bluuebunny/crossref_metadata_2025 huggingface dataset:
A Clinical Approach of Renal Involvement in Granulomatosis with Polyangiitis
Authors: Stoian Marilena , Indrei Lucia , Stoica Victor
Published: May 2020

Granulomatosis with polyangiitis (GPA, Wegener’s granulomatosis) is one of the antineutrophil cytoplasmic antibody (ANCA) - associated small vessel vasculitis, involving various organs such as nasal septum, sinuses, upper respiratory tract, lungs, and kidneys. GPA is pathologically characterized by necrotizing granulomatous inflammation. ANCA-associated small vessel vasculitis represent a major challenge in hospital admissions; therefore, early and accurate diagnosis with aggressive treatment is essential to improve the disease outcome.

Renal involvement of granulomatosis with polyangiitis is characterized morphologically by extensive crescent formation (extracapillary proliferation in Bowman’s space), and clinically by crescentic or rapidly progressive glomerulonephritis that causes hematuria, erythrocyte casts, and proteinuria with progressive loss of renal function. The diagnosis of granulomatosis with polyangiitis is established most securely by biopsy specimens showing the triad of vasculitis, granulomata, and large areas of necrosis (known as geographic necrosis) admitted with acute and chronic inflammatory cells. Usually, renal involvement is severe and is the leading cause of mortality. The combination of high-dose corticosteroids and cyclophosphamide is the mainstay of treatment for vasculitis and disease resistance to this combination is rare.
Catastrophic Caustic Ingestion: A Case Report
Authors: Bouchard Kerri L
Published: May 2020

Introduction

The majority of oral ingestion of caustic material by adults is intentional, and the aftermath varies widely with potentially fatal results. Injuries range from superficial burns of facial and oropharyngeal structures to extensive necrosis of the gastrointestinal tract. Management focuses on the identification of the ingested substance and prompt treatment and supportive care of the multiple complications stemming from the ingestion. Complications following caustic ingestion include both immediate and long term.

Case presentation

A fifty-seven-year-old man presented following intentional ingestion of drain cleaner. The patient was intubated and underwent emergent esophagogastroduodenoscopy [EGD], which revealed extensive damage to his oesophagus and stomach. He survived his initial injury but had a prolonged hospital course and ultimately died after developing tracheoesophageal and bronchooesophageal fistulas which were too extensive for surgical repair.

Conclusion

The sequelae of caustic ingestion can be minor or severe, both immediate and delayed. Despite appropriate prompt management and supportive care, patients may die as a result of the initial injury or subsequent complications.
Some remarks on enhanced total internal reflection
Authors: Šumichrast L’ubomír , Franek Jaroslav , Dosoudil Rastislav , Červeňová Jozefa
Published: May 2020

The regime of total internal reflection of plane wave on the boundary between a lossless dielectrics and the lossy, or gainy, medium is analysed. It is shown that in order to achieve enhanced total internal reflection (TIR), ie magnitude of the reflection factor larger than one, the existence of the second boundary, virtually maybe infinitely far away, is inevitable. Some contradictory results published in literature are discussed.
Deriving the exchange times for a model of trap-assisted tunnelling
Authors: Racko Juraj , Mikolášek Miroslav , Kadlečíková Magdaléna , Benko Peter , Chvála Aleš
Published: May 2020

The work presents a physical model of trap-assisted tunnelling that allows assessing the impact of traps upon the total current through metal/semiconductor heterostructures. The model is based on expressing the occupation probability of the trapping centres by electrons in terms of thermal and tunnelling capture and emission times, commonly referred to as exchange times. The occupation probabilities calculated in this way are then used to evaluate the generation-recombination rates occurring in the continuity equations.
Preventing method of acoustic resonance in the high-pressure discharge lamps
Authors: Medvid Volodymyr , Beliakova Iryna , Piscio Vadim , Savkiv Volodymyr , Duchon Frantisek
Published: May 2020

The article analyzes available methods for preventing acoustic resonance of high pressure lamps. A new method is proposed, the main idea of which is the filing of a high-voltage lamp modulated by a pseudo-random signal. An analysis of the spectral characteristics of the signal entering the lamp is made, the mathematical modeling of the set of a “discharge lamp - prototype of the device” - is implemented, which implements the proposed control method of the lamp. The results of simulation and oscillograms, taken from the prototype, which confirms the results of theoretical research, are presented.
Properties of a modelled call centre
Authors: Baronak Ivan , Hartmann Matej , Polacek Robert
Published: May 2020

To detect the number of agents needed to serve customers, it is necessary to consider the call centre as a mass service system. Then it is possible to asses the convenient number of agents according to the probability of the system receiving a request and the time in which the request is serviced by employing a Markov chain and the Erlang model. In an archetypal call centre, the incoming calls are added to a waiting queue and subsequently they are assisted by an agent. In case all agents are occupied, the customer has to wait in the queue until one of the agents becomes available. It is, therefore, important to compromise on the number of agents and the time the customers spend waiting in the queue. The result should be that there are enough agents in the call centre to serve the customers in the time required. This article focuses on solving this problem.
Power saving technique based on traffic channels reallocation in GSM mobile network
Authors: Kosjer Vladimir , Mitić Dragan , Lebl Aleksandar , Matić Vladimir , Markov Žarko
Published: May 2020

