Importance of van der Waals interaction on structural, vibrational, and thermodynamics properties of NaCl

Thermal equations of state (EoS) are essential in several scientific domains. However, experimental determination of EoS parameters may be limited at extreme conditions, therefore, {\it ab~initio} calculations have become an important method to obtain them. Density Functional Theory (DFT) and its extensions with various degrees of approximations for the exchange and correlation (XC) energy is the method of choice, but large errors in the EoS parameters are still common. The alkali halides have been problematic from the onset of this field and the quest for appropriate DFT functionals for such ionic and relatively weakly bonded systems has remained an active topic of research. Here we use DFT + van der Waals functionals to calculate vibrational properties, thermal EoS, thermodynamic properties, and the B1 to B2 phase boundary of NaCl. Our results reveal i) a remarkable improvement over the performance of standard Local Density Approximation and Generalized Gradient Approximation functionals for all these properties and phase transition boundary, as well as ii) great sensitivity of anharmonic effects on the choice of XC functional

Strategic evaluation study on child-centred community development - Synthesis report

This strategic formative evaluation was carried out by Wageningen International Capacity Development & Institutional Change (CD&IC) programme from May to September 2009. The evaluation aims to obtain insight into the understanding of CCCD within Plan, and to learn more about the factors that favour or obstruct the implementation of Child Centred Community Development (CCCD) in practice. Suggestions on improving CCCD as an approach to development are provided, as well as an analysis of capacity development needs for CCCD implementation. This evaluation report is a product of Phase I of the complete anticipated evaluation trajectory. Phase II will most likely include an international workshop around the findings of Phase I. The findings of Phase I will contribute to the track record for the MFS II application to the Dutch Ministry of Foreign Affairs which Plan Netherlands is currently preparing. The study comprised a desk research stage, which reviewed relevant Plan documentation as well as consultations with key stakeholders within Plan worldwide. During this stage face to face interviews were conducted in Plan IH office in Woking, and at NLNO in Amsterdam. Other interviews with stakeholders in ROs and NOs were done using Skype. Furthermore two field studies were conducted in Kenya and Bangladesh. Given the fact that the topic of the study is broad, it is limited to analysis of the wider issues pertaining to CCCD rather than in-depth detailed analysis of these issues

The Effects of Oral Pain Medication Being Administered in Phase I as Compared to Oral Pain Medications Administered in Phase II

Healthcare and the provision of care are ever-changing as governing bodies over-see and regulate the way institutions provide care for patients. Pain assessment, reassessment, and pain management are a focus nationally and healthcare providers are held accountable for how pain is managed for patients. One piece to this broad topic is the use of oral pain medications, more specifically in the ambulatory surgical patient. The purpose of this project was to compare the length of stay, reported pain scores, and total amount of IV medications administered between patients who receive the first dose of oral pain medications in Phase I recovery and those who received the first dose of oral pain medication in Phase II recovery. Effective pain management can have numerous benefits for the patient, decreasing the amount of medications used and their length of stay in the hospital may be of two those benefits

Quantum Criticality in Heavy Fermion Metals

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points. There have been considerable efforts, both experimental and theoretical, which use these magnetic systems to address problems that are central to the broad understanding of strongly correlated quantum matter. Here, we summarize some of the basic issues, including i) the extent to which the quantum criticality in heavy fermion metals goes beyond the standard theory of order-parameter fluctuations, ii) the nature of the Kondo effect in the quantum critical regime, iii) the non-Fermi liquid phenomena that accompany quantum criticality, and iv) the interplay between quantum criticality and unconventional superconductivity.Comment: (v2) 39 pages, 8 figures; shortened per the editorial mandate; to appear in Nature Physics. (v1) 43 pages, 8 figures; Non-technical review article, intended for general readers; the discussion part contains more specialized topic

Effects of Using Graphic Calculators in the Teaching and Learning of Mathematics on Students’ Performance and Metacognitive Awareness

