Japanese Industrial Standards Research Articles

A Proposal of a New Temperature Rise Test Method for Series Reactors Connected with High Voltage Power Capacitors

In substation, phase advance capacitors are used to improve the power factor. Series reactors are generally connected with the capacitors to reduce the waveform distortion and suppress the inrush current. The fifth harmonic current usually flows into the series reactors for a high voltage power capacitor. Japanese Industrial Standards provide three types of temperature rise test methods. Each test method has its own problems. To alleviate them, we have devised a new test method called “Middle Frequency Test” which uses a meddle frequency between the fundamental and fifth harmonics for excitation. This paper presents an implementation method and demonstrates the usefulness of the proposed test method.

PRODUCTION PROCESS OF ZX - 200 5G SIDE FRAME AT PT. OHGISHI INDONESIA

Excavator is one of the heavy equipment used to move material from one place to another. The excavator consists of several parts, one of which is the side frame. The side frame is the bottom part of the excavator which functions to hold the load, steer, support the unit and act as the driving force for the heavy equipment. The data collection method was taken by reading data supporting books, making direct observations and conducting question and answer. The side frame uses SS400 material, SS 400 steel is low carbon steel with carbon content (max 0.17% C) or low carbon steel according to ASTM (American Society for Testing Materials) A36 or JIS (Japanese Industrial Standards) G3101 standards. SS 400 steel can only be hardened by surface hardening such as caburizing. In the process of making the ZX – 200 5G side frame, the first process is tack welding idler bracket and motor bracket which uses 322 watt amperes and 29 – 36 V voltage. Then full idler and motor bracket welding takes ±42 minutes. Followed by the process of full welding of the idler and motor bracket with the middle body using amperes of 275 – 300 A, voltage 33 – 35 V. Then the process of making the center line and ending the process of visual inspection of the welds.

DEPENDENCE OF POLYURETHANE CONTENT ON PHYSICAL AND MECHANICAL PROPERTIES OF WOOD FIBER/PALM KERNEL SHELL COMPOSITES

Wood-based composites with different ratiosof wood fiber (WF)/palm kernel shell (PKS) and polyurethane (PU) content have been prepared using the wet-process method. Samples of WF85/PKS15 and WF75/PKS25 were fabricated where each sample was applied with 20% and 70% of PU contents and itsphysical and mechanical properties had beenstudied. The physical results show that the samples with 70% of PU content were denser, had low porosity, low moisture content,and low water absorption. Surface morphology observation shows both series samples with high PU content tend to form tube-like shape with different diameter. Inmechanical studies, generally, the sample with high PKS and PU possesseshigh flexural strength, flexural modulus, tensile strength, tensile modulus,and hardness. However, theincreased of PKS content in the composite reduces the tensile strength for both sampleswith 20% and 70% of PU. The effects of the binder and palm kernel shell in the composite were also explained. Based on the Japanese Industrial Standard (JIS) A 5905 standard, the sample composites meet therequirement under medium density fiberboard (MDF) category and classified as board type 5 which suitable as furniture, house,and automotive interior design and construction materials.

In situ scanning electron microscopy of hydrogen embrittlement by near atmospheric-pressure hydrogen microplasma jet.

Elucidation of microstructures responsible for hydrogen embrittlement is hoped for research and development of high-strength low-alloy steel. For this purpose, a novel in situ scanning electron microscopy method of hydrogen embrittlement was developed by using a near atmospheric-pressure hydrogen microplasma jet excited by pulsed glow discharge. By the developed method, propagations of hydrogen embrittlement cracks in typical martensitic steel, Japanese Industrial Standards SCM435 steel, were successfully observed at frame rates at least up to 10.2Hz with the same image quality as in high vacuum. The hydrogen microplasma jet neither elevated the specimen temperature nor damaged the specimen surface. Strain evolution prior to the crack propagations was also successfully observed in conjunction with the digital image correlation technique. It was found that a small electron scattering cross section of the hydrogen molecule, a large density of hydrogen ions in the near atmospheric-pressure microplasma jet, and stabilization of the glow discharge by the electron beam of the scanning electron microscope play a crucial role in the realization of the in situ observations.