A mobile users’ network with power control on traffic channels, as it is GSM, is considered in this paper. It is analyzed the influence of busy channels reallocation on the necessary emission power. The main principle in reallocation is that users who need greatest power for their connections take traffic channels of the first carrier where power is always maximum. It is assessed that reallocation process is not more complicate than the simplest handover processes. It is proved that this method may be used to decrease emission power of carriers after the second one. Power saving depends on number of carriers, environmental propagation coefficient and users’ density distribution in the cell. The results are verified by originally developed simulation program.
A hairpin DGS resonator for application to microstrip lowpass filters
Authors: Chen Rong-Bin , Ou Xiao-Ou
Published: May 2020

A hairpin shaped DGS, consisting of two tilted slots with a separation angle, is studied as a unit cell in this contribution. It is further served as a microwave resonator for microstrip lowpass filter applications. Two prototype filters that respectively cascade the same unit cells and the scaled cells with a different scale ratio are analyzed. For demonstration purposes, the two prototype filters are optimally developed, fabricated and examined both from numerical simulations and from experimental validations. Results show the cascaded scaled type demonstrator features a high stopband suppression level within a wide frequency band.
Mathematical Model of Military Equipment Products Maintenance for the Condition-Based Operation Strategy Taking Into Account Type I Errors
Authors: Mirnenko Volodymyr , Pustovyi Serhii , Radko Oleg , Yablonskyi Petro
Published: May 2020

For military equipment products maintained according to the condition-based operation strategy with control of parameters a mathematical model is constructed using semi-Markov random process. The diffusion-monotonic distribution law which is inherent in mechanical type products is taken for the fault model. The model takes into account type I errors. The analytical dependence of the utilization factor on the parameters of the scale and shape of the diffusion-monotonic distribution, the of regulated maintenance periodicity, the duration of complete restoration of a sample of equipment, the reliability of its control, is established. Graphs of the dependence of the utilization factor on the given parameters of the model are shown.
Methodology for Conducting Preliminary and State Tests of an Aerial Jet Target Set
Authors: Rykaczewski Dariusz , Jastrzębski Grzegorz , Sibilski Krzysztof , Szczepaniak Paweł
Published: May 2020

The article presents a methodology for the implementation of preliminary and state tests on the example of the project entitled “Jet air targets with a programmable flight route” conducted by the Air Force Institute of Technology. The experience in the field of maneuvering aerial targets has allowed for implementation of an aerial jet target set. The further stages of research necessary to implement the set for operation have been presented. Investigations of the aerial jet targets were carried out based on the regulations in force in the Polish Armed Forces.
A New Strategy for Developing of Space Logistics
Authors: Augustyn Sławomir
Published: May 2020

This paper shows a new strategy for developing of space logistics which is supported by safety engineering for the operational techniques and technologies in space. A new strategy is a very important for developing of space technology because account improvement range and its independence from most terrestrial network failures. The developing space logistics is observable during make of satellites which are ensuring wide-ranging continuous information flow among people, businesses and governments for assuring of safety and security when terrestrial network connections are disrupted. The main goal in this publication is presenting example of analysis and assessment in an industrial enterprise of space logistics.
Evaluation of cardiac function in patients with sickle cell disease with left ventricular global longitudinal strain
Authors: Morissens Marielle , Besse-Hammer Tatiana , Azerad Marie-Agnès , Efira Andre , Rodriguez José Castro
Published: May 2020

Background and Objectives

The importance of myocardial dysfunction in sickle cell disease (SCD) is currently debated. It is difficult to find a reliable index of function in patients with chronic overload as in SCD. Speckle tracking echocardiography, a new mean of evaluating cardiac function, might be a useful tool in SCD. It has been applied in many fields to detect early cardiac function deterioration, and it is less load dependent compared with other function parameters. Studies in patients with SCD are rare, and the results are conflicting. The present study aimed to determine whether left ventricular global longitudinal strain (LV-GLS) was abnormal in a population of adults with SCD and whether it was correlated with clinical or biological parameters.

Methods

We prospectively enrolled 37 patients and 34 age- and sex-matched healthy controls. Echocardiography was performed in patients and controls.

Results

We found that the left ventricular diameter and mass were higher and the ejection fraction and longitudinal strain were lower in patients compared with controls. Diastolic dysfunction was uncommon. LV-GLS was abnormal in 21% of the patients. No correlation was observed between strain and clinical or biological parameters.

