Filters
total: 2251
filtered: 1834
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: LOCKING
-
Towards Safety Case Integration with Hazard Analysis for Medical Devices
PublicationSafety case is one of system safety lifecycle products and should be consistent with other lifecycle products like hazard analysis results. In this paper we present a method of safety case integration with hazard tables based on the use of parametrized argument patterns. We describe a hazard table metamodel, a safety argument pattern and a mechanism of pattern instantiation using a linking table which represents references to system...
-
The Influence of Limiters UEL and OEL (The power angle, stator's current and excitation current) ot the possibility of voltage collapse development
PublicationVoltage stability has been a major concern for power system utilities because of event of voltage collapses in the recent past. Sometimes, power system events have shown the need for generators to operate in the overexcited and underexcited region to support stable operation. Modern excitation systems include devices for controlling or limiting machine terminal voltage (overvoltage limiters), volts per hertz ratio (V/Hz limiters),...
-
Theoretical Organic Rankine Cycle efficiency depending on different thermodynamic work variables.
PublicationOne of promising technologies of utilizing low- temperature waste heat is through ORC (Organic Rankine Cycle) system implementation. A primary objective in designing in-stallations based on such systems is to maximize the installation's work efficiency. On the other hand, ecological factors are commonly considered a natural barrier in introducing new, often very expensive technologies. Ecological effect of a potential modernization...
-
Analysing selection of low-temperature medium for cogeneration micro power plant
PublicationThe article analyses the ORC system working with dry and wet low-boiling media which are most frequently used in installations of this type. Two types of cycles were examined, which were the cycle with heat regeneration for dry media: fc72, hfe7100, R227ea, R245fa, R423a and R600a, and the cycle without heat regeneration for wet media: R11, R12, R134a, R718 and 507a. The calculations were performed for the assumed required thermal...
-
Diagnostics of commutation unit in satellite pumps and motors
PublicationThe article describes a part of the research on the development of satellite pumps and motors, conducted on Gdansk University of Technology as a part of grant "New elaborate of hydraulic satellite machines for drives with vegetable liquids and non-flammable liquids" (LIDER/35/102/L-2/10/NCBiR/2011) funded by the National Centre for Research and Development in Poland. The presented area includes the diagnostics of commutation units...
-
Analysing selection of low-temperature medium for cogeneration micro power plant
PublicationThe article analyses the ORC system working with dry and wet low-boiling media which are most frequently used in installations of this type. Two types of cycles were examined, which were the cycle with heat regeneration for dry media: fc72, hfe7100, R227ea, R245fa, R423a and R600a, and the cycle without heat regeneration for wet media: R11, R12, R134a, R718 and 507a. The calculations were performed for the assumed required thermal...
-
Two tests for adhesive bonding long term characterization: principles and applications
PublicationThis article describes recent refinement of the traditional wedge test technique used to characterize durability of the adhesive joints. We propose two types of measuring protocols to monitor precisely and continuously the propagation of an "effective" crack during long term mode I fracture mechanic test. First method is directly derived from the traditional wedge test technique and consist in monitoring the surface strain of adherent...
-
Molecular dynamics and verisimilitude - to what extent can one trust a computational simulation?
PublicationFor the last several tens of years, computer simulations have become of undeniable importance. Molecular Dynamics (MD) simulation techniques are used to examine the phenomena which occur at the level that cannot be observed directly. Thus, they can be successfully exploited in many different scientific fields such as: materials science, applied mathematics and theoretical physics, biochemistry, biophysics or drug design. Despite...
-
Thermoplastic polyurethane/(organically modified montmorillonite) nanocomposites produced by in situ polymerization
PublicationA series of polyurethane nanocomposites were synthesized from thermoplastic polyurethanes (with different hard segment ratios) and two types of organically modified montmorillonites (OMMT) - Cloisite® 10A and Cloisite® 20A. The thermal behavior was examined by non-isothermal thermogravimetry (TG, DTG), Differential Scanning Calorimetry (DSC) and Dynamic-Mechanical Thermal Analysis (DMTA). The results of X-ray analyses showed that...
-
Influence of the addition of citric acid on the physico-chemical properties of poly(sorbitol sebacate-co- butylene sebacate)
PublicationThe article presents the results of the physicochemical properties of poly(sorbitol sebacate- co-butylene sebacate) (PSBS) obtained with 0.25; 0.5; 0.75; 1 mol of citric acid (KC). It was shown that PSBS obtained with 0.25 and 0.5 mol KC is characterized by the most optimal mechanical and thermal properties. As a result of the study, it was found that the use of sorbitol and citric acid allows obtaining ester materials with...
