bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective oxidation of AlGaAs aperture layers of a Vertical-cavity surface-emitting laser with a generation wavelength of 850 nm
Authors: Voropaev K O , Grebennikov V A , Zhelannov A V , Prokhorov A Yu , Seleznev B I 
Published: November 2021

Abstract
A study of the technology of selective oxidation of the buried AlGaAs layer used as an aperture layer in the structure of a Vertical-cavity surface-emitting laser has been carried out. Oxidation process was made as thermal oxidating in a humidified nitrogen atmosphere. The conditions of the oxidation process are described, images of the oxidation results and the dependence of the growth rate of the oxidized layer on the process temperature are presented. A technology for the formation of an oxide current aperture has been developed for vertical cavity surface emitting lasers with a generation wavelength of 850 nm, which makes it possible to accurately control the size and shape of the resulting aperture.
Data transformations when constructing a composite system quality index
Authors: Zhgun T V 
Published: November 2021

Abstract
The features of the data distribution can significantly affect the composite characteristics of objects, so composite indexes of objects must necessarily take into account the features of the data. Some types of data are characterized by distributions with a significant anomaly, when the vast majority of observations are concentrated near the boundary values. This type of data cannot always be characterized by an asymmetry coefficient. In addition, if the values of a variable are approximately symmetric with respect to zero or are concentrated near zero, the sample cannot also be characterized by the coefficient of variation. The paper proposes a transformation that allows us to identify the anomalous nature of variables using the signal-to-noise ratio. Variables are evaluated in the standard range, which is shifted to the right relative to zero. If it is necessary to logarithm, such a transformation will avoid the pressure of small values of variables that, after direct logarithm, would have large negative values. The application of logarithmic correction for the detected anomalous variables redistributes the values of the obtained weighting coefficients in the direction of a more correct interpretation and, in particular, solves the problem with the negativity of the weighting coefficients.
Synthesis, characterization and Stydy thermal stabilization effect of calcium complex of anthocyanin on the poly (vinyl chloride)
Authors: Ali Hikmat A , Shnawa Hussein A , Abidalimam Dhiaa A 
Published: November 2021

Abstract
In this study, calcium complex of anthocyanin was synthesized from anthocyanin, a flavonoid type natural phenolic product, which was extracted from eggplant peel. The structure of Ca-anthocyanin was characterized by FTIR spectroscopy. Its efficiency as bio-based thermal stabilizer to stabilize poly (vinyl chloride) was investigated and compared to that of Reapak B-NT/7060, a Ca/Zn-based commercial stabilizer. The influence of Ca-anthocyanin complex on the thermal degradation reaction of PVC was monitored by differential scanning calorimetry (DSC). The results indicated that the Ca-anthocyanin complex is an efficient thermal stabilizer and it reduces the rate of dehydrochlorination reaction of PVC already at a concentration as small as 2 phr, part per hundred of PVC resin. The thermal degradation reaction of PVC through the first degradation stage is clearly limited by the addition of Ca-anthocyanin complex as single (primary) stabilizer. Its efficiency is similar to that of Reapak B-NT/7060 used as reference stabilizer and it can enhance the performance of commercial stabilizer when used as co-stabilizer at mixing ratio (1:1). This study has allowed verifying and validating the usefulness of environmental friendly thermal stabilizer for PVC with very evident stabilization effect.
Preparation of Ethanol-Free Hand Sanitizers Gels and Studying its Sterile Efficacy
Authors: Fahad Mahmood M. , Al-Khuzaie Mohammed G.A. 
Published: November 2021

Abstract
Due to the spread of the Corona pandemic, the demand for hand sanitizers has increased dramatically. This led to a global scarcity of sterilizers. Therefore, this study was performed to produce and evaluate the effectiveness of new commercially available, cheap and ethanol-free hand sanitizers from various sources. The new hand sanitizers were prepared by mixing (glycerin) as a moisturizer and (carbomer) as thickening agents to form the gel with (tri-ethanolamine base) as pH neutralizer and (Tea tree oil, Aloe vera extract or Povidone 10%) respectively as antiseptic agents. All prepared hand sanitizers were examined with four kinds of bacteria (Enterococcus faecalis, E. coli, Pseudomonas aeruginosa and Staphylococcus aureus) And two kinds of fungi (Candida albicans and Aspergillus flavus). The prepared hand sanitizer gels showed good sterilization efficacy and similar to commercially prepared hand sanitizers (70% ethanol).
Removal of Carcinogenic Dyes Congo red (CR) and Bismarck brown Y (BBY) by Adsorption onto Reusable Hydrogels Derived from Acrylamide
Authors: Al-Niaeem Huda S , Abdulwahid Ali A , Hanoosh Whidad S 
Published: November 2021

