Uniform Component Research Articles

Robust Responses of the Sahelian Hydrological Cycle to Global Warming

How the globally uniform component of sea surface temperature (SST) warming influences rainfall in the African Sahel remains insufficiently studied, despite mean SST warming being among the most robustly simulated and theoretically grounded features of anthropogenic climate change. A prior study using the NOAA Geophysical Fluid Dynamics Laboratory (GFDL) AM2.1 atmospheric general circulation model (AGCM) demonstrated that uniform SST warming strengthens the prevailing northerly advection of dry Saharan air into the Sahel. The present study uses uniform SST warming simulations performed with 7 GFDL and 10 CMIP5 AGCMs to assess the robustness of this drying mechanism across models and uses observations to assess the physical credibility of the severe drying response in AM2.1. In all 17 AGCMs, mean SST warming enhances the free-tropospheric meridional moisture gradient spanning the Sahel and with it the Saharan dry-air advection. Energetically, this is partially balanced by anomalous subsidence, yielding decreased precipitation in 14 of the 17 models. Anomalous subsidence and precipitation are tightly linked across the GFDL models but not the CMIP5 models, precluding the use of this relationship as the start of a causal chain ending in an emergent observational constraint. For AM2.1, cloud–rainfall covariances generate radiative feedbacks on drying through the subsidence mechanism and through surface hydrology that are excessive compared to observations at the interannual time scale. These feedbacks also act in the equilibrium response to uniform warming, calling into question the Sahel’s severe drying response to warming in all coupled models using AM2.1.

A novel vibration-assisted slurry impregnation to fabricate Cf/ZrB2-SiC composite with enhanced mechanical properties

The three dimensional needle-punched carbon fiber reinforced ZrB2-SiC composite (Cf/ZrB2-SiC) with highly uniform distribution was fabricated successfully via a novel vibration-assisted slurry impregnation and low-temperature (1450 °C) hot pressing technique using nanosized ZrB2 powders. The carbon fiber/ceramic matrix interfaces were clear without obvious reaction products detected by the high resolution transmission electron microscopy (HR-TEM), indicating the degradation of carbon fiber was effectively inhibited. The Cf/ZrB2-SiC composite exhibited a typical non-brittle fracture feature with a high work of fracture of 1104 J/m2, which was approximately twice that of composite fabricated only by slurry impregnation and hot pressing. The enhancement in work of fracture was attributed to multiple toughening mechanisms of continuous carbon fibers such as extensive fiber bridging and pull-out accompanied by obvious crack deflection and branching. This work provides a valuable potential of preparing continuous carbon fiber reinforced ceramic composites with uniform component distribution and enhanced mechanical properties.

Methods to improve the estimation of time-to-event outcomes when data is de-identified.

Technological advancements in recent years have sparked the use of large databases for research. The availability of these large databases has administered a need for anonymization and de-identification techniques, prior to publishing the data. This de-identification alters the data, which in turn can impact the results derived post de-identification and potentially lead to false conclusions. The objective of this study is to investigate if alterations to a de-identified time-to-event data set may improve the accuracy of the estimates. In this data set, a missing time bias was present among censored patients as a means to preserve patient confidentiality. This study investigates five methods intended to reduce the bias of time-to-event estimates. A simulation study was conducted to evaluate the effectiveness of each method in reducing bias. In situations where there was a large number of censored patients, the results of the simulation showed that Method 4 yielded the most accurate estimates. This method adjusted the survival times of censored patients by adding a random uniform component such that the modified survival time would occur within the final year of the study. Alternatively, when there was only a small number of censored patients, the method that did not alter the de-identified data set (Method 1) provided the most accurate estimates.

Microfluidic Formation of Coculture Tumor Spheroids with Stromal Cells As a Novel 3D Tumor Model for Drug Testing.

