bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multicenter Comparison of Seven 25Oh Vitamin D Automated Immunoassays / Multicentrično Poređenje Sedam Automatizovanih Imunoeseja Za 25Oh Vitamin D
Authors: Lippi Giuseppe , Salvagno Gian Luca , Fortunato Antonio , Dipalo Mariella , Aloe Rosalia , Rin Giorgio Da , Giavarina Davide 
Published: May 2014

SummaryBackground: The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multicenter study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique.Methods: One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vita - min D was measured with a reference HPLC system and with seven automated commercial immunoassays (Roche Cobas E601, Beckman Coulter Unicel DXI 800, Ortho Vitros ES, DiaSorin Liaison, Siemens Advia Centaur, Abbott Architect i System and IDS iSYS).Results: Compared to the reference method, the regression coefficients ranged from 0.923 to 0.961 (all p<0.001). The slope of Deming fit ranged from 0.95 to 1.06, whereas the intercept was comprised between -15.2 and 9.2 nmol/L. The bias from the reference HPLC technique varied from 14.5 to 8.7 nmol/L. The minimum performance goal for bias was slightly exceeded by only one immunoassay. The agreement between HPLC and the different immunoassays at 50 nmol/L 25OH Vitamin D varied between 0.61 and 0.85 (all p<0.001). The percentage of samples below this cut-off was significantly different with only one immunoassay.Conclusions:The excellent correlation with the reference HPLC technique attests that all seven automated immuno - assays may be reliably used for routine assessment of 25OH-D in clinical laboratories. The significant bias among the different methods seems mostly attributable to the lack of standardization and calls for additional efforts for improving harmonization of 25OH-D immunoassays.
The Relative Impacts of Design Effects and Multiple Imputation on Variance Estimates: A Case Study with the 2008 National Ambulatory Medical Care Survey
Authors: Lewis Taylor , Goldberg Elizabeth , Schenker Nathaniel , Beresovsky Vladislav , Schappert Susan , Decker Sandra , Sonnenfeld Nancy , Shimizu Iris 
Published: May 2014

Abstract
The National Ambulatory Medical Care Survey collects data on office-based physician care from a nationally representative, multistage sampling scheme where the ultimate unit of analysis is a patient-doctor encounter. Patient race, a commonly analyzed demographic, has been subject to a steadily increasing item nonresponse rate. In 1999, race was missing for 17 percent of cases; by 2008, that figure had risen to 33 percent. Over this entire period, single imputation has been the compensation method employed. Recent research at the National Center for Health Statistics evaluated multiply imputing race to better represent the missing-data uncertainty. Given item nonresponse rates of 30 percent or greater, we were surprised to find many estimates’ ratios of multiple-imputation to single-imputation estimated standard errors close to 1. A likely explanation is that the design effects attributable to the complex sample design largely outweigh any increase in variance attributable to missing-data uncertainty.
Surface and subsurface reworking by storms on a Cambrian carbonate platform: evidence from limestone breccias and conglomerates
Authors: Chen Jitao 
Published: May 2014

Abstract
Some limestone breccias and conglomerates from the Furongian (Late Cambrian) Chaomidian Formation (Shandong Province, China) were investigated in order to understand the depositional and deformational processes induced by storms. The sediments under study occur in a hummocky cross-stratified peloidal grainstone layer. The limestone conglomerates consist of well-rounded clasts that are mostly flat-lying or imbricated, and have erosional bases. They formed by surface reworking (erosion and rip-up) of thin-bedded grainstones by storm waves and currents. The limestone breccias consist of subangular to subrounded clasts of grainstone, which are often associated with small-scale grainstone clastic dykes. The breccias and dykes resulted from subsurface soft-sediment deformation (i.e., differential liquefaction and fluidization of heterogeneously cemented carbonate grains), most likely triggered by storm-wave loading. The limestone breccias and conglomerates bear important implications for understanding the reworking mechanisms of storms on ancient carbonate platforms
Metamodels for New Designs of Outer-Rotor Brushless Synchronous Electric Motors
Authors: Dirba J. , Lavrinovicha L. 
Published: May 2014

Abstract
The authors consider the possibilities to synthesise metamodels for the analysis and optimisation of brushless synchronous motors. The metamodels are presented for new designs of the outer-rotor permanent magnet synchronous motor and the outer-rotor reluctance motor. The metamodels are synthesised based on the results obtained by the numerical calculations of magnetic field taking into account magnetic saturation. Analysis of the results for the motor magnetic field and tests of the metamodels at the selected and intermediate points shows that these can be synthesised with acceptable accuracy using numerical calculations instead of expensive real experiments.
Power Generation Investment Planning in a Modern Power System With High Share of Renewables
Authors: Oleinikova I. , Ruksans O. , Turcik M. 
Published: May 2014

