Generalized Uncertainty Principle, Modified Dispersion Relation and Barrier penetration by a Dirac particle

We have studied the energy band structure of a Dirac particle in presence of a generalised uncertainty principle (GUP). We start from defining a modified momentum operator and derive corresponding modified dispersion relation (MDR) and GUP. Apart from the forbidden band within the range $\pm m$, $m$ being the mass of the particle, we find the existence of additional forbidden bands at the both ends of the spectrum. Such band structure forbids a Dirac particle to penetrate a potential step of sufficient height ($\sim E_P$, $E_P$ being Planck energy). This is also true for massless particle. Unlike the relativistic case, a massless particle also can reflect from a barrier of sufficient height. Finally we discuss about the Klein's paradox in presence of the GUP.Comment: 10 pages, 7 figures, LaTe

Model Pembelajaran Kelompok dalam Meningkatkan Sosial Anak di TK Al-Jama’iyah

Penelitian ini bertujuan untuk menganalisa model pembelajaran kelompok dalam meningkatkan sosial anak di TK Al-Jama’iyah. Penelitian ini dilaksanakan di TK Al-Jama’iyah, namun model pembelajarannya memiliki kelebihan dan kekurangan. Dengan model pembelajaran kooperatif atau Cooperative Learning ini ialah suatu pola pembelajaran yang berbentuk kelompok-kelompok dan adanya interaksi kerjasama antar siswa dan guru dalam memahami materi pembelajaran. Sumber data penelitian ini meliputi kepala sekolah, guru kelas, dan anak murid. Untuk pengumpulan data yang dilakukan dengan cara observasi, wawancara, dan dokumentasi di TK Al-Jama’iyah. Hasil penelitian ini dapat disimpulkan bahwa model pembelajaran di TK Al-Jama’iyah adalah guru memberikan tugas kepada masing-masing kelompok dan meminta masing-masing kelompok untuk menyelesaikan tugas yang diberikan oleh guru

Heavy-to-light baryonic form factors at large recoil

We analyze heavy-to-light baryonic form factors at large recoil and derive the scaling behavior of these form factors in the heavy quark limit. It is shown that only one universal form factor is needed to parameterize Lambda_b to p and Lambda_b to Lambda matrix elements in the large recoil limit of light baryons, while hadronic matrix elements of Lambda_b to Sigma transition vanish in the large energy limit of Sigma baryon due to the space-time parity symmetry. The scaling law of the soft form factor eta(P^{\prime} \cdot v), P^{\prime} and v being the momentum of nucleon and the velocity of Lambda_b baryon, responsible for Lambda_b to p transitions is also derived using the nucleon distribution amplitudes in leading conformal spin. In particular, we verify that this scaling behavior is in full agreement with that from light-cone sum rule approach in the heavy-quark limit. With these form factors, we further investigate the Lambda baryon polarization asymmetry alpha in Lambda_b to Lambda gamma and the forward-backward asymmetry A_{FB} in Lambda_b to Lambda l^{+} l^{-}. Both two observables (alpha and A_{FB}) are independent of hadronic form factors in leading power of 1/m_b and in leading order of alpha_s. We also extend the analysis of hadronic matrix elements for Omega_b to Omega transitions to rare Omega_b to Omega gamma and Omega_b to Omega l^{+} l^{-} decays and find that radiative Omega_b to Omega gamma decay is probably the most promising FCNC b to s radiative baryonic decay channel. In addition, it is interesting to notice that the zero-point of forward-backward asymmetry of Omega_b to Omega l^{+} l^{-} is the same as the one for Lambda_b to Lambda l^{+} l^{-} to leading order accuracy provided that the form factors \bar{\zeta}_i (i=3, 4, 5) are numerically as small as indicated from the quark model.Comment: 19 page

Longitudinal jerk and celeration as measures of safety in bus rapid transit drivers in Tehran

Traditionally, analysis of individual differences in road traffic crash risk has relied on after the fact crash data. Nowadays with the help of technologies like GPS, new measures are developed to assess driving risk, inferred from naturalistic driving behavior of drivers. In this study, two main ways of modelling driver behavior in naturalistic driving research were discussed and compared to each other. For this purpose, 176 Bus Rapid Transit (BRT) drivers were investigated during their normal driving on Tehran BRT routes. Their speed was continuously recorded by a smart phone app from which was derived deceleration, jerk, and celeration measures. Analysis showed that all of the proposed measures had positive correlations with culpable crashes and that one of the jerk variables yielded the highest correlation. Measurements of speed derivatives like jerk and celeration can help to identify dangerous driving styles in public transportation and reduce the number of crashes. Although the results of this study are encouraging, further studies for longer periods are needed to improve the reliability of the measures

The views of traditional healers on health-seeking behaviour for malaria treatment: a qualitative study in Makurdi, Nigeria

Background: There is a dearth of evidence reporting the role of traditional healers in health-seeking behaviours for Malaria treatment in Nigeria. The existing evidence base presents empirical research from the viewpoint of healthcare providers such as doctors, nurses and pharmacists on factors influencing delays in treatment-seeking for Malaria. Understanding the perspectives of traditional healers is also essential in formulating appropriate treatment policies that capture the health needs of the communities they serve and promote prompt and effective health-seeking behaviours for Malaria treatment in Nigeria. Therefore, this study aimed to explore the views of traditional healers on their perceptions and attitudes towards delays in health-seeking behaviours for Malaria treatment in Makurdi, Nigeria. Methods: A qualitative interpretative research design was used. Seven semi-structured interviews were conducted with traditional healers. Four traditional healers were based in the Northern bank region of Makurdi, and three were in the Southern bank. Data were analysed using a framework analysis approach. Results: The main themes that emerged from the interviews were: perceptions of the effectiveness and safety of traditional vs. allopathic treatments; views about malaria risk factors, severity and treatment; access to hospitals and cost of allopathic treatment; and competition between traditional healers and healthcare providers. Conclusion: Traditional healers are important Malaria treatment providers in Nigeria, and they contribute significantly to influencing the health-seeking behaviours, choices and decisions of people towards non-use and/or delay of biomedical treatment services for Malaria treatment in Nigeria. Malaria policy should recognise the important role that traditional healers play in health-seeking behaviour and develop and deliver community-based targeted interventions to prevent delays in health-seeking for Malaria. Keywords: Traditional healers; Delay in health-seeking; Malaria treatment; Makurdi (North-Central); Nigeri

