Suitability of Palm Based Oil as Dielectric Insulating Fluid in Transformers

Azis, Norhafiz,Jasni, Jasronita,Kadir, Mohd Zainal Abidin Ab,Mohtar, Mohd Nazim The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

Mineral oil has been widely used as dielectric insulating fluid in transformers due to its excellent performance in-service. However, there are few issues with mineral oil such as it has poor biodegradability and could contaminate the environment if a spillage occurs. With the increasing tight regulation on safety and environment, alternative fluids for mineral oil are currently being investigated and among the suitable candidate is the vegetable oil. There are different types of vegetable oils and one of them is the palm based oil. At the moment, extensive research works are carried out to examine its feasibility to be applied in transformers. This paper will review the previous research works that were carried out to examine the suitability of palm based oil as dielectric insulating fluid in transformers. The physical and chemical properties of palm based oil are studied based on viscosity, acidity, oxidation stability and flash point. Next, the electrical characteristics of palm based oil are examined based on AC breakdown voltage, relative permittivity, dissipation factor and partial discharge.

The linear model for wave generation of a bump

AZIS S. SANI,L.H. WIRYANTO 장전수학회 2019 Proceedings of the Jangjeon mathematical society Vol.22 No.1

A channel with a bump over at bottom will aect the pro- le of the water surface that ows over it. This phenomenon can be modeled by the nondimensional Boussinesq equation. The governing equation used is expressed in variable of speed, elevation, the height of bump and Froude number. Here, we will investigate the dependance of wave formed by a bump on Froude number and dimension of the bump. In this paper, we focus only on the case of supercritical ow or Froude number greater than 1. We will derive the analytical solution for the free surface prole over a bump. From the analytical solution, we conclude that a bump generate waves with 1 peak and 2 dales. The formed peak does not propagate anywhere, but the two dales propagate to the direction of the ow with dierent speed and amplitude. For- ward Time Backward Space (FTBS) method is implemented to solve the equation numerically. The obtained numerical results conrm the analytical solution well.

Examining the Intrapreneurship Drivers and Strategy: Case Study of Property Services in Indonesia

AZIS, Pusfitalisya,AMIR, Muhammad Taufiq Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

This study examines the drivers and implementation of intrapreneurship strategy in a property service company. Using a qualitative case study approach, the study interviewed four managers involved in related intrapreneurship initiatives. The data was validated by an expert and a practitioner from a different company. The implementation of the company's intrapreneurship strategy is limited to improving new ways of working and developing products and services. However, business development and the creation of new business models are still limited. From several intrapreneurship driving factors, it was observed that the company practices are considered adequate with regard to top management support, leadership, flexibility in carrying out work, as well as in fairly harmonious arrangements for ongoing business relationships with the intrapreneurship projects. On the other hand, human resources with entrepreneurial behavior are still minimal. Similarly, the driving factors in reward and training that promote entrepreneurial behavior are also considered to be insufficient. The application of intrapreneurship as a strategy requires understanding and commitment from all parties in the organization. This study provides insight into the Indonesian context and proposes that intrapreneurship initiatives are less likely to succeed if they are not supported by developing a more systematic entrepreneurial mindset, behavior, and culture.

HLA-C*17, DQB1*03:01, DQA1*01:03 and DQA1*05:05 Alleles Associated to Bullous Pemphigoid in Brazilian Population

( Azis Arruda Chagury ),( Luiz Ubirajara Sennes ),( Julio Miranda Gil ),( Jorge Kalil ),( Helcio Rodrigues ),( Claudia B. Rosales ),( Ivan Dieb Miziara ) 대한피부과학회 2018 Annals of Dermatology Vol.30 No.1

Background: Bullous pemphigoid (BP) is an autoimmune disease with bullous vesicles and an incidence of 0.2 to 1.4 per 100,000 inhabitants. Many studies have been published demonstrating the association of pemphigoid with HLA class II system alleles in different populations, however there are no data on the BP, one of the most heterogeneous in the world. Objective: To typify HLA alleles in Brazilians with Bullous pemphigoid. Methods: The study group included 17 Brazilian patients with a confirmed diagnosis of BP from a hospital in Sao Paulo city, southeast Brazil. DNA was extracted from peripheral blood using Qiagen kits and HLA A, B, C, DR and DQ typing was performed using polymerase chain reaction. The control group was composed of a database of 297 deceased donors from the city of Sao Paulo. The statistical significance level was adjusted using the Bonferroni correction depending on the phenotypic frequencies evaluated for HLA class I (A, B and C) and class II (DRB1, DQB1 and DQA1). Results: Our findings show that alleles HLA C*17, DQB1*03:01, DQA1*01:03 and DQA1*05:05 are associated with the onset of the disease in the Brazilian pop- lation, with relative risks of 8.31 (2.46 to 28.16), 3.76 (1.81 to 7.79), 3.57 (1.53 to 8.33), and 4.02 (1.87 to 8.64), respectively (p<0.005). Conclusion: Our data indicate that Brazilian patients with BP present the same genetic predisposition linked to HLA-DQB1*03:01 previously reported in Caucasian and Iranian individuals and our study introduces three new alleles (C*17, DQA1*01:03 and DQA1*05:05) involved in the pathophysiology of BP. (Ann Dermatol 30(1) 8∼12, 2018)

Determination of Fungal Glucosamine Using HPLC with 1-napthyl Isothiocyanate Derivatization and Microwave Heating

Azis Boing Sitanggang,Ho-Shing Wu,Shaw S. Wang 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.6

A rapid method for the determination of fungal glucosamine (GlcN) from Aspergilus BCRC 31742 was developed. The hydrochlorination process using microwave effectively reduced reaction time needed for GlcN analysis. The analytical method consisted of two steps: (1) hydrochlorination of fungal cells and (2) derivatization process. