3,649 research outputs found
Microscopic thin shell wormholes in magnetic Melvin universe
We construct thin shell wormholes in the magnetic Melvin universe. It is
shown that in order to make a TSW in the Melvin spacetime the radius of the
throat can not be larger than in which is the
magnetic field constant. We also analyze the stability of the constructed
wormhole in terms of a linear perturbation around the equilibrium point. In our
stability analysis we scan a full set of the Equation of States such as Linear
Gas, Chaplygin Gas, Generalized Chaplygin Gas, Modified Generalized Chaplygin
Gas and Logarithmic Gas. Finally we extend our study to the wormhole solution
in the unified Melvin and Bertotti-Robinson spacetime. In this extension we
show that for some specific cases, the local energy density is partially
positive but the total energy which supports the wormhole is positive.Comment: 8 pages, 6 figure
Basin-level use and productivity of water: examples from South Asia
Water managementWater conservationRiver basinsWater useProductivityCase studiesIrrigated farmingIndicatorsWater scarcity
Stability of thin-shell wormholes supported by ordinary matter in Einstein-Maxwell-Gauss-Bonnet gravity
Recently in (Phys. Rev. D 76, 087502 (2007) and Phys. Rev. D 77, 089903(E)
(2008)) a thin-shell wormhole has been introduced in 5-dimensional
Einstein-Maxwell-Gauss-Bonnet (EMGB) gravity which was supported by normal
matter. We wish to consider this solution and investigate its stability. Our
analysis shows that for the Gauss-Bonnet (GB) parameter stability
regions form for a narrow band of finely-tuned mass and charge. For the case
, we iterate once more that no stable, normal matter thin-shell
wormhole exists.Comment: 11 pages, 4 figure
Zoonotic disease management and infection control practices among veterinarians in the United Arab Emirates
This study was conducted to assess zoonotic disease management and infection control practices (ICPs) among veterinarians in the United Arab Emirates (UAE). A questionnaire was developed in SurveyMonkey, an online tool, and was distributed by email during February–May 2020 to 470 veterinarians practicing across the UAE. A total of 110 individuals completed the survey, giving a response rate of 23.4% (110/470). Results indicate that reported hand hygiene, sharps management, barrier or isolation practices, and personal choices for personal protective equipment (PPE) in common practice scenarios varied among practitioners. The majority (>75%) of veterinarians in all practice types reported always washing their hands before eating, drinking, or smoking at work. The survey revealed that 19% and 10% of large and small animal veterinarians indicated they sterilized and reused disposable needles. Veterinarians among all practices indicated high rates (75% to 80%) of recapping needles before disposal. When handling an animal suspected of having a zoonotic disease, most (90%) of small animal veterinarians reported always using practices such as isolating the animal and removing outwear before contact with other animals. However, only half (55%) of the large animal respondents reported always isolating the animal or sterilizing all equipment used on the animal of concern. Fewer than half of the large animal (35%) and mixed practice (44%) veterinarians indicated they would always be limiting human contact with the animal of concern. All of the small animal respondents reported full compliance with PPE while performing surgery and necropsy. Among large animal veterinarians, 44% reported not using respiratory or eye protection when aiding with parturition or handling conception products. Failure to use appropriate PPE when handling blood samples was the second most common noncompliant practice among large animal (39%) veterinarians and mixed practice (41%) respondents. Our study indicates a need for continuous education regarding ICPs in the veterinary community in the UAE. Better awareness of the risk of zoonotic disease exposure and options for managing this risk and liability issues could drive the adoption of infection control practices
Producing Ceramic Water Purifiers Made Of Iraqi Bentonite Type (Bpl1)
In this study, ceramic purifier (CP) was produced from a mixture of Iraqi raw materials. This ceramic mixture was prepared using Bentonite as a Clay, Porcelanite as a Silica, and Limestone as a flux. The produced ceramic filter was formed by semi-dry compressing method and was fired at 1200 C?.
Physical properties of the produced CP were measured. A hydraulic test rig was constructed to study the hydraulic conductivity of the produced CP. The average hydraulic conductivity of the produced CP was 55 times that of commercial types of ceramic filters.
The mineral composition of the produced ceramics was found by X-Ray tests. Tests results showed that all of the produced ceramics filters composed mainly of low Cristobalte and Tridoymite in addition to some of other minerals.
Both of the raw and the water purified by produced ceramic were tested for a number of water quality parameters. that the ceramic disc purifier could remove, as an average percentages of removal, 99.98% of turbidity, 78.86% of the electrical conductivity , 81.61% of the total dissolved solids, 73.45% of Ca++, 49.69% of Na+, 55.63% of NO3-, 37.54% of HCO3- .
