Classical Analogue of the Ionic Hubbard Model

In our earlier work [M. Hafez, {\em et al.}, Phys. Lett. A {\bf 373} (2009) 4479] we employed the flow equation method to obtain a classic effective model from a quantum mechanical parent Hamiltonian called, the ionic Hubbard model (IHM). The classical ionic Hubbard model (CIHM) obtained in this way contains solely Fermionic occupation numbers of two species corresponding to particles with \up and \down spin, respectively. In this paper, we employ the transfer matrix method to analytically solve the CIHM at finite temperature in one dimension. In the limit of zero temperature, we find two insulating phases at large and small Coulomb interaction strength, $U$, mediated with a gap-less metallic phase, resulting in two continuous metal-insulator transitions. Our results are further supported with Monte Carlo simulations.Comment: 12 figure

Clinical, radiological, laboratory and bronchoscopic features characterizing each type of bronchogenic carcinoma

Background: To analyse the clinical, radiological, laboratory, and bronchoscopic findings characterizing each type of bronchogenic carcinoma.Methods: A cross-sectional study was conducted on 123 bronchogenic carcinoma patients. They were subjected to history taking, laboratory investigations, computed tomographic scan and fiberoptic bronchoscopy.Results: The mean age of the patients was 56.9±6.7 years, 76.4% were males and 78.9% were smokers. Most of them were symptomatic, adenocarcinoma (ADC) being the highest symptomatic one. Expectoration, fingers clubbing, and fever were common in ADC and small cell lung cancer (SCLC). Dyspnea, haemoptysis, dysphonia, dysphagia, vocal cord paralysis, anorexia and weight loss were common in SCLC and squamous cell carcinoma (SCC). Deep venous thrombosis was common in ADC and SCC. Mass lesion, atelectasis, chest wall invasion and elevated hemidiaphragm were common in SCLC and SCC. Ipsilateral mediastinal lymph nodes enlargement, cavitary lesion, and apical lesion were common in SCC and ADC. Contralateral mediastinal lymph nodes enlargement was common in SCLC. Nodular lesion, consolidation and pleural effusion were common in ADC. Hypercalcemia and hyponatremia were common in SCC. Malignant pleural effusion was common in ADC. Most of the patients had bronchoscopically-visible lesions; SCLC and SCC being the highest visible types. Most of the SCC and SCLC were centrally located, while LCC and ADC were mainly peripherally located. Most of cases were diagnosed via bronchoscopy. More than half of the studied cases were inoperable at presentation, especially SCLC and SCC.Conclusions: The 4 pathological types are distinguished from each other’s by certain clinical, radiological, laboratory and bronchoscopic features

A Radio Determination of the Time of the New Moon

The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5--100\,GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of $\sim 10$ GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0$^\circ{}\!\!$.6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was $72.7 \pm 2.2$ in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detectable at $\sim 2^{\circ}$ from the Sun. Our observations at 16\,hr\,36\,min UT indicated that the Moon would have been at closest approach to the Sun 16\,hr\,25\,min earlier; this was the annular solar eclipse of 00\,hr\,00\,min\,UT on 21 May 2012.Comment: 11 pages, 15 figures, accepted for publication in MNRA

Simple training tricks for mastering and taming bypass procedures in neurosurgery

Background: Neurosurgeons devoted to bypass neurosurgery or revascularization neurosurgery are becoming scarcer. From a practical point of view, 'bypass neurosurgeons' are anastomosis makers, vessels technicians, and time-racing repairers of vessel walls. This requires understanding the key features and hidden tricks of bypass surgery. The goal of this paper is to provide simple and inexpensive tricks for taming the art of bypass neurosurgery. Most of these tricks and materials described can be borrowed, donated, or purchased inexpensively. Methods: We performed a review of relevant training materials and recorded videos for training bypass procedures for 3 years between June 2014 and July 2017. In total, 1,300 training bypass procedures were performed, of which 200 procedures were chosen for this paper. Results : A training laboratory bypass procedures is required to enable a neurosurgeon to develop the necessary skills. The important skills for training bypass procedures gained through meticulous practice to be as reflexes are coordination, speed, agility, flexibility, and reaction time. Bypassing requires synchronization between the surgeon's gross movements, fine motoric skills, and mental strength. The suturing rhythm must be timed in a brain-body-hand fashion. Conclusion: Bypass-Training is a critical part of neurosurgical training and not for a selected few. Diligent and meticulous training can enable every neurosurgeon to tame the art of bypass neurosurgery. This requires understanding the key features and hidden tricks of bypass surgery, as well as uncountable hours of training. In bypass neurosurgery, quality and time goes hand in hand. © 2017 Surgical Neurology International | Published by Wolters Kluwer - Medknow.Peer reviewe

