bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Ship Hull Optimisation of High-Speed Ship Based on Viscous Flow/Potential Flow Theory
Authors: Baoji Zhang 
Published: May 2020

Abstract
In order to quickly obtain practical ship forms with good resistance performance, based on the linear wave-making resistance theory, the optimal design method of ship forms with minimum total resistance is discussed by using the non-linear programming (NLP) method. Taking the total resistance as the objective function (the Michell integral is used to calculate the wave-making resistance and the equivalent plate friction resistance formula is used to calculate the frictional resistance), the hull surface offset as the design variable and appropriate displacement as the basic constraints, and considering the additional constraints, the hull bow shape and the whole ship are optimised, and an improved hull form is obtained. The resistance of the ship before and after optimisation is calculated by the CFD method to further evaluate the resistance reduction effect and performance after optimisation. Finally, an example of optimisation calculation of an actual high-speed ship is given. The obvious resistance reduction results confirm the reliability of the optimisation design method.
Adaptive Self-Regulation PID Control of Course-Keeping for Ships
Authors: Zhang Qiang , Ding Zhongyu , Zhang Meijuan 
Published: May 2020

Abstract
To solve the nonlinear control problems of the unknown time-varying environmental disturbances and parametric uncertainties for ship course-keeping control, this paper presents an adaptive self-regulation PID (APID) scheme which can ensure the boundedness of all signals in the ship course-keeping control system by using the Lyapunov direct method. Compared with the traditional PID control scheme, the APID control scheme not only is independent of the model parameters and the unknown input, but also can regulate the gain of PID adaptively and resist time-varying disturbances well. Simulation results illustrate the effectiveness and the robustness of the proposed control scheme.
The Effect of 5-Aminosalicylic Acid on Intestinal Microbiota
Authors: Sargautiene Vanda , Ligere Renāte , Kalniņa Ineta , Jākobsone Ida , Nikolajeva Vizma , Derovs Aleksejs 
Published: May 2020

Abstract
The article discusses the possible relationships between intestinal microbiota and the therapeutic efficacy of 5-aminosalicylic acid (5-ASA) in inflammatory bowel diseases. Intestinal microbiota may be involved in 5-ASA enzymatic biotransformation, but the metabolism of drugs by the intestinal microbiota has been studied in less detail, and little is known about the relationships between anti-inflammatory efficacy of 5-ASA with bacterial viability, quantity and activity. It remains unclear whether 5-ASA affects the microbiota depending on the different segments of gastrointestinal tract. Drugs and diet can both improve and worsen the composition of the intestinal microbiota. However, it is not known whether drugs affect the intestinal microbiota regardless of diet. Further research is needed to answer these questions.
The Level of Cytokeratin 18 in Patients with HIV and Viral Hepatitis C Co-Infection in Latvia
Authors: Koļesova Oksana , Madelāne Monta , Ekšteina Ilze , Koļesovs Aleksandrs , Krūmiņa Angelika , Vīksna Ludmila 
Published: May 2020

Abstract
Cytokeratin 18 (CK18) is a specific marker of hepatocellular apoptosis, which is a useful noninvasive indicator of liver fibrosis in the HIV/HCV group. However, data on the CK18 level in serum are limited for this group. This study demonstrated CK18 levels in serum in HIV/HCV co-infected and HIV mono-infected patients; investigated the association of CK18 levels with other non-invasive markers of liver fibrosis; and presents CK18 dynamics in a four-month-long period. The sample included 273 patients with HIV infection (128 of them were with HIV/HCV co-infection) aged from 23 to 65 (35% females). Levels of hyaluronic acid, CK18, ALT, and AST were determined in serum, and the FIB4 index was calculated. All markers had higher levels in the HIV/HCV group than in the HIV mono-infection group. The HIV/HCV group demonstrated coherent correlations among the markers and their associations with the level of CK18 than the HIV mono-infection group. During the four-month-long period, the CK18 level in serum showed no significant changes.
Culture Based Evaluation of Microbiota in Children with Acute Appendicitis
Authors: Kroiča Juta , Reinis Aigars , Kakar Mohit , Delorme Mathilde , Broks Renārs , Asare Lāsma , Berezovska Marisa , Jansins Vladislavs , Zviedre Astra , Enģelis Arnis , Saxena Amulya , Pētersons Aigars 
Published: May 2020

Abstract
Treatment strategies for acute uncomplicated appendicitis have evolved and now conservative antibacterial treatment is recommended over surgical treatment, especially for paediatric patients. The aim of this study was to evaluate microbiota in paediatric patients with acute uncomplicated and complicated appendicitis, and antibacterial susceptibility of the causative microorganisms. Bacteriological identification was conducted using the VITEK2 analyser. Antibacterial susceptibility tests were performed and the results were evaluated in accordance with the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) “Clinical breakpoints and dosing of antibiotics” (Version 7.0, January 2019). Serodiagnosis of Yersinia enterocolitica was performed using indirect haemagglutination. The results revealed differences in microbiota in cases of acute complicated and acute uncomplicated appendicitis. Pseudomonas aeruginosa was identified more frequently in cases of acute complicated appendicitis. Mixed culture was prevalent in cases of both acute complicated and acute uncomplicated appendicitis. Very few positive extended spectrum beta-lactamase (ESBL) Escherichia coli cultures were identified. Most of strains of Pseudomonas aeruginosa were resistant to amoxicillin with clavulanic acid, ertapenem, ampicillin and cefotaxime. Some of E. coli isolates were resistant to ampicillin and to amoxicillin with clavulanic acid.
Liver Abscesses — Seven-Year Experience of a Single Tertiary Care Hospital
Authors: Krūmiņa Angelika , Laivacuma Sniedze , Drjagunovs Iļja , Zeltiņa Indra , Vīksna Ludmila , Derovs Aleksejs 
Published: May 2020

Abstract
We reviewed medical records of cases of liver abscesses (LA) registered in Rīga East University Hospital clinical centre “Gaiïezers” from January 2012 to October 2018 to assess sociodemo-graphic factors, clinical, laboratory, microbiological and radiological findings, as well as therapeutic modalities and their efficacy associated with LA. A total of 95, including five recurrent, cases were included in this study. No statistically significant differences in gender distribution were found. Mean patient’s age was 64.5 ± 15.9. The most common documented risk factors for the development of LA were underlying biliary tract abnormalities (37.9% of cases), and diabetes mellitus (12.7%), while in 21.1% of cases, LA were defined as cryptogenic. Most patients presented with fever (70.5%); right upper abdominal pain was reported in 61.1%, while vomiting and / or nausea — in 25.3% of cases. The most common isolates identified from LA were Klebsiella pneumonia (40.3% of cases), mainly in monomicrobial LA, and Escherichia coli (22.6% of cases), predominantly in polymicrobial LA. Ceftriaxone and metronidazole intravenous formulations were used in 35.5% cases as the principal antimicrobial combination at hospital. Median overall expected duration of antimicrobial treatment was 15 days. LA drainage was performed in 87.4% of cases for the median duration of seven days. In 86.3% of cases both approaches were combined.
Association of Dunbar, May-Thurner and Nutcracker Compression Syndromes in One Patient
Authors: Zalizko Poļina , Tropina Evija , Scholbach Thomas , Puķītis Aldis 
Published: May 2020

Abstract
We report a case of Dunbar syndrome, May–Thurner syndrome and Nutcracker syndrome diagnosed in one patient with clinical presentation and imaging findings on Doppler ultrasonography. Dunbar syndrome or truncus coeliacus compression syndrome is an under-diagnosed vascular compression syndrome with a lot of controversy around it because of insufficient differentiation from celiac artery stenosis. May–Thurner syndrome or iliac vein compression syndrome is an anatomically variable condition of venous outflow obstruction caused by extrinsic compression by the right common iliac artery as it crosses the iliac vein anteriorly. In Nutcracker syndrome due to compression the outflow from the left renal vein into the inferior vena cava is obstructed. The combination of all these syndromes in one patient was not described before.
2. Choosing the Teaching Career by Students in the Arts
Authors: Anghel Ona Ionica 
Published: May 2020

AbstractIn order to build strategies for the permanent improvement of the educational offer in higher education institutions, taking into account the expectations of the beneficiaries can be an important direction to consider. Thus, the present study aims to radiograph the reasons why the students of the National University of Arts “George Enescu” in Iași (UNAGE) also choose a training trajectory for the route of the teaching career. To achieve this objective, we used in our research the linguistically adapted questionnaire “Orientations for Teaching Survey - OTS” (Ferrell, C.M., Daniel, L.G, 1993), which was answered by 140 UNAGE students. The hypothesis that the reasons why these students prepare to become teachers are intrinsic, extrinsic and altruistic was confirmed by statistical analyzes.
Economic Freedom and its Impact on Foreign Direct Investment: Global Overview
Authors: Singh Devesh , Gal Zoltán 
Published: May 2020

Abstract
The purpose of this research is to examine the economic freedom (EF) along with its macroeconomic determinants impact on Foreign Direct Investment (FDI) inflow in South Asia, East Asia, Latin America, Middle East, and North Africa, Northern Europe, Southern Europe, Western Europe, Eastern Europe and Sub Saharan Africa. We use Heritage Foundation economic freedom index data over the period of 1999 to 2018 and employ the stepwise multi regression on variables of business freedom, government spending, tax burden, government integrity, property rights, investment freedom, trade freedom and monetary freedom. The results show that EF has a significant positive impact in South Asia, Latin America, East Asia, North Europe and West Europe. However, for the Middle East and North Africa, East European and South European economies EF has an insignificant influence on FDI inflow.
Considerations about the quality of UML and GML application schemas
Authors: Chojka Agnieszka 
Published: May 2020

Abstract
Exchange of and access to spatial data is the principal goal of any Spatial Data Infrastructure, therefore, one of the key concepts of SDI is interoperability, especially semantic and syntactic. Whereas application schemas and quality issues are one of the aspects that have to be considered to ensure a successful data interchange in SDI.
Two types of application schema are widely used in the European SDI as well as in the Polish SDI. They cover both semantic and syntactic interoperability and are an integral parts of spatial data specifications and relevant regulations in the form of data models. However, working out accurate and correct application schemas may be a challenge.
Additionally, faulty or too complex application schemas can influence the ability for valid data interchange, and consequently, prevent achieving interoperability within SDI. Therefore, the capability to examine and estimate the UML and GML application schemas quality seems to be a worthwhile and important issue in the context of semantic and syntactic interoperability in SDI.
The main subject of this article it to set out the context of performed studies, among others, the role of application schema in the interoperable data exchange, issues related to the concept of quality and its measures.
Development of a precise local quasigeoid model for the city of Krakow – QuasigeoidKR2019
Authors: Banasik Piotr , Bujakowski Kazimierz , Kudrys Jacek , Ligas Marcin 
Published: May 2020

Abstract
A geoid or quasigeoid model allows the integration of satellite measurements with ground levelling measurements in valid height systems. A precise quasigeoid model has been developed for the city of Krakow. One of the goals of the model construction was to provide a more detailed quasigeoid course than the one offered by the national model PL-geoid2011. Only four measurement points in the area of Kraków were used to build a national quasigeoid model. It can be assumed that due to the small number of points and their uneven distribution over the city area, the quasigeoid can be determined less accurately. It became the reason for developing a local quasigeoid model based on a larger number of evenly distributed points. The quasigeoid model was based on 66 evenly distributed points (from 2.5 km to 5.0 km apart) in the study area. The process of modelling the quasigeoid used height anomalies determined at these points on the basis of normal heights derived through levelling and ellipsoidal heights derived through GNSS surveys. Height anomalies coming from the global geopotential model EGM2008 served as a long-wavelength trend in those derived from surveys. Analyses showed that the developed height anomaly model fits the empirical data at the level of single millimetres – mean absolute difference 0.005 m. The developed local model QuasigeoidKR2019, similar to the national model PL-geoid2011, are models closely related to the reference and height systems in Poland. Such models are used to integrate GNSS and levelling observations. A comparison of the local QuasigeoidKR2019 and national PL-geoid2011 model was made for the reference frame PL-ETRF2000 and height datum PL-KRON86-NH. The comparison of the two models with respect to GNSS/levelling height anomalies shows a triple reduction in the values of individual quartiles and a mean absolute difference for the developed local model. These summary statistics clearly indicate that the accuracy of the local model for the city of Krakow is significantly higher than that of the national one.
Serum malondialdehyde (MDA) level as a potential biomarker of cancer progression for patients with bladder cancer
Authors: Lepara Zahid , Lepara Orhan , Fajkić Almir , Rebić Damir , Alić Jasmin , Spahović Hajrudin 
Published: May 2020

