632 research outputs found
Effects of restrictions to Income Support on health of lone mothers in the UK: a natural experiment study
Background:
In the UK, lone parents must seek work as a condition of receiving welfare benefits once their youngest child reaches a certain age. Since 2008, the lower age limit at which these Lone Parent Obligations (LPO) apply has been reduced in steps. We used data from a nationally representative, longitudinal, household panel study to analyse the health effects of increased welfare conditionality under LPO.
Methods:
From the Understanding Society survey, we used data for lone mothers who were newly exposed to LPO when the age cutoff was reduced from 7 to 5 years in 2012 (intervention group 1) and from 10 to 7 years in 2010 (intervention group 2), as well as lone mothers who remained unexposed (control group 1) or continuously exposed (control group 2) at those times. We did difference-in-difference analyses that controlled for differences in the fixed characteristics of participants in the intervention and control groups to estimate the effect of exposure to conditionality on the health of lone mothers. Our primary outcome was the difference in change over time between the intervention and control groups in scores on the Mental Component Summary (MCS) of the 12-item Short-Form Health Survey (SF-12).
Findings:
The mental health of lone mothers declined in the intervention groups compared with the control groups. For intervention group 1, scores on the MCS decreased by 1·39 (95% CI −1·29 to 4·08) compared with control group 1 and by 2·29 (0·00 to 4·57) compared with control group 2. For intervention group 2, MCS scores decreased by 2·45 (−0·57 to 5·48) compared with control group 1 and by 1·28 (−1·45 to 4·00) compared with control group 2. When pooling the two intervention groups, scores on the MCS decreased by 2·13 (0·10 to 4·17) compared with control group 1 and 2·21 (0·30 to 4·13) compared with control group 2.
Interpretation:
Stringent conditions for receiving welfare benefits are increasingly common in high-income countries. Our results suggest that requiring lone parents with school-age children toseek work as a condition of receiving welfare benefits adversely affects their mental health.
Funding:
UK Medical Research Council, Scottish Government Chief Scientist Office, and National Health Service Research Scotland
Thermocline Circulation Driven at Surface Outcrops of Isopycnal Surfaces
Potential vorticity (PV) defined as: q = Δθ .(fk + Ω)
where θ is density anomaly, Ω (Δ x u) is relative vorticity, k is unit vertical vector and f the coriolis parameter, is used as a dynamical tracer to study the interior thermocline circulation. Using the generalized flux form of PV equation (Haynes and McIntyre, 1987), wind stress and buoyancy fluxes at surface outcrops of isopycnal surface are translated into PV fluxes. The PV flux condition so derived considers seasonal movement of the isopycnal outcrops and geostrophic turbulence.
A constant layer depth model, forced by the above flux condition, is used to study its influence on the interior circulation. The impermeability theorem of Haynes and McIntyre (1987), justifies treatment of a single isopycnic layer in isolation. Non-linear, quasi-geostrophic equations are used to study the dynamics on a rectangular basin model. The model is forced by PV at the northern boundary of the domain, which represents the location where the PV flux enters the thermocline interior.
PV input at the northern boundary allows the circulation to build up until opposite PV input at some other boundaries limits the process. The model simulation shows active northern, eastern and western boundary layers, and an interior circulation pattern with properties similar to those inferred by the homogenization theory of Rhines and Young (1982a). However, in the present study, the boundary layers control the key features of the circulation unlike in the classical models driven by Ekman pumping. The results show that the anticyclonic gyre forming in response to negative PV input on the northern boundary, has a strength depending on the intensity of the forcing, lateral diffusivity and the eastern boundary condition. In the case of an upwelled isopycnal (free slip eastern wall), the eastern boundary layer is stable and penetrates to a considerable distance south. On the contrary, for isopycnal intersecting the eastern boundary (no-slip wall), the eastern boundary layer separates at a short distance from the northeast corner, injecting massive amounts of positive vorticity into the basin. Cyclonic eddies are shed at a constant frequency near the eastern boundary, in the no-slip case, propagate towards the west and dissipate near the western boundary. Experiments with realistic subduction rates show that the PV transport due to the total pressure gradient along the isopycnal outcrop dwarfs the transport due to subduction. The results obtained mimic to a certain extent features of subtropical gyre circulation near eastern boundaries, notably in the Azores frontal area
Impact of PowerPoint and Chalkboard teaching in Physiotherapy Undergraduates.