The results showed that CP has excellent adsorption ability for solutes of seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn, at concentrations of 1 mg/leach and 10 mg/l each. The adsorption capacities of each filter to adsorb seven heavy metals were computed according to Langmuir model and Freundlich models. The results showed variety in adsorption capacities for each heavy metal
Intervensi Psikologis Pada Pendidikan Anak Dengan Keterlambatan Bicara
As the ability to ride a bike, speech is a child's ability to learn. The more frequent practice, these abilities will be more perfect. Many factors affect the process of learning or practice speaking. Among others is the maturity or physical and mental readiness, a good model to be emulated, the motivation they need, the opportunities provided by the environment, and the existence guidance of significant others. Then, how to help children who have spent time to learn speech and due to several factors as mentioned above, have experienced delays in speech?. Excavation data about the causes of overdue talking to children, followed by the deepening problems in a mature, will find the steps that can be taken to help overdue talking children in speech
Multinational transfer pricing of intangible assets and tax audit adjustments: evidence from Indonesia
Purpose – This paper examines the challenges faced by Indonesian tax auditors in auditing multinational transfer prices of intangible assets. This study then explores the suitability of mechanisms currently used by Indonesian tax auditors to ensure appropriate tax audit adjustments. Design/Methodology/Approach – We use a qualitative research method involving semi-structured and open-ended interviews with the tax auditors in Indonesia. We also include some Indonesia court decisions pertinent to the research question above. Findings – Findings indicate that Indonesian tax auditors face a number of difficulties during the audit of transfer pricing cases derived from intangible property, including a lack of transparency in taxpayers’ bookkeeping; limited taxpayer cooperation in providing data and documents; transfer pricing regulations; and problems related to organization and human resources. The study also finds that Indonesian tax auditors and tax officials handle transfer pricing cases by using a legal basis as reference and by performing a number of activities, including among others, comparable analysis. Originality/Value – The findings of this study should assist researchers and policy makers to improve the understanding of transfer pricing audit. Also, tax auditors and account representatives who do not have enough experience in auditing transfer pricing cases derived from intangible property rights would be benefited from outcomes of this study
Higher dimensional thin-shell wormholes in Einstein-Yang-Mills-Gauss-Bonnet gravity
We present thin-shell wormhole solutions in Einstein-Yang-Mills-Gauss-Bonnet
(EYMGB) theory in higher dimensions d\geq5. Exact black hole solutions are
employed for this purpose where the radius of thin-shell lies outside the event
horizon. For some reasons the cases d=5 and d>5 are treated separately. The
surface energy-momentum of the thin-shell creates surface pressures to resist
against collapse and rendering stable wormholes possible. We test the stability
of the wormholes against spherical perturbations through a linear
energy-pressure relation and plot stability regions. Apart from this restricted
stability we investigate the possibility of normal (i.e. non-exotic) matter
which satisfies the energy conditions. For negative values of the Gauss-Bonnet
(GB) parameter we obtain such physical wormholes.Comment: 9 pages, 6 figures. Dedicated to the memory of Rev. Ibrahim Eken
(1927-2010) of Turke
Magnetic stimulation of mammalian peripheral nerves in vivo: An alternative to functional electrical stimulation
pre-printFunctional electrical stimulation is the current gold standard for stimulating neuronal interfaces for functional neuromuscular and cortical applications, but it is not without its drawbacks. One such fault is the need to have direct electrical contact with the nerve tissue, and any side effects this causes. Functional magnetic stimulation, which works though electromagnetic induction, does not require electrical contact and may be a viable alternative to functional electrical stimulation. We are investigating the capabilities of magnetic stimulation with centimeter scale (<2.5 cm) coils in feline and rodent sciatic nerves in vivo. We have shown that magnetic stimulation can consistently produce the same levels of neuromuscular activation as electrical stimulation. Additionally, the position of the coil relative to the nerve influences neuromuscular activation, suggesting the possibility of selective muscle activation
Switching cells and their implications for power electronic circuits
Journal ArticleThis paper will introduce two basic switching cells, P-cell and N-cell, along with their implications and applications in power electronic circuits. The concept of switching cells in power electronic circuits started in the late 1970's. The basic cells presented in this paper have one switching element (transistor) and one diode. The P-cell is the mirror circuit of the N-cell and vice-versa, and this paper suggests that (1) most power electronic circuits can be analyzed and re-constructed using these basic switching cells, (2) single, dual, and 6-pack switching modules should be configured and laid-out according to the basic switching cells and not necessarily the conventional way used by industry, and (3) many benefits such as minimal parasitic inductance and dead-time elimination or minimization may come about. The present paper will describe the construction and operation of these basic switching cells, and it will also show a sequential method to reconstruct several classical dc-dc converters, a voltage source inverter (VSI), and a current source inverter (CSI) using these basic switching cells. In addition, the use of basic switching cells introduces some new topologies of dc-dc converters that originate from the buck, boost, and Cuk converter for negative input voltages. This paper will also illustrate the experimental results of the new and existing topologies constructed from basic switching cells
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