Three-dimensional (3D) tumor spheroids offer unprecedented capability for drug screening because of their unique features such as spatial 3D structure, relevant physiological responses, more complex intercellular network, and stroma-cancer cell interactions. Microfluidic technology provides a facile strategy to make uniform tumor spheroids with potential of high-throughput production. In this article, we develop a microfluidic approach to produce core-shell alginate particles, which allows the separate confinement of different cells in the core and shell structure. To reconstitute the complex tumor structure, we encapsulated tumor cells in the core and stromal fibroblast cells in the shell. These coculture tumor spheroids were applied for drug evaluation showing similar drug resistance as those prepared using conventional methods in well plates. These results demonstrated that our microfluidic approach are facile and versatile for making various tumor spheroids with uniform size but different components to better mimic tumor microenvironment. Moreover, the production rate of around 200 spheroids/min indicates the great potential of this approach for high-throughput drug screening.

Structural response of a concrete cable-stayed bridge under thermal loads

Daily and seasonal temperature variations have a significant influence on the structural response of bridges, inducing strains, displacements or rotations of the same order of magnitude, or even larger, than those due to dead or live loads. Besides understanding the structural behaviour under the operational loads, the characterization of the structural response induced by the daily and seasonal temperature variations is mandatory for the critical assessment of the bridge structural condition and when proactive conservation is envisaged. In this study, a methodology is proposed for the simulation of the structural response of large concrete bridges under the effects of realistic temperature variations, aiming at the optimum compromise between accuracy and simplicity of the involved procedures. The transient temperature field in a set of representative cross-sections is obtained from the available meteorological data via two-dimensional thermal analyses. The temperature field is decomposed into uniform, linear and non-linear components, the former two being introduced in a mechanical model of the bridge to obtain the transient structural response. The methodology is applied to a concrete cable-stayed bridge equipped with a permanent structural monitoring system. The measured and calculated hourly temperatures, deflections, bearing displacements, rotations and stay-cable forces are compared during a period of 17 months and good agreement is generally found. The consideration of the radiative cooling effects is demonstrated to be essential in other to obtain a good estimation of the thermal field of the bridge. The behaviour of the bridge is discussed and the relative contribution of each temperature component to a given structural response is disclosed. A discussion on the optimal deployment location of a minimum set of embedded temperature sensors in order achieve the best estimators of the temperature components (uniform and linear) is also presented.

Multiscale analysis of non-contact splices at drilled shaft to bridge column interface

The contact and non-contact splices of the longitudinal steel bar and dowel bar have been widely adopted as the interface connection between pier columns and drilled shafts in bridge engineering. With the popularization and application of bridge substructures composed of the rectangular column and circular drilled shaft, the suitability and accuracy of the design provision specified in the current codes, which is derived from the investigation of the uniform circular components, are becoming the research hotspots in engineering and academia. In order to further study the mechanical behavior of the pier column-drilled shafts interface with inconsistent geometrical shapes, the experimental and numerical analysis of the interfaces with the overlap spacing of 0, 4, 6 and 8 in. are carried out systematically. The experimental results indicate that with the increment of lap spacing, the load-bearing capacity of the components will be consistently reduced, and the material strength also plays an important role in the structural performance. Compared with the specimen with the contact splice, the non-contact lap splice between the longitudinal bar and dowel bar will lead to additional shearing cracks and splitting cracks, and the inclination angle of the shearing cracks gradually increases with the enlargement of lap spacing as well. The relationship of the lateral displacement at the top of the column and the vertical reaction agrees well with that of the numerical analysis. Moreover, the fracture distribution and the interface separation can be explicitly depicted by 3D/2D numerical models based on homogeneous concrete assumption, which fully validates the rationality of the experimental observations. In order to exclude the influence caused by the variation of the concrete strength in tested specimens, the material properties in 3D and 2D simulation are uniformly specified according to the measured material strength of Specimen 1 and the numerical findings show that the structural stiffness of Specimens 1–4 decrease with the increment of lap spacing. However, the ultimate bearing capacity of the component is not apparently affected while using non-contact splices, accompanied by satisfied ductility. The detailed failure pattern and the crack evolution between overlapped steel bars are explicitly revealed by the 2D multiscale models. The maximum angle of diagonal cracks can be detected at the end of the overlap area, which is about 45°. The inclination of shearing cracks within the overlap area is slightly smaller and deteriorates with the enlargement of lap spacing. Meanwhile, the microcracks located in the non-overlap area are typically horizontal bending fractures. The research conclusion of this study based on large-scale experimental and numerical investigation is highly referential for the practical application of the interface connection of bridge column to drilled shaft with inconsistent geometry using non-contact splices.