Conclusions

We concluded that LV-GLS could be a useful tool for evaluating these patients. However, the clinical impact of reduced LV-GLS remains to be determined.
Mechanical and corrosion properties of iron-mangan materials sintered in the presence of plasma
Authors: Orságová Králová Z. , Kupková M. , Hrubovčáková M. , Zeleňák A. , Oriňaková R. , Morovská Turoňová A. , Žáková K. , Kupka M. , Kovaľ K. , Šišoláková I.
Published: May 2020

The current trend in development of new metallic materials for certain types of implants is turning away from permanent, biologically inert materials to the use of biodegradable materials. Fe–Mn alloys represent high perspective material for development of new generation of temporary and biodegradable implants. The aim of this work was to study mechanical and corrosion characteristics of powder samples containing 25, 30 and 35 wt % of Mn which are fabricated by pressing, sintering, and additional spark plasma sintering. The influence of preparation method (pressing and sintering) to microstructure, phased composition and corrosion behavior of prepared alloys was studied.
A statistical approach to estimates of geomorphological-morphotectonic diversity for evaluating the scientific value of geosites: a case study from the southeastern Lut desert, Iran
Authors: Sadeghi-Farshbaf Pouya , Khatib Mohammad Mahdi , Rezaei Naser
Published: May 2020

The present study aims to investigate the diversity index (dv-index) of morphotectonic and geomorphological land-forms as one of the scientific value indices for evaluation of the geotouristic potential of the southeastern Lut desert using topographic statistical analysis. Scientific index scoring in most models is based on descriptive assessment by geotourists and experts. Statistical analysis of the dv-index in the present study helps experts to base their scoring on scientific methods. The dv-index is controlled by several items. In the present study, we analyse two of these, including the classification of topographic continuity pattern (TCP) and topographic slope position correlation (TSPC). For this purpose, a network of section lines is used to analyse slope continuity. The TSPC analysis is performed by using two parameters of absolute value and slope position. Results for these two evaluated items indicate a score of 1.46 (out of 2) for the dv-index. Given a rating of 5, the score obtained for the two items is a high one. Therefore, an initial estimate of the dv-index indicates a significant scientific value of the study area.
Study of Feed Horn Solutions for Irbene RT-32 Radio Telescope
Authors: Bleiders M.
Published: May 2020

Various feasible solutions of Irbene RT-32 secondary focus feed antennas are designed and compared in the present study. The examined feed antennas include smooth wall and corrugated horns with linear and shaped profiles. Mode matching technique is employed for simulation of scattering parameters and radiation patterns. Genetic algorithm is used for optimisation of horn profile for the best cross-polarization, and aperture efficiency performance. Although the presented horns are valid for any frequency band, different solutions allow choosing the best combination of factors, such as electrical parameters, bandwidth, physical size and complexity of manufacturing.
The LOFAR Long-Baseline Calibrator Survey Classification
Authors: Nikolajevs A. , Prūsis K.
Published: May 2020

Data manipulation of the LOFAR Long-Baseline Calibrator Survey (LBCS) and the Westerbork Northern Sky Survey (WENSS) catalogues are carried out in the present study. The aim of the study is to make calibrator classification statistics plots and estimations for further observations and upcoming stations. First, mean flux densities of LBCS calibrators against declination and observed station baseline length to the tied core station are plotted and the classified sources are marked. Second, we provide the designation – naming it the success rate – for the number of sources with the correlated signal against all the LBCS catalogue sources. Third, there is a trend in mean peak flux densities between stations – longer the baseline, higher mean peak flux density. Finally, estimations for upcoming and recent stations are made and some results are not encouraging.
Electrochemical Detection of Small Volumes of Glyphosate with Mass-Produced Non-Modified Gold Chips
Authors: Mizers V. , Gerbreders V. , Sledevskis E. , Kokina I. , Tamanis E. , Krasovska M. , Mihailova I. , Orugcovs A. , Bulanovs A.
Published: May 2020

Mass-produced printed circuit board (PCB) electrodes were used as electrochemical cells to detect the widely-used herbicide glyphosate. Square wave voltammetry (SWV) was used to determine the presence of glyphosate in aqueous Cu(NO3)2 solution. Optimal measurement conditions for the detection of glyphosate with PCB electrodes were found. It was determined that glyphosate was able to soak into the growing plants from the substrate. Glyphosate-contaminated plant juice was distinguished from control samples using the PCB electrode. Glyphosate-contaminated plants were found to have DNA mutations.
The Fabrication of Natural Zeolite Via Co-Precipitation Method as Cu, Pb and Zn Metal Absorbent
Authors: Sirait M. , Saragih K.Sari Dewi , Nurfajriani  , Gea S.
Published: May 2020

