Search

One of the possible ways to transfer the tractive power of a drive unit to the traction element is to use fibre friction. When a steel rope is used as the traction element, there is a transfer of tractive power in the groove created on the perimeter of the rim of the driving rope sheave. The transmission capability of the drive is directly proportional to the size of the angle of wrap and the shear friction coefficient of the rope surface when the rope is in contact with the surface of the groove wall. The relationship for calculating the size of friction coefficient in the grooves is given by relevant technical standards. The coefficient of friction determined in this way does not take into account the state of possible operational contamination of the groove or the diameter of the rope used. Using a unique laboratory instrument, tensile forces were measured for both rope sides in the state of a non-rotating sheave or when the sheave started to rotate rope. Experimental measurements were carried out for two different diameters of steel ropes, which were guided by two types of grooves for the rope sheave under two limit operating states of the groove wall surface: clean and dirty with oil. By evaluating the measured tensile forces in the approaching and outrunning rope side girded with the groove of the rope sheave, it was found (using a measuring apparatus) that a rope of a larger diameter acquires a higher value of the friction coefficient for the groove than a rope of a smaller diameter. The coefficient of friction in the groove decreases with the increasing size of the sum of the acting tensile forces on both sides of the rope. Lower values of the coefficient of friction achieve semi-circular grooves, and V-shaped grooves show higher values. Lower values for the coefficient of friction, close to theoretical values which were calculated using the relevant relationships specified in the standards, were found for grooves contaminated with oil as opposed to dry and clean grooves.

Now all world tendencies of energy are sent on the use and combining of renewable energy sources. Combination of a few renewable energy sources bringing in of not renewable sources results in partial independence. In this work was the tested laboratory device for heating and cooling of liquid. During an experiment rules were used Carnot, hydrodynamics, dynamic compression of gases and many other principles. The offered combination of a few systems of replaceable energy, marked in graphic arts, represented the amount of sources, necessary for work of experimental settlement. There were the taken off indexes in the different terms of work of experimental settlement, for this purpose it was equipped plenty of pickoffs.A this job performance is development and testing of pilot laboratory plant. Constructed the laboratory setting behaves to difficult, but possibility experimentally to probe its work and get static descriptions appeared. There was the accepted decision to find out functional connection of initial sizes from changes an entrance. A major index is a temperature in a hot capacity. After treatment of the collected indexes the experimental line of regression was built and the mean values of indexes, which was needed for finding of coefficient of correlation, are found. The probed time, temperature, pressure, on the different intervals of settlement is managed on-line from a mobile device.For a construction and estimation of adequacy of mathematical exemplary collection of indexes from touch-controls depending on the temperature indexes of condition of exploitation, which requires more detailed supervisions, for this research it may need anymore the river, depending on time of annual and desired temperature in an apartment. Taken off indexes, allowed to get the approximated information for the construction of diagrams of dependences of festering of pressure from temperatures. By an experimental result graphic dependences of pressure became built on temperatures on three basic areas of settlement. Findings are given by possibilities to build a mathematical model for successive modernization of settlement.

Paper presents diagnostic analysis of automotive ignition system for various working and adverse conditions in laboratory. Description and importance of basic diagnostics of automotive ignition system are examined in the first part of the paper. In the second the focus is placed on the basic principles and solution of the spark plug model. The test laboratory device is proposed in the following and the specialized measurements were executed by the proposed measurement system. The faults were simulated by application of oil and gasoline between the electrodes and failing by the driver to make the ignition contact on the spark plug.

Challenges for prediction of tension loads and deformations in geosynthetic mechanically stabilised earth (MSE) walls are proper characterisation of the in-soil material properties and stress trans...

The use of additive technologies allows increasing the availability of scientific equipment in educational centres. The research is dedicated to designing, assembling and testing a laboratory device for measuring the mechanical moduli of granular media. The mechanics of a granular media depend on both the mechanical parameters of individual granules such as particle size, elastic moduli, friction and macro-parameters of the granular media, such as internal structure or humidity. The laboratory device was designed in CAD software package and printed on the 3D printer DF-Print 3.5 using ABS plastic. Comparing to the other similar devices, the advantage of the one we are developing consists in the quick and cheap replicating of its parts on any available 3D printer. The device was tested for different materials, the available range of measuring data and applied loads were determined.