Rapid Visualisation of Microarray Copy Number Data for the Detection of Structural Variations Linked to a Disease Phenotype

Whilst the majority of inherited diseases have been found to be caused by single base substitutions, small insertions or deletions (<1Kb), a significant proportion of genetic variability is due to copy number variation (CNV). The possible role of CNV in monogenic and complex diseases has recently attracted considerable interest. However, until the development of whole genome, oligonucleotide micro-arrays, designed specifically to detect the presence of copy number variation, it was not easy to screen an individual for the presence of unknown deletions or duplications with sizes below the level of sensitivity of optical microscopy (3–5 Mb). Now that currently available oligonucleotide micro-arrays have in excess of a million probes, the problem of copy number analysis has moved from one of data production to that of data analysis. We have developed CNViewer, to identify copy number variation that co-segregates with a disease phenotype in small nuclear families, from genome-wide oligonucleotide micro-array data. This freely available program should constitute a useful addition to the diagnostic armamentarium of clinical geneticists

Gold, power, protest: Digital and social media and protests against large-scale mining projects in Colombia

Colombia’s Internet connectivity has increased immensely. Colombia has also ‘opened for business’, leading to an influx of extractive projects to which social movements object heavily. Studies on the role of digital media in political mobilisation in developing countries are still scarce. Using surveys, interviews, and reviews of literature, policy papers, website and social media content, this study examines the role of digital and social media in social movement organisations and asks how increased digital connectivity can help spread knowledge and mobilise mining protests. Results show that the use of new media in Colombia is hindered by socioeconomic constraints, fear of oppression, the constraints of keyboard activism and strong hierarchical power structures within social movements. Hence, effects on political mobilisation are still limited. Social media do not spontaneously produce non-hierarchical knowledge structures. Attention to both internal and external knowledge sharing is therefore conditional to optimising digital and social media use

Parameters estimation of induction machine single-cage and double-cage model using Hybrid Simulated Annealing–Evaporation Rate Water Cycle algorithm

This paper presents the usage of the hybrid simulated annealing—evaporation rate water cycle algorithm (SA-ERWCA) for induction machine equivalent circuit parameter estimation. The proposed algorithm is applied to nameplate data, measured data found in the literature, and data measured experimentally on a laboratory three-phase induction machine operating as an induction motor and as an induction generator. Furthermore, the proposed method is applied to both single-cage and double-cage equivalent circuit models. The accuracy and applicability of the proposed SA-ERWCA are intensively investigated, comparing the machine output characteristics determined by using SA-ERWCA parameters with corresponding characteristics obtained by using parameters determined using known methods from the literature. Also, the comparison of the SA-ERWCA with classic ERWCA and other algorithms used in the literature for induction machine parameter estimation is presented. The obtained results show that the proposed algorithm is a very effective and accurate method for induction machine parameter estimation. Furthermore, it is shown that the SA-ERWCA has the best convergence characteristics compared to other algorithms for induction machine parameter estimation in the literature

Efficient power management strategy of electric vehicles based hybrid renewable energy

This article belongs to the Special Issue Future Perspectives of Safety and Reliability Assessment for Electric-Powered Vehicles.Copyright © 2021 by the authors. This paper presents a straightforward power management algorithm that supervises the contribution of more than one energy source for charging a vehicle, even if the car is in motion. The system is composed of a wireless charging system, photovoltaic (PV) generator, fuel cell (FC), and a battery system. It also contains a group of power converters associated with each energy resource to make the necessary adaptation between the input and output electrical signals. The boost converter relates to the PV/FC, and the boost–buck converter is connected with the battery pack. In this work, the wireless charging, FC, and PV systems are connected in parallel via a DC/DC converter for feeding the battery bank when the given energy is in excess. Therefore, for each of these elements, the mathematical model is formulated, then the corresponding power management loop is built, which presents the significant contribution of this paper. The efficient power management methodology proposed in this work was verified on Matlab/Simulink platforms. The battery state of charge and the hydrogen consumption obtained results were compared to show the effectiveness of this multi-source system

Shear friction strength of monolithic concrete interfaces

YesThis paper presents an integrated model for shear friction strength of monolithic concrete interfaces derived from the upper-bound theorem of concrete plasticity. The model accounts for the effects of applied axial stresses and transverse reinforcement on the shear friction action at interfacial shear cracks. Simple equations were also developed to generalize the effectiveness factor for compression, ratio of effective tensile to compressive strengths and angle of concrete friction. The reliability of the proposed model was then verified through comparisons with previous empirical equations and 103 push-off test specimens compiled from different sources in the literature. The previous equations considerably underestimate the concrete shear transfer capacity and the underestimation is notable for the interfaces subjected to additional axial stresses. The proposed model provides superior accuracy in predicting the shear friction strength, resulting in a mean between experimental and predicted friction strengths of 0.97 and least scatter. Moreover, the proposed model has consistent trends with test results in evaluating the effect of various parameters on the shear friction strength