Heavy metal waste is very dangerous, which can change the condition of water into a solid substance that can be suspended in water and can reduce the cleanliness level of water consumed by living things. To date, heavy metals can be managed through several processes, namely physics, biology or chemistry. One of the ways to overcome heavy metal pollution is to use natural zeolite applying a co-precipitation method, as it is known that zeolite is a powerful natural material to be used for certain purposes. In order to justify the research results, several analyses have been performed, such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Surface Area Analyser (SAA), and Atomic Adsorption Spectrophotometric (AAS). From the XRD results, it has been found out that the size of each zeolite with variations in size of 150 mesh, 200 mesh, and 250 mesh is 29.274 nm, 38.665 nm and 43.863 nm, respectively. Moreover, the SEM-EDX has shown that the zeolite under consideration is a type of Na-Zeolite and that the co-precipitation method successfully removes impurity elements, namely, Fe, Ti, and Cl. The results of SAA testing have indicated that the total surface area for each variation of zeolite sizes is 63.23 m2/g, 45.14 m2/g and 59.76 m2/g. The results of the AAS test analysis have demonstrated that the optimal absorption of metal content is observed in a size of 150 mesh zeolite with adsorption power of 99.6 % for Pb metal, 98 % for Cu metal, and 96 % Zn metal.
A Cross Sectional Survey of Chicken Astroviruses Antibody in Broiler and Sonali (Cross-Bred) Chickens in Selected Areas in Bangladesh
Authors: Ali Md Zulfekar , Moula Mohammad Moktader , Bhuiyan Zafar Ahmed , Javed Muhammad Tariq
Published: May 2020

Chicken astroviruses (CAstV) are enteric viruses of poultry causing gastroenteritis, malabsorption, gout and white chick disease commonly known as runting-stunting syndrome (RSS). It can affect the wide range of poultry birds, especially chicken, turkey and duck worldwide. To our best knowledge there is no published report on presence of antibodies against CAstV in Bangladesh. Therefore, the study aimed to detect the presence of CAstV antibodies in broilers and sonali chickens (a cross-bread) in Bangladesh through a cross-sectional survey. A total of 454 blood samples from 66 flocks of broiler (n=343) and sonali chickens (n=111) of different ages were obtained during 2017 from four districts. The birds were healthy but were not vaccinated against CAstV. The samples were tested for specific antibodies against CAstV Group B by using commercially available ELISA kit. Overall, 16.74% (76/454) samples and 34.84% (23/66) flocks were positive for CAstV antibodies. The seroprevalence of CAstV was significantly (p=0.001) higher in sonali chickens (36.96%) than broiler (10.20%), while it was significantly higher (p=0.001) in birds of Bogura district (36.94%) than the other three districts. Regarding the age groups, seroprevalence was insignificantly (p=0.192) higher in sonali chicken before laying age (45%) than during laying age (27.45%). Regarding the seasons, CAstV infection was prevalent significantly (p=0.001) higher in winter season. Thus, the present study indicated the presence of CAstV in poultry in Bangladesh, so further studies are required to find out the magnitude of the problem in the country.
Job Expectations and Satisfaction Among Scientists
Authors: Feldy Marzena , Bojko Marta
Published: May 2020

The decreasing supply of qualified people ready to take up employment, observed for several years on the labour market, results in the strengthening of the employee’s position. The consequences of this process affect not only the companies but also scientific institutions. The employee’s market, which is shaped as a result of the following changes, forces employers to focus increasingly on activities aimed at attracting and retaining individuals who constitute their human capital. The aim of our article is to diagnose satisfaction levels of various job facets and differences in attachment to the workplace in groups of scientists with varied job expectation profiles. On this basis, it will be possible to indicate the job facets that scientific institutions should take into consideration in order to provide researchers with a high level of job satisfaction. To broaden knowledge about the subject, we used data collected by the National Information Processing Institute in 2017 in a nationwide representative sample of 840 scientists who were at various stages of their academic career, represented all areas of science and worked in all types of scientific units in Poland. By performing factor analysis and a clustering procedure on variables describing researchers’ job expectations we were able to categorize the respondents into three groups: 1) demanding, 2) aspiring and 3) unengaged. The demanding employees have high expectations in all job facets that we examined, i.e.: economic and organizational matters, developmental and social opportunities as well as employment flexibility. The aspiring scientists above all appreciate developmental and social opportunities more than other groups. On the contrary, the unengaged employees value developmental and social opportunities the least while other job facets are moderately significant for them. The survey of satisfaction of particular groups of scientists with their current employer indicates the need to focus the scientific institutions employing them on different aspects of work. In the case of demanding employees, it is important to take care of their economic well-being. On the other hand, in order to increase satisfaction from work of scientists from the aspiring group, it will be important to provide them with a higher level of satisfaction from the development and social sphere. The greatest challenge may be the satisfaction of unengaged employees who declare a relatively low general level of satisfaction with the workplace, and at the same time do not have well-established expectations towards the institutions employing them.
Methods of Measuring the Effects of Public Relations Activities Applied by PR Specialists in their Professional Work
Authors: Szuba Przemysław , Tworzydło Dariusz
Published: May 2020

The purpose of the article is to identify the ways in which Polish PR specialists measured the effects of their own activities in the last year and to analyze the universality of application of specific solutions. A comparative analysis was also conducted based on available research on the tools used by PR consultants. The research was conducted by means of an auditorium questionnaire during the Congress of Public Relations Professionals in 2019. The research sample was comprised of representatives of various organizations operating on the Polish market, 253 respondents in total. Analyses have shown that the use of broadly understood media monitoring is key support for people who build reliable relationships with the environment on a daily basis. It should be noted that the PR industry remains strongly committed to using the AVE indicator, despite the fact that both global and domestic industry organizations are seeking to limit its role in measuring PR effects.
Synthesis of α-Fe2O3 nanoparticles and analyzing the effect of annealing temperature on its properties
Authors: Thimmiah Bhargavi Ram , Nallathambi Gobi
Published: May 2020