Abstract
Hydrogels of acrylamide (AM), acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid (AMS), and acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid\graphene oxide (AMSGO) were prepared as adsorbents to remove carcinogenic dyes Congo red (CR) and Bismarck brown Y (BBY) from aqueous solutions. Hydrogels were characterized using FSEM and XRD analyses. For both dyes, the synthesized hydrogels demonstrated high adsorption capability at near-neutral pH. Experimental adsorption data were analyzed using the Langmuir and Freundlich isotherm models. It was found that the Langmuir model was more suitable for the experimental data. Kinetic studies found that the pseudo-second-order model demonstrated the best fitting to the experimental data. In addition, thermodynamic studies suggest that the adsorption process was spontaneous and endothermic. The prepared hydrogels were regenerated and reused in four consecutive cycles and it could be applied to remove anionic dyes from aqueous solutions as an effective adsorbent.
Synthesis, spectroscopic, and thermal studies of azo compounds from luminol and procaine with acetylacetone and their complexes
Authors: AlBaheley Noor Al , Fahad T A , Ali Asaad A 
Published: November 2021

Abstract
This The study entails the synthesis of two newly synthesized azo dyes luminol and procaine with acetylacetone (N1 and N2 correspondingly). Elementalanalysis, 1HNMR, T.G.A, and FTIR. have all been used to characterize dyes. These new dyes were reacted with Cpper and Nikel ionin 1:2 molar ratios to form of complexes of metals (II) with a general stoichiometry; CuL2, and NiL2 in complexes., FT IR, as well as the corresponding metal (II) complex, were used to characterize them. The dye acts as a bidentate ligand, according to elemental analysis and spectral results. The thermal properties of these compounds were investigated using thermogravimetric analysis (TGA). Thermal decomposition of these compounds is a process that occurs in stages.,
Production of biodiesel from heat-treated edible oil
Authors: Ahmed Hamza M , Abdeldaim Siddig O , Erwa Ibrahim Y 
Published: November 2021

Abstract
Among the urgent needs of developing countries are renewable sources of energy and a pollution-free climate. Acid-catalyzed transesterification for production of biodiesel from heat-treated peanut oil was investigated, and the produced biodiesel was characterized. The change in oil properties during the heating process was studied. The results showed an increase in the saponification number with heating time (from 115.47 mg KOH/g for crude oil, to 156.19, 172.7 and 184.68 mg KOH/g after 30, 60 and 120 minutes of heating respectively), a slight decrease in the acid value was observed after heating (from 5.91 to 5.87, 5.87 and 5.88 mg KOH/g after 30, 60, and 120 minutes of heating respectively) There is no obvious change in the refractive index during heating. The peroxide value increased from 2.87 to 3.95 meq O2/kg as the heating time was increased up to 60 minutes. The characteristics of the produced biodiesel were compared to ASTM D 6751 biodiesel standards and ASTM D 975 fossil diesel standards to validate their acceptability as a fuel in diesel engines, and a good agreement was observed. In contrast, to international standards, we notice that ethanol-based fuel has properties that are similar to those of global fuels. Peanut oil can be used to make renewable, low-cost biofuels that can meet a significant portion of the world’s energy needs.
Isolation, Preparation and Characterization of Polylactic Acid Film Reinforced with Nano silica
Authors: Ali Zainab A , Niamah Alaa Karem , Widad Salih Hannosh 
Published: November 2021

