Volume 20 Issue 2

Increasing concerns regarding plastic waste and its impact on the environment have prompted a global trend to replace plastic films with fiber-based packaging solutions. Though the heat-sealing of polyolefin films provides a simple approach for realizing flexible packaging, paper does not have the natural attributes required for such applications. Therefore, paper sealability must be achieved by other means such as coating or varnishing. This study accordingly investigated the basics of imparting heat-sealability to packaging paper using overprint varnish applied with a lab coater simulating flexographic printing. The sealing and grease resistance properties of the resulting paper were compared with those of commercially available polyethylene dispersion-coated paper and oriented polypropylene/polyethylene laminate. The results confirmed that sufficient capabilities were realized using the proposed method; though the varnished paper exhibited a lower seal strength than the reference plastic films, it exhibited adequate properties for package sealing regardless of applied temperature. These observations were subsequently discussed to inform recommendations for further investigation and development.

The heat and sound insulation properties of the heartwood and sapwood of willow (Salix alba L.) were investigated.  Based on the experimental results, it was determined that the density value of the heartwood of the willow tree was higher than that of sapwood, while the moisture value was lower in the sapwood. The thermal conductivity coefficient was 0.090 W/m.K in sapwood and 0.103 W/m.K in heartwood; thermal transmittance coefficient was 3.954 W/m².K in sapwood and 4.738 W/m².K in heartwood. The sound absorption coefficient was highest in sapwood at 1000 Hz frequency level with 0.37, while the highest in heartwood was 0.50 at 800 Hz frequency level. These results would be useful in willow wood structural applications.

The seung instrument is played in one key (minor key) because the fret spacing creates a diatonic scale. Due to the fact that the frets are not uniformly spaced on the fretboard, the fret spacing produces a diatonic scale (do-re-mi-fa, etc.) instead of a chromatic scale of a guitar, where all the flats and sharps are available. The partial frequency (Hz) versus harmonic number for string 1 and 2 are very linear. The gradients of the linear equations fit very well with the fundamental frequency of the open string 1 and 2 and fret 1 to fret 9. The sounds were digitally captured using a PicoScope oscilloscope and were subsequently examined utilizing PicoScope software, emphasizing Fast Fourier Transform (FFT). The Time Frequency Analysis (TFA) was obtained via Adobe Audition. The notes for open string 1 and 2 are A4 followed by B4, C5, D5, E5, F5, G5, A5, B5, C6, and D4 followed by E4, F4, G4, A4, B4, C5, D5, E5, F5 from the 9 frets respectively. The 10 notes up to the 9^th frets for string 1 and 2 are A4 to C5 and D4 to F5 respectively.

Hot water-treated cow waste (HWTCW) was used as an efficient, low-cost, and sustainable adsorbent for the removal of cresol red dye and chromium(VI) from aqueous solutions. Functional groups present on the biomass surface were identified by Fourier Transform Infrared Spectroscopy as -OH, C=O, C=C, and C-O. The scanning electron microscopy analysis showed the structure relating to plant tissue and rough surfaces that were heterogeneous and irregular, revealing the origin of the biomass to be cellulose, lignin, hemicellulose, and other water-soluble components. Maximum adsorption capacity was attained at biomass dosage of 40 and 50 mg, 120 and 140 min as the time of contact, pH of 4 and 3, and temperature of 40 and 45 °C for CR and Cr (VI) adsorption. The equilibrium data from the adsorption of CR and Cr (VI) followed Langmuir and Freundlich models with maximum uptake of 73.3 and 66.4 mg/g. For the adsorption of CR by HWTCW, a pseudo-first-order kinetic model provided a better fit, whereas a pseudo-second-order model provided a better fit for Cr (VI) ions adsorption. The analysis of ΔH gave positive values of 22.4 kJ/mol for CR and 46.0 kJ/mol for Cr (VI) indicating the endothermic process.

The cooling of pellets is necessary because pellets reach 70 to 90 °C after the pellet press. The reduction in temperature solidifies the pellets, which increases the pellet quality and reduces the risk of self-heating during storage. Industrially, pellet plants use outdoor air in counterflow coolers and cooling ends when the pellet temperature is approximately 5 °C above ambient temperature. Cooling performed in the summer could result in high temperatures in the pellet stacks during storage, and cooling at low temperatures and high airflows in the winter could cause quality problems. Therefore, the aim was to determine how cooling air temperature, airflow, and storage time impact the durability, hardness, and off-gassing of the pellets. The results showed that the highest durability (97.7%) and hardness (310 N) were achieved when cooling with low-temperature air and low airflow. Additionally, durability and hardness stabilized at high values (98.9% and 640 N) after 30 to 40 days of storage, regardless of the airflow and cooling air temperature used. Furthermore, it was found that high airflows reduce off-gassing regardless of the cooling air temperature. It is recommended that the industry reduce airflow during the winter and increase it during the summer to produce high-quality pellets and minimize the risk of self-heating.