Introduction Highly sensitive reagents for detecting SARS-CoV-2 antigens have been developed for accurate and rapid diagnosis till date. In this study, we aim to clarify the frequency of false-positive reactions and reveal their details in SARS-CoV-2 quantitative antigen test using an automated laboratory device. Methods Nasopharyngeal swab samples (n = 4992) and saliva samples (n = 5430) were collected. We measured their SARS-CoV-2 antigen using Lumipulse® Presto SARS-CoV-2 Ag and performed a nucleic acid amplification test (NAAT) using the Ampdirect™ 2019 Novel Coronavirus Detection Kit as needed. The results obtained from each detection test were compared accordingly. Results There were 304 nasopharyngeal samples and 114 saliva samples were positive in the Lumipulse® Presto SARS-CoV-2 Ag test. All positive nasopharyngeal samples in the antigen test were also positive for NAAT. In contrast, only three (2.6%) of all the positive saliva samples in the antigen test were negative for NAAT. One showed no linearity with a dilute solution in the dilution test. Additionally, the quantitative antigen levels of all the three samples did not decrease after reaction with the anti-SARS-CoV-2 antibody. Conclusions The judgment difference between the quantitative antigen test and NAAT seemed to be caused by non-specific reactions in the antigen test. Although the high positive and negative predictive value of this quantitative antigen test could be confirmed, we should consider the possibility of false-positives caused by non-specific reactions and understand the characteristics of antigen testing. We recommend that repeating centrifugation before measurement, especially in saliva samples, should be performed appropriately.

The paper describes the structural design of a laboratory device that allows for presenting operation, simulating work procedures and checking functionality of the elevator “rope sensors” when equalizing different tensile forces in partial ropes of a rope system of traction elevators. The laboratory device is modified for checking operations of commonly used rope sensors. In an overwhelming number of cases, elevator technicians use them for setting up the unequally distributed tensile forces in elevator ropes. The device is equipped with three, mutually attached pulleys, over which the rope is installed. The unknown tensile force in the rope is determined by an “indirect method”, i.e. from the resultant of the forces of the rope bent over the pulleys, which have an effect on the force sensor. The tensile force along the rope axis can be determined numerically, but also experimentally, from the inclination angle of the rope installed on the pulleys, diameter of the pulleys, diameter of the rope and the force detected by the force sensor of the stretched rope. The paper presents experimentally obtained tensile force values at the rope sensor, deduced from stretching the rope. The paper also describes the procedure for determining the measured load in the rope by rope sensors of the SWR, SWK and RMT-1 types based on the variable axial force in the rope.

Embedding is an anatomical pathology laboratory device that is very important for producing quality slices and is also a device used to process paraffin tissue, so that the tissue can be cut with higher precision using a microtom (slicer). From the process of melting paraffin crystals using a manual heating process with bunsen flame heaters (fire heaters) so that the paraffin crystals can be transformed from the crystal into liquid. While paraffin crystals that have been processed from the crystal to liquid form are poured into the mold and left to freeze. In this case, an embedding system device will be made equipped with heating and cooling. The temperature used for the liquefaction process is 50C while the temperature for cooling is 17C. After making the process of making device, experiment device, and retrieving data, the error percentage results were 0.016% at the heating temperature and 0.08% at the coolant temperature, and the percentage of heating samples obtained in the sample was 61.3%, while the percentage samples for parts coolers get a value of 92%

Population extended life expectancy has significantly increased the risk of septic shock in an ageing population. Sepsis affects roughly 20 million people every year, resulting in over 11 million deaths. The need for faster more accurate diagnostics and better management is therefore paramount in the fight to prevent these avoidable deaths. Here we report the development of a POC device with the ability to identify a broad range of pathogens on a lateral flow platform. Namely Gram-positive and Gram-negative bacteria. The simple to use laboratory device has the potential to be automated, thus enabling an operator to carry out solid-phase lysis and room temperature RPA in situ, providing accurate results in hours rather than days. Results show there is a potential for a fully automated device in which concepts described in this paper can be integrated into a lateral flow device.