Background: A teacher's basic tool for displaying lectures are through blackboards, pegboards, bulletin boards, transparencies with an overhead projector (TOHP), PowerPoint presentation and walk and talk. Nowadays PowerPoint presentation is commonly used as it has ability to present the information in a clear, organized and simpler manner. The present study was carried out to find out the best method of teaching amongst the undergraduate Physiotherapy students. Objective: To compare the impact of the PowerPoint multimedia presentation and chalkboard in teaching by assessing the knowledge based on the marks obtained in the pretest and posttest. Methodology: 40 students were divided into two groups and a selected content-based lecture in pharmacology was delivered. For one group lecture was delivered using PowerPoint presentation, for second group using Chalkboard. Single - best Multiple Choice Questions [MCQs] paper was used for assessing the knowledge gained. The differences in the marks obtained in the two groups were analyzed Results: Students who attended the class on chalkboard obtained significantly higher score in single best MCQ examination compared to those students who attended the same content based lecture on the PowerPoint. Conclusion: The chalkboard method of teaching was found more suitable tool of teaching and learning than PowerPoint for small group
Impact of PowerPoint and Chalkboard teaching in Physiotherapy Undergraduates.
Background: A teacher\u27s basic tool for displaying lectures are through blackboards, pegboards, bulletin boards, transparencies with an overhead projector (TOHP), PowerPoint presentation and walk and talk. Nowadays PowerPoint presentation is commonly used as it has ability to present the information in a clear, organized and simpler manner. The present study was carried out to find out the best method of teaching amongst the undergraduate Physiotherapy students. Objective: To compare the impact of the PowerPoint multimedia presentation and chalkboard in teaching by assessing the knowledge based on the marks obtained in the pretest and posttest. Methodology: 40 students were divided into two groups and a selected content-based lecture in pharmacology was delivered. For one group lecture was delivered using PowerPoint presentation, for second group using Chalkboard. Single - best Multiple Choice Questions [MCQs] paper was used for assessing the knowledge gained. The differences in the marks obtained in the two groups were analyzed Results: Students who attended the class on chalkboard obtained significantly higher score in single best MCQ examination compared to those students who attended the same content based lecture on the PowerPoint. Conclusion: The chalkboard method of teaching was found more suitable tool of teaching and learning than PowerPoint for small group
Robust Control Of Flexible Structures Using Multiple Shape Memory Alloy Actuators
The design and implementation of control strategies for large, flexible smart structures presents challenging problems. To demonstrate the capabilities of shape-memory-alloy actuators, we have designed and fabricated a three-mass test article with multiple shape-memory-alloy (NiTiNOL) actuators. The force and moment actuators were implemented on the structure to examine the effects of control structure interaction and to increase actuation force. These SMA actuators exhibit nonlinear effects due to dead band and saturation. The first step in the modeling process was the experimental determination of the transfer function matrix derived from frequency response data. A minimal state space representation was determined based on this transfer function matrix. Finally in order to reduce the order of the controller, a reduced order state space model was derived from the minimal state space representation. The simplified analytical models are compared with models developed by structural identification techniques based on vibration test data. From the reduced order model, a controller was designed to dampen vibrations in the test bed. To minimize the effects of uncertainties on the closed-loop system performance of smart structures, a LQG/LTR control methodology has been utilized. An initial standard LQG/LTR controller was designed; however, this controller could not achieve the desired performance robustness due to saturation effects. Therefore, a modified LQG/LTR design methodology was implemented to accommodate for the limited control force provided by the actuators. The closed-loop system response of the multiple input-multiple output (MIMO) test article with robustness verification has been experimentally obtained and presented in the paper. The modified LQG/LTR controller demonstrated performance and stability robustness to both sensor noise and parameter variations
