Work functions, ionization potentials, and in-between: Scaling relations based on the image charge model

We revisit a model in which the ionization energy of a metal particle is associated with the work done by the image charge force in moving the electron from infinity to a small cut-off distance just outside the surface. We show that this model can be compactly, and productively, employed to study the size dependence of electron removal energies over the range encompassing bulk surfaces, finite clusters, and individual atoms. It accounts in a straightforward manner for the empirically known correlation between the atomic ionization potential (IP) and the metal work function (WF), IP/WF$\sim$2. We formulate simple expressions for the model parameters, requiring only a single property (the atomic polarizability or the nearest neighbor distance) as input. Without any additional adjustable parameters, the model yields both the IP and the WF within $\sim$10% for all metallic elements, as well as matches the size evolution of the ionization potentials of finite metal clusters for a large fraction of the experimental data. The parametrization takes advantage of a remarkably constant numerical correlation between the nearest-neighbor distance in a crystal, the cube root of the atomic polarizability, and the image force cutoff length. The paper also includes an analytical derivation of the relation of the outer radius of a cluster of close-packed spheres to its geometric structure.Comment: Original submission: 8 pages with 7 figures incorporated in the text. Revised submission (added one more paragraph about alloy work functions): 18 double spaced pages + 8 separate figures. Accepted for publication in PR

CovidCTNet: an open-source deep learning approach to diagnose covid-19 using small cohort of CT images

Coronavirus disease 2019 (Covid-19) is highly contagious with limited treatment options. Early and accurate diagnosis of Covid-19 is crucial in reducing the spread of the disease and its accompanied mortality. Currently, detection by reverse transcriptase-polymerase chain reaction (RT-PCR) is the gold standard of outpatient and inpatient detection of Covid-19. RT-PCR is a rapid method; however, its accuracy in detection is only ~70�75. Another approved strategy is computed tomography (CT) imaging. CT imaging has a much higher sensitivity of ~80�98, but similar accuracy of 70. To enhance the accuracy of CT imaging detection, we developed an open-source framework, CovidCTNet, composed of a set of deep learning algorithms that accurately differentiates Covid-19 from community-acquired pneumonia (CAP) and other lung diseases. CovidCTNet increases the accuracy of CT imaging detection to 95 compared to radiologists (70). CovidCTNet is designed to work with heterogeneous and small sample sizes independent of the CT imaging hardware. To facilitate the detection of Covid-19 globally and assist radiologists and physicians in the screening process, we are releasing all algorithms and model parameter details as open-source. Open-source sharing of CovidCTNet enables developers to rapidly improve and optimize services while preserving user privacy and data ownership. © 2021, The Author(s)

Identification and characterization of pathogenic viruses in aquatic animal using advanced techniques in order to develop rapid diagnostic kit (shrimp viral disease kit as well as TSV, HPV and MBV )

Shrimp production increasing rapidly in the world and in2013 the production reaches 4.2 MT. In Iran the shrimp production is under development and estimated in 1393, 20 thousand tons produced. In this regards the important subject is health and disease in shrimp farm. The white spot syndrome virus for second time appears in chabahar and damage many farms. Because the aquaculture activity expand in the world in national, regional and international scale, many emerge disease are endanger. In this regard the viral disease is very important and not only decrease the production but also has a side effect in business and national economy. For control and prevention the viral disease, the accurate methods such as PCR kit were developed. In this project the PCR methods with sensitivity, specificity and efficacy was designed and used for detection viral disease. Many viruses have several serotypes and in different area maybe new serotype induce the disease. For this reason, the specific kit will be design. Three viruses consist of MBV, TSV and IHHNV are very pathogenic in shrimp farm and need the specific PCR kit for detection them. In this project the MBV virus was identified and designs a new primer with Oligo software and the primer amplified a part of DNA with 185 bp in the gel. The specificity and sensitivity of primer were checked by IQ2000 Kit and the primer used for detection unknown samples