Experimental investigations and computer simulations to solve acoustic problems in the modern church

Architectural acoustics of contemporary sacred buildings is still an under-appreciated issue. Many contemporary churches are not functional enough due to acoustic defects which occur there. The study discusses issues of the modern Catholic church, where acoustic problems surface as high reverberant noise levels. The building under investigation, i.e. the Church of the Visitation of the Blessed Virgin Mary, is the biggest contemporary church in Poznań, Poland, as its internal volume amounts to 16,800 m³. On the basis of in situ investigations, a computer model of the church was built and a series of simulations were carried out to determine correct treatment in order to achieve satisfactory acoustic conditions. The main assumption was to find such a solution as not to affect the modernist architecture of the church

Estimation of the regenerative braking process efficiency in electric vehicles

In electric and hybrid vehicles, it is possible to recover energy from the braking process and reuse it to drive the vehicle using the batteries installed on-board. In the conditions of city traffic, the energy dissipated in the braking process constitutes a very large share of the total resistance to vehicle motion. Efficient use of the energy from the braking process enables a significant reduction of fuel and electricity consumption for hybrid and electric vehicles, respectively. This document presents an original method used to estimate the efficiency of the regenerative braking process for real traffic conditions. In the method, the potential amount of energy available in the braking process was determined on the basis of recorded real traffic conditions of the analysed vehicle. The balance of energy entering and leaving the battery was determined using the on-board electric energy flow recorder. Based on the adopted model of the drive system, the efficiency of the regenerative braking process was determined. The paper presents the results of road tests of three electric vehicles, operated in the same traffic conditions, for whom the regenerative braking efficiency was determined in accordance with the proposed model. During the identi-fication of the operating conditions of the vehicles, a global positioning system (GPS) measuring system supported by the original method of phenomenological signal correction was used to reduce the error of the measured vehicle’s altitude. In the paper, the efficiency of the re-cuperation process was defined as the ratio of the accumulated energy to the energy available from the braking process and determined for the registered route of the tested vehicle. The obtained results allowed to determine the efficiency of the recuperation process for real traffic conditions. They show that the recuperation system efficiency achieves relatively low values for vehicle No. 1, just 21%, while the highest value was achieved for vehicle No. 3, 77%. Distribution of the results can be directly related to the power of electric motors and battery capacities of the analysed vehicles

Giant cerebral aneurysms in children

Although children are a minority among patients with cerebral artery aneurysms, aneurisms in this age group remain a problem not to be ignored. The cause of this is a much higher incidence of giant aneurisms in child - ren in comparison to adults, sometimes with dramatic manifestation. Two children with giant aneurysms of cerebral arteries, operated on at the Department of Neurosurgery Polish Mother Memorial Hospital Research Institute in Łódź are presented in this paper. Thirteen-year-old girl had an aneurysm on the left internal cerebral artery (25 mm in diameter). Ten-year-old boy had an aneurysm on the right medial cerebral artery (40 mm in diameter). Both aneurysms presented with subarachnoid hemorrhage. Surgical treatment consisted of aneurysm clipping in the case of the boy and proximal internal cerebral artery ligation in case of the girl. In spite of surgery, the treatment was unsuccessful. on the basis of presented cases some problems connected with the management of pediatric patients with giant cerebral aneurysms are discussed.Wśród ogółu pacjentów z tętniakami naczyń mózgowych pacjenci pediatryczni stanowią zdecydowaną mniejszość, jednak w tej grupie wiekowej stanowią one istotny problem kliniczny. Wynika to między innymi z faktu znacznie częstszego w stosunku do populacji dorosłych występowania tętniaków olbrzymich, których przebieg kliniczny bywa niekiedy dramatyczny. W pracy przedstawiono przypadki dwojga dzieci z tętniakami olbrzymimi naczyń mózgowych leczonych operacyjnie w Klinice Neurochirurgii Instytutu Centrum Zdrowia Matki Polki w Łodzi. U 13-letniej dziewczynki stwierdzono obecność tętniaka o średnicy 25 mm położonego na lewej tętnicy szyjnej wewnętrznej. U 10-letniego chłopca rozpoznano tętniaka o średnicy 40 mm zlokalizowanego na prawej tętnicy środkowej mózgu. Chorzy zostali przyjęci do szpitala z objawami krwotoku podpajęczynówkowego, w stanie ciężkim. W obu przypadkach zastosowano leczenie chirurgiczne polegające na zaklipsowaniu szyi tętniaka u chłopca oraz zaklipsowaniu naczynia doprowadzającego u dziewczynki. U obojga dzieci dalszy przebieg leczenia był niepomyślny. W oparciu o prezentowane przypadki w pracy omówiono problemy związane z leczeniem dzieci z tętniakami olbrzymimi naczyń mózgowych

Long-term MRI cell tracking after intraventricular delivery in a patient with global cerebral ischemia and prospects for magnetic navigation of stem cells within the CSF.