Performance of glued laminated timber (glulam) made from Rubberwood with different lamina assembly patterns and adhesive spreads rates

Glued laminated timber (glulam) is a great building material with strong mechanical properties that comprises laminated layers of wood (lamina) glued together with long-lasting structural adhesives. As the supply of large dimensional lumber for construction projects has been in shortage, glulam is the ideal material to replace the lumber because it can be made in various sizes and shapes, including unique arches using relatively small dimensional lumber. This research aims to investigate the effects of different lamina assembly patterns and adhesive spread rates on the physical and mechanical properties of rubberwood glulam. For this purpose, the lab scale of the 3-ply glulam was made from homogenous grades lamina of low-MOE, average-MOE, and high-MOE. In addition, the lab scale of the 3-ply glulam was also produced from mixed grades lamina of low-high-low-MOE and high-low-high-MOE. The glulam was tested to evaluate the physical and mechanical properties based on the Japanese Industrial Standards for glulam (JAS 234-2003). The results show that the lamina assembly patterns significantly affect the mechanical properties of the glulam. Accordingly, the glulam made from a high-MOE lamina at its compression and tension surfaces has the best mechanical properties compared to that made from the other assembly patterns. In addition, although the difference was insignificant, the results showed that adhesive spread rate has positively affected the mechanical properties of the glulam. The results showed that Rubberwood has the potential to be used as raw material for glulam production.

Three-dimensional modelling of tensile behaviour for standard aluminium specimens

The effect of specimen width and incorporation of a circular hole on the tensile behaviour of commercially available aluminium alloy AA 1100 was studied using finite element analysis (FEA) for convergence with the already published experimental work of other researchers. Static structural analysis was conducted to simulate tensile loading of Japanese industrial standard (JIS) specimen JIS Z 2201 No. 13B and No. 5 until the point of the ultimate tensile strength (UTS) was reached. A strain rate of 0.25 mm/s was used for both the neat specimen and the one bearing a circular hole of 8 mm in diameter at the centre of the specimen. The numerical results exhibited a good agreement with the experimental work by comparison of the percentage elongation for numerical and experimental data. The normal stresses calculated using analytical and numerical approaches also reflected a good convergence. For neat specimens of JIS Z 2201 No. 13B and No. 5, a 100 % increase in specimen width enhanced the load required to reach UTS by 100 %, while elongation was increased by 30 %. On the other hand, for specimens of JIS Z 2201 No. 13B and No. 5, bearing an 8 mm circular hole reduced the load required to reach UTS by 300 %, while elongation was only increased by 25 %. The 200 % decrease in load required to reach UTS and 57 % reduction in elongation was observed by incorporating an 8 mm circular hole in the neat specimens.

Fabrication and Characterization Studies of Alginate Biocomposite Film for Potential Use in Food Sensing Application

This research is about the fabrication and properties study of the alginate bio-composites film for potential use in food sensing applications. A response surface methodology (RSM) was employed to optimize the concentration of sodium alginate (1 to 5% w/v), glycerol (0.4 to 0.8% w/v), and maltodextrin (0.4 to 0.8% w/v) as a function of the tensile strength (TS) and elongation at break (EB) and toughness (T) of the biofilms. The coefficientdetermination (R2) result obtained for TS against alginate, glycerol and maltodextrin is 81.05%, while for EB and T are 32.07% and 64.70% respectively. It showed that the addition of sodium alginate, glycerol and maltodextrin at different concentrations had significantly affected the TS but no effect on EB and T was observed. The optimization study of the film produces two conditions which are conditions 1 and 2. The optimum conditions parameter for condition 1 is a film with 3.0% alginate concentration, 1.0g/g of glycerol content, and 1.50g/g of maltodextrin content while condition 2 was 1.0% of alginate concentration, 1.0g/g of glycerol content and 0.0g/g maltodextrin content. The values of the TS obtained at the optimized condition were 4.75 MPa and 22.99 MPa which is lower than the predicted value of condition 1 (7.0 MPa) or the maximized TS at condition 2 respectively. The thickness value of edible films in this study had an average of 0.54 mm which was higher than the maximum standard thickness of edible films according to the Japanese Industrial Standard (JIS) which is 0.25 mm. Water Vapour Permeability (WVTR) study indicated that all alginate films in this study had a value higher than the JIS 1975 standard of WVTR for edible films which is at a maximum of 10 g/m2/24 hours. The natural colour from Clitoria Ternatea was successfully immobilized into the alginate-based film and the film become dark purple. Based on the result obtained, prediction equations for responses studied are adequate to describe the experimental data on tensile strength, elongation at break, and toughness. However, further modifications are necessary for improvements in mechanical characteristics in the future.

