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The equipment of airport security screening checkpoints undergoes frequent modifications due to technological or organizational changes. New solutions complement or replace existing ones to improve the effectiveness of the equipment or formal requirements. An example of this process is the replacement of the walk-through metal detection gate with a newer solution: the body scanner. The present study aimed to analyze the capacity of an airport security checkpoint under different operational conditions, depending on the equipment used. For this purpose, a previously created model (implemented as a colored, timed, stochastic Petri net) was used. Simulation studies were performed in four real-world operational scenarios, and their results were compared to those of a nominal scenario. The results show that, in terms of capacity, it may be advantageous to redirect a more significant stream of passengers to a station equipped with a specific device, depending on the specific operational situation. The results demonstrate the necessity of analyzing the applied strategy of operation with each change in the operational environment. In particular, for an airport with characteristics similar to Katowice Airport, using older technology is beneficial under nominal conditions and after increasing the staffing so that both genders work simultaneously. In other cases, the more intensive use of Body Scanner-equipped security screening checkpoints is advantageous. [ABSTRACT FROM AUTHOR]

The development of airport security screening systems requires the use of increasingly sophisticated and effective equipment to detect prohibited or hazardous items and substances. However, this can lead to a reduction in the throughput of the security checkpoint (SCP). This paper addresses the operationally important problem of the dilemma between screening effectiveness and screening checkpoint throughput, which is important to the real operational capabilities of an airport. In this paper, a comparison of traditional walk-through metal detectors (WTMD) gates and newer technology body scanners (BSs) was carried out in terms of SCP throughput as an element determining the operational capabilities of the airport. For this purpose, a simulation model was developed to study throughput based on a colored timed Petri net. The analysis showed that, depending on the characteristics of the available staff, the level of terrorist and epidemic threat, as well as the time of year, it is advantageous to use different strategies to vary the size of the stream of passengers directed for screening by the WTMD gate and BS. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present characteristics, toxicity and environmental behavior of nanoparticles (NPs) (silver, copper, gold, zinc oxide, titanium dioxide, iron oxide) that most frequently occur in consumer products. In addition, NPs are addressed as the new aquatic environmental pollutant of the 21st century. NPs are adsorbed onto particles in the aquatic systems (clay minerals, fulvic and humic acids), or they can adsorb environmental pollutants (heavy metal ions, organic compounds). Nanosilver (nAg) is released from consumer products into the aquatic environment. It can threaten aquatic organisms with high toxicity. Interestingly, copper nanoparticles (Cu-NPs) demonstrate higher toxicity to bacteria and aquatic microorganisms than those of nanosilver nAg. Their small size and reactivity can cause penetration into the tissues and interfere with the metabolic systems of living organisms and bacterial biogeochemical cycles. The behavior of NPs is not fully recognized. Nevertheless, it is known that NPs can agglomerate, bind with ions (chlorides, sulphates, phosphates) or organic compounds. They can also be bound or immobilized by slurry. The NPs behavior depends on process conditions, i.e. pH, ionic strength, temperature and presence of other chemical compounds. It is unknown how NPs behave in the aquatic environment. Therefore, the research on this problem should be carried out under different process conditions. As for the toxicity, it is important to understand where the differences in the research results come from. As NPs have an impact on not only aquatic organisms but also human health and life, it is necessary to recognize their toxic doses and know standards/regulations that determine the permissible concentrations of NPs in the environment.

The aim of this study was to determine the adsorption capacity of the smectite clays (from the overburden of the lignite deposit in Belchatow) for two anionic dyes, i.e. Reactive Blue 81 (RB-81) and Direct Blue 74 (DB-74). Additionally, the influence of the thermal and chemical (acid and alkali) clay modifications on the amount of bonded dyes was investigated. The adsorption capacity of the clay (natural and modified) was different for studied dyes and depended on the initial concentration and modification type. All the modified clays adsorbed the dyes at pH>pHPZC as the negatively charged surfaces of their particles (in accordance with the formula: AOH ↔ AO- + H+) prevented the formation of electrostatic bonds between the anionic dyes and the clay surface. The dyes were mainly bound with the hydrogen bonds forming between the donor groups in the dyes and the acceptor groups (-SiO and -Al2OH) in the clays. The coefficients in the adsorption isotherms were estimated with the linear and non-linear regression. The linear regression method was found that the Freundlich and Dubinin-Radushkevich isotherms described the dye sorption much better than the Langmuir model. On the other hand, all three models described well the experimental data in the non-linear regression method. Furthermore, the 1/n value (

The paper presents selected financial benefits for organizations resulting from the use of outsourcing in logistics services. The research conducted in the organization indicated that conducting transport services on their own requires significant cash outlays related to: the employment of employees, purchase and maintenance of means of transport, insurance, purchase of fuel, etc. Estimated costs were compared with expenses incurred by the hypermarket as a result of employing an outsourcing company. The results of the research have confirmed the importance of using outsourcing in the analyzed organization. The aim of the study is to compare the costs that the organization would incur without excluding transportation services and the outsourcing costs of the aforementioned services, the profit of a company can have from using outsourced services is estimated in the paper. [ABSTRACT FROM AUTHOR]

Sorption capacities of low-moor peats and Neogene clays from the overburden of lignite beds in Central Poland for Cr(III) ions as chloride and metalorganic complex ions have been investigated. The binding mechanisms and sorption parameters were determined based on the Freundlich and Langmuir nonlinear sorption isotherms. The sorption capacities of studied materials for Cr(III) ions depended on their properties (porosity, average pore diameters, specific surface area and content of Fe hydroxyoxides) as well as charge of Cr(III) ions, functional groups and their diagonal lengths. Cr(III) ions from chlorides were bound onto sorbents via Coulomb attraction and by Fe hydroxyoxides. However the complex Cr(III) ions were bound to the sorbent surface via hydrogen bonds between the dye -OH groups and =O of the sorbent functional groups. The equation parameters of sorption isotherms indicate cooperative heterogeneous adsorption at low Cr(III) concentrations and chemisorption at high Cr(III) concentrations. [ABSTRACT FROM AUTHOR]