조리사 유니폼의 구성요소가 직무만족과 생산성 향상에 미치는 영향: 직무만족의 매개효과를 중심으로

조리사 유니폼의 구성요소가 직무만족과 생산성 향상에 미치는 영향: 직무만족의 매개효과를 중심으로

Tidal Deformabilities and Radii of Neutron Stars from the Observation of GW170817.

We use gravitational-wave observations of the binary neutron star merger GW170817 to explore the tidal deformabilities and radii of neutron stars. We perform a Bayesian parameter estimation with the source location and distance informed by electromagnetic observations. We also assume that the two stars have the same equation of state; we demonstrate that, for stars with masses comparable to the component masses of GW170817, this is effectively implemented by assuming that the stars' dimensionless tidal deformabilities are determined by the binary's mass ratio q by Λ_{1}/Λ_{2}=q^{6}. We investigate different choices of prior on the component masses of the neutron stars. We find that the tidal deformability and 90% credible interval is Λ[over ˜]=222_{-138}^{+420} for a uniform component mass prior, Λ[over ˜]=245_{-151}^{+453} for a component mass prior informed by radio observations of Galactic double neutron stars, and Λ[over ˜]=233_{-144}^{+448} for a component mass prior informed by radio pulsars. We find a robust measurement of the common areal radius of the neutron stars across all mass priors of 8.9≤R[over ^]≤13.2 km, with a mean value of ⟨R[over ^]⟩=10.8 km. Our results are the first measurement of tidal deformability with a physical constraint on the star's equation of state and place the first lower bounds on the deformability and areal radii of neutron stars using gravitational waves.

Causes of the Uncertainty in Projections of Tropical Terrestrial Rainfall Change: East Africa

AbstractUnderstanding the causes of regional climate projection uncertainty is a critical component toward establishing reliability of these projections. Here, four complementary experimental and decomposition techniques are synthesized to begin to understand which mechanisms differ most between models. These tools include a variety of multimodel ensembles, a decomposition of rainfall into tropics-wide or region-specific processes, and a separation of within-domain versus remote contributions to regional model projection uncertainty. Three East African regions are identified and characterized by spatially coherent intermodel projection behavior, which interestingly differs from previously identified regions of coherent interannual behavior. For the “Short Rains” regions, uncertainty in projected seasonal mean rainfall change is primarily due to uncertainties in the regional response to both the uniform and pattern components of SST warming (but not uncertainties in the global mean warming itself) and a small direct CO2 impact. These primarily derive from uncertain regional dynamics over both African and remote regions, rather than globally coherent (thermo)dynamics. For the “Long Rains” region, results are similar, except that uncertain atmospheric responses to a fixed SST pattern change are a little less important, and some key regional uncertainties are primarily located beyond Africa. The latter reflects the behavior of two outlying models that experience exceptional warming in the southern subtropical oceans, from which large lower-tropospheric moisture anomalies are advected by the mean flow to contribute to exceptional increases in the Long Rains totals. Further research could lead to a useful assessment of the reliability of these exceptional projections.

Kumaraswamy Distribution and Random Extrema

Objective:We provide a new stochastic representation for a Kumaraswamy random variable with arbitrary non-negative parameters. The representation is in terms of maxima and minima of independent distributed standard uniform components and extends a similar representation for integer-valued parameters.Result:The result is further extended for generalized classes of distributions obtained from a “base” distribution functionFviz.G(x) =H(F(x)), whereHis the CDF of Kumaraswamy distribution.