Natural compounds have received extra attention through the current decade to suppress Helicobacter pylori growth. This study investigated the phytochemical characterization of Murraya paniculata fruit extract (MPFE) and its estimation against different activities of H. pylori. Moreover, the molecular docking interactions (MDI) of catechin and kaempferol with H. pylori proteins were examined. Several compounds were detected via high performance liquid chromatography in MPFE with various concentrations. Of these, catechin, kaempferol, chlorogenic acid, and vanillin were measured as 11,000, 4960, 4610, and 65.8 µg/g, respectively. Excellent inhibition of H. pylori was recorded with an inhibition zone 24.3 mm using MPFE compared to the activity of standard antibiotic (16.2 mm). Both minimum inhibitory concentration and minimal bactericidal concentration (MBC) of MPFE were 60.5 µg/mL, whereas it was 15.6 µg/mL using standard antibiotic. The biofilm of H. pylori was inhibited by 25, 50, and 75% of MPFE MBC to a level of 68.2, 84.1, and 90.4%, respectively. Hemolysis caused by MPFE was prevented to a level of 21.2, 6.8, and, 3.3% at 25, 50, and 75% of MIC, respectively. The authors implemented the MDI using Molecular Operating Environment (MOE) software. The screened compounds interacted well with the H. pylori protein (PDB ID: 3K1H).

Changes in the number of mold spores and the color difference values of cardboard were evaluated during the molding process of paper wine boxes. The experiment utilized three types of cardboard: single white industrial paperboard (Q), grey-offset paperboard (S), and grey-coated white paperboard (T), along with nine strains of mold collected from mold-contaminated paper wine box samples. The molds were identified using both morphological and molecular techniques. These nine strains were inoculated on the surface of the cardboard and incubated at 28 °C and 98% relative humidity for 28 days to assess the number of mold spores and the color difference values. The results indicated a gradual increase in both the number of mold spores and the color difference values over the 28-day period. The total spore count was highest on cardboard type Q, followed by S and T (T < S < Q), whereas the average color difference value followed the reverse order (S < Q < T). A linear correlation model between the color difference value and spore count was developed using Matlab software to fit the data, providing a method to predict the number of mold spores based on the color difference values of the cardboard.

The broomcorn plant (Sorghum bicolor (L.) Moench) is one of the main cereal crops and its grains are used in food and feed sectors while its stems are used in broom production and as a building material. Polylactic acid (PLA) is a biobased polymer that is widely used as a matrix material in natural fiber-reinforced composites. In this study, the aim is to use broomcorn plant stems, which are agricultural waste, as reinforcement in composite production. For this purpose, fiber was obtained by purifying broomcorn plant stems from woody cells with enzyme and NaOH. To easily comb the fibers, 10 wt% cotton was added and blended and turned into nonwoven fabric via needle punching. Then, PLA was combined with the matrix using the hot press method to produce single and double-layered composites. To characterize the broomcorn fiber reinforced composite material, strength, elongation, scanning electron microscopy, and Fourier transform infrared instrumental methods were used within the standards. According to the analysis results, broomcorn fiber has a high potential as a new reinforcement material suitable for composite production.

Vibrational methods, which are widely recognized non-destructive testing (NDT) techniques for timber, have garnered significant attention due to their ease of use, broad applicability, and reliable data output. These methods analyze the vibrational response of wood to external stimuli to assess its mechanical properties and internal structure. With advancements in sensor technology, signal processing, and computer simulation, the role of the vibrational methods in timber inspection has been largely expanded, enhancing both the scientific application and quality assurance of timber. This paper provides a comprehensive review of applications of vibrational methods in timber performance evaluation, focusing on its vibrational characteristics, underlying principles, and utility in detecting the physical and mechanical properties as well as internal defects of timber. Furthermore, potential future trends are discussed. Through analysis and research, valuable insights into the evolution of non-destructive timber testing technology are aimed to be provided by this review, and technological innovation in the timber industry is encouraged.

Silver nanoparticles (AgNPs) was synthesized via cheap bio-reduction and green method from leaf extracts of Azadirachta indica. The technique was optimized by studying variables such as  pH, temperature and concentration of the plant extracts. Gas Chromatography Mass Spectroscopy (GC-MS) results indicated the presence of phytonutrients such as Piperidine, 2-Azacyclooctanone, 4-Dibenzofuranamine, Lauric anhydride, Cyclododecanol and Sorbic acid as the phytonutrients responsible for the reduction and resilience process. FT-IR results gave absorption bands indicating the presence of -OH, -NH and -C=O functional groups, while particle size analysis revealed an average particle size which is less than 100 nm, thus confirming the formation of a nanoparticle. UV-Vis investigation of the nanoparticles synthesized with concentration of 12.5 mg/mL produced a strong plasmon resonance band with an absorbance of 0.223 at 400 nm after 24 hrs incubation time and at a minimal concentration of 6.25 mg/mL, the absorbance further decreased with a hypsochromic shift to 600 nm. The synthesized silver nanoparticles showed excellent optical property towards the selected heavy metals with virtual color change and a shift in absorbance towards higher value. Selective detection of Pb²⁺, Cu²⁺ and Cd²⁺ was also confirmed by UV-visible spectra which is well pronounced with Pb²⁺ having the highest absorbance.