Abstract
This article is focused on investment planning in power generation industry, which becomes an important direction of research under the conditions of newly formed environment of electricity market. The authors emphasize the key role of effective instruments and methods for estimation of the costs and economic efficiency of a generating capacity and its adequacy in a modern power system. In the paper, cost-based concepts are analyzed which form a basis for decision-making and long-term planning of investments in the power generation sector for a power system with high share of renewable energy sources.
Wear Calculation for Sliding Friction Pairs
Authors: Springis G. , Rudzitis J. , Avisane A. , Leitans A. 
Published: May 2014

Abstract
One of the principal objectives of modern production process is the improvement of quality level; this means also guaranteeing the required service life of different products and increase in their wear resistance. To perform this task, prediction of service life of fitted components is of crucial value, since with the development of production technologies and measuring devices it is possible to determine with ever increasing precision the data to be used also in analytical calculations. Having studied the prediction theories of wear process that have been developed in the course of time and can be classified into definite groups one can state that each of them has shortcomings that might strongly impair the results thus making unnecessary theoretical calculations. The proposed model for wear calculation is based on the application of theories from several branches of science to the description of 3D surface micro-topography, assessing the material’s physical and mechanical characteristics, substantiating the regularities in creation of the material particles separated during the wear process and taking into consideration definite service conditions of fittings.
Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine
Authors: Nouh Mostafa A. , Arafa Nadim M. , Abdel-Rahman Ehab 
Published: May 2014

Abstract
A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack’s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack’s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, ςk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient Γ, is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine’s most powerful operating point.
Investigation of Design Features of Compressor Casing Treatment
Authors: Nezym Vitaliy 
Published: May 2014

Abstract
Casing treatment in the form of circumferential grooves over a rotor blade tips is used for improvement of an axial compressor performance. Usually, these grooves extend compressor’s stall range (stable operational range) but decrease its efficiency. In the paper, there are presented main results of investigations on grooves that influence positively efficiency of compressor. There were investigated traditional (typical) and newly developed groove configurations. Certain grooves combine increase in efficiency with extension in stall range.
Key Factors for Development of Export in Polish Food Sector
Authors: Łącka Irena , Stefko Olga 
Published: May 2014

Abstract
Background: The accession of Poland to the European Union in 2004 facilitated increased exports of food products. It revealed a significant competitive advantage of Polish foreign trade in agri-food products compared to the countries of the ≫old EU≪. After nearly 10 years of Polish membership in the EU, the food sector has still a considerable potential, fostering a further increase in exports.
Objectives: The purpose of the paper was an attempt to establish the current determinants for the possibility to increase the exports of the Polish food sector and to identify potential opportunities and potential threats in the future. It was also decided to give an answer to the question whether any of the group factors has a greater impact on the development of exports than the other, and which issues play only a minor role in the development of international exchange.
Method: The analysis used involved the review of the relevant literature and forming a group of experts to specify the key factors of success in the food sector export. Basing on the experts research the STEEPVL analysis was carried out.
Results: It turned out that apart from a number of organizational, financial and marketing factors the most important are: the level of the IT infrastructure and the fluctuation of the demand on the international markets for the goods offered by the sector.
Conclusion: Therefore, the focus on the new distribution channels, integrated company management IT systems and changes in the demand on the market is the key challenge for securing the current potential and for the further development of the sector.
Weibull Decision Support Systems in Maintenance
Authors: Aboura Khalid , Agbinya Johnson I. , Eskandarian Ali 
Published: May 2014

Abstract
Background: The Weibull distribution is one of the most important lifetime distributions in applied statistics. Weibull analysis is the leading method in the world for fitting and analyzing lifetime data. We discuss one of the earliest decision support system for the assessment of a distribution for the parameters of the Weibull reliability model using expert information. We then present a different approach to assess the parameters distribution.
Objectives: The studies mentioned in this paper aimed to construct a distribution of the parameters of the Weibull reliability model and apply it in the domain of Maintenance Optimization.
Method: The parameters of the Weibull reliability model are considered random variables and a distribution for the parameters is assessed using informed judgment in the form of reliability estimates from vendor information, engineering knowledge or experience in the field.
Results: The results are the development of modern maintenance optimization models that can be embodied in decision support systems.
Conclusion: While the information management part is important in the building of maintenance optimization decision systems, the accuracy of the mathematical and statistical algorithms determines the level of success of the maintenance solution.
Mesenteric ischemia after capecitabine treatment in rectal cancer and resultant short bowel syndrome is not an absolute contraindication for radical oncological treatment
Authors: Perpar Ana , Brecelj Erik , Kozjek Nada Rotovnik , Anderluh Franc , Oblak Irena , Vidmar Marija Skoblar , Velenik Vaneja 
Published: May 2014

Abstract
Background. Thrombotic events, arterial or venous in origin, still remain a source of substantial morbidity and mortality in cancer patients. The propensity for their development in oncology patients is partially a consequence of the disease itself and partially a result of our attempts to treat it. One of the rarest and deadliest thromboembolic complications is arterial mesenteric ischemia. The high mortality rate is caused by its rarity and by its non-specific clinical presentation, both of which make early diagnosis and treatment difficult. Hence, most diagnoses and treatments occur late in the course of the disease. The issue survivors of arterial mesenteric ischemia may face is short bowel syndrome, which has become a chronic condition after the introduction of parenteral nutrition at home.
Case report. We present a 73-year-old rectal cancer patient who developed acute arterial mesenteric thrombosis at the beginning of the pre-operative radiochemotherapy. Almost the entire length of his small intestine, except for the proximal 50 cm of it, and the ascending colon had to be resected. After multi-organ failure his condition improved, and he was able to successfully complete radical treatment (preoperative radiotherapy and surgery) for the rectal carcinoma, despite developing short bowel syndrome (SBS) and being dependent upon home-based parenteral nutrition to fully cover his nutritional needs.
Conclusions. Mesenteric ischemia and resultant short bowel syndrome are not absolute contraindications for radical oncological treatment since such patients can still achieve long-term remission.
Aspects of Fibre Composite Machining
Authors: Zębala Wojciech , Matras Andrzej 
Published: May 2014

Abstract
Paper presents some aspects of fibre composite milling. Composites are particularly applied in the sectors such as aircraft, aerospace and automotive industries for they are light and relatively easy can be forming in the desired shapes. The purpose of research was optimization of free form milling considering the machined surface quality (mainly roughness). After proper cutting parameters selection (feed and cutting speed) the example parts with free form surface were machined.
Tool Life Reliability of Indexable Cutting Inserts
Authors: Janásek Adam , Čep Robert , Čepová Lenka , Kratochvíl Jiří , Vrba Vladimír , Petřkovská Lenka 
Published: May 2014

Abstract
This paper presents experimental testing of the cutting ability for indexable cutting inserts. The main goal will be to select a suitable test for determine the cutting abilities of cutting inserts. Nowadays all manufacturers want to achieve lower cutting forces so can permit higher speeds and feeds, without increasing the risk of chipping. For evaluating we had to design such testing procedure that it would be possible to compare and evaluate the cutting ability of the selected cutting inserts used for tests. In today’s competitive global market, quality and precision is the most important parameter. Tight tolerances and urgent deadlines are normal. In the machine tool business, companies must keep their cutting edge, or your company will lose its competitive edge.
Finishing Operation Turning of Flangesfor and Its Intensification
Authors: Stančeková Dana , Ščotka Peter , Hurka J. 
Published: May 2014

Abstract
The paper is focused on intensifying of turning of flange with a finishing operation. It provides a range of cutting plates suitable for turning, their experimental verification and evaluation. In the experimental measurements were made durability test selected cutting plates, compared to the parameters, wear, chips, measure and record made of machined surface roughness of the material.
Deformation Structures and Tool Wear during High-Speed Machining
Authors: Vasilko Karol 
Published: May 2014

Abstract
Tendencies towards increasing cutting speeds during machining can be observed recently. The first wave of increasing cutting speeds occured in the 60s of the previous century. However, suitable tool material was not available at that time. Increasing cutting speed is possible only following the development of cutting material, resistant against high temperatures, abrasive, adhesive and diffusive wear. It is obvious that the process of chip creation, quality of machined surface, dynamics of machining process and temperature of cutting change considerably with cutting speed. To be able to apply higher cutting speeds in production machining, it is necessary to know the dependence of those characteristics on cutting speed. Some of those phenomena, which are linked with cutting speed, will be explained in the paper. Key words: machining, cutting speed, tool durability, surface quality
Calculation of Bonded Joint of Window Panels Railway Vehicles
Authors: Pavlica Marek , Kratochvíl Jiří , Petrů Jana 
Published: May 2014

Abstract
The article is focused on the calculation of bonded joint of window panels railway vehicles. It is bonding with a 1K- polyurethane between glass and aluminum vehicle frame. In assessing the deformation is necessary first of all to assess changes of length due to thermal expansion. In addition, the calculation focuses on the glass plate deflection when passing trains and at last calculates the allowable voltage that is compared with the allowable stress. Calculation of bonded joints is very important for critical bonded joints, which may endanger the lives of people.
Optimization of High-Precision Reaming Holes with Small Diameters
Authors: Fiala Stanislav , Kouřil Karel , Pagáč Marek 
Published: May 2014

