3) 96–7 do not refer to the offence that causes the fool's death but are a description of his success, the destruction of the hated enemy population. That success stands in ironic contrast with his subsequent death.
In this paper, we are interested in positive solutions of
$$ \begin{align*}\left\{ \begin{array}{@{}ll} -\Delta u = a(x)v^{p-1}, \quad &\text{ in } \Omega,\\ -\Delta v = b(x)u^{q-1}, \quad &\text{ in } \Omega,\\ u,v>0, \quad &\text{ in } \Omega,\\ u=v=0, \quad &\text{ on } \partial\Omega, \end{array} \right. \end{align*} $$
where $\Omega $ is a bounded annular domain (not necessarily an annulus) in ${\mathbb {R}}^N (N \ge 3)$ and $ a(x), b(x)$ are positive continuous functions. We show the existence of a positive solution for a range of supercritical values of p and q when the problem enjoys certain mild symmetry and monotonicity conditions. We shall also address the symmetry breaking phenomena where the system is fully symmetric. Indeed, as a consequence of our results, we shall show that problem (1) has $\Bigl \lfloor \frac {N}{2} \Bigr \rfloor $ (the floor of $\frac {N}{2}$) positive non-radial solutions when $ a(x)=b(x)=1$ and $\Omega $ is an annulus with certain assumptions on the radii. In general, for the radial case where the domain is an annulus, we prove the existence of a non-radial solution provided
where $\lambda _H$ is the best constant for the Hardy inequality on $\Omega .$ We remark that the best constant $\lambda _H$ for the Hardy inequality is just the characteristic of the domain, and is independent of the choices of p and $q.$ For this reason, the aforementioned inequality plays a major role to prove the existence and multiplicity of non-radial solutions when the problem is fully symmetric. Our proofs use a variational formulation on appropriate convex subsets for which the lack of compactness is recovered for the supercritical problem.
This study aimed to parse between-person heterogeneity in growth of impulsivity across childhood and adolescence among participants enrolled in five childhood preventive intervention trials targeting conduct problems. In addition, we aimed to test profile membership in relation to adult psychopathologies. Measurement items representing impulsive behavior across grades 2, 4, 5, 7, 8, and 10, and aggression, substance use, suicidal ideation/attempts, and anxiety/depression in adulthood were integrated from the five trials (N = 4,975). We applied latent class growth analysis to this sample, as well as samples separated into nonintervention (n = 2,492) and intervention (n = 2,483) participants. Across all samples, profiles were characterized by high, moderate, low, and low-increasing impulsive levels. Regarding adult outcomes, in all samples, the high, moderate, and low profiles endorsed greater levels of aggression compared to the low-increasing profile. There were nuanced differences across samples and profiles on suicidal ideation/attempts and anxiety/depression. Across samples, there were no significant differences between profiles on substance use. Overall, our study helps to inform understanding of the developmental course and prognosis of impulsivity, as well as adding to collaborative efforts linking data across multiple studies to better inform understanding of developmental processes.
In this paper, the results of an experimental investigation for a Y-shaped engine inlet are presented. The experiment is performed at subsonic flow conditions. The main focus is given to time-dependent total pressures measured at the aerodynamic interface plane. Distinctive frequencies carrying high energy contents of the fluctuating total pressures are given and the relation between time-dependent and time-average performance parameters is presented. The cross-correlation coefficients of the high frequency probe readings distributed through the aerodynamic interface plane are also investigated.