Effect of maleic anhydride compatibilizer addition on mechanical properties of polylactic acid (PLA)/cellulose acetate (CA) composites film

Environmental problems caused by the use of undegradable conventional plastics are still the major issue. According to the Badan Pusat Statistik (BPS) in 2021, plastic waste in Indonesia accumulated as much as 66 million tons per year and is expected to raise gradually. PLA and CA, derived from renewable resources, are biodegradable, thermoplastic, resistant to pressure, and are often used as raw materials for the manufacture of composite plastics. PLA is hydrophobic and CA is hydrophilic, so a compatibilizer is needed as a substance that can improve the mechanical properties, compatibility, and homogeneity of the resulting composite film. This research aims to obtain the ratio of PLA/CA and the concentration of maleic anhydride (MA) compatibilizer to produce PLA/CA composites film with good mechanical strength and according to packaging material standards. The method in this research is solvent casting by synthesizing composite films through sample preparation, modification of CA with MA, grafting of PLA/CA and MA, synthesis of composite films of PLA/CA and MA, as well as several characteristic tests. The results showed that the obtained films were identified as having PLA, CA, and MA, had a relatively smooth surface and were degraded at a temperature treatment of 543 o C. The best film was obtained from mass variations of PLA/CA and MA (6:4:1.5 gram) with a tensile strength of 7.38 MPa, and elongation at break reached 18.11% and met the packaging standard values by Japanese Industrial Standard (JIS).

Pengaruh Konsentrasi Pemlastis Pada Aplikasi Edible Coating Dari Tepung Pektin Apel Pada Buah Tomat

The edible coating is a protective layer that can regulate the rate of respiration. The purpose of the study is to see the effect of adding a plasticizer to the edible coating application of apple pectin flour on tomatoes. Edible coating was made with 2% apple pectin flour and plasticizers glycerol and sorbitol in concentrations of 0.5 percent, 0.6 percent, 0.7 percent, 0.8 percent, 0.9 percent, and 1 percent (v/v). Plasticizer concentrations of 1 percent glycerol and 0.7 percent sorbitol were found to be optimal. The addition of 1% glycerol resulted in 3.673 percent tomato fruit weight loss with a shelf life of more than 20 days, and the addition of 0.7 percent sorbitol resulted in 5.718 percent tomato fruit weight loss with a shelf life of more than 7 days. The percentage of elongation (2.47 percent and 1.125 percent), tensile strength (17.10 and 6.61 Mpa), water vapor transmission rate (5.955 and 7.070 g/m2/day), and thickness (0.06 mm) of edible coating with 1 percent glycerol and 0.7 percent sorbitol were obtained. The thickness, tensile strength, and water vapor transmission rate all met Japanese Industrial Standards, according to these results.