Three-dimensional flow measurements in a vaneless radial turbine scroll
The flow behavior in a vaneless radial turbine scroll was examined experimentally. The data was obtained using the slant sensor technique of hot film anemometry. This method used the unsymmetric heat transfer characteristics of a constant temperature hot film sensor to detect the flow direction and magnitude. This was achieved by obtaining a velocity vector measurement at three sensor positions with respect to the flow. The true magnitude and direction of the velocity vector was then found using these values and a Newton-Raphson numerical technique. The through flow and secondary flow velocity components are measured at various points in three scroll sections
Relation between outgoing longwave radiation and findlater jet over Arabian Sea during summer monsoon and influence on Indian monsoon rainfall
428-435This work analyses the relationship between outgoing Longwave radiation (OLR) and Findlater jet (FLJ) intensities
at 850 hPa pressure level and also their relation with Indian summer monsoon rainfall (ISMR; June-September) for a period of 1997-2010 over Arabian Sea and India. FLJ is a low-level jet (LLJ) which can be observed during southwest monsoon months. This LLJ generally supports the large-scale moisture and momentum transport from ocean to atmosphere, which results in rainfall over India. FLJ and OLR are associated during the monsoon months. However FLJ (positively) and OLR (negatively) are related with ISMR. Monthly and seasonal correlation coefficients among FLJ, OLR and ISMR presented and the deviations during El Nino/La Nina are discussed. Based on this analysis we recommend that the variations in FLJ should include interannual variability in atmospheric dynamics
Use of fly ash admixed concrete for pavement construction
The portland cement used for construction of rigid pavements is an energy intensive material and hence efforts are being made to find substitute materials for partial replacement of cement in concrete, and conserve energy. On the other hand, utilisation of coal for
generation of power is increasing rapidly. This has resulted in production of large quantities of fly ash from coal burning power plants. Fly ash from thermal power plants can be used as an admixture to concrete for saving cement as well as to provide solutions for its disposal
problems. Use of fly ash in concrete would be an environmentally friendly way of utilising a waste material like fly ash. Currently fly ash finds application in road pavement structure,mainly for sub-base /base course and embankment. Fly ash admixed concrete can be a very
good material for construction of pavement. It is generally designed as a partial replacement of cement or aggregate or both. This paper describes the different methods of using fly ash in concrete as a paving material, advantages gained by using fly ash in concrete and
mechanism of durability increase in fly ash admixed concrete. The experiences of CRRI for
using fly ash admixed concrete are also highlighted
Development of a Telescoping Vaned Exhaust Nozzle for the ASTOVL LiftFan(Trademark) Application
A discussion on the development of a Telescoping, Vaned, Exhaust Nozzle (TEVEN) is presented. This nozzle was challenged to meet the thrust vectoring requirements of an Advanced Short Takeoff and Vertical Landing (ASTOVL) aircraft. The nozzle underwent a development process from concepts to detail design using computational flow analyses and from subscale performance verification tests to full-scale hardware design. The LiftFan(Trademark) nozzle is capable of providing a pitch vector range of about 80 degrees from up to 20 degrees forward to 60 degrees aft. In addition, a set of post exit yaw doors provide +/- 10 degrees yaw while maintaining a relatively high performance at all operating conditions. Further, the nozzle is axially compact, to be stowable in very short length (LJD less than 0.3), while efficiently converging the upstream nozzle flow from an annular cross section to a "D" shape at the nozzle exit. The discussion includes a review of various nozzle concepts, viscous flow analyses, and results from 1/3 scale nozzle model tests conducted at NASA LeRC Powered Lift Facility (PLF) in 1994
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