α-Fe2O3 nanoparticles were synthesized via co-precipitation technique using ferric and ferrous salts and potassium hydroxide as precipitation agents. The samples were calcined at 350 °C, 550 °C and 750 °C for 3 hours. The obtained iron oxide was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Crystallinity of the sample was studied by X-ray diffraction. SEM micrographs showed nonuniform size distribution of the particles forming agglomerates. TGA analysis revealed trace amount of weight loss and material stability for the samples calcined at temperatures above 500 °C. DLS results indicated that increasing of annealing temperature resulted in reduction of the particle size and more uniform size distribution. At the maximum annealing temperature of 750 °C, the mean diameter of the particles of 100 nm was observed.
Radiation-induced cancer risk and decision-making in a simulated Cs-137 urban event
Authors: Andrade Edson R. , Gomes Renato G. , Stenders Ricardo , Brum Tercio , Lima Sergio X. , Castro Mariana S. C. , Silva Ademir X.
Published: May 2020

The triggering of a “dirty bomb” generates a complex scenario, with enormous challenges for the responders due to initial misinformation and the urgency to act quickly yet effectively. Normally, the first 100 h are decisive for perceiving the risk in a more realistic dimension, but the support of methodologies that rely on computational simulations can be valuable when making key decisions. This work seeks to provide support for the early decision-making process by using a Gaussian model for the distribution of a quantity of Cs-137 spread by a radiological dispersive device (RDD). By sequentially joining two independent programs, HotSpot Health Physics codes and RESidual RADiation (RESRAD)-RDD family of codes, we came up with results that suggest a segmented approach to the potentially affected population. These results advocate that (a) the atmospheric stability conditions represented by the Pasquill–Gifford classes and (b) the population subgroups defined by radiation exposure conditions strongly influence the postdetonation radiological effects. These variables should be taken into account in the elaboration of flexible strategies that include many climatic conditions and to priori-tize attention to different groups of public at risk. During the initial phases of such an event, it is believed that simulations using Gaussian models may be of value in anticipating the possible changes in key variables during the decision-making process. These variables may severely affect the effectiveness of the actions of responders and the general public’s safety.
Effects of coupling agent on antioxidant properties and structure of PP/cotton stalk lignin composites
Authors: He Mingyu , Musajian Dilhumar , Hasan Gvlmira , Hou Gongbo , Yimit Mamatjan
Published: May 2020

In this paper, the effects of coupling agent and lignin extracted from waste cotton stalks in Xinjiang on thermal-oxygen aging properties of polypropylene (PP) composites were studied. The melt index test and indoor thermal oxygen aging test was carried out on the samples treated with coupling agent. The mechanical properties, surface micromorphology, rheological properties and element composition of the materials before and after 30 days of aging were studied. The results showed that the titanate coupling agent was the best for improving the melt index and mechanical properties of PP/cotton stalk lignin composites. After the 30-day thermal oxygen aging test, the samples with 2% lignin had the best impact strength and retention rate of fracture elongation, reaching 68.9% and 77.3% respectively. The sample with 3% lignin content had the smoothen surface, no crack appeared. After aging, the increase of C=O was the least, and the crystal peak area decreased less.
Occupational radiation exposures for medical workers in Pakistan – An overview
Authors: Ahmad Misbah , Ahmad Iftkhar , Khan Aakif Ullah , Khan Amin Ali , Shah Kamran Ali , Ahmad Jamil
Published: May 2020

The imperative use of ionizing radiation in medicine causes the inevitable occupational exposure of the medical workers during the course of routine duties. The magnitude of health risk due to such radiation exposures has been described in terms of occupational radiation doses. In this context, it is obligatory to monitor, measure and document the radiation dose of occupationally exposed medical workers. This study aims to review the whole-body occupational radiation exposures of medical workers in Pakistan. Specifically, online literature published during 2000-2018 was reviewed for the occupational radiation exposures of Pakistani medical workers. Analysis of the extracted personal dosimetry data revealed that the total number of monitored medical occupational workers was 26046. The range of total cumulative and annual average effective doses was 94-15785 Person-mSv and 0.66-7.37 mSv, respectively. A significant number of the workers (25477; ~98%) received an annual dose below 5 mSv, while only 18 workers received an occupational exposure exceeding the annual dose limit of 20 mSv. It is expected that this study will provide a useful reference for evaluating and improving radiation protection and safety policies in the country.
Propeller Hydrodynamic Characteristics in Oblique Flow by Unsteady Ranse Solver
Authors: Nouroozi Hossein , Zeraatgar Hamid
Published: May 2020