-
Increase of power and efficiency of the 900 MW supercritical power plant through incorporation of the ORC
PublicationThe objective of the paper is to analyse thermodynamical and operational parameters of the supercritical power plant with reference conditions as well as following the introduction of the hybrid system incorporating ORC. In ORC the upper heat source is a stream of hot water from the system of heat recovery having temperature of 90 °C, which is additionally aided by heat from the bleeds of the steam turbine. Thermodynamical analysis...
-
Experimental study of the multi-disc negative brake for a hydraulic motor
PublicationThis paper describes the methodology for experimental testing of a multi-disc brake. The construction of this brake was also present. The brake is dedicated to hydraulic motors with a small working volume. Experimental tests were carried out on a brake with plates immersed in oil and, for comparison, tests were carried out on a dry brake. As a result of the tests, the permissible torque (load) that is able to transfer the brake...
-
Fracture prediction in flat PMMA notched specimens under tension - effectiveness of the equivalent material concept and fictitious material concept
PublicationThe fracture of notched elements under mode I loading (tension) remains an inexhaustible research topic, especially when it comes to the fracture of thermoplastic materials such as polymethylmethacrylate (PMMA), which experience considerable plastic strains under tension. The paper points out that traditional brittle fracture criteria such as mean stress (MS) or maximum tangential stress (MTS) criteria used to predict this phenomenon do...
-
An Innovative Floating System with a Savonius Rotor as a Horizontal-Axis Wind Turbine
PublicationIn this project, an innovative wind turbine was designed for a floating plant. A large Savonius rotor was replaced with a double-rotor wind turbine implemented as a horizontal-axis turbine. This double rotor was positioned on the tip of a thrust plate and fixed to the deck of a catamaran. Simple 2D numerical simulations were performed to confirm the effectiveness of the concept. An analysis of the floating system configuration...
-
Wpływ właściwości czynników chłodniczych na straty egzergii w pompie ciepła (Influence of Refrigerants Properties for Exergy Losses in Heat Pump)
PublicationArtykuł poświęcony jest wpływowi występujących w pompie ciepła strat egzergii na jej efektywność energetyczną, a co za tym idzie koszty funkcjonowania instalacji. Autorzy prezentują tu metodologię obliczeniową, która może być zastosowana w procesach projektowania układów cieplno-przepływowych. Obliczenia zostały wykonane na podstawie typowego układu powietrznej pompy ciepła pracującej w klimacie środkowo-europejskim. Ponadto w...
-
System sejsmiki refleksyjnej do poszukiwania morskich złóż węglowodorowych
PublicationW poszukiwaniu morskich złóż węglowodorowych wykorzystywane są różne metody zaliczane do tzw. sejsmiki refleksyjnej. Jedną z nich jest wykorzystanie systemu sejsmiki refleksyjnej holowanego za statkiem specjalistycznym przeznaczonym do badań sejsmicznych. Jest to złożony ruchomy układ techniczny składający się z wielu elementów składowych, takich jak: system wzbudzania fal akustycznych, system rejestracji odbijanych fal akustycznych...
-
Technological vs. Non-Technological Mindsets: Learning From Mistakes, and Organizational Change Adaptability to Remote Work
PublicationThe permanent implementation of the change in working methods, e.g., working in the virtual space, is problematic for some employees and, as a result, for management leaders. To explore this issue deeper, this study assumes that mindset type: technological vs. non-technological, may influence the organizational adaptability to change. Moreover, the key interest of this research is how non-technological mindsets...
-
Mission impossible for cellular internalization: When porphyrin alliance with UiO-66-NH2 MOF gives the cell lines a ride
PublicationIs it possible to accelerate cell internalization by hybridization of nanomaterials? Herein we support the realization of using metal-organic frameworks (MOFs) with the assistance of rigid porphyrin structure (H2TMP) aimed at drug loading, drug release, relative cell viability, and targeted in vitro drug delivery. There are several MOFs, i.e., UiO-66-NH2 (125 ± 12.5 nm), UiO-66-NH2 @H2TMP (160 ± 14 nm), UiO-66-NH2 @H2TMP@DOX, and...
-
Functional fluorine-doped tin oxide coating for opto-electrochemical label-free biosensors
PublicationSensors operating in multiple domains, such as optical and electrochemical, offer properties making biosensing more effective than those working in a single domain. To combine such domains in one sensing device, materials offering a certain set of properties are required. Fluorine-doped tin oxide (FTO) thin film is discussed in this work as functional optically for guiding lossy modes and simultaneously electrochemically, i.e....
-
INVESTIGATIONS OF THE EMISSION CHARACTERISTICS OF A DUAL-FUEL GAS TURBINE COMBUSTION CHAMBER OPERATING SIMULTANEOUSLY ON LIQUID AND GASEOUS FUELS
PublicationT his study is dedicated to investigations of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. As the object of the research, a low-emission gas turbine combustion chamber with partial premixing of fuel and air inside the outer and inner radial-axial swirls was chosen. The method of the research is based on the numerical solution of the system of differential...
-
Tuning of microstructure in engineered poly (trimethylene terephthalate) based blends with nano inclusion as multifunctional additive
PublicationImmiscible blends and their composites are heterogeneous and have variable morphology due to variation in mesophase regions. Tuning, i.e. controlling the phase dimension is important, thereof we report a “super-combo” effect of multiwalled carbon nanotubes (MWCNTs) in poly (trimethylene terephthalate)/polypropylene (PTT/ PP) blend system. MWCNTs act as a good reinforcing agent and compatibilizer in the otherwise immiscible PTT/...
-
Modified Peptide Molecules As Potential Modulators of Shelterin Protein Functions; TRF1
PublicationIn this work, we present studies on relatively new and still not well-explored potential anticancer targets which are shelterin proteins, in particular the TRF1 protein can be blocked by in silico designed "peptidomimetic" molecules. TRF1 interacts directly with the TIN2 protein, and this protein-protein interaction is crucial for the proper functioning of telomere, which could be blocked by our novel modified peptide molecules....
-
Scholarly communication activities in the fields of chemistry and economics. A Polish perspective
PublicationThis study examines the scholarly communication activities in two scientific fields, chemistry and economics, in a Polish context. The dissertation aims at investigating what characterises the publishing choices of researchers and what supplementary forms for the dissemination of research output are used by scholars. In addition, the paper is looking into what are the views and awareness of open access and institutional repositories...
-
Building Information Modeling in Small and Middle Sized Buildings – Case Study
PublicationBuilding Information Modeling (BIM) is a technology designed to improve and integrate all engineering aspects in the construction design process. Tools that incorporate the idea of BIM are becoming more advanced and also more popular. Available software solutions have already reached an assumable high level of development, but still are not as widespread and used on nearly as many construction projects as could be expected. Therefore...
-
Molecular targets for antifungals in amino acid and protein biosynthetic pathways
PublicationFungi cause death of over 1.5 million people every year, while cutaneous mycoses are among the most common infections in the world. Mycoses vary greatly in severity, there are long-term skin (ringworm), nail or hair infections (tinea capitis), recurrent like vaginal candidiasis or severe, life-threatening systemic, multiorgan infections. In the last few years, increasing importance is attached to the health and economic problems...
-
In silico assessment and sonochemical synthesis of 2-alkynyl 3-chloropyrazines as prospective ligands for SARS-CoV-2
PublicationThe recent global pandemic caused by COVID-19 has triggered an intense effort worldwide towards the development of an effective cure for this disease. In our effort we have explored the 2-alkynyl substituted 3-chloropyrazine framework as a potential template for the design of molecules for this purpose. Our strategy was supported by the in silico studies of representative compounds to assess their binding affinities via docking...
-
Analysis of the impact of AOP on source code quality: Paradox of aspect-oriented separation of concerns
PublicationAlmost four decades ago, Parnas advocated modularity for the sake of changeability, independent development, and comprehensibility. The recipe for modularization is to define a clean interface, hide an implementation detail, keep low coupling and high cohesion. Although modules have taken many forms over the years from functions and procedures to classes, no form has been capable of expressing so-called crosscutting concerns in...
-
Neutralising Responsibility: A Critical Analysis of an Airline’s Climate Disclosures
PublicationSustainability reporting provides companies with a medium through which they can communicate their non-financial impacts to stakeholders. The airline industry has been much at the centre of the climate change debate in recent years, which is why it is hardly surprising that airlines seek to take a proactive stance in such reporting. This study critically assesses how an airline based in the Scandinavian region constructs sustainability...
-
Observation of the Hydrogen Migration in the Cation-Induced Fragmentation of the Pyridine Molecules
PublicationThe ability to selectively control chemical reactions related to biology, combustion, and catalysis has recently attracted much attention. In particular, the hydrogen atom relocation may be used to manipulate bond-breaking and new bond-forming processes and may hold promise for far-reaching applications. Thus, the hydrogen atom migration preceding fragmentation of the gas-phase pyridine molecules by the H+, H2+, He+, He2+, and...