High Precision Nut Threading Using Real-Time Tapping Torques Monitoring

With the increasing demand for safety and automatically locking nuts, it’s important to guarantee a consistent nut quality. Traditionally, a floating tapping machine has been used for high-speed production, but it has unstable thread quality because of the existing gap between the tap and nuts holder. To overcome this problem, a stable tapping machine must be considered for tapping high precision threaded nuts and the tapping process must be monitored in real-time for the internal threads quality to reduce the inspection time. First, this article used the relative movement between a nut and its tap to establish the dimensionless tapping material removal rate. Furthermore, for creating the tapping torque curve of a specific nut, a few nuts were tapped to obtain the maximum value and variation of the tapping torque at various tapping speeds. Then, based on the differences in the hole sizes, chamfer depths, and material nature, the quality assurance range can be constructed as a real-time monitoring model for high precision thread manufacturing. To demonstrate the feasibility of the proposed procedure, tapping for carbon steel, alloy steel, and titanium alloy nuts was performed and the monitored tapping torques matched the nut quality classification of Japanese Industrial Standards (JIS).

EIS and Electrical Investigations on (1D) Multiwall Carbon Nanotubes as NAM Additive for Automotive Lead-Acid Battery

Currently, an application like Start-Light-Ignition (SLI) for the automotive industry prefers flooded type lead-acid energy storage and is also vastly adopted energy storage. Lead-acid cells in a battery comprise negative and positive electrodes, separated by an insulating material with industrial-grade H2SO4 as an electrolyte. The objective of the present investigation is to overcome the progressive sulphation in the negative electrode and improve the battery’s electrical performance. With one dimensional (1D) carbon nano tubes (CNTs) as an additive in the negative electrode of an automotive flooded lead-acid battery (LAB), we try to improve the battery performance. In this study, negative electrodes of LAB were prepared by loading traditional constituents like lead oxide, H2SO4, H2O, polyester binder, lignosulphonate, and Blanc Fixe while limiting MWCNTs to 0.2%. The performance studies of the prepared batteries were conducted, as per Japanese Industrial Standards (JIS). Both the batteries prepared with and without MWCNTs as an additive in negative active materials (NAM) were subjected to electrical assessments to understand the cold cranking ability, cycling stability, and charge acceptance. The batteries were also analyzed by electrochemical impedance spectroscopy (EIS) where the lower charge transfer resistance was observed with the battery having MWCNTs when compared to the control (without MWCNTs) battery. The present investigations established that the MWCNT material, as an additive, played a vital role in laying an improved conductive network across the negative electrodes for higher cycling applications (ISS/Hybrid/EV).

Characteristics of Particleboard from Sorghum and Nypa Fruit Skin Fiber Bonded with Citric Acid-Sucrose Adhesive

Sorghum (Sorghum bicolor L.) and nypa fruit skin fiber (Nypa fruticans Wurmb.) can be used as raw materials in the manufacture of eco-friendly particleboard (PB) using natural adhesives based on citric acid and sucrose. This study aimed to determine the characteristics of PB from sorghum and nypa fruit skin fiber using citric acid-sucrose adhesive and also to determine the optimum composition of raw materials and adhesives in the manufacture of PB. The PB panel was made by mixing raw materials and adhesives with variations in the composition of nypa fruit skin fiber:sorghum raw materials 100:0, 25:75, 50:50, and 0:100, and variations in the concentration of citrate-sucrose adhesive were 20% and 30%. The target dimensions and density of PB were 25 cm x 25 cm x 0.9 cm and 0.8 g/cm3, respectively. The PB was hot-pressed for 10 min at 200oC with a pressure of 11 MPa. The physical and mechanical properties of PB were determined using the Japanese Industrial Standard (JIS) A 5908:2003 standard. The results showed that the PB has average values of moisture content of 11.94%, density of 0.79 g/cm3, water absorption of 52.96%, thickness swelling of 13.21%, modulus of elasticity of 1029.55 N/mm2, modulus of rupture of 6.46 N/mm2, internal bonding of 0.18 N/mm2, and screw holding power of 43.12 N. Variation of raw materials composition has a significant effect moisture content, water absorption, thickness swelling, modulus of elasticity, and modulus of rupture. Applying 30% adhesive content significantly affected water absorption, thickness swelling, and screw holding power. Keywords: citric acid-sucrose, nypa fruit skin, particleboard, sorghum