The evaluation of tire grip on the road is costly and consumes high energy and time, but is essential for safety. Prediction of tire grip on a laboratory scale is therefore always of interest and of utmost importance for research and material developments. It mostly suffers from lack of comparison with actual tire data. To involve all influencing factors on tire grip in a laboratory scale measurement is very complex. Therefore, it has always remained challenging to obtain a strong correlation between laboratory results and road data. In the present study, a new test method is developed for a Laboratory Abrasion Tester, LAT100, which enables to exploit the device as a tribometer. The objective was to develop a technique on a laboratory device to mimic the common test modalities for evaluating tire grip on the road with a trailer tester: lateral (α) and longitudinal (κ) sweep tests. The new method is validated by correlating the laboratory data with the two test modalities of real tire grip on a dry road using a trailer tester for six different tire tread compositions. For the LAT100 tests, solid rubber wheels are characterized at three different normal loads. The effects are comparable with actual tire data. The outcome of the new test method is in good agreement with actual tire trailer α-sweep tests. Graphical abstract

Mobility of nZVI is a vital parameter for designing effective in situ remediation strategy. This chapter describes the utilization of a laboratory device developed for the characterization of migration of differently modified nZVI materials based on their ferromagnetic properties. The one-dimensional column is suitable for comparing the migration properties of different types of nZVI and is less demanding for the material, while the cascade column simulates the process after nZVI injection into the treated well more realistically.

Understanding the cut and chip (CC) effect in rubber is important for successful product development for tires used in off-road or poor road conditions and for other demanding applications of rubbe...

The coefficient of thermal conductivity of particulates and powders is of great importance in the process of engineering. The prediction of thermal properties of powders using empirical equations is still difficult due to the wide range of specific attributes. This article describes a new measurement methodology for a laboratory device, which can be used to determine the thermal conductivity of bulk solids. The presented results show that the created device is very well applicable for industrial practice. It is possible to examine the coefficient of thermal conductivity depending on the sample temperature, granulometry and morphological composition, moisture content, degree of consolidation and other variables that may enter into the entire process and affect it significantly.

The trajectory of the web at the exit of a roll coating operation can influence the quality of the final coating. While methods to model the web trajectory have been given in the literature, these methods are limited in various ways. A method is proposed to describe the web trajectory and the pressure distribution in the fluid at the exit of a forward roll coater. The Reynolds lubrication equations for the fluid are coupled with the web by a force balance on web node points. The fluid pressure in the coating layer generates forces on the web. These forces deflect the web. Integration in time gives the web dynamics. The angle that the web is pulled from the nip and the tension are found to influence the pressure pulse in the divergent section of the nip to a large extent. Low tensions lead to a second pressure pulse followed by a sub-ambient or tack pressure. Pulling the web at various angles from the nip can cause the tack pressure to increase or decrease. Pressure pulses are predicted that are comparable to measurements by a laboratory device.

Gathering information about soil properties in an efficient way is essential for many soil applications also for very shallow geothermal systems (e.g. collector systems or heat baskets). In the field, electrical resistivity tomogramphy measurements enable non-invasive and extensive analyses regarding the determination of soil properties. For a better understanding of measured electrical resistivity values in relation to soil properties within this study, a laboratory setup was developed. The structure of this laboratory setup is geared to gather electrical resistivity or rather electrical conductivity values which are directly comparable to data measured in the field. Within this setup grain size distribution, moisture content, and bulk density, which are the most important soil parameters affecting the electrical resistivity, can be adjusted. In terms of a better estimation of the geothermal capability of soil, thermal conductivity measurements were also implemented within the laboratory test sequence. The generated data reveals the serious influence of the water content and also provides a huge impact of the bulk density on the electrical as well as on the thermal conductivity. Furthermore, different behaviour patterns of electrical and thermal conductivity in their particular relation to the different soil parameters could be identified.

