Showing papers by "Abu Bakar published in 2020"
TL;DR: There should be a greater focus on providing appropriate oral health education to people with intellectual disability, improving the health literacy and quality of care of caregivers, and providing more dentists with specialized training in special needs dentistry.
Abstract: People with intellectual disability have a higher risk of oral health problems. This study assessed the clinical oral health status and behaviors and treatment needs of people living in an institution in Padang, West Sumatra, Indonesia. We quantified oral health status of 65 individuals with intellectual disability using Oral Hygiene Index Simplified (OHIs), Angle’s classification of malocclusion, Community Periodontal Index and Treatment Need (CPITN), and decay index and also recorded their brushing behavior. We found that males had significantly lower OHIs (p < 0.001), more malocclusion (p < 0.001), greater caries number (p < 0.001), greater CPITN (p = 0.001) and higher need of dental treatment (p < 0.01) than females. Additionally, we found that high caries number was associated with poor OHIS, malocclusion, periodontal disease, and dependent brushing behavior (p < 0.001). The findings of this study imply that there is a gap in appropriate oral health care in individuals with intellectual disability. There should be a greater focus on providing appropriate oral health education to people with intellectual disability, improving the health literacy and quality of care of caregivers, and providing more dentists with specialized training in special needs dentistry.
22 citations
TL;DR: In this article, a review paper focused on the fabrication of composite materials based on some natural sources macromolecules was presented, where wood, silk and wool based macromolescules were described, where Wood was from plant sources and silk & wool was animal sources.
Abstract: The consciousness of environmental & ecological impact has attained great attention for the preparation of new material & various end-used applications. Macromolecules synthesized from natural resources have increased compared to synthetic resources in recent years. The fabrication of composite materials has another concept for increasing the durable properties of composite materials. This review paper focused on the fabrication of composite materials based on some natural sources macromolecules. Different types of macromolecules present in different fiber used in various fabrication. Here, wood, silk & wool based macromolecules are described, where wood was from plant sources and silk & wool was animal sources. The data cover the application of these natural macromolecules for the fabrication of composite materials. This review concludes that the fabrication of composite materials is one of the emerging areas in polymer science that gain attention for use in various applications.
4 citations
TL;DR: In this article, the degradability of linear low-density polyethylene/polyvinyl alcohol (LLDPE/PVOH) composites with untreated kenaf and silane-treated Kenaf at filler loadings of 0, 10, and 40 phr were prepared via the melt mixing process.
Abstract: In recent decades, natural fibers have become widely used with petroleum based polymers such as polyethylene (PE) and polypropylene (PP) because of their light weight, lower cost, and inherent biodegradability. In the present work, linear low-density polyethylene/polyvinyl alcohol (LLDPE/PVOH) composites with untreated kenaf and silane-treated kenaf at filler loadings of 0, 10, and 40 phr were prepared via the melt mixing process. The soil burial test was used to evaluate the degradability of the composites for different durations (90 and 180 d). The tensile properties, surface morphology, chemical composition, percentage of weight loss, and crystallinity of the composites before and after degradation were evaluated. With increased kenaf loading and soil burial duration, all the composites showed a decrease in tensile properties. This was further confirmed by the changes in surface morphology and chemical structure of the buried composites. The increase in weight loss percentage and crystallinity after soil burial indicated that the longer burial duration had increased the degradation of composites. Composites with silane-treated kenaf exhibited lower degradability than that of composites with untreated kenaf after being buried for 90 and 180 d. This may be attributed to the improved adhesion of kenaf to the LLDPE/PVOH matrix via silane treatment.
3 citations
TL;DR: In this paper, the structural, vibrational and thermodynamic properties of Samarium-based Chalcogenides are studied for structural optimization using generalized gradient approximation as an exchange correlation potential in Density Functional Theory (DFT).
Abstract: In this research work, Samarium based Chalcogenides are studied for structural, vibrational and thermodynamic properties. The structural optimization is performed by using Generalized Gradient Approximation as an exchange correlation potential in Density Functional Theory (DFT) and vibrational properties are computed by using norm-conserving Martins–Troullier pseudo-potential in Density Functional Perturbation Theory (DFPT). The Quasi Harmonic Debye model is used for the investigation of thermodynamic properties in temperature range 0–1000 K in Gibbs-code. There is no imaginary phonon frequency in phonon dispersion curves of SmS, SmSe and SmTe proving the dynamical stability. SmS has the largest while SmTe has the smallest phonon band gap which somehow suggests the polar property of these materials. For all Chalcogenides, acoustic phonon modes near the gamma point have a linear behavior. At low temperature, C v is a function of T 3 while for higher temperatures it asymptotically tends to a constant as expected.