-
Interaction of human serum albumin with volatiles and polyphenols from some berries
PublicationHeadspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (HS-SPME/GC GCeTOFMS) identified 19 and quantified 6 monoterpenes in gooseberries, blueberries and cranberries. As a protein model human serum albumin (HSA) was used in interaction with terpenes. Specific binding of terpenes to HSA under the physiological conditions was a result of the formation...
-
Integration of protein tethering in a rapid and label-free SERS screening platform for drugs of abuse
PublicationSurface enhanced Raman spectroscopy (SERS) has emerged as a promising technique for the rapid and ultrasensitive detection of molecular species such as drugs of abuse in biofluids. Yet, it remains a significant challenge to create a viable screening tool for multiple drug classes, owing to the lack of affinity of certain species for the SERS substrate and to the matrix interference in complex media. Here we report a protein tethering...
-
Hat problem on a graph
PublicationThe topic of our paper is the hat problem. In that problem, each of n people is randomly fitted with a blue or red hat. Then everybody can try to guess simultaneously his own hat color looking at the hat colors of the other people. The team wins if at least one person guesses his hat color correctly and no one guesses his hat color wrong, otherwise the team loses. The aim is to maximize the probability of win. In this version every...
-
Open Strategy for Digital Business. Managing in ICT-Driven Environments
PublicationThis book offers the reader a novel perspective on how digital contexts and open strategy approaches – the act of opening up strategic initiatives beyond company managers to involve front-line employees, stakeholders, and entrepreneurs – are related. Going beyond the claim that digital media drives open strategy by containing a detailed analyses of the interrelations between the two, the authors examine how ICT have diffused globally...
-
Three-Dimensional Fractography for Conventional and Additive Manufactured Steels After Bending-Torsion Fatigue
PublicationIn this study, fracture surface topography parameters were measured to investigate the effects of multiaxial loading. In order to assess the metrological aspects of fracture for notched specimens made of high-strength steels processed by both conventional and additively manufacturing (AM) techniques, an optical surface profilometer was used. Three bending moment to torsion moment ratios (B/T) were studied, i.e. 2, 1 and 2/3. The...
-
Fixed Pattern Noise Reduction and Linearity Improvement in Time-Mode CMOS Image Sensors
PublicationIn the paper, a digital clock stopping technique for gain and offset correction in time-mode analog-to-digital converters (ADCs) has been proposed. The technique is dedicated to imagers with massively parallel image acquisition working in the time mode where compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. Fixed pattern noise (FPN) reduction has been experimentally validated...
-
Evaluating Business Accelerator Participants’ Experiences – Effectuation at Play?
PublicationResponding to the new phenomena in entrepreneurship ecosystems in Poland, the author undertakes the study that aims to explore experiences of participants of (pre)accelerator programme for start-ups. Clipster is a business an acceleration incubation programme, where participants have a unique co-living opportunity and work on their new venture ideas. With phenomenological interviews with six nascent entrepreneurs - participants...
-
The effect of an active force while slide diamond burnishing of wooden shafts upon process quality
PublicationThe quality of the surface of wooden elements that have been turned and burnished has got a crucial meaning in the whole production process flow, since the obtained effects affect the quality of the wooden surface after finishing (coating, painting). In the paper, selected results of the investigation of the effect of the burnishing process on the surface quality of the elements after turning are presented. Research experiments...
-
Investigation of the temperature modulation parameters on semiconductor gas sensor response
PublicationIn this work we present the results of the investigation of the sensing properties of semiconductor gas sensors with a sinusoidally modulated temperature in the presence of synthetic air (SA) and three volatile air pollutants, i.e. NH3, NO2 and SO2. The measurements were performed for different average sensor heater temperatures and the amplitude of the modulation signal. In addition, the extraction of features from the sensor...
-
Comparison of the powers of energy losses in a variable capacity displacement pump determined without or with taking into account the power of hydraulic oil compression
PublicationPowers of energy losses in a variable capacity displacement pump are compared with or without taking into account the power of hydraulic oil compression. Evaluation of power of liquid compression in the pump was made possible by the use of method, proposed by the Author, of determining the degree of liquid aeration in the pump. In the method of determining the liquid aeration in the pump and of powers of volumetric losses of liquid...
-
Performance of the flat plate solar collector operated with water-Al2O3 nanofluid
PublicationThe paper discusses the effect of application of water-Al2O3 nanofluid, as a working fluid, on the efficiency of a flat plate solar collector. The mass concentration of nanoparticles was 0.1%, 0.2% and 0.4%. The tests were conducted for two values of radiation of about 1050 W/m2 and 400 W/m2, and volume flow rates of 60 l/h, 120 l/h and 170 l/h. The efficiency was calculated according to recommendations of the Polish Standard....