Surface Functionalization of Carbon Nanotubes for Energy Applications

Carbon nanotubes (CNTs) are receiving a great deal of attention as a catalyst support for different energy applications, due to their high surface area and high conductivity. Recent literature studies have shown that the application of CNTs mainly depends on their surface functionalization process. Typically, pristine CNTs (as produced) have no functional groups, which is usually considered as an obstacle to their widespread application. In this chapter, we highlight the different techniques used to functionalize the surface of CNTs, including physical and chemical functionalization processes. We show the advantages and the drawbacks of the different functionalization processes. Additionally, we explain in detail the different techniques used to characterize the CNTs before and after functionalization processes. Furthermore, we focus on polymer wrapping techniques of CNTs to create active nanocomposite materials for energy applications, in particular the applications in the agriculture field to fight pollution and make farming activity easier and more efficient

INFLUENCE OF WELL LOCATION ON DRAWDOWN IN AREA SURROUNDED BY VERTICAL CUTOFF WALLS

Dewatering systems with vertical partially penetrating cutoff walls are usually used in the case of deep excavation for side support system and further increases the efficiency of the groundwater control system. In this study a parametric analysis was carried out using the finite difference software VISUAL MODFLOW4.2® to study the effect of placing a deep well at different locations inside the excavated area surrounded by impervious wall on drawdown results. The dewatering system under consideration consists of a single partially penetrating deep well having a penetration depth (lw) and well yield (Q). The well is located at variable distances from the corner (the origin of X and Y axes) inside the excavated area surrounded by an impervious wall. The vertical impervious wall has a depth (lc), and the excavated area (A) surrounded with impervious wall is square and having a width (W). The aquifer is unconfined with a depth (H) and is underlain by an impervious layer. The aquifer consists of an extended layer of fine to medium sand having permeability (k). The soil is assumed to be homogenous and isotropic

Approach to Acute Heart Failure in the Emergency Department

Acute heart failure (AHF) patients rarely present complaining of ‘acute heart failure.’ Rather, they initially present to the emergency department (ED) with a myriad of chief complaints, symptoms, and physical exam findings. Such heterogeneity prompts an initially broad differential diagnosis; securing the correct diagnosis can be challenging. Although AHF may be the ultimate diagnosis, the precipitant of decompensation must also be sought and addressed. For those AHF patients who present in respiratory or circulatory failure requiring immediate stabilization, treatment begins even while the diagnosis is uncertain. The initial diagnostic workup consists of a thorough history and exam (with a particular focus on the cause of decompensation), an EKG, chest X-ray, laboratory testing, and point-of-care ultrasonography performed by a qualified clinician or technologist. We recommend initial treatment be guided by presenting phenotype. Hypertensive patients, particularly those in severe distress and markedly elevated blood pressure, should be treated aggressively with vasodilators, most commonly nitroglycerin. Normotensive patients generally require significant diuresis with intravenous loop diuretics. A small minority of patients present with hypotension or circulatory collapse. These patients are the most difficult to manage and require careful assessment of intra- and extra-vascular volume status. After stabilization, diagnosis, and management, most ED patients with AHF in the United States (US) are admitted. While this is understandable, it may be unnecessary. Ongoing research to improve diagnosis, initial treatment, risk stratification, and disposition may help ease the tremendous public health burden of AHF