Mental health in postgraduate social work curriculum: Review of training contents in Indian schools of social work

AbstractTraining of social workers according to the changing needs of the society is important. To this end, we decided to review the adequacy of mental health training in postgraduate programme in social work. The Mental Health Care Act defines psychiatric social worker (PSW) in India to have additional higher qualification beyond post‐graduation in social work. The number of such qualified PSWs appears to be limited due to small number of institutes that offer advanced training in the country. Though, the number of available PSWs with such qualifications is rising, the manpower in proportion to the mental health needs in the country continues to remain low. It is therefore, relevant to review the quality of psychiatric social work education at postgraduate level if this level is to be considered as the desirable qualification for PSW. In this context, postgraduate social work syllabi from 71 universities including autonomous institutions were reviewed using semi‐structured assessment. The results show a lack of uniform teaching components, training methods and insufficient skill orientation towards mental health interventions. These observations suggest that curricula and training are modified with strengthening and enhancing the quality of training of mental health at post‐graduate level in Social Work.

The Integrated Management of Sustainable Development: Methodological Prerequisitesand Their Practical Realization

Subject. “Integrated management of sustainable development: methodological prerequisites and their practical realization” in a complex covers a set of problems in global tendencies of the modern world. Complex system disclosure of interrelation between various operating rooms and functional units and the capitals which the organization uses or on which she makes impact became an object of research on this subject. At the same time, connectivity and interdependence between various factors influencing the ability of the organization to create a cost for a long time are especially distinguished. The uniform information component of sustainable development is expressed in the international standards on drawing up the reporting in the field of sustainable development and The Integrated Reporting standard. Synthesis of such information and administrative decisions according to a hypothesis of a research predetermines opportunities and the directions of strategic development of the organization in close interrelation with external factors and conditions of global character. The purpose of the article is considerations of a control system in the synthesis of components of sustainable development and its reporting, the establishment of methodological unity that is necessary conditions for integrated strategic management of the organization and economy of regions. In article integrated, system approach in studying of a problem of sustainable development of regions of the country, methods of the group are used, the horizontal and vertical analysis of the compared indicators is carried out. The content of management of strategic stability of the organization on the basis of a wide range of the capitals and indicators predetermined by the international standards in the field of sustainable development and The Integrated Reporting standard reveals. Authors make recommendations on the example of the operating enterprises for the creation of the integrated system of management of sustainable development. Keeping and interrelation of types of the capitals in the management of sustainable development are considered. The integrated thinking as a basis of management of the interconnected types of the capitals which are contained in the reporting in the field of sustainable development reveals. An example of carrying out the analysis of separate indicators of sustainable development is reviewed.

The enhanced piezoelectricity in compositionally graded ferroelectric thin films under electric field: A role of flexoelectric effect

Compositionally graded ferroelectric thin films are found to produce large strain gradients, which can be used to tune the physical properties of materials through the flexoelectric effect, i.e., the coupling of polarization and the strain gradient. The influences of the flexoelectric effect on the polarization distribution and the piezoelectric properties in compositionally graded Ba1−xSrxTiO3 ferroelectric thin films are investigated by using an extended thermodynamic theory. The calculation results show that the presence of the flexoelectric effect tends to enhance and stabilize polarization components. The polarization rotation induced by the flexoelectric field has been predicted, which is accompanied by more uniform and orderly polarization components. A remarkable enhancement of piezoelectricity is obtained when the flexoelectric field is considered, suggesting that compositionally graded Ba1−xSrxTiO3 ferroelectric thin films with a large strain gradient are promising candidates for piezoelectric devices.