-
Modeling SPMD Application Execution Time
PublicationParallel applications in a Single Process Multiple Data paradigm assume splitting huge amounts of data to multiple processors working in parallel at small data packets. As the individual data packets are not independent, the processors must interact with each other to exchange results of the calculations with their adjacent partners and take these results into account in their own computations. An example of SPMD is geometric parallelism...
-
Intercultural Challenges in Virtual Teams
Publication: Virtual teams are usually geographically dispersed and consist of members from different countries and cultures. They influences internal communication processes and can cause personal conflicts, misunderstandings or lack of trust. Intercultural diversity is also significant for goal setting and team effectiveness. The aim of this article is to check if virtual team members appreciate the cultural diversity or rather suffer from lack...
-
THE USE OF FEM FOR DETERMINATION OF RESONANT FREQUENCIES OF CIRCULAR SAW BLADES WITH INDIRECT TEETH IN GULLETS
PublicationUnderstanding the dynamical properties of the circular saw blade is necessary, since, there is a really need for a stable work at working rotational speeds, which are determined by frequencies at which the circular saw blade tends to vibrate. It was observed that the resonant frequency depend on the circular saw blade shape, a collar diameter and on saw’s teeth shape. In the presented work an attention was paid to the effect of...
-
ATTEMPT AT EVALUATING THE INFLUENCE OF BENDING STRESS ON SHAFT WEAR PROCESSES IN WATER LUBRICATED SLIDING BEARING WITH A RUBBER BUSHING
PublicationWater lubricated bearings find increasingly wide application in shipbuilding or hydro–power industry, the popularity stemming from their numerous advantages. Unfortunately, as it turns out, water lubricated bearings do not always meet expectations, as on occasion they become subject to intense, premature wear which requires costly repair. One of the still unexplained phenomena is the process of excessive bearing wear, in particular...
-
Evaluating Business Accelerator Participants’ Experiences – Effectuation at Play?
PublicationResponding to the new phenomena in entrepreneurship ecosystems in Poland, the author undertakes the study that aims to explore experiences of participants of (pre)accelerator programme for start-ups. Clipster is a business an acceleration and incubation programme, where participants have a unique co-living opportunity and work on their new venture ideas. With phenomenological interviews with six nascent entrepreneurs - participants...
-
RÓWNOWAŻNOŚĆ METOD POMIAROWYCH CIĄGŁYCH I ODNIESIENIA STOSOWANYCH DO OZNACZANIA PM2,5
PublicationW pracy przedstawiono wyniki testu terenowego przeprowadzonego na terenie województwa pomorskiego w okresie od 01-01-2013 do 31-12-2013 w celu wykazania równoważności wyników stężeń pyłu zawieszonego PM2,5 uzyskanych za pomocą analizatora automatycznego BAM 1020 w stosunku do wyników uzyskanych za pomocą wagowej metody odniesienia. Przedstawiono sposób określania równoważności wyników uzyskanych za pomocą analizatora i szacowania...
-
Comparative study of selected fluids for use in supercritical Organic Ranking Cycles
PublicationIn view of increasing interest in improving energy efficiency of energy conversion devices, there is an increasing requirement of combined production of heat and electricity as well as demand for increased implementation of renewable energy resources. The micro cogenerative units utilizing the Organic Rankine Cycle are focusing the attention of many research centres around the world. In the present paper calculations of ORC cycles...
-
Analiza i ocena smarności olejów w ujęciu energetycznym i działania układu tribologicznego = Analysis and evaluation of oil lubricity from the viewpoint of energy apects and of the tribological system action
PublicationBased on measurement results, an interpretation is presented of the tribological system boundary layer action in the form of a four-ball tester friction node. The evaluation was performed of the boundary layer action understood as transfer of energy Ep resulting from loading the tribological system in a determined time t with work Lp, which may lead to breaking the boundary layer. That energy and time are the values unequivocally...
-
Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublicationThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
-
A XAS study of a highly diluted Pt electrocatalyst operating in PEM fuel cells
PublicationWe present an X-ray absorption spectroscopy (XAS) study of a low Pt content catalyst layer(Pt loading 0.1 mg c2) operating at the cathode of a proton exchange membrane fuel cell(PEMFC). This catalyst is based on the use of a mesoporous inorganic matrix as a support forthe catalyst Pt nanoparticles. Due to the high Pt dilution, in situ measurements of itsstructural properties by XAS are challenging and suitable experimental strategies...