KARAKTERISTIK FISIKOKIMIA EDIBLE FILM BERBASIS PEKTIN KULIT JERUK BABY JAVA (Citrus sinensis) DAN PATI JAGUNG DENGAN PLASTICIZER GLISEROL

Baby Java orange is one sweet orange variant with a high pectin content on its skin. Pectin and starch are examples of the main ingredients in making edible films. Besides its economical price, corn starch is also commonly used in preparing edible films as the biopolymer material that can produce a matrix used for the edible film preparation process. The addition of glycerol plasticizers can improve the structure of the film. This study aimed to determine the effect of pectin concentration of Baby Java orange peel and glycerol on the physicochemical characteristics of the resulting edible film and determine the formulation with the highest value in the manufacture of the edible film according to the Japanese Industrial Standard (JIS). This study used a Completely Randomized Design (CRD) with two factors. The first factor is Baby Java skin pectin concentration (15%, 25%, and 35% %b b/b starch), while the second factor is glycerol concentration (10%, 20%, and 30% v/v). The edible films were then analyzed for their moisture content, thickness, solubility, color, tensile strength, and water vapor permeability. The results show that the concentration of pectin and glycerol with the addition of corn starch significantly affects the parameters of moisture content, solubility, thickness, tensile strength, color, and water vapor permeability tests. The optimum formulation in the preparation of edible films according to JIS was the formulation with the addition of 15% pectin and 20% glycerol, which resulted in 6.24% of moisture content, 76.57% solubility, 0.25 mm thickness, 0.50 MPa tensile strength, 54.98 lightness, 3.66 blueness, -1.48 appearances and 1.42 g.mm/m2.h.kPa water vapor permeability

Characteristics of Liquefied Adhesive Made of Oil-Palm Trunk (OPT) and their Application for Particleboard’s Binding

Liquefied adhesive made of oil-palm trunk (OPT) was produced according to bio-refinery concept. In this context, OPT was converted into 20-60 mesh powder and it was converted into liquid via liquefaction process involving reaction of thermo-chemical and resulting in pre-polymer like phenol-formaldehyde (PF). The characteristics were determined based on Indonesian Standard (SNI) 06-4567-1998 for PF resin. The pre-polymer then was used for binding of three composition types of particleboards, namely 100% OPT particle, 50:50 mixture of OPT and jabon wood particles, and 100% jabon wood particle. Evaluation of the board was carried out based on Japanese Industrial Standard (JIS) A 5908-2003 for particleboard. Results of this study exhibited properties of the pre-polymer generally met the SNI except its viscosity was too high. For overcoming this, the pre-polymer was then diluted in solvent until it was appropriate to be placed in spray gun and passed the nozzle for further use as binder. Physical properties of the board showed moisture content (MC) and density fulfilled JIS standard however thickness swelling was up to limit. Mechanical properties of the board showed only modulus of elasticity (MoE) met the criteria of JIS while modulus of rupture (MoR) and internal bonding were below the target. Statistically, two parameters, namely MC and MoE were different among the boards. For sum up, making adhesive from oil-palm stem using bio-refinery method was feasible and it can be applied for particleboard binding.

Antimicrobial effects of bacterial binding to a dialkylcarbamoyl chloride-coated wound dressing: an in vitro study.