The purpose of the study was to evaluate the long-term clinical tracking of magnetically labeled stem cells after intracerebroventricular transplantation as well as to investigate in vitro feasibility for magnetic guidance of cell therapy within large fluid compartments.After approval by our Institutional Review Board, an 18-month-old patient, diagnosed as being in a vegetative state due to global cerebral ischemia, underwent cell transplantation to the frontal horn of the lateral ventricle, with umbilical cord blood-derived stem cells labeled with superparamagnetic iron oxide (SPIO) contrast agent. The patient was followed over 33 months with clinical examinations and MRI. To evaluate the forces governing the distribution of cells within the fluid compartment of the ventricular system in vivo, a gravity-driven sedimentation assay and a magnetic field-driven cell attraction assay were developed in vitro.Twenty-four hours post-transplantation, MR imaging (MRI) was able to detect hypointense cells in the occipital horn of the lateral ventricle. The signal gradually decreased over 4 months and became undetectable at 33 months. In vitro, no significant difference in cell sedimentation between SPIO-labeled and unlabeled cells was observed (p = NS). An external magnet was effective in attracting cells over distances comparable to the size of human lateral ventricles.MR imaging of SPIO-labeled cells allows monitoring of cells within lateral ventricles. While the initial biodistribution is governed by gravity-driven sedimentation, an external magnetic field may possibly be applied to further direct the distribution of labeled cells within large fluid compartments such as the ventricular system

The effect of applying an external magnetic field on HUCB-NSC sedimentation process. Scale bar for the magnet and the tubes is indicated on bottom left.

<p>The effect of applying an external magnetic field on HUCB-NSC sedimentation process. Scale bar for the magnet and the tubes is indicated on bottom left.</p

Multi-Criteria Optimisation of Liquid Cargo Transport According to Linguistic Approach to the Route Selection Task

The main aim of the paper is to present the possibility of use of the multi-criteria optimization method Analytical Hierarchy Process (AHP) to liquid cargo transportation by sea. Finding the optimal solution is not simple. There are many factors influencing the shipping process. In the case of liquid cargo, the most important thing is the safety of the crew, ship, and environment. Therefore, the Mathematical Theory of Evidence is introduced and used to determine the optimal path in terms of time and safety of transport. Moreover, the details of liquid cargo transport process are described with particular attention to ship to ship operations. Besides, the basic concept of the AHP method, steps of the algorithm are introduced. Finally, the multicriteria optimization of the transport of the liquid cargo from the Persian Gulf to Port of Gdansk is done. It is based on the experts’ opinions

Time course of sedimentation for SPIO-labeled (dashed line) and unlabeled (solid line) HUCB-NSC (n = 6) presented as means±SD (A) and regression lines (B).

<p>No statistically significant difference was observed between SPIO-labeled and unlabeled cells.</p

Regression lines show the presence of cells within particular sections in a function of distance between the magnet and the chamber.

<p>Statistically significant difference was observed between the cell presence in the upper and lower sections (marked by asterisk). Upper section = green line, middle section = red line, lower section = green line.</p

Imaging of SPIO-labeled autologous cord blood derived cells in a patient with global cerebral ischemia.

<p><b>A</b>) Volume rendering of MRI data of the patient’s head obtained 24 hours post transplantation. Semi-automatic segmentation is based on pixel intensity, showing the projection of the ventricular system (<i>green</i>) and the distribution of the SPIO signal from the transplanted cells within the occipital horn of the right ventricle (<i>red</i>). Note the supine configuration of the head, corresponding to positioning during surgery. The route and trajectory of cell transplantation via the frontal horn is represented by the needle. <b>B</b>) Postero-superior view of the patient’s head, emphasizing the location of the hypointense SPIO signal from autologous cord blood derived cells transplanted within the occipital horn. <b>C</b>) T2*-weighted image with an orthogonal view centered on the cellular SPIO signal in the occipital horn (white arrowhead). <b>D–I</b>) Sagittal T2*-weighted MRI scans showing a longitudinal dispersion of SPIO signal within the occipital horn (white arrowheads); <b>D</b>) pre-transplantation, <b>E</b>) 24 hours post transplantation (PT), <b>F</b>) 7 days PT, <b>G</b>) 2 months PT, <b>H</b>) 4 months PT, and <b>I</b>) 33 months PT.</p