Advances in the Standards and Applied Sciences
Volume:1 Issue: 1, Autumn 2022

Nowadays, medical implants are widely used in treating, monitoring, and restoring limb function. These implants are made of biocompatible artificial materials and are planted in patients’ bodies for medical purposes usually for a long time. One reason for the boost in the applications of these devices is the increase in the elderly population given the rise in life expectancy, especially in developed countries. Implantation of fake implant can cause infection and pain in the patient who use the implant. Therefore, the existence of a reliable supply chain is necessary. Blockchain is a good candidate as a platform for supply chain. blockchain transactions are irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks. Also register of new information should be done conditionally by nodes consensus, so the trustworthiness can be improved. The aim of this study is to develop a “Medical Implants Blockchain” as a national tracking supply chain system based on blockchain technology. This system is designed to support medical implants traceability and can be used to address the problems of implants expiration and record fraud. Registering and monitoring medical implants in an integrated system plays a key role in improving consumer safety. The system could provide valuable information for various levels of users, such as supervisory bodies, manufacturers, and consumers. Based upon blockchain information, design of a secure recommender system with preserving privacy is possible.

A nanofluid is a fluid in which particles with a size between 1 and 100 nm are permanently suspended in the base fluid. The addition of nanoparticles affects the thermophysical properties of the liquid. In this study, the effect of temperature and concentration of alumina and titanium dioxide nanoparticles on the thermal conductivity and dynamic viscosity of a base fluid comprised of water and ethylene glycol was investigated. The volume fraction of the nanoparticles was 0.05, 0.1, 0.5, and 1 %vol. and the test temperatures were chosen to be between 260 and 305 K. SEM and TEM were used to examine the nanoparticles' morphology and microstructure. XRD analysis was used to detect phases in nanoparticles. BET analysis was also used to determine the specific area and porosity of the nanoparticles. The hybrid nanofluids' thermal conductivity and dynamic viscosity were measured and compared to the base fluid. The results showed that the thermal conductivity of the Al2O3-TiO2/ethylene glycol-water hybrid nanofluid depended on the concentration of nanoparticles and temperature. The findings revealed that the thermal conductivity of hybrid nanofluids increases with temperature and nano-additive concentration. Moreover, the viscosity increases with the increasing volume fraction of nanoparticles. As the results show, the viscosity changes with temperature are more pronounced at higher concentrations.

We present the construction of a biodegradable colorimetric sensor on the microtube lid for formaldehyde determination via naked-eye detection and /or UV–Vis spectrophotometry. Alizarin Red S (ARS) was subjected as the effective reagent for formaldehyde detection by incorporation in a thin film of starch. The sensor was accredited by the reaction of formaldehyde with ARS based on a color response from purple to yellow at pH 12. The sensor characterization was obtained by Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscope (FE-SEM), and energy-dispersive X-ray (EDX) spectroscopy analytical methods. The effect of the main parameters on the detection of formaldehyde was studied and optimized. Under optimal conditions, the linearity range of colorimetric response was obtained in the concentration range of 0.15-10 mg L−1 with a determination coefficient (R2) of 0.9923. A limit of detection (LOD) of 0.05 mg L−1 and a relative standard deviation (RSD, n=5) of 1.2 % were achieved. This method presented a short response time (within 15 min) for the application as biosensing. Subsequently, the concentrations of formaldehyde in hair care products (hair shampoo and conditioner samples) were successfully obtained with good recoveries.

Portland cement (PC) is the most widely used material in the world. Cement production is one of the leading industries that cause pollution and emission of greenhouse gases. Alkali-activated cement concrete (AACC) has received particular attention as a suitable alternative to Portland cement concrete due to its acceptable properties and environmental impact. In this research, the type and amount of alkaline activator on the mechanical properties and workability of alkali-activated slag concretes are investigated. For this purpose, two types of sodium hydroxide and powdered sodium silicate activators were used in amounts of 2, 6, 10, and 14 weight percent of slag. The flexural and compressive strength of the concretes, were measured after 3, 7, 28, and 90 days of curing in water at a temperature of 20±2°C. X-ray fluorescence (XRF) and X-ray diffraction (XRD) were used for Chemical and phase analysis of slag. The flexural and compressive strength of the samples were measured according to ISO 679 and the results were compared with ASTM C150 requirements. The results showed that the highest strength was obtained in the sample with 10% sodium hydroxide and 6% sodium silicate. The strength value in 90 days is higher in the sample activated with sodium silicate than the sample activated with sodium hydroxide. The results of comparing the mechanical properties of the samples with PC, disclosed that AASC could be a suitable alternative to Portland cement.

The quality of the manufactured poly(vinyl chloride) (PVC) products depends on the type and amount of modifier or additive used in the formulation. Determination of this quality was performed according to the standard tests. In this study swelling test and degree of gelation, were used along with the two comparative methods including Differential Scanning Calorimetryand tensile tests. For this purpose, the PVC samples stabilized with the three type's commercial stabilizers, including commercial lead-based, Ca/Zn and OBS conducted with melt mix method in the laboratory internal mixer. In terms of thermal properties by the relation between the measured enthalpy of fusion of two crystallites phases, with chemical swelling results proved the qualitative re-sults of the dichloromethane resistance test (DCMT). Glass transition temperature of the modified PVC with all examined heat stabilizers were determined equal to 79°C for PVC stabilized with Ca/Zn compared with the value of about 77°C in lead stabilized PVC and 76°C in OBS stabilized PVC. The onset temperature corresponded to melting point of primary crystallites represented in highest value, around 195.1°C for PVC - Ca/Zn sample. Quantified degree of gelation measured with enthalpy ratio of two crystalline phases showed good agreement with the results of the chemical swelling test. From mechanical analysis, tensile strength at room temperature of PVC stabilized with Ca/Zn stabilizer showed the highest value among the other stabilizers. From all the results, it is evident that Ca/Zn showed high potential use as a safe and effective heat stabilizer for PVC to substitute traditional lead compounds

Mycotoxins in food and feed are important risk factor for public health. There are many test methods for determination mycotoxins in food and feed and their products. The most common mycotoxins test method is based on high-performance liquid chromatography, but depend on the matrix, it is essential to develop validated methods of analysis and detection of them in food products. This study evaluated two different detection methods for the determination and confirmation of ochratoxin A (OTA) in liquorice extract powder. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined with fluorescence detector and Liquid Chromatography with tandem mass spectrometry (LC-MS/MS). The results indicate that the LC-MS/MS method was more specific and sensitive for the analysis and confirmation of OTA in liquorice extract than HPLC method because of false positive in HPLC method in some sample. So to comply with OTA legislation and consumer health protection, improvements in OTA analytical methodology is essential.