Wound dressings that inactivate or sequestrate microorganisms, such as those with a hydrophobic, bacteria-binding dialkylcarbamoyl chloride (DACC) surface, can reduce the risk of clinical infections. This 'passive' bioburden control, avoiding bacterial cell wall disruption with associated release of bacterial endotoxins aggravating inflammation, is advantageous in hard-to-heal wounds. Hence, the full scope of DACC dressings, including the potential impact of higher inoculum densities, increased protein load and different pH on antibacterial activity, needs to be evaluated. The Japanese Industrial Standard (JIS) L 1902 challenge test was used to evaluate the antimicrobial activity of the DACC-coated dressing against several World Health Organization (WHO)-prioritised wound pathogens (e.g., meticillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, microorganisms with extended-spectrum beta-lactamases and Acinetobacter baumannii), the effect of repeated bacterial challenge in an adverse wound environment, and antimicrobial performance at wound-related pH. High antibacterial activity of the DACC-coated dressing against the WHO-prioritised bacteria strains by its irreversible binding and inhibition of growth of bound bacteria was confirmed using JIS L 1902. At increased inoculation densities, compared to standard conditions, the DACC-coated dressing still achieved strong-to-significant antibacterial effects. Augmenting the media protein content also affected antibacterial performance; a 0.5-1 log reduction in antibacterial activity was observed upon addition of 10% fetal calf serum. The pH did not influence antibacterial performance. The DACC-coated dressing also sustained antibacterial activity over subsequent reinfection steps. It can be assumed that the DACC-coated dressing exerts beneficial effects in controlling the wound bioburden, reducing the overall demand placed on antibiotics, without using antimicrobial substances.

Permanent-Magnetically Amplified Brake Mechanism Compensated and Stroke-Shortened by a Multistage Nonlinear Spring

Electromagnetic (EM) brakes are widely used but consume electricity continuously to maintain their activated state. In this letter, for efficient braking and idling of robots and vehicles, we proposed a concept of a brake mechanism using a permanent magnet for the amplification of the pressing force between brake pads, allowing for the brake torque to be steplessly regulated by a minimal external force. The prototype of the proposed mechanism was developed with a newly devised compensation spring—not the conventional conical coil springs—comprising two linear springs to shorten the pad-detaching stroke. For proof of concept, evaluation experiments based on the Japanese Industrial Standards were conducted. Both the maximum static and average dynamic friction torques increased to 161.0% and 192.9%, respectively, when identical pads of an EM brake were used for comparison. Power saving was also achieved when braking for longer than 0.43 s; the torque–energy efficiency increased by 8.7 when measured for 1.0 s, successfully revealing the effectiveness of the proposed principle. Further, based on the force–displacement characteristic of the compensated magnet, the theoretical response time was numerically analyzed as 13.6 ms—comparable to the contrasted EM brake—validating the actual behavior of 14.0 ms.

Wind Loading of Photovoltaic Panels Installed on Hip Roofs of Rectangular and L-Shaped Low-Rise Buildings

Many residential houses in Japan have hip roofs with pitches ranging from 20° to 30°. Recently, roof-mounted photovoltaic (PV) panels have become popular all over the world for environmental conservation. The design of PV systems in Japan is usually based on the Japanese Industrial Standard (JIS) C 8955 (2017). However, the standard does not provide wind force coefficients for PV panels installed near roof edges (up to 0.3 m from the edge) because flow separation at the roof edges causes large up-lift forces on such panels. In this paper, we investigated the wind force coefficients for designing PV panels installed on hip roofs of rectangular and L-shaped low-rise buildings. The roof pitch was set to 25° as a typical value. Rectangular panels were installed almost over the whole roof, including the edge zones. Because the thickness of PV panels and the distance between PV panels and the roof are both as small as several centimeters, it is difficult to make wind tunnel models of PV systems with the same geometric scale as that for buildings. We focused on a numerical simulation using the unsteady Bernoulli equation to estimate the pressures in the space between PV panels and the roof. In the simulation, we used the time histories of wind pressure coefficients on the bare roof, which were measured in a turbulent boundary layer. We propose installing PV panels with small gaps between them along their short sides. The gaps may reduce the wind loads not only on the PV panels but also on the roofing due to pressure equalization. We discuss the optimum gap width from the viewpoint of wind load reduction.

A sheet pocket to prevent cross-contamination of formalin-fixed paraffin-embedded block for application in next generation sequencing.