Propellers may encounter oblique flow during operation in off-design conditions. Study of this issue is important from the design and ship performance points of view. On the other hand, a propeller operating in oblique flow may sometimes result in a better propulsion efficiency. The main goal of the present study is to provide an insight on the propeller characteristics in the oblique flow condition. In this research, the performance of the DTMB 4419 propeller is studied by the numerical method based on solving Reynolds Averaged Navier–Stokes (RANS) equations in several inflow angles. The sliding mesh approach is used to model the rotary motion of the propeller. Initially, the numerical method is verified by grid and time step dependency analysis at various inflow angles. Additionally, computed results at zero inflow angle are compared with the available experimental data and good agreement is achieved. Finally, the forces and moments acting on the propeller are obtained for 0° to 30° inflow angles. It is concluded that the inflow angle up to 10° has no significant influence on the thrust and torque coefficients as well as the propeller efficiency. However, at high angles up to 30°, the thrust and torque coefficients increase as the inflow angle increases, which may result in a significant improvement of propeller efficiency.
Generation of H2 on Board Lng Vessels for Consumption in the Propulsion System
Authors: Fernández Ignacio Arias , Gómez Manuel Romero , Gómez Javier Romero , López-González Luis M.
Published: May 2020

At present, LNG vessels without reliquefaction plants consume the BOG (boil-off gas) in their engines and the excess is burned in the gas combustion unit without recovering any of its energy content. Excess BOG energy could be captured to produce H2, a fuel with high energy density and zero emissions, through the installation of a reforming plant. Such H2 production would, in turn, require on-board storage for its subsequent consumption in the propulsion plant when navigating in areas with stringent anti-pollution regulations, thus reducing CO2 and SOX emissions. This paper presents a review of the different H2 storage systems and the methods of burning it in propulsion engines, to demonstrate the energetic viability thereof on board LNG vessels. Following the analysis, it is identified that a pressurised and cooled H2 storage system is the best suited to an LNG vessel due to its simplicity and the fact that it does not pose a safety hazard. There are a number of methods for consuming the H2 generated in the DF engines that comprise the propulsion plant, but the use of a mixture of 70% CH4-30% H2 is the most suitable as it does not require any modifications to the injection system. Installation of an on-board reforming plant and H2 storage system generates sufficient H2 to allow for almost 3 days’ autonomy with a mixture of 70%CH4-30%H2. This reduces the engine consumption of CH4 by 11.38%, thus demonstrating that the system is not only energy-efficient, but lends greater versatility to the vessel.
Modelling and Optimisation of Vacuum Collection System for Cruise Ship Kitchen Garbage
Authors: Jun Du , Ruonan Li , Xin Wu , Hang Zhao
Published: May 2020

Pollution of the marine environment by ship garbage is an urgent problem to be solved at home and abroad. The ship kitchen garbage vacuum collection system is a new environmental protection scheme for garbage disposal. It has many advantages, such as using a pipeline instead of manual operation, creating high-level sanitary conditions, realising completely closed garbage collection and transportation, eliminating cross-pollution, saving space and so on. In this paper, the system is modelled, and the calculation of pipeline pressure loss, the vacuum degree of the vacuum tank and the energy consumption of the system are briefly introduced. In order to reduce the energy consumption, an algorithm for the emptying and discharging port is presented. In order to solve the problem of optimising relevant parameters, the vacuum transport mechanism of garbage is studied based on an optimisation model of the pipe network, and the experimental platform of a simulation device is set up. In engineering, this is of great significance to the design of cruise ship garbage collection and treatment systems and the development of supporting technology.
Application of Vibroacoustic Diagnosis in Assessing Bridges Connecting Teeth and Implants to Treat Tooth Absence in Sea Vessel Crews
Authors: Rasinski Artur , Klekot Grzegorz , Skopiński Piotr
Published: May 2020

Implant treatment is a proven method in dentistry for partial and complete missing teeth reconstruction. In some clinical situations it is advisable to limit the number of implants, which can be obtained by making a bridge connecting the patient’s own tooth with the implant. So far, the possibility of using safe and permanent connections of natural teeth with implants has been examined to a small extent due to the dangers resulting from the different mobility of dental implants and teeth.

An attempt was made to use vibro-acoustic techniques to evaluate various combinations of teeth and implants. Pilot studies were carried out on cadavers-pig mandibles with implants. There were recorded sounds in the immediate vicinity of the mandible formed in response to impulse excitations carried out with a point hit against a tooth or implant before and after their joining with a bridge. The comparison of spectra allows to see features indicating a high probability of being able to distinguish between the examined configurations.