Abstract
Lactic acid was isolated by using microbial fermentation in whey media which was carried out by local strain Lactobacillus paraplantarum then polymerized using the acidic medium’s polycondensation method. FTIR and H-NMR were used to characterize the isolated lactic acid monomer and polyalctic acid (PLA), and the results confirmed the chemical structures of the isolated lactic acid and PLA. GPC techniques were used to determine the molecular weight and molecular weight distribution of the prepared PLA; the result showed that the Polydispersity index (PDI) was 2.51. The Biodegradable composite films of poly lactic acid (PLA)/Nano silica powder were prepared by the composite film casting method using dichloromethane as solvent. In contrast, Nano silica was synthesis from hydrolysis of tetra ethoxysilane and was loaded in PLA in 1 to5 wt. %. The films were subjected to a tensile strength study. Thermogravimetric analysis (TGA) and differential thermal analysis (DSC) were used to evaluate PLA. Also, water absorption of the prepared composites was studied, and the result showed that the thermal stability and water absorption of these prepared films were increased with an increasing percentage of Nano silica, while the percentage of crystallinity of the PLA evaluated from DSC was 28 %.
A mathematical optimization model for secondary settler
Authors: Bakiri Zahir 
Published: November 2021

AbstractThe study of secondary settler modelling, which aims to establish the main model (one-dimensional-1D model), which is involved in some fundamental processes of the hydrodynamic behaviour of this liquid/solid separation unit and to engender variations of the sludge blanket height as a function of the operating parameters and maintaining of the municipal wastewater treatment plant of Setif. The objective of this research is focused on solid/liquid separation in the secondary settler by attempting a mathematical model that allows us to evaluate the sedimentation velocity as a function of the sludge settleability parameters.
A review on graft compatibilizer for thermoplastic elastomer blend
Authors: Nitiyah K.K. , Musa Luqman , Rasidi M.S.M. , Rahim Shayfull Zamree Abd , Rahman Rozyanty , Azmi Ahmad Azrem , Rennie Allan 
Published: November 2021

Abstract
A biodegradable thermoplastic elastomer (TPE) blend is developed by blending poly (lactic acid) (PLA) and natural rubber (NR) or epoxidized natural rubber (ENR) and it is a sustainable substitution in recent years for synthetic polymers. PLA is high in mechanical strength and compostable, but it is highly stiff and brittle. The incorporation of NR or ENR to PLA increases the impact strength and toughness of PLA. However, the disparity in polarity between PLA and elastomer phase like NR and ENR results in TPE blend being incompatible. Hence, compatibilization is essential to improve its polarity and develop interactions. Compatibilizer that composed of two different polymer is known is graft compatibilizer with the aid of grafting agent. The graft compatibilizers are divided into two categories. The first type is made up of one polymer and grafting agent and, the other one is composed of two polymer groups and grafting agent. These two types of graft compatibilizer can be prepared via two different method such as direct melt blending and solution. Apart from this, the TPE blend is produced via the melt blending technique with mixing machines such as internal mixer and extruder. This article has reviewed the preparation of the graft compatibilizer and blending technique of TPE. Based on the findings, the graft compatibilizers has a significant role in improving miscibility and compatibility across blend composed of different phase.
A green approach of superhydrophobic surface fabrication on recycled high-density polyethylene using sodium chloride
Authors: Azizan Muhammad Aidil Adz’ryl Nor , Zakaria Muhammad Salihin , Nordin Razif Muhammed , Halim Khairul Anwar Abdul , Lim Bee Ying , Abdurrahman Muslim 
Published: November 2021

Abstract
In this work, the water-dissolved surface modifier method was introduced to recycled high-density polyethylene (rHDPE) matrix to fabricate green superhydrophobic surfaces. Surface cavities on rHDPE are formed by sodium chloride particles which can be readily rinsed off and reused. Water contact angle, self-cleaning properties, and surface morphology were characterized. By creating porosity onto the rHDPE matrix, the surface exhibits an excellent self-cleaning property with a water contact angle larger than 150°. Surface morphology reveals the porosity and roughness of the surface. In this fabricating process, no chemicals are used while rHDPE is selected for the purpose. Based on the findings, it is proven that the superhydrophobic surface can be fabricated with a simple yet green approach.
The potential of using sucrose particles for self-cleaning surface fabrication on recycled high-density polyethylene
Authors: Yap Yee Wen , Zakaria Muhammad Salihin , Nordin Razif Muhammed , Halim Khairul Anwar Abdul , Lim Bee Ying , Abdurrahman Muslim 
Published: November 2021