Formalin-fixed paraffin-embedded (FFPE) blocks are used as biomaterials for next-generation sequencing of cancer panels. Cross-contamination is detected in approximately 5% of the DNA extracted from FFPE samples, which reduces the detection rate of genetic abnormalities. There are no effective methods available for processing FFPE blocks that prevent cells from mixing with other specimens. The present study evaluated 897 sheets that could potentially prevent cell transmission but allow for the movement of various solvents used in FFPE blocks. According to the International Organization for Standardization and Japanese Industrial Standards, six requirements were established for the screening of packing sheets: 1) filter opening ≤5 μm, 2) thickness ≤100 μm, 3) chemical resistance, 4) permeability ≥1.0 × 10−3 cm/s, 5) water retention rate <200%, and 6) cell transit test (≤2 cells/10 high-power fields). Polyamide, polyethylene terephthalate, and polypropylene/polyethylene composite sheets met all criteria. A pocket, which was designed to wrap the tissue uniformly, was made of these sheets and was found to effectively block the entry of all cell types during FFPE block processing. Using a sheet pocket, no single cell from the cell pellet could pass through the outer layer. The presence or absence of the sheet pocket did not affect hematoxylin and eosin staining. When processing FFPE blocks as a biomaterial for next-generation sequencing, the sheet pocket was effective in preventing cross-contamination. This technology will in part support the precise translation of histopathological data into genome sequencing data in general pathology laboratories.

Analysis of dynamic fracture propagation in steel pipes using a shell-based constant-CTOA fracture model

In this paper, a finite element (FE) model with shell elements using a constant crack tip opening angle (CTOA) as fracture criterion was implemented for the simulation of dynamic fracture propagation in steel pipes. The new model was developed to improve computational efficiency over current CTOA models while retaining a high level of numerical accuracy. The commercial FE code ABAQUS was used to generate the meshes and perform the analyses. The proposed model was first used to reproduce data from an existing CTOA model of an American Petroleum Institute (API) X65 steel, matching the steady-state fracture velocity within a maximum difference of 5% while drastically reducing the computational time required. The model was then used to analyze recent experimental data from a full-scale pipe burst test of a Japanese Industrial Standard (JIS) steel STPG370, matching the crack velocity data within 4%. It was thereby demonstrated that FE analysis using this shell-based constant-CTOA model is an efficient method for describing dynamic fracture propagation in steel pipes and can be used as an engineering tool to develop fracture driving force based on CTOA.

Effects of Additional Polyvinyl Alcohol (PVA) on the Physiochemical Properties of Chitosan-Glutaraldehyde-Gelatine Bioplastic

This study investigated the effects of additional PVA on the physicochemical properties of the chitosan-glutaraldehyde/gelatin bioplastic composite. The best results of the bioplastic film were obtained at a concentration of 3% PVA, with a tensile strength value of 3.3 MPa, flexibility reached 54%, a thickness value of 0.24 mm, percentage of inhibition against E. coli and S. aureus was 21.8% and 8.8% respectively. The FTIR spectrum results showed no change in the wavenumber of the chitosan and gelatin chitosan spectrum with OH, CO, and NH functional groups. The spectrum indicates that only physical interactions occurred. The bioplastics are similar in thermal stability and have slight differences in bioplastic morphological contours. The average thickness of the bioplastics is between 0.20–0.26 mm. Based on the Japanese Industrial Standard (JIS), all bioplastics meet the standard thickness, which is &lt; 0.25 mm, excluding chitosan, which has a thickness of 0.26 mm. The addition of PVA into the bioplastics structure increased the hydrophobicity, pH resistance, and flexibility of bioplastics. Meanwhile, additional PVA decreased biodegradability, only degraded by 60% at eight weeks. Based on these data, not all bioplastics can meet the degradation time criteria set by the international bioplastic standard ASTM D-6002, that bioplastics must be 100% degraded within eight weeks. Bioplastics made from chitosan and chitosan-gelatin have been degraded by 90% for 48 weeks. Based on the antibacterial properties, the inclusion of PVA into the bioplastic structure enhances the antibacterial properties.