The results of the research should contribute to a better understanding of the mutual relations between the dental implant and the tooth, which are included in bridge. In the perspective, it will enable to assess the level of safety and to identify clinical situations that allow to obtain dental bridges based on teeth and implants.
NoMoATS: Towards Automatic Detection of Mobile Tracking
Authors: Shuba Anastasia , Markopoulou Athina
Published: May 2020

Today’s mobile apps employ third-party advertising and tracking (A&T) libraries, which may pose a threat to privacy. State-of-the-art detects and blocks outgoing A&T HTTP/S requests by using manually curated filter lists (e.g. EasyList), and recently, using machine learning approaches. The major bottleneck of both filter lists and classifiers is that they rely on experts and the community to inspect traffic and manually create filter list rules that can then be used to block traffic or label ground truth datasets. We propose NoMoATS – a system that removes this bottleneck by reducing the daunting task of manually creating filter rules, to the much easier and scalable task of labeling A&T libraries. Our system leverages stack trace analysis to automatically label which network requests are generated by A&T libraries. Using NoMoATS, we collect and label a new mobile traffic dataset. We use this dataset to train decision tree classifiers, which can be applied in real-time on the mobile device and achieve an average F-score of 93%. We show that both our automatic labeling and our classifiers discover thousands of requests destined to hundreds of different hosts, previously undetected by popular filter lists. To the best of our knowledge, our system is the first to (1) automatically label which mobile network requests are engaged in A&T, while requiring to only manually label libraries to their purpose and (2) apply on-device machine learning classifiers that operate at the granularity of URLs, can inspect connections across all apps, and detect not only ads, but also tracking.
SoK: Differential privacies
Authors: Desfontaines Damien , Pejó Balázs
Published: May 2020

Shortly after it was first introduced in 2006,differential privacybecame the flagship data privacy definition. Since then, numerous variants and extensions were proposed to adapt it to different scenarios and attacker models. In this work, we propose a systematic taxonomy of these variants and extensions. We list all data privacy definitions based on differential privacy, and partition them into seven categories, depending on which aspect of the original definition is modified.

These categories act like dimensions: variants from the same category cannot be combined, but variants from different categories can be combined to form new definitions. We also establish a partial ordering of relative strength between these notions by summarizing existing results. Furthermore, we list which of these definitions satisfy some desirable properties, like composition, postprocessing, and convexity by either providing a novel proof or collecting existing ones.
Angel or Devil? A Privacy Study of Mobile Parental Control Apps
Authors: Feal Álvaro , Calciati Paolo , Vallina-Rodriguez Narseo , Troncoso Carmela , Gorla Alessandra
Published: May 2020

Android parental control applications are used by parents to monitor and limit their children’s mobile behaviour (e.g., mobile apps usage, web browsing, calling, and texting). In order to offer this service, parental control apps require privileged access to system resources and access to sensitive data. This may significantly reduce the dangers associated with kids’ online activities, but it raises important privacy concerns. These concerns have so far been overlooked by organizations providing recommendations regarding the use of parental control applications to the public.

We conduct the first in-depth study of the Android parental control app’s ecosystem from a privacy and regulatory point of view. We exhaustively study 46 apps from 43 developers which have a combined 20M installs in the Google Play Store. Using a combination of static and dynamic analysis we find that: these apps are on average more permissions-hungry than the top 150 apps in the Google Play Store, and tend to request more dangerous permissions with new releases; 11% of the apps transmit personal data in the clear; 34% of the apps gather and send personal information without appropriate consent; and 72% of the apps share data with third parties (including online advertising and analytics services) without mentioning their presence in their privacy policies. In summary, parental control applications lack transparency and lack compliance with regulatory requirements. This holds even for those applications recommended by European and other national security centers.
Long-Term Observation on Browser Fingerprinting: Users’ Trackability and Perspective
Authors: Pugliese Gaston , Riess Christian , Gassmann Freya , Benenson Zinaida
Published: May 2020

Browser fingerprinting as a tracking technique to recognize users based on their browsers’ unique features or behavior has been known for more than a decade. We present the results of a 3-year online study on browser fingerprinting with more than 1,300 users. This is the first study with ground truth on user level, which allows the assessment of trackability based on fingerprints of multiple browsers and devices per user. Based on our longitudinal observations of 88,000 measurements with over 300 considered browser features, we optimized feature sets for mobile and desktop devices. Further, we conducted two user surveys to determine the representativeness of our user sample based on users’ demographics and technical background, and to learn how users perceive browser fingerprinting and how they protect themselves.
2L of Polyethylene Glycol as the Main Small Bowel Cleansing Regimen Component Prior to Video Capsule Endoscopy: Interim Analysis
Authors: Derovs Aleksejs , Derova Jeļena , Kleina Regīna , Pokrotnieks Juris
Published: May 2020

