In this study, a variety of test matrices from tobacco and nicotine delivery products were assessed against a 3R4F Kentucky reference cigarette using the in vitro micronucleus assay. Testing was ...conducted using two Chinese hamster cell lines (CHO and V79), and a human lymphoblastoid cell line (TK6), in accordance with established guidelines.
Total particulate matter (TPM) from a 3R4F Reference cigarette was compared to an electronic cigarette e-liquid, electronic cigarette TPM and TPM from a commercial tobacco heating product using a standard and an extended treatment condition with recovery period.
Cells were assessed with 3R4F TPM prior to assessment of the other tobacco and nicotine product test matrices. These cell lines gave varied responses to 3R4F TPM with the most robust response using V79 cells. The use of an extended exposure/recovery period was seen to increase assay sensitivity for CHO and V79 cell lines but was less clear for TK6 cells.
Negative responses were observed for all products except 3R4F across all treatment conditions in V79 cells. The most potent response to cigarette smoke was following extended treatment with recovery, suggesting this may be a more appropriate treatment for the future assessment of tobacco and nicotine product test matrices.
•Particulate matter from a cigarette was compared against a commercial e-liquid e-cigarette and commercial THP.•Data were contextualised against nicotine equivalents to enable comparisons between different test matrices and products.•An extended recovery period of 1.5–2 cell cycles was used to increase assay sensitivity.•All cells (CHO, V79 and TK6) showed an increase in IVMNBN cells following the extended recovery period.•None of the NGPs tested produced a positive response, whereas cigarette smoke was positive under all test conditions.
Summary
This paper proposes a three‐level three port isolated converter (3L3PIC), which can be employed as an intermediate power conversion circuit for connecting different DC bus voltages in a DC ...microgrid. This topology utilize half bridge multilevel structure to reduce voltage stress across the transformer windings and the semiconductor switches. Conventionally the power transfer between the ports of a 3PIC were attained by traditional phase‐shift modulation (TPM), but this will impose increased current stress and associated losses in the converter at wide change in voltage conversion ratio. To minimize these losses, this paper introduces a 3L3PIC, that is, by employing dual phase‐shift modulation (DPM) in 3PIC. Steady state analysis of 3L3PIC are presented and derived the power transfer equations between the ports. The current equations through each port are determined at different combinations of voltage conversion ratios. Procedure for obtaining optimized phase‐shift values for both TPM and DPM techniques in 3PIC are explained. A comparison between the modulation schemes in 3PIC is performed and found better results for the DPM technique in terms of reduced current stress, reduced circulating power flow, and extended soft switching region. This in turn leads to a reduction in conduction losses and transformer losses in the converter. A hardware prototype of 1.5 kW 3PIC has been implemented and tested. The experimental results obtained validates with the theoretical analysis.
This paper proposes a Three‐Level Three Port Isolated Converter (3L3PIC), which can be employed as an intermediate power conversion circuit for connecting different DC bus voltages in a DC microgrid. This topology utilize half bridge multilevel structure to reduce voltage stress across the transformer windings and the semiconductor switches. Conventionally the power transfer between the ports of a 3PIC were attained by traditional phase‐shift modulation (TPM), but this will impose increased current stress and associated losses in the converter at wide change in voltage conversion ratio. To minimize these losses, this paper introduces a 3L3PIC, that is, by employing dual phase‐shift modulation (DPM) in 3PIC. Steady state analysis of 3L3PIC are presented and derived the power transfer equations between the ports. The current equations through each port are determined at different combinations of voltage conversion ratios. Procedure for obtaining optimized phase‐shift values for both TPM and DPM techniques in 3PIC are explained. A comparison between the modulation schemes in 3PIC is performed, and found better results for the DPM technique in terms of reduced current stress, reduced circulating power flow, and extended soft switching region. This in turn leads to a reduction in conduction losses and transformer losses in the converter. A hardware prototype of 1.5 kW 3PIC has been implemented and tested. The experimental results obtained validates with the theoretical analysis.
Flexible job shop scheduling problem (FJSP) has been extensively considered; however, multiobjective FJSP with energy consumption threshold is seldom investigated, the goal of which is to minimize ...makespan and total tardiness under the constraint that total energy consumption does not exceed a given threshold. Energy constraint is not always met and the threshold is difficult to be decided in advance. These features make it more difficult to solve the problem. In this paper, a two-phase meta-heuristic (TPM) based on imperialist competitive algorithm (ICA) and variable neighborhood search (VNS) is proposed. In the first phase, the problem is converted into FJSP with makespan, total tardiness and total energy consumption and the new FJSP is solved by an ICA, which uses some new methods to build initial empires and do imperialist competition. In the second phase, new strategies are provided for comparing solutions and updating the nondominated set of the first phase and a VNS is used for the original problem. The current solution of VNS is periodically replaced with member of the set <inline-formula> <tex-math notation="LaTeX">\Omega </tex-math></inline-formula> to improve solution quality. An energy consumption threshold is obtained by optimization. Extensive experiments are conducted to test the performance of TPM finally. The computational results show that TPM is a very competitive algorithm for the considered FJSP.