Material distributions

The concept of material distribution is introduced as describing the geometric material structure of a general non-uniform body. Any smooth constitutive law is shown to give rise to a unique smooth integrable singular distribution. Ultimately, the material distribution and its associated singular foliation result in a rigorous and unique subdivision of the material body into strictly smoothly uniform components. Thus, the constitutive law induces a unique partition of the body into smoothly uniform sub-bodies, laminates, filaments and isolated points.

A new multi-material level set topology optimization method with the length scale control capability

Multi-material level set topology optimization methods conventionally rely on the overlap of multiple level set functions to realize the multi-material structural representation. However, this representation may produce redundant material phases and the signed distance information is no longer available within the individual material regions. To fix these issues, a new multi-material level set topology optimization method is proposed in this paper, where m level set functions represent m material phases plus the void, and the signed distance information is straightforwardly available in each material phase. To be specific, each level set function corresponds to a material phase and the overlapping areas are filled with an artificial material type, the property of which is weaker than any of the involved material types. This artificial material plays the role of penalizing the overlap areas to vanish, which is different from the close-to-zero property material type for the void. Hence, the optimization process starts with any multi-level set interpolated input and the overlapping areas will gradually vanish. Based on this new method, we have successfully realized the component length scale control on multi-material structures and innovatively, an approach has been proposed to realize the uniform component thickness control without need of pre-specifying the thickness target.

Convective heat transfer in non-uniformly heated corrugated slots

An analysis of heat transfer in non-uniformly heated corrugated slots has been carried out. A sinusoidal corrugation is placed at the lower plate that is exposed to heating consisting of uniform and sinusoidal components, while the upper smooth plate is kept isothermal. The phase difference ΩTL describes the shift between the heating and geometric non-uniformities. The analysis is limited to heating conditions that do not give rise to secondary motions. Depending on ΩTL, the conductive heat flow is directed either upwards, or downwards, or is eliminated. Its magnitude is smallest for the long-wavelength systems and largest for the short-wavelength systems, and it increases proportionally to the corrugation amplitude and heating intensity. The same heating creates horizontal temperature gradients that give rise to convection whose form depends on ΩTL. Convection consists of counter-rotating rolls with the size dictated by the system wavelength when the hot spots (points of maximum temperature) overlap either with the corrugation tips or with the corrugation bottoms. Thermal drift forms for all other values of ΩTL. The convective heat flow is always directed upwards, and it is the largest in systems with wavelengths comparable to the slot height. The magnitude of the overall heat flow increases proportionally to the heating intensity when conductive effects dominate and proportionally to the second power of the heating intensity when convection dominates. It also increases proportionally to the corrugation amplitude. The system characteristics are dictated by convection when the relative position of the heating and corrugation patterns eliminates conduction. Addition of the uniform heating component amplifies the above processes, while uniform cooling reduces them. The processes described above are qualitatively similar for all Prandtl numbers of practical interest with the magnitude of the convective heat flow increasing with Pr.

Nonlinear screening of dust grains and structurization of dusty plasma: II. formation and stability of dust structures

The second part of the review on dust structures (the first part was published in Plasma Phys. Rep. 39, 515 (2013)) is devoted to experimental and theoretical studies on the stability of structures and their formation from the initially uniform dusty plasma components. The applicability limits of theoretical results and the role played by nonlinearity in the screening of dust grains are considered. The importance of nonlinearity is demonstrated by using numerous laboratory observations of planar clusters and volumetric dust structures. The simplest compact agglomerates of dust grains in the form of stable planar clusters are discussed. The universal character of instability resulting in the structurization of an initially uniform dusty plasma is shown. The fundamental correlations described in the first part of the review, supplemented with effects of dust inertia and dust friction by the neutral gas, are use to analyze structurization instability. The history of the development of theoretical ideas on the physics of the cluster formation for different types of interaction between dust grains is described.