Capsule Enteroscopy (CE) is a fundamentally new method in diagnostic endoscopy. However, there are several factors influencing the quality of this procedure, including impermeable fluids, food remains etc. The aim of the study was to assess one of the most popular currently used bowel preparation methods and evaluate possible effects of various factors. 136 CE examinations were analysed. Each patient was prepared using 2 litres of polyethylene glycol (PEG) one day prior to examination. There was a special form filled in for each patient, which included relevant parameters (anamnesis, CE data etc.). Of 136 CE cases, 84 (61.8%) were female patients and 52 (38.2%) were male. The small bowel (SB) transit time in 112 patients varied from 39 to 502 minutes, but in 24 cases the capsule did not reach caecum. The degree of bowel cleanliness was as follows: very good — 30 (22.1%) patients, satisfactory — 97 (71.3%), and poor — 9 (6.6%). A positive correlation was observed between the degree of SB cleanliness and the SB transit time (p = 0.015). A longer SB transits time was associated with poor SB cleanliness. The results obtained in this study showed that the quality of SB cleanliness is affected by SB transit time. A relatively large percentage of cases rated as satisfactory bowel cleanliness and comparatively small percentage of bowel cleanliness cases rated as “very good” were observed when 2 litres of PEG were used prior to CE, indicating an important issues in preparation of the bowel prior to CE.
Pathogenic Escherichia coli Among Asymptomatic Children and Associated Factors
Authors: Zelča Egija , Brūmane Aiva , Kārkliņa Daiga , Perminovs Dmitrijs , Gavars Mikus , Remberga Silvija , Rumba-Rozenfelde Ingrīda , Daugule Ilva
Published: May 2020

Although Escherichia coli is a part of the commensal flora of the gastrointestinal tract, pathogenic types of E. coli can cause diarrhea, especially in children. Pathogenic types are found also in healthy individuals, but prevalence of pathogenic E. coli among asymptomatic children varies and has not been studied in Latvia. The aim of the study was to determine prevalence of pathogenic E. coli among asymptomatic children and identify factors associated with presence of bacterium. Children (aged 0.5–8 years) without acute gastrointestinal symptoms were included in a cross-sectional study. Parents were asked to answer a questionnaire (demographic data, parental education, type of delivery, breastfeeding, antibacterial therapy, and allergic diseases) and bring a faecal sample of their child. The prevalence of pathogenic E. coli was detected by polymerase chain reaction and analysed in respect to risk factors. Statistical analyses included Chi-Square test, one-way ANOVA, and logistic regression. The patient sample group contained 245 children, mean age 4.5 SD ± 2.1; 46.5% (114/245) had allergies. In total, 16% (39/245) of isolates were positive for pathogenic E. coli. Prevalence of pathogenic types of E. coli was significantly higher among children without allergy compared to children with allergy: 21% (27/131) vs. 11% (12/114), p = 0.03. Prevalence did not differ significantly in respect to other studied factors. In logistic regression analysis pathogenic E. coli positivity was inversely associated with presence of allergy (OR = 0.45, CI: 0.21–0.94, p = 0.03). Asymptomatic carriage of pathogenic E. coli was identified in our paediatric patient sample and was inversely associated with an allergic disease. Microbiota changes related to pathogenic E. coli, as well as duration of carriage of bacterium, should be studied further.
2. Achieving Harmony Through Music: A Comparison Between Ancient Greek and Chinese Thought
Authors: Marisi Rossella
Published: May 2020

Ancient Greek and Chinese philosophers held music as a fundamental component of education and deemed it effective in guiding students at gaining harmony within themselves and with one another. A quality music education was thus considered relevant in the Bildung of individuals, the preservation of the state, and the maintenance of harmony between heaven and earth. This study makes a comparison between the thought of Plato and his Greek predecessors on one side, and the one of Confucianism on the other, identifying fascinating similarities which offer a source of inspiration to modern educators.
11. The Vocal-Chamber Music Recital – Theoretical and Practical Aspects of an Interdisciplinary Approach
Authors: Petrescu Cezara Florentina , Petrescu Alexandru Radu
Published: May 2020

In a world of spectacle in which everything seems to have already been told, the vocal-chamber music recital is found in an identity crisis. The economic, social and cultural context in which it takes place is labile and determines the performers to ask themselves what is their position within the sctructures in which they function/operate. The purpose of the research is to identify and reevaluate links, configurations, structures and elements of a type of an aparently morally obsolet musical performance and marked by the passage of time. The originality of the thesis spans from its interdisciplinary character and from its multifaceted approach of the performative phenomenon.
1. Historical Evolution of Adagio (Analysis of the Choreographic Concept)
Authors: Todi Cristina
Published: May 2020

By this study we propose to expose the steps that led to the development of the choreographic adagio. Without excluding the importance of the precursory period, the approach of the discourse introduces us into the middle of the 18th century, exactly in the age when this miracle of dancing began to assume clear contours. We remind of the entrées full of effects with high elevations of Auguste Vestris, the expressivity of Marie Salle, the Noverian manifesto certainly the pas de deux formula - which is used even nowadays - of Marius Petipa. The transformations of the subjects - from the mythology to the eternal theme of love - are completed by the different states of the danced dialogue. The deciphering of the symbols founding its gesticulation and explains the step or the choreographic element is visible through the scene of the balcony of ballet Romeo and Juliet by Prokofiev and by the meeting between Spartacus and Flavia in the ballet of Avram Haciaturian. The state of poetry, of dreaming, noble rise of the soul towards unsuspected horizons, the adagio, confesses to us its filiation even beyond the border of the age. We consider that this paper is useful both for the teaching staff who must instruct the youngsters in vocational schools a profound and qualitative choreographic culture, and to those who are training in the art of dance.