Abstract
Degradation properties of recycled plastic causing it less widely used. By adding extra physical properties, its commercial value and usage can be increased. In this current work, green self-cleaning surfaces from recycled high-density polyethylene (rHDPE) were fabricated using sucrose particles. Water contact angle and sliding angle, self-cleaning properties and surface morphology were characterized. Furthermore, the surface texture was also evaluated by conducting a surface roughness test. By creating porosity onto the rHDPE matrix, the surface exhibits an excellent self-cleaning property with a water contact angle larger than 150°. Surface morphology reveals the porosity and roughness of the surface. In this fabricating process, no chemicals were used while rHDPE is selected for the purpose. Hence, the process is environmentally friendly and low cost for self-cleaning surface fabrication.
Study on Mechanical Properties of Polyester with Addition of Recycle Gift or Members Card
Authors: Dam Aimimi Mat , Kamdi Zakiah 
Published: November 2021

Abstract
Increasing usage of gift cards will end up increasing the waste. Instead of throwing in the dustbin, re-cycling the cards may help in increasing the product usage and contribute to the environment sustainability. In this study, the re-cycle gift cards were combined with polyester to produce polymer blend. The composition of re-cycle gift cards was 2, 4 and 6 wt%. The gift card was crush and mix with the polyester and hardener followed by casting to get the suitable shape based on the testing. Three testing was undergone to evaluate the polymer blend properties which are tensile test, Charpy’s impact test and Durometer hardness test. Similar trend was shown for all mechanical testing which showing an increase of performance from 2 to 4 wt% addition of recycle cards but reduce when achieved 6 wt%.
Contact Force Measurement Approach for Measuring Glove-Skin Interfacial Pressure
Authors: Chen C. X. , Nasir S. H. , Sadun A. S. , Mustafa El Bakri H. 
Published: November 2021

Abstract
Pressure garments for medical had been widely used to enhance the recovery after an operation, for treatment of arthritis, deep vein thrombosis, leg ulcers, varicose veins or hypertrophic scars. This research aims to develop a contact force measuring approach to measure glove-skin interfacial pressure. With the aid of a force measuring sensors system, it is easier to study the efficiency of pressure garments. Besides, occupational therapists can also design a user-friendly pressure garment that is comfortable and easy to donning and doffing, especially for children. Two types of flexible force sensors were used to measure the glove-skin interfacial pressure using two types of pressure therapy gloves. Pressure therapy glove is selected to represent pressure garments. The measuring sensors were placed at three different locations on the dorsal side of the hand, and the glove-skin interfacial pressure was measured in two different postures, which is full fist and tabletop posture. It was found that different postures had led to different interfacial pressure. The glove-skin interfacial pressure was found to be greater during full fist posture compared to tabletop posture. This show that the applied glove-skin interfacial pressure is affected by postures and movement.
Effect of graphene nanoplatelet addition on the electrical conductivity of poly(hydroxybutyrate-co-hydroxyvalerate) biocomposites
Authors: Mahamud Syarifah Nuraqmar Syed , Ganesan Ovinesh , Pisal Mohd Hanif Mohd , Rabat Nurul Ekmi 
Published: November 2021

Abstract
Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is one of the most promising biodegradable polymers used in many applications due to its biodegradability and non-toxicity. However, the usage of PHBV in electronic, biomedical, and biosensor applications has been limited due to its poor electrical properties. This study shows a simple method of producing and enhancing the electrical conductivity of PHBV-based biocomposites by adding graphene nanoplatelet (GNP) as a conductive filler. The biocomposite films were prepared using the solvent casting method, consist of five GNP loading (0-5 wt. %). The prepared PHBV/GNP biocomposites show enhanced electrical conductivity compared to neat PHBV. PHBV/GNP biocomposite with 5 wt. % filler loading exhibits the highest electrical conductivity at 3.83 × 10−3 S/cm. Higher crystalline regions in the PHBV/GNP biocomposites have facilitated the transfer of electrons between PHBV, resulting in the formation of conductive biocomposites, as evident from X-ray diffraction (XRD) characterization.
The Study of Recycled Ethylene Propylene Diene Monomer (EPDM-r)/Polypropylene (PP) Polymeric Blends
Authors: Zulkifli MH , Rasidi MSM , Rahim NAM , Musa L , Masa Abdul Hakim 
Published: November 2021