A Generalization of Rényi’s Parking Problem

Background . A generalization of the A. Renyi’s stochastic parking model is considered. In our model, the probability distribution of the left end of a parked car is a mixture of a uniform distribution and a degenerated one. This allows distinguishing drivers with different skills. Objective. The aim of the paper is an asymptotic study of the mean number of parked cars \[m_{p}(x) \] when the length of parking space \[x\] increases unboundedly. Methods. A functional-integral equation satisfied by the function \[m_{p}\] is derived. This equation admits an explicit solution in terms of the Laplace transform which allows for applying Tauberian theorems to study the required asy­mp­totics. Results. For the above model it is shown, that \[m_{p}(x)=\lambda_{p}x+o(x) \] as \[x\rightarrow\infty.\] The explicit form of the constant \[\lambda_{p}\] is given by \[\frac{1}{1-p}\int_{0}^{\infty} \mathrm{exp}\left(-2\int_{0}^{S}\frac{e^{\tau}-1}{\tau({e^{\tau}-p})}d\tau\right)ds.\] A similar asymptotic bound is obtained for a wider class of models in which the uniform component of the mixture of distributions is replaced by a more general one. Conclusions. As a generalization of the classical A. Renyi’s random parking model, a new parking model is proposed. In this model the uniform distribution of the parking point is replaced by a mixture of a uniform distribution and a degenerated one. In the new model, a counterpart of the Renyi’s theorem on the asymptotic behavior of the mean number of parked cars is deduced.

Intertwined orders in holography: pair and charge density waves

Building on [1], we examine a holographic model in which a U(1) symmetry and translational invariance are broken spontaneously at the same time. The symmetry breaking is realized through the Stückelberg mechanism, and leads to a scalar condensate and a charge density which are spatially modulated and exhibit unidirectional stripe order. Depending on the choice of parameters, the oscillations of the scalar condensate can average out to zero, with a frequency which is half of that of the charge density. In this case the system realizes some of the key features of pair density wave order. The model also admits a phase with co-existing superconducting and charge density wave orders, in which the scalar condensate has a uniform component. In our construction the various orders are intertwined with each other and have a common origin. The fully backreacted geometry is computed numerically, including for the case in which the theory contains axions. The latter can be added to explicitly break translational symmetry and mimic lattice-type effects.

Effects of plant growth regulators on growth and yield of pre-basic seed potato production under glasshouse condition

A glasshouse experiment was carried out to study the effect of Plant Growth Regulators (PGRs) on the production of pre-basic seed (PBS) potatoes, cv. Janakdev at Khumaltar, (1360 masl) Lalitpur, Nepal during autumn and spring seasons of 2014 and 2015 respectively. Four - week old virus free in vitro plantlets grown in tissue culture laboratory were planted with 20 cm distance between rows and 10 cm between plantlets under glasshouse in completely randomized design. Three growth regulators, paclobutrazol (50 ppm), daminozide (100 ppm), chlormequat chloride (Cycocel) (200 ppm) and simple water as control were used for single foliar spray 6 weeks after transplanting with four replications. Analysis showed that there were significant differences on growth parameters; plant survival, plant uniformity, plant height and yield components; number of minitubers per plant and per square meter in both the seasons. Significantly maximum number of potato minitubers was recorded in growth retardants treated plants as compared to control. Experimental results showed that maximum number of minituber (22.9/plant and 668.2/m2) in autumn and (23.7/plant and 1185.0/m2) in spring season were gained from paclobutrazole spray, which were statistically differed from those of other growth regulators and control. Plants without PGR and treated with daminozide produced the least amount of minituber per unit area. Plant height decreased in all growth regulators over control due to their inhibiting effect on growth of the plants. paclobutrazol significantly reduced plant height but produced larger and heavier minitubers compared to other treatments. Hence, the best PGR for optimum enhancement of minituber number and size was paclobutrazol. The results suggested that paclobutrazol could be used in pre-basic seed potato production, leading to maximum minituber production which ultimately gave higher returns. The study concluded that spraying growth retarding chemicals at grand growth stage checked the excessive vegetative growth and increased the number and size of minituber.SAARC J. Agri., 15(1): 149-160 (2017)