Abstract
In many applications, it is at the final machining precision holes, very advantageous to use a reamer whose cutting portion is made of a cermet, but also other performance materials (PCD, CBN). In these modern tools can be compared with the instruments of conventional cemented carbides apply significantly higher cutting speeds at longer blade life cutting edges. Specific problems and significant demands on the tech-nical design and implementation of these instruments arise from their use for reaming holes with small diameters. Especially in cases where it is required to have high productivity, a high cutting speed and feed. Especially for small diameter tools it is extre-mely difficult to supply the necessary amount of process fluid to the cutting point in real time. A sufficient quantity of liquid will not only provide cooling but also chip. The requirement is to achieve high operational reliability as well as reduced costs using intensive cutting conditions. This situation helps to solve the present structural design of composite reaming tools. Specifically, the optimization of the reamer for reaming holes ø 4,2 H8 with a depth of 8 mm in body components for the automotive industry .
Study of Force Relations when HPM Milling
Authors: Rakoci Jozef , Bobrovský Róbert , Czán Andrej , Stančeková Dana , Košút Mário , Ščotka Peter 
Published: May 2014

Abstract
Paper deals with forces´ ratios which are originated in milling process and applications where high-feed milling cutters are used for machining of steel by HPM technology. Particular elements of total cutting force F were written in the form of records by using three-element piezoelectric scanner of Kistler dynamometer. Comparison of static and dynamic loads during milling and application of tool movement orientation is considered as a result of experiments.
The Possibility of Using Numerical Modeling for Assessment of Welded Joint Load-Bearing Capacity / Možnost Využití Numerického Modelování Pro Posouzení Únosnosti Svařovaného Styčníku
Authors: Jurčíková Anežka , Rosmanit Miroslav 
Published: May 2014

Abstract
The subject of this paper the practical example of the steel lattice structure was used. Specifically, the joint consisting of H-profile bottom chord and a RHS (Rectangular Hollow Section) brace members has been elected. This particular joint has an exceptional feature which is a deviation from the geometric conditions required by Eurocode. The aim is to create a numerical model that will adequately reflect the actual behavior of this type of joint as well as comparison of such behavior with that expected on the basis of assessment according to standardized formulas.
Origin of Dangerous Conflict Situations on Intersection with Inappropriately Designed Building Elements / Vznik Nebezpečných Situací Na Křižovatce S Nevhodně Navrženými Stavebními Prvky
Authors: Křivda Vladislav , Mahdalová Ivana 
Published: May 2014

Abstract
The traffic safety on intersections is influenced by a lot of external factors - for example by inappropriately designed building elements. Inadequate radius of corners, narrow traffic lanes etc. can cause dangerous situations - above all, during passage by large vehicles. The paper describes conflict situations on intersection which are caused by inappropriately designed building elements above mentioned. The paper points out possibility of use of video analysis of conflict situations for monitoring of these phenomena and also necessity of correct verification of passage through intersection by rupture curves.
Acoustic Qualities of a Ceiling From Prefabricated Timber – Concrete Composite Panels / Akustické Vlastnosti Stropu Z Prefabrikovaných Dřevo – Betonových Spřažených Panelů
Authors: Oravec Pavel , Hamala Michal 
Published: May 2014

Abstract
This article describes the acoustic qualities (sound insulation and a level of acoustic pressure of impact sound) composite construction, composite timber - concrete ceiling. The qualities of the ceiling construction were discovered in the experimental measurements in the acoustic testing laboratory certified by CSI Zlin on a sample of a 3 x 3,6 m size. One type of a floor composition was created. Three phases of measurement have been performed on the tested floor. The aim of the experiment was to determine whether the devised ceiling can be used as a separating element between apartments.
Seismic Response Hydraulic Hammer on the Secundary Lining Tunnel / Seizmická Odezva Hydraulického Bouracího Kladiva Na Definitivní Ostění Tunelu
Authors: Pinka Miroslav , Stolárik Martin 
Published: May 2014

Abstract
Construction and subsequent tunnels collapse of the Jablunkovsk’s pass are already among well known of the professional public. After the collapse left part of the tunnel already standing with secondary lining. The second part was temporarilied concrete secured stopper and heavy bridge formwork. During the progress of work was already reached that stage when plug must be removed. The stopper was removed by combination of blasting operations and hydraulic hammer. This article deals with seismic effect hydraulic hammer. It is therefore a unique measuring effect of vibration on the final tunnel lining. A vibration downturn was monitored in the first meters of the lining and the records were evaluated in the amplitude and frequency resort. This assessment was made on the basis CSN 73 0040.