Abstract
In this study, recycled ethylene propylene diene monomer (EPDM-r) were blended with polypropylene (PP) by compounding via heated two roll mills with the various ratio of EPDM-r. Certain blends were included with PP-g-MA as a compatibilizer. In tensile tests, the increasing of EPDM-r content in blends resulted in the reduction of tensile strength and Young’s Modulus but increased elongation at break. Furthermore, the presence of compatibilizer in blends enhanced the tensile properties. It was found all the samples with compatibilizer performs better results in tensile strength, Young’s Modulus, and elongation at break than samples without compatibilizer. On the other hand, the aging affected were studied on compatibilized and uncompatibilized blends. It was found that aging affects the samples by decreasing the tensile strength, Young’s Modulus, and elongation at break. The crosslink density had been found higher in the blends with high EPDM-r content as the EPDM-r had the ability to swell. The morphological study related to the structure with the tensile properties. It was confirmed that the presence of a compatibilizer increased the compatibility between EPDM-r and PP matrix.
Effect of Carbon Nanotube Loading on Electrical Properties of Electrospun Polyvinylidene Fluoride (PVDF) Fiber
Authors: Lee Jia Wei , Sharifah Shahnaz S.B , Nur Hidayah A.Z , Yahud S. , Samat Noorasikin 
Published: November 2021

Abstract
Polyvinylidene fluoride (PVDF) is a high purity thermoplastic fluropolymer that use in the aircraft, electronics, and chemical industry. Carbon nanotube (CNTs) is made up of rolled up of graphite sheets, exhibits excellent chemical, thermal, mechanical properties, and large surface areas. PVDF fibers blended with CNTs were able to enhance the β-phase which contributes to piezoelectric properties. Electrospinning is the simplest and low-cost method to produce PVDF/CNT fibers by dissolving PVDF in solvent N, N-Dimethylformamide (DMF). 15wt% PVDF solution was used. CNT loading were varied at 0.0wt%, 0.35wt%, 0.80wt% and 1.00wt% with parameters of 20kV, tip-to-collector distance (TCD) 15cm and flow rate 1.0mLh-1. Scanning Electron Microscope (SEM), four-point probe and X-ray Diffraction (XRD) were used to determine the morphology and crystallinity of electrospun PVDF/CNT fibers. The SEM analysis concluded all fibers showed beaded structure due to low concentration of PVDF solution with insufficient ultrasonification and stirring, cause electrospraying and agglomeration. XRD and four-point probe analysis concluded PVDF/0.35wt%CNT showed the highest β-phase content with intense XRD peak and highest electrical conductivity. However, shift peak is observed among all fibres due to short electrospinning time leads to insufficient thickness of electrospun mat, which affects the mechanical properties of fibres and causes peak shift.
Citric acid leaching process for removal of iron (Fe) from rice husk
Authors: Pa Faizul Che , Chik Abdullah , Abdullah Hasan Zuhudi 
Published: November 2021

Abstract
Rice husk containing the highest amount composition of silica (SiO2) compared with other agricultural waste. With such a large availability of rice husk, it becomes economical to industrial by the implementation concept of sustainability beside decompose the rice rusk into ash. The extraction of silica and elimination of metallic element, such as iron (Fe) from rice husk (RH) was treated by leaching process. With this, the RH can be utilized to produce various types of useful renewable resources such as silica (SiO2). Using the organic acid as leaching solution is more eco-friendly instead using the inorganic acid that classified as very dangerous chemical due to the high level of hazard. The treated and untreated rice husk ash characterizes using scanning electron microscopy and X-ray diffraction spectroscopy. The morphology of treated rice husk shows the tubular aggregate due to the presence of alkaline earth metal such as Ca and Mg. Under the optimum condition with 90 °C solution temperature, 60 minutes stirring time, 3% of citric acid and calcination temperature of 800 °C for 3 hours, amorphous silica with more than 78% was prepared via citric acid leaching treatment and combustion process.