Abstract

Introduction. Bladder cancer is the most common malignancy involving the urinary system. Recent research tends to emphasize the role of oxidative stress products in the carcinogenesis of bladder cancer. The level of oxidative stress can be measured by assessing the MDA levels. This study aimed to evaluate serum MDA levels in patients with bladder cancer, as well as to determine its potential role as a biomarker in the diagnosis of the disease and progression risk considerations.

Methods. The study was designed as a cross-sectional study and included 90 patients, divided into three groups with 30 patients each: Ta, T1and T2–T4 group, based on histopathological findings after transurethral resection of the tumor. The control group included 30 healthy volunteers. MDA level was determined using the spectrophotometric method.

Results. Serum MDA level in patients with bladder cancer [0.86 (0.78–1.05) μmol/L] was significantly higher than the serum MDA level in control group [0.70 (0.69–0.72) μmol/L] (p < 0.001). Serum MDA level in Ta group [0.73 (0.70–1.05) μmol/L], T1 group [0.85 (0.80–1.12) μmol/L] and in T2–T4 group [0.91 (0.84–1.04) μmol/L] was significantly higher than the serum MDA level in control group [0.70 (0.69–0.72) μmol/L] (p < 0.01). MDA level in T1 and T2–T4 group was significantly higher than the MDA level in Ta group (p < 0.01). No significant difference was observed in MDA level between T1 and T2–T4 group (p = NS). A statistically significant positive correlation was found between tumor size and serum MDA level in patients with bladder cancer (rho = 0.254 p < 0.01).

Conclusions. The results of the present study suggest that MDA serum level might play a significant role as a biomarker in the diagnosis of bladder cancer, as well as in the monitoring of its progression.
Environmental Impacts of Mixed Aggregates for use in Unbound Layers in Road Construction
Authors: Gostečnik Metka , Šinik Predrag , Mladenovič Ana , Ščančar Janez , Milačič Radmila 
Published: May 2020

Abstract
During carbon steel manufacturing, large amounts of electric arc furnace (EAF) slag are generated. EAF slag, if properly treated and processed into aggregate, is an alternative source of high-quality material, which can substitute the use of natural aggregates in most demanding applications in the construction sector, mostly for wearing asphalt courses. In this screening process of high-quality aggregates, a side material with grain size 0/32 mm is also produced, which can be used as an aggregate for unbound layers in road construction. In this study, the environmental impacts of slag aggregate (fraction 0/32 mm) were evaluated in mixed natural/slag aggregates. Different mixtures of natural/slag aggregates were prepared from aged (28 days) and fresh slag, and their environmental impacts were evaluated using leaching tests. It was shown that among the elements, chromium (Cr) was leached from some mixed aggregates in quantities that exceeded the criterion for inert waste. The data from the present investigation revealed that mixed aggregates, prepared from aged slag (fraction 0/32 mm) and natural stone in the ratio 10/90, are environmentally acceptable and can be safely used in unbound materials for road construction.
Tooth Contact Analysis of Helical Gears Having Modified Straight Teeth by Changing of the Number of Teeth on the Pinion
Authors: Bodzás Sándor 
Published: May 2020

