Numerical Investigation of Excitation of Various Lamb Waves Modes in Thin Plastic Films

Ultrasonic-guided waves are widely used for the non-destructive testing and material characterization of plates and thin films. In the case of thin plastic polyvinyl chloride (PVC), films up to 3.2 MHz with only two Lamb wave modes, antisymmetrical A0 and symmetrical S0, may propagate. At frequencies lower that 240 kHz, the velocity of the A0 mode becomes slower than the ultrasonic velocity in air which makes excitation and reception of such mode complicated. For excitation of both modes, we propose instead a single air-coupled ultrasonic transducer to use linear air-coupled arrays, which can be electronically readjusted to optimally excite and receive the A0 and S0 guided wave modes. The objective of this article was the numerical investigation of feasibility to excite different types of ultrasonic-guided waves, such as S0 and A0 modes in thin plastic films with the same electronically readjusted linear phased array. Three-dimensional and two-dimensional simulations of A0 and S0 Lamb wave modes using a single ultrasonic transducer and a linear phased array were performed. The obtained results clearly demonstrate feasibility to excite efficiently different guided wave modes in thin plastic films with readjusted phased array.

Screening And Genome Sequencing of a di-n-butyl Phthalate Degrading Bacterium J2 Isolated From Peanut Field Soil

Di-n-butyl phthalate (DBP) is commonly used plasticizers in agricultural plastic films, and is a priority pollutant due to its toxicity to human health. A newly isolated strain J2, which used DBP as its sole carbon source, was screened from peanut filed soil by continuous enrichment cultivation. Based on morphological, physiological characteristics and 16S rRNA gene sequence analysis (GenBank accession No. OK598965), it was identified as Priestia sp. J2. The research results revealed the optimal conditions for DBP degradation as 35 oC and pH 8.0. The strain could effectively degrade 97.6% DBP within 5 days. Substrate tests showed that strain J2 could utilize shorter side-chained PAEs, but could not utilize long-chained PAEs. The whole genome comprises a complete chromosome of 5,067,299 bp and four plasmids of 147,924 bp, 75,940 bp, 11,604 bp, 11,333 bp (GenBank accession No. CP086208-CP086212). This genome harbors 5,585 predicted protein-encoding genes, 130 tRNA genes, and 42 rRNA genes. Gene annotation analyses showed a DBP-degrading gene contained an open reading frame of 930 bp, and the enzyme was named Est-J2-1. The amino acid sequence of the Est-J2-1 exhibited no significant homology with those of reported DBP-degrading enzymes, suggesting the enzyme is a novel enzyme. The gene of Est-J2-1 was found to be located on the chromosome. This study provided strain resource for DBP removal from farmland and other environments.

Temperature profile measurement applications of moving webs and roll structures with intelligent roll embedded sensor technology

An intelligent roll for sheet and roll cover temperature profiles is a mechatronic system consisting of a roll in a web handling machine that is also used as a transducer for sensing cross-machine direction (CD) profiles. The embedded temperature sensor strips are mounted under or inside the roll cover, covering the full width of the roll’s cross-dimensional length. The sensor system offers new opportunities for online temperature measurement through exceptional sensitivity and resolution, without adding external measurement devices. The measurement is contacting, making it free from various disturbances affecting non-contacting temperature measurements, and it can show the roll cover’s internal temperatures. This helps create applications that have been impossible with traditional technology, with opportunities for process control and condition monitoring. An application used for process analysis services without adding a roll cover is made with “iRoll Portable Temperature” by mounting the sensor on the shell in a helical arrangement with special taping. The iRoll Temperature sensors are used for various purposes, depending on the application. The two main targets are the online temperature profile measurement of the moving web and the monitoring of the roll covers’ internal temperatures. The online sheet temperature profile has its main utilization in optimizing moisture profiles and drying processes. This enables the removal of speed and runnability bottlenecks by detecting inadequate drying capacity across the sheet CD width, the monitoring condition of the drying equipment, the optimization of drying energy consumption, the prevention of unnecessary over-drying, the optimization of the float drying of coating colors, and the detection of reasons for moisture profile errors. This paper describes this novel technology and its use cases in the paper, board, and tissue industry, but the application can be extended to pulp drying and industries outside pulp and paper, such as the converting and manufacture of plastic films.

Antimicrobial Potential of Plastic Films Incorporated with Sage Extract on Chicken Meat

The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in prolonging the storage of chicken breast meat without affecting their quality.

Evaluation of Starch-Biopolymer Synthesized from Chaffs of Common Beans (Phaseolus Vulgaris)

The resilience and resistance of plastics to decomposition have led to the imperative need to develop biodegradable plastics as a viable solution. Starch biodegradable films have been synthesized recently as a sustainable replacement for synthetic plastics. Acid hydrolysis was used to synthesize starch nanoparticles from the chaffs of Common Beans (Phaseolus vulgaris) which was mixed with varying percentages of Low-Density Polyethene (LDPE: C-S; 95:5, 90:10, 85:15, 80:20) by the heating process. Characterization of the starch nanoparticles was done using the FTIR, TEM, and EDX while the physicochemical properties (Compression, Hardness, and Biodegradation) of the produced biopolymers (LDPE-Starch) were also studied. Starch spectrum was observed at 3436cm-1 and other functional groups such as Carbonyl group, Sulphones, and Acetylenic groups were also revealed by Fourier Transmission Infra-Red Spectroscopy. The starch nanoparticles were observed to be flake-like shapes with a size of 50nm as shown by the TEM analysis. Of all the varying compositions of starch biopolymer synthesized, 90:10LDPE/B-S had the best hardness properties with 40.78HD and constant degradation was observed within weeks 3 and 4 in 95:5 (LDPE-B.S) with a peak value of 0.7705%. The study revealed the economical and sustainable production of starch nanoparticles from the chaffs of Common beans (Phaseolus vulgaris) and its use for the improvement of biodegradable plastic films.