3 citations
TL;DR: In this article, the phonon properties of CoFeCrZ (Z=Al, Si, Ga, Ge) equiatomic Quaternary Heusler Alloys were investigated.
Abstract: Density Functional Theory (DFT) is used to investigate the phonon properties of CoFeCrZ (Z=Al, Si, Ga, Ge) equiatomic Quaternary Heusler Alloys. These alloys crystallize in face centered cubic (FCC...
2 citations
TL;DR: In this article, the Half Heusler Alloy (HHA) MnCrP has been studied theoretically for structural, elasto-mechanical and phonon properties.
Abstract: The Half Heusler alloy (HHA) MnCrP has been studied theoretically for structural, elasto-mechanical and phonon properties. The structure is optimized and the calculated structural parameters are cl...
2 citations
TL;DR: In this article, the antibacterial activity of M. oleifera freeze-dried extract on staphylococcus aureus was determined using two methods, microdilution method and agar diffusion method.
Abstract: Objective: The aim of this study is to determine the antibacterial activities of M. oleifera freeze dried extract on Staphylococcus aureus. Material and Methods: The antibacterial activities using two methods, microdilution method and agar diffusion method. The minimum inhibitory concentration is determined. The measurement of absorbance in microdilution method using a spectrophotometer at length wave 590 nm. The inhibition zone is measured using scalimeter. Results: The results showed both microdilution method and agar diffusion method present the inhibition activity of M. oleifera freeze dried extract on staphylococcus aureus. Conclusion: The finding confirmed M. oleifera freeze dried extract as the promising antibacterial natural agent, particularly on inhibiting S.
2 citations
Journal Article•
TL;DR: The surface treatment of KNF using lysine was studied for the first time on prepared composites with linear low-density polyethylene, poly(vinyl alcohol), and kenaf as mentioned in this paper.
Abstract: Kenaf (KNF) was treated at room temperature with the amino acid lysine. The surface treatment of KNF using lysine was studied for the first time on prepared composites with linear low-density polyethylene, poly(vinyl alcohol), and kenaf. The LLDPE/PVOH/KNF composites with different loadings of lysine-treated and untreated KNF were studied at levels of 10, 20, and 40 parts per hundred resin (phr). The melt mixing of all the composites were prepared by using an internal mixer for 10 min at a temperature and rotor speed of 150 °C and 50 rpm, respectively. The results showed that tensile strength and tensile modulus were improved for the lysine-treated KNF composites compared to the untreated KNF composites. Fourier transform infrared (FTIR) spectroscopy revealed the presence of protonated amino (NH3+) and carboxylate (COO-) groups in the LLDPE/PVOH/KNF composites after the lysine treatment. Scanning electron microscopy analysis showed good adhesion between the lysine treated KNF and the LLDPE/PVOH matrices. Thermogravimetric analysis (TGA) showed that the lysine treated KNF composites possessed a higher thermal stability than the untreated KNF composites.
1 citations
TL;DR: A theoretical study of SmXO3 cubic perovskites for vibrational properties and Reststrahlen band is done within the framework of Density Functional Perturbation Theory (DFPT) implemente....
Abstract: A theoretical study of SmXO3 (X = Al, Co) cubic perovskites for vibrational properties and Reststrahlen band is done within the framework of Density Functional Perturbation Theory (DFPT) implemente...
16 Jan 2020
TL;DR: In this paper, aktual pada proses assembly selalu terjadi gap ying berlebih dengan nilai ying bervariasi and berulang-ulang antara rib 1341 and rib 1495 terhadap stoper jig 6302 332A 24 2000 00/36.
Abstract: Berdasarkan pada spesifikasi IFMA ( Instruction Fabrication Marignane ) 297 dan gambar 332A 24 0031 bahwa tidak diperbolehkan adanya gap yang berlebih (out of tolerance) sebelum dilakukan perivetan, tetapi aktual pada proses assembly selalu terjadi gap yang berlebih dengan nilai yang bervariasi dan berulang-ulang antara rib 1341 dan rib 1495 terhadap stoper jig 6302 332A 24 2000 00/36. Studi kasus dilakukan di Hanggar Perakitan Superpuma MK 2 EC 225 PT Dirgantara Indonesia Bandung. Setelah dilakukan analisis, dapat diambil kesimpulan bahwa terjadinya gap yang berlebih adalah sesuatu yang akan terus berulang jika tidak dilakukan improvement metode perakitan rib 1341 dan rib 1495 yaitu dengan cara melakukan modifikasi pada Jig Transmission Deck Assy 6201 332A 24 0540 00 yang berfungsi sebagai alat bantu.