Abstract
The helical gears are widely used in different engineering applications especially in case of vehicles on the gear boxes. The aim of this research is the analysis of the effect of number of teeth on the pinion beside of the constancy number of teeth on the driven gear. Five types of helical gears have to be designed for the comparative analysis. Own-designed designing software are necessary for the facilitation of the designing and modelling process. During this research the normal stresses and normal deformations will be analysed into different directions by TCA method. After the analysis the functions of the mechanical properties and the number of teeth will be determined.
Performance Evaluation of Surface Modified Nano Al2o3 (P) Reinforced AZ91E Composites Under Impact and Fatigue Loading Conditions
Authors: Sameer Kumar D , Suman K N S , Poddar Palash , Tara Sasanka C 
Published: May 2020

Abstract
This paper confers to compare the behavior of AZ91E, AZ91E with 2 wt. % plain and surface modified alumina reinforced composites under different loading conditions. The composites were prepared and specimens were cut in accordance with standard procedures to conduct impact and fatigue tests. Surface modified alumina reinforced AZ91E magnesium based composites resulted in improved impact and fatigue strength because of good interactions between the matrix and reinforcement. The results are discussed.
A Novel Computational Method for Coupled Two Point Boundary Value Problem
Authors: Narender Ganji , Govardhan Kamatam 
Published: May 2020

Abstract
The paper deals with Finite difference Method of solving a boundary value problem involving a coupled pair of system of Ordinary Differential Equations. A novel iterative scheme is given for solving the Finite Difference Equations. Quasi-linearization used to convert a nonlinear problem into a series of linear problems. A problem from a flow of a nanofluid is presented as an example.
Effect of Machine Feed Rate on Kerf-Width, Material Removal Rate, and Surface Roughness in Machining of Al/SiC Composite Material with Wire Electrical Discharge Machine
Authors: Modi Manoj , Agarwal Gopal , Chaugaonkar Swati D , Bhatia Umesh , Patil Veerendra 
Published: May 2020

Abstract
The impact of machine feed rates of Wire Electric Discharge Machining on the kerf-width (K-width), material-removal-rate (MR-R), and surface-roughness (S-R) in the machining of Al/SiC composite is practically analysed. The relation among the feed rates of machine and K-width, MR-R, S-R is graphically acquired. It is demonstrated that lesser rate of feed is responsible for generation of larger K-width, lesser MR-R, and good finish as compared to more feed rate.
Environmental Assessment of Buildings – A Suggestion
Authors: Jamnický Martin , Rabenseifer Roman 
Published: May 2020

Abstract
This article proposes to contribute to the discussion on environmental product declarations for buildings. Using a simple life-cycle analysis of a low-energy detached house and CO2-equivalent emissions as a comparative unit, the case study presented illustrates the problems with the initial input data related to embodied energy and a definition of the criteria for an assessment of the environmental quality of buildings. The actual case study compares the expected energy demand of a detached house in the course of its service life and the energy input (embodied energy) necessary for its assembly and for the manufacture of the individual building products. The operation of the building during its service life is described using a computer-aided building performance simulation. The input data related to the embodied energy are based on information from classical works on life cycle analyses. In addition, the article discusses the limits of building envelope improvements in terms of the thickness of thermal insulation and also stresses the increasing significance of embodied energy in the environmental assessment of buildings.
Connections and Joints in Precast Concrete Structures
Authors: Holly Ivan , Abrahoim Iyad 
Published: May 2020

Abstract
The structural integrity of precast concrete structures mainly depends on the connections between the precast structural elements. The purpose of a connection is to transfer loads, restrain movement, and/or to provide stability to a component or an entire structure. Therefore, the design of connections is one of the most important aspects in the design of precast concrete structures. All the connections should be designed according to the valid codes. All precasters have developed connection details over the years that suit their particular production and erection preferences. It is common that the structural engineer shows the internal forces and connection locations, and the manufacturer’s engineering department provides the final design and details of the connections. This paper describes basic types of connections and joints used in precast concrete structures