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Radon (222Rn), a radioactive gas resulted from the natural decay of other radioactive elements, pose a threat to the exposed human population. Radon gas emits along the seismically active faults and increased the 222Rn contamination in sorrounding water and soil. This study investigated the concentration of 222Rn in drinking water and soil after the September 24, 2019, Mw 5.8 earthquake, Mirpur District, Azad Jammu, and Kashmir (AJK). For this purpose, water (n = 24) samples were collected from the bore wells of orderly located houses and soil field sampling (n = 12) along with the NE-SW directions of fracture in the Mirpur District. Determined 222Rn in drinking water surpassed the maximum contamination level (MCL, 11.1 kBq/m3) set by the US Environmental Protection Agency (US EPA) in 83%, 50%, and 33% of the sampling point at the site I, site II, and site III, respectively. However, that of soil 222Rn concentration was observed with the normal range (10–50 kBq/m3). Potential exposure of 222Rn consumption in drinking water was the mean effective dose through ingestion (EWing, 0.003 ±

Chemical graph theory is a field of mathematics that studies ramifications of chemical network interactions. Using the concept of star graphs, several investigators have looked into the solutions to certain boundary value problems. Their choice to utilize star graphs was based on including a common point connected to other nodes. Our aim is to expand the range of the method by incorporating the graph of hexasilinane compound, which has a chemical formula $\mathrm{H}_{12} \mathrm{Si}_{6}$ H 12 Si 6 . In this paper, we examine the existence of solutions to fractional boundary value problems on such graphs, where the fractional derivative is in the Caputo sense. Finally, we include an example to support our significant findings.

The purpose of this short note is to present some corrections and clarifications concerning the proof of the main result given in the paper “On analytic model for two-choice behavior of the paradise fish based on the fixed point method, J. Fixed Point Theory Appl. 2019, 21:56”.

The purpose of this paper is to discuss a special type of functional equation that describes the relationship between the predator animals and their two choices of prey with their corresponding probabilities. Our aim is to find the existence and uniqueness results of the proposed functional equation using the Banach fixed point theorem. Finally, we give an illustrative example that supports our main results.

In this paper, we are dealing with a particular type of predator–prey model in which a predator has two choices of preys with probabilities x and $$1-x$$ , respectively. Our aims are to analyze the behavior of predator animals in such situation and to construct a general functional equation for it, which covers all the aspects of such type of relationship. The Banach fixed point theorem is being used to investigate the existence and uniqueness results of the proposed predator–prey model; Hyers–Ulam and Hyers–Ulam–Rassias type stability of the functional equation has also been discussed in it.

This paper deals with a specific type of traumatic avoidance for the learning process of normal dogs enclosed into a small compartment with a steel grid floor. Our aim is to analyze the behavior of the dogs in such situations and to construct a suitable mathematical model for it. The existence and uniqueness results of the proposed traumatic avoidance learning model are being investigated by the use of the Banach fixed point theorem.

Having a mild acidic pH of 5-6.5, Hypochlorous acid (HOCl) is a harmless disinfectant having excellent sterilizing capability for use in agriculture, medicine and food industry. Recently, the use of non-diaphragm electrolytic cell has shown great potential in producing Slightly acidic electrolyzed water (SAEW). However, the effect of various physical properties such as electrode gap, flow rate, current, bubble formation and temperature conditions are still under investigation. In this study, we produced 40 ppm SAEW by using a self-developed non-diaphragm electrolytic cell that electrolyzed 6 % Hydrochloric acid (HCl) with H2 and Cl2 gas as by products. The tested range of electrolyte flow rate was 2-4 mL/min. The effect of current was studied in the range of 10-15 A. The results indicate that bubble generation by increased current decreased the average convection heat transfer coefficient between the electrode and electrolyte resulting in increased temperature. Moreover, the bubbles reduced the surface area for an efficient electrolytic reaction resulting in a decrease in available chlorine concentration. Hence, an optimized flow rate of 3 mL/min at 13 A current were found to be best process conditions for SAEW generation when the electrode size is 4 cm by 14 cm. Furthermore, the produced high concentrated HOCl showed excellent sanitization efficacy against various Escherichia coli concentrations (105-108 cfu/mL).

The choice behavior model is the model which describes the spiritual process of thinking which is concerned with the process of judging the merits of the numerous options and making the decision to determine one of them for action. The aim of this paper is to analyze the one specific type of choice behavior model for the learning process of the paradise fish. The existence and uniqueness results of the solution of the proposed choice behavior model are investigated via the fixed point tool.

Time–temperature indicators are devices employed for monitoring thermal history of perishable food products from storage to consumption. As the food industry has opted for intelligent packaging, which also involves thin foldable wrappings, a requirement arises for a flexible device capable of attaching and sensing on a curved product surface. In this study, we have fabricated a distance-based flexible time–temperature indicator (FTTI) by employing electronic cutting machine and through press lamination of thermoplastic films; we have incorporated the FTTI with a unique starting actuation switch made of thin (150 μm) cover glass. Flow profile in 0.45 μm nitrocellulose membrane is measured for oleic, octanoic, and decanoic acids representing test temperatures of 5, 15 and 30 °C, respectively. Results demonstrate the sensor to be robust and flexible with precise responsiveness to oscillating temperature conditions. Further improvement in time-scale is achieved by employing a series of fan-shaped cut channels. This two-dimensional flow increases the device time by 170% in comparison with straight channel and improves scale readability by achieving a linear distance-time relation in the porous membrane. The advantages of low cost, simple design, freedom from equipment, robustness, and flexibility render the FTTI a versatile platform for distance-based diagnostics, food quality control, and environmental monitoring devices.