Three phases of quasi-experimental study with non-equivalent control group posttest only design were conducted to investigate the effects of using graphing calculators in mathematics teaching and learning on Form Four Malaysian secondary school students’ performance and their level of metacognitive awareness. Experiment in Phase I was conducted for two weeks to provide an initial indicator of the effectiveness of graphing calculator strategy on students’ performance and their metacognitive awareness. Graphing calculator strategy refers to the use of TI-83 Plus graphing calculator in teaching and learning of Straight Lines topic. The first phase involved one experimental group (n=21) and one control group (n=19) from two Form Four classes in a randomly selected school in Selangor. The experimental group underwent learning using graphing calculator while the control group underwent learning using conventional instruction. Experiment for Phase II was further carried out for six weeks incorporating measures of mathematical performance, focused on metacognitive awareness during problem solving and in addition, measures of mental effort and instructional efficiency. This phase involved two experimental groups (n=33) and two control groups (n=32) from four Form Four classes in one randomly selected school in Malacca. As in Phase I, the same learning conditions were given for both experimental and control groups. Finally, experiment in Phase III was carried out for six weeks incorporating comparison on two levels of mathematics ability (low and average) and two types of instructional strategy (graphing calculator strategy and conventional instruction strategy). Form Four students from one of schools in Malacca were the sample for Phase III. Altogether there were four groups of students given four learning conditions vis-à-vis: the average mathematical ability given the use of graphing calculators (n=15), the low mathematical ability also given graphing calculators (n=19), the average mathematical ability given the conventional instruction (n=16) and the low mathematical ability given also the conventional instruction (n=20).Four instruments were used in this study namely, Straight Lines Achievement Test, Paas Mental Effort Rating Scale, Metacognitive Awareness Survey and Graphing Calculator Usage Survey. The data for Phases I and II were analysed using independent t-test and planned comparison test while data for Phase III were analysed using multiple analysis of variance and planned comparison test. The study shows that the graphing calculator instruction enhanced students’ performance and induced higher levels of their metacognitive awareness with less mental effort invested during the learning and test phases and hence increased 3-dimensional instructional efficiency index in learning of Straight Lines topic for both groups of low and average mathematics ability. These findings indicated that the graphing calculator instruction is superior in comparison to the conventional instruction, hence implying that integrating the use of graphing calculator in teaching and learning of mathematics was more efficient than the conventional instruction strategy. The average mathematics ability group benefited more from the graphing calculator instruction as it decreased the amount of mental effort by double than the low mathematics ability group. Further, most students in graphing calculator strategy group showed an overall favourable view towards integrating the use of the graphing calculator in the teaching and learning of mathematics. Even though some students experience difficulties in using graphing calculators initially during learning, they responded overwhelmingly that graphing calculator improves their understanding of the Straight Lines topic and hence, the usage of the graphing calculator was an effective strategy in teaching and learning of mathematics

Lorentz violation effects on astrophysical propagation of very high energy photons

Lorentz violation (LV) is predicted by some quantum gravity (QG) candidates, wherein the canonical energy-momentum dispersion relation, $E^2=p^2+m^2$, is modified. Consequently, new phenomenons beyond the standard model are predicted. Especially, the presence of LV highly affects the propagation of astrophysical photons with very high energies from distant galaxies. In this paper, we review the updating theoretical and experimental results on this topic. We classify the effects into three categories: (i) time lags between photons with different energies; (ii) a cutoff of photon flux above the threshold energy of photon decay, $\gamma \rightarrow e^++e^-$; (iii) new patterns in the spectra of multi-TeV photons and EeV photons, due to the absorption of background lights. As we can see, the details of LV effects on astrophysical photons depend heavily on the "phase space" of LV parameters. From observational aspects, nowadays available and upcoming instruments can study these phenomenons hopefully, and shed light onto LV issues and QG theories. The most recent progresses and constraints on the ultra-high energy cosmic rays (UHECRs) are also fully discussed.Comment: 9 pages, 1 figure, final version for publication in MPLA as a review articl