The work is devoted to research and intensification of the process of boiling of solutions with different viscosities in evaporators of a tubular type with forced circulation and a drift boiling zone. The main factors that influence the change in the hydraulic resistance of the heating chamber under various operating conditions and the dependence of the loss on vapor content are determined on the developed laboratory device. The optimum value of the circulation velocity of the working solution at various temperatures and the boiling zones is also found in the article

High ratio penetration of power electronic devices have added many inter-harmonics to the power system. These dynamically changing inter-harmonics raise new security issues, such as sub-synchronous oscillations (SSO) and frequency stability control, which propose new requirements to power system monitoring devices. In this paper, a fast synchronized measurement method with wide frequency bandwidth is proposed by using super-resolution characteristics of spatial spectrum estimation, and a kurtosis based method for estimating the number of signal frequency components is proposed, the stability under low SNR conditions of the method is improved, and the fast and high-precision measurement of the wide frequency bandwidth signal is realized. And then, a prototype of wide frequency bandwidth measurement is developed. The results of simulation test, laboratory device test and field data test verify the validity of the proposed method.

Coal and gas outbursts usually generate a large amount of coal fragment of various sizes. This phenomenon is assumed to be related to the exploding and shattering of coal containing high-pressure adsorbed gas when it is suddenly exposed. To verify this assumption, a laboratory device has been developed to test the shatter proneness of coal blocks at high pressure. Experiments were conducted by using coal blocks sampled from four different mines. The experiments show that if the gas pressure is high enough, all coal blocks can be shattered. The particle size of the shattered coal follows the Weibull distribution. Under specific gas pressure, the shatter proneness of coal can be represented by the scale parameter in the Weibull distribution function derived from experiments. This parameter represents the susceptibility of outburst and may be used as one of the outburst predictive indicators in the future.

In this chapter, we will illustrate the synthesis and experimental results of the MPC-reference governor (MPC-RG) strategy as described in Sect. 4.2. The MPC-RG optimization problem will be solved parametrically and implemented in a real-time fashion on a microchip with limited computational and memory resources. The viability of the MPC-RG strategy is tested on a laboratory process of a magnetically suspended ball. This section describes the mathematical modeling of the magnetically suspended ball. Here, we also present the primary stabilizing PID controller and the state space model closed-loop system. Second, we introduce the laboratory device and experimental setup.

Mandarin thinning is done by hand, increasing labor cost and raising total crop production costs. Mechanical thinning has been tested in peaches and other fruits. To achieve the maximum efficiency thinning requires to be applied at a specific stage of vegetative development. In this research study the mechanical thinning of mandarin branches during the different fruit developing stages has been assessed using a vibratory laboratory device (amplitudes 0.015 m and 0.030 mm and frequencies 34.8 Hz and 37.8 Hz). Branches with flower buds, flowers, small green fruits and medium green fruits were tested during 12 weeks and two different seasons. It was possible to detach mechanically flower buds, flowers and green fruits using different combinations of amplitudes and frequencies. Removal percentage decreased when increasing retention traction force, according to a logarithmic regression model. During fruit setting (weeks 5, 6 and 7) removal percentage was higher, when the retention force is very low. The first weeks just after the natural thinning could be consider the adequate time for a mechanical thinning operation.

Nowadays, cell characterization represents a fundamental task widely diffused in different fields. The main purpose of this paper is the design and development of a device for cellular characterization based on a pyroelectric sensor. After a brief introduction dedicated to the methods actually employed for cell counting, the pyroelectric sensor, the electronic readout unit, and the prototype will be introduced. Different cell concentration samples have been analyzed in order to highlight how the induced pyroelectric response is related to the cell properties. Experimental results shown that sensor output is strongly affected by cell type, concentration and viability. Particularly, it has been observed an increase in output signal related to an increase in cell concentration, mainly due to a lower thermal conductivity. No significant variation has been observed by the drastic reduction of cell viability also by varying cell concentration. The aforementioned results are probably due to the induction of a decrease in mitochondrial activity. Obtained results are very promising for the realization of a low cost laboratory device with all the characteristics listed above.

The current study presents the design and evaluation of a laboratory device combining mechanical motion of wheat grain and turbulent air streaming inside a positive pneumatic conveyor system. The device recovers microparticulate nano-engineered alumina insecticide powders (NAIP) from treated grain. The particle removal efficiency of the conveying system was experimentally quantified by using a laboratory prototype assembled by attaching an electrostatic filter (EF) to the conveyors exhaust. Then, the NAIP particles detached from the grain inside the conveyor were drawn by the conveyors’ exhaust air stream into the EF, where particles bound to the electrodes due to electric charge differences. The NAIP particle load bound to the EF electrodes was removed and weighed to determine the efficiency of the wheat grain cleaning process. Our experimental results, under laboratory conditions, show that the recovery efficiency of the prototype averaged 98.0% (±1.4). Thus, the present study provides an innovative strategy to remove NAIP insecticide particles after storage, once their role as insecticide in stored grain has been fulfilled. This technology provides advancement in grain technology allowing the possibility to provide insecticide-free grain to the food market.

The design and test results for a prototype laboratory device capable of condensing and solidifying gases is presented. This equipment is a new approach to the fabrication of NH 3 material for polarized target experiments in nuclear physics experiments. The formed solids have a cylindrical geometry with 32 mm diameter and 50 mm height. With Computational Fluid Dynamics (CFD) analysis we designed and established operational parameters for the condenser. The system designed for initial testing with CO 2 is now ready to use for growing good quality crystals of NH 3 with a novel shape, featuring cooling channels for polarized target experiments.

Electronic cigarettes are the most popular tobacco product among middle and high schoolers and are the most popular alternative tobacco product among adults. High quality, reproducible research on the consequences of electronic cigarette use is essential for understanding emerging public health concerns and crafting evidence based regulatory policy. While a growing number of papers discuss electronic cigarettes, there is little consistency in methods across groups and very little consensus on results. Here, we describe a programmable laboratory device that can be used to create extracts of conventional cigarette smoke and electronic cigarette aerosol. This protocol details instructions for the assembly and operation of said device, and demonstrates the use of the generated extract in two sample applications: an in vitro cell viability assay and gas-chromatography mass-spectrometry. This method provides a tool for making direct comparisons between conventional cigarettes and electronic cigarettes, and is an accessible entry point into electronic cigarette research.

Due to its negative impact on the yield and quality of stored grains, the aim of this research was to study the influence of Rhyzopertha dominica F. on rheological properties of wheat flour obtained from grains infested by examined pest. A rheological laboratory device - Mixolab was employed in order to simulate the production process of bread (from the beginning of dough mixing until the end of bread baking). Wet gluten and gluten index, as significant flour quality parameters, were also determined. The flour of wheat varieties Planeta and Kruna was used in these experiments. The samples of both varieties infested with R. dominica (infested samples) were characterized and compared to their uninfested counterparts (control samples). Infested samples expressed a lower gluten index content, greater weakening of the gluten network upon mixing and heating, as well as lower starch gelatinization viscosity in comparison to control samples. Changes in the gluten index value were more pronounced in Planeta variety which was characterized with a higher degree of infestation. Determined changes in rheological properties of infested wheat were mainly dependent on a degree of infestation. However, a varietal dependency on the intensity of changes in technological quality cannot be neglected.

The 4SPIN® desktop laboratory device has been developed for the deposition of nanomaterials dedicated not only to medical applications, but also to other fields such as nanoelectronics, optics, filtration, etc. The apparatus integrates various methods to enable the preparation of nanostructured materials according to researching demands. Nine principally different emitters (most of them are usable in the method called electroblowing) and six different collectors enable researchers to perform various types of experiments. This allowed nanofibrous materials with different microscopic and macroscopic structures to be successfully prepared. The 4SPIN® laboratory device was developed at Contipro Biotech Ltd. and seven principles used were patented. The device has been certified for electrical safety by the CE mark and has been marketed since January 2013.

We undertook the first clinical evaluation of a novel, non-invasive device for the continuous measurement of plasma haemoglobin concentration in 25 patients undergoing elective cardiac surgery. At four pre-determined intervals, samples of blood were taken for plasma haemoglobin estimation on a blood gas analyser and a laboratory device and were compared with the plasma haemoglobin estimation on the novel device using the Bland-Altman method. The 95% limits of agreement for estimation of plasma haemoglobin concentration for the device vs. laboratory, the device vs. the blood gas analyser and the blood gas analyser vs. the laboratory were 101.3 g.l(-1) , 103.1 g.l(-1) and 14.5 g.l(-1) , respectively. The bias (mean difference) in each case was 27.4 g.l(-1) , 25.1 g.l(-1) and 2.4 g.l(-1) , respectively. We conclude that the novel device in its current form is not a suitable replacement for more invasive methods of determining plasma haemoglobin concentration in patients in the setting of cardiac surgery; however, lessons learnt from the study will help to improve the device's future performance.

In this study a thermal desorption procedure (HgTPD) was used to identify mercury species in samples of gypsum obtained from wet flue gas desulphurization plants (WFGD). Gypsum from industrial coal combustion power plants and gypsum from a laboratory device that simulates mercury retention in the WFGD process were studied. It was concluded that mercury sulphide (HgS) is the mercury species present in WFGD gypsums unless an additive is used. Mercury speciation in this kind of residue can contribute to a better understanding of the reaction and adsorption behaviour of mercury species in the WFGD process and provide a deeper knowledge of the environmental impact caused by the disposal or reuse of these Hg-containing residues., The financial support for this work was provided by the project CTM2011-22921. The authors thank the Spanish Research Council (CSIC) for awarding Ms. Marta Rumayor a JAE-predoc fellowship.

Chemostat refers to a laboratory device used for growing microorganisms in a cultured environment and has been regarded as an idealization of nature to study competition modeling in mathematical biology. The simple form of chemostat model assumes that the availability of nutrient and its supply rate are both fixed. In addition, the tendency of microorganisms to adhere to surfaces is neglected by assuming the flow rate is fast enough. However, these assumptions largely limit the applicability of chemostat models to realistic competition systems. In this paper, we relax these assumptions and study chemostat models with random nutrient supplying rate or random input nutrient concentration, with or without wall growth. This leads to random dynamical systems and requires the concept of random attractors developed in the theory of random dynamical systems. Our results include existence of uniformly bounded non-negative solutions, existence of random attractors, and geometric details of random attractors for different value of parameters. Copyright © 2015 John Wiley & Sons, Ltd.

The effectiveness of the removal process of milk soil was studied using a laboratory device called bath-substrate-flow and three different types of milk: sheep, skimmed cow, and milk for infants. Experiments were performed using different surfactants and operation conditions. The washing efficiency was related to the temperature of the process, type of soiling agent and wash-bath composition. The highest detergency in all cases was detected at high pH levels with surfactants. The results show that the cleaning of these soils differed for each type of milk and depended on the composition of the residue formed. The use of specific surfactant formulations for each soiling agent under the appropriate conditions proved to be a useful option to reduce the cleaning times for clean-in-place processes of milk foulants in the dairy industry, guaranteeing cleaning with a lower environmental and economic impact over the final products.

Hydraulic pumps are the most important components of hydraulic circuits in agricultural tractors. Their durability is influenced by flow characteristics and thus the flow efficiency. This paper presents the laboratory test of an ecological synthetic hydraulic fluid of UTTO type. This fluid is currently under development. In terms of a decrease in hydraulic pump flow efficiency, laboratory tests of these fluids did not show negative effects of its application. It can be stated that after completion of laboratory tests, it will be needed to continue with trials under operational conditions.