Total Productive Maintenance (TPM) has gain increasing relevance into the companies, which can help in increasing the productivity due to less equipment stoppages. The unavailability of the equipment ...directly affects the company's performance, which can be measured through the OEE. However, the organization of SMEs is not always properly organized, to have a concrete sense of the losses that can accumulate due to equipment unavailability. This work aimed to develop a framework capable of responding effectively in the beginning of the implementation process of a TPM system. A novel sequence of application of tools was created, both linked to lean and quality, which, when applied in the correct sequence, allow solving some persistent problems in a few steps, resulting in significant gains for companies. The model was applied to a company in the cork industry, and it was possible to verify its effectiveness.
The focus of this investigation lies on the development of a two-scale homogenization scheme for poro-elastic fluid-saturated porous media. For this purpose, the general concepts of the Theory of ...Porous Media (TPM) are combined with the FE2 method. After an introduction of the basics of TPM, the weak forms for the macroscopic and the microscopic scale will be formulated and the averaged macroscopic tangent moduli considering the microscale will be derived. Additionally, the formulation of lower level boundary conditions, which refer to the quantities that will be transmitted from the macro- to the microscale, in strict compliance with the Hill–Mandel homogeneity condition, is derived. Finally, a numerical example will be presented, pointing out the gained features of the methodology.
It generally takes 2.5 to 3 years for an enterprise to implement total productive maintenance (TPM) in a full swing; however, the actual duration depends on each company's corporate status. Generally ...speaking, for a company with big staff, it even takes 3 to 5 years, but the major consideration should depend on whether the actual benefit is remarkable or not. This research aims to find out whether TPM was carried out by enterprises, to inspect the enterprises’ current performance, and to make comparison with those enterprises that have successfully carried out TPM. Through the findings, we hope to provide reference for enterprise owners when they carry out TPM, so as to reduce the cost for fumble.
Conventionally, the transition probabilities in the interacting multiple model (IMM) are often fixed based on the prior information. However, this conservative setting may result in inaccurate state ...estimations. To solve this problem, a Bayesian-based online correction function is proposed in this paper, which can adaptively adjust the transition probabilities. To deal with the response lag and the short-term peak estimation error problem during the respond to model jump, a model jumping threshold is defined, so that the current information of the models can be fully utilized by the IMM algorithm and the correction function of the transition probabilities can be further improved. Subsequently, an adaptive transition probability-based parallel IMM algorithm is proposed in this paper. Finally, three maneuvering target tracking simulations are conducted to verify the performance of the proposed algorithm, the results show that the proposed algorithm can improve the response speed of the system model jump and the state estimation accuracy. The effectiveness and feasibility of the algorithm are proven.
Data storage security has become the core of many network security issues. In order to achieve trusted storage and trusted measurement of network community data, this paper proposes a secure storage ...model based on trust extension for existing trusted storage technologies. In the process of document encryption, the key information is encrypted as well as decentralized stored by optimizing the ciphertext inverted index structure and update policy to ensure the security of index information. In the process of user access control mechanism, SAML and XACML are used in combination with role-based access control in order to achieve flexible and efficient authorization and access control. In the process of result query, ontology technology is introduced to better express the user’s query intention and improve the query accuracy. A large number of experiments demonstrate the effectiveness and feasibility of the scheme.
In the last decade, remarkable developments have concerned the methods of space charge measurement in the field of insulation systems diagnostic. In particular, methods based on acoustic and thermal ...phenomena have been largely used. The present review provides a broad overview on the different techniques used describing, for each of them, the working principle, the main features and the most relevant applications. Further details are provided for the Pulsed Electro-Acoustic (PEA) method, as it seems to be the most used. This article provides more details on its historical evolution, showing evidence for its technological limits and taking into consideration the advantages and drawn from the different configurations of the measuring cell. A similar approach has been used for the group of thermal methods, whereas for the optical methods only the basic working principle and latest applications are reported.
Five potential additives, three zeolites and two silicates, have been studied for reducing the amount of compounds generated when smoking Heet tobacco. Pyrolysis-gas chromatography-mass spectrometry ...experiments (Py-GC/MS) show that this type of tobacco generates large amounts of nicotine and glycerol and compounds such as phenol, acetaldehyde, acetone and formaldehyde that are classified as harmful components and potentially harmful (HPHC). USY and SBA-15 are the additives that present major reductions in inert and oxidative atmosphere, being these reductions greater for SBA-15. These results have been confirmed by smoking experiments that show significant reductions for SBA-15, especially in the total particle matter (TPM) where a reduction of more than 40% is obtained for most of the compounds, being for several compounds even higher than 60%. These additives may further reduce the toxicity of Heet tobacco.
•Heet tobacco is less harmful than conventional tobacco but generates large amounts of nicotine and glycerol and various compounds classified in FDA’s HPHC list.•The effect of five potential additives has been studied by Py-GC/MS and SBA-15 shows the major reductions in inert and oxidative atmosphere.•Smoking experiments confirm that SBA-15 permits reducing the toxicity compounds generated when smoking Heet tobacco.
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