Graduate Seminar, 26th February

Speaker: Szymon Nakoneczny

Title: Natural language processing methods in biological activity prediction and quasar detection in large scale photometric surveys.

Abstract: The first part will focus on my master ‘s thesis. Virtual screening is a process in which databases of chemical compounds are searched in order to f ind structures characterized with a high biological activity, possible drug candidates. The goal is to classify active compounds by combining the natural language processing methods with a text representation of compounds. The second part is going to cover an approach of detecting quasars with means of machine learning. Because it is not possible to fully sample extragalactic objects with spectroscopy, quasars analysis requires a proper automated approach based on photometric surveys. We are going to focus on describing a problem and showing preliminary results of our approach.

Graduate Seminar, 19th February

Speaker: Grzegorz Żarnecki

Title: Measurement of muon-antineutrino charged current cross section with single pion production in the near detector of T2K experiment

Abstract: Cross section measurement is a basic tool to examine agreement between theoretical models and experimental data. The fundamental struggle is to separate signal sample from background events. Decent measurement requires nontrivial methods in order to minimize dependency on the default model and include characteristics of the detector. This will be illustrated on the example of muon-antineutrino CC interaction on carbon with single pion production in ND280 detector of the T2K experiment.

Thesis topic proposal: design, construct and test a prototype neutron detector

Helium-3 isotope is commonly used as detection medium in detectors applied for neutron detection in many fields of industry and physics. The world crisis of He-3 isotope is forcing for a research and development of other neutron detection methods. Recently, a multigrid gas detector based on boron coated blades has been developed at Institut Laue-Langevin (ILL) in Grenoble as an alternative for commonly applied He-3 proportional counters in neutron scattering experiments. However, it may be considered to use this solution for other applications.

Continue reading Thesis topic proposal: design, construct and test a prototype neutron detector

Graduate Seminar 22nd January

Speaker: Joanna Reszczyńska

Title: Hyper-radiosensitivity phenomenon and significance of human individual radiosensitivity in modeling of Low Dose Radiation Biological Effects.

Abstract: For ionization radiation (IR) induced cancer, a linear non-threshold (LNT) model at very low doses is the default used by a number of international organizations and in regulatory law. However, experimental observations and theoretical biology have found that other dose-response curves can exist at those very low doses. This approach includes detailed, molecular descriptions of cells mechanisms to develop a dose-response model either through a set of nonlinear, differential equations or a stochastic approach based on Monte Carlo simulations. Both methods are subject to the body’s reaction.The existence of heritable radiosensitivity syndromes and clinical observations in radiotherapy patients suggests that human cellular radiosensitivity differs among individuals. The assessment of the more radiation-sensitive and the more cancer-prone people is very important issue. This seminar discusses the bases of low-dose hyper-radiosensitivity (HRS) with reference to the molecular regulation of DNA repair and cell cycle control processes. The aim of the presented study was to examine, using the micronucleus (MN) assay, the low-dose radiation response of blood cells lymphocytes from healthy donors and to determine whether the method can be used to verify the hypothesis of the HRS phenomenon occurrence in general population.

Graduate Seminar, 15th January

Speaker: Piotr Kalaczyński

Title: Search for directional correlations of HE muon neutrinos in IceCube and Radio Sources in NVSS

Abstract: The seminar briefly describes IceCube and VLA detectors and the method of angular cross-correlation using power spectra from the multipole expansion of the sky. The analysis aims at determining, whether astrophysical neutrino flux could be originating from extragalactic radio sources contained in the NVSS survey. Since the survey is not exclusively extragalacic, appropriated cuts have to be applied. Performance of the analysis is shown and compared to a standard point-source IceCube analysis.

Graduate seminar, 8th January 2018

Speaker: Paritosh Verma

Title: Gravitational wave signals from highly magnetic accreting millisecond neutron stars

Abstract: This seminar is focused on brief introduction on  gravitational waves as well as their emission from accreting millisecond neutron stars. These binary systems consist of a millisecond pulsar with a rotation period 1-10 ms accreting material from a companion star. Neutron stars can undergo different modes of oscillations, each with different characteristic behavior. Among these, r-modes, or rotational modes, only appear in rotating stars and are caused by the Coriolis force acting as restoring force along the surface of the star. The r-modes have an important role in the physics of millisecond neutron stars: they excite the emission of gravitational waves which carry away energy and angular momentum from the star and lead to differential rotation. 

Graduate Seminar, 18th December

Speaker: Albin Nilsson

Title: The Standard Model Extension, Gravitational tests and Cosmology

Abstract: Combining the standard model and general relativity into quantum gravity is a task which has occupied physicists for over 50 years. These two theories are expected to merge at the Planck scale (E_p \approx 10^{19} GeV). However, experiments at this energy are beyond the reach of humanity at present. As such, we need a way to study the Planck scale effects that trickle down to accessible energies, thereby learning about the true dynamics of quantum gravity. This can be done using effective field theory, and since many theories of quantum gravity predict Lorentz and/or CPT violation, searching for signals of this is a good place to start. The Standard Model Extension (SME) is an effective field theory containing the standard model of particle physics, general relativity, as well as all possible operators which break Lorentz symmetry. Since CPT violation implies Lorentz violation, the SME also includes operators which both break and preserve CPT symmetry. In this talk, I will describe the structure of the SME, focusing on the gravitational sector. I will review some of the gravitational tests performed and discuss how we can study the SME in a cosmological setting

Graduate seminar, 11th December

Speaker: Szymon Domański

Title: Application of the ultrahigh dose thermoluminescence dosimetry for radiation-hardness testing

Abstract: In radiation processing, where large absorbed doses and dose rates from photon sources have to be measured with reasonable accuracy, dosimetry systems serve an important function. Proven methods are demanded to perform radiation measurements in development of new processes, validation, qualification, and verification of established processes and archival documentation of day to day processing uniformity. Implementation a system corresponding to recognised standards from scratch is not the simplest task. However, it is possible. During my presentation I wish to discuss the possible application of LiF:Mg,Cu,P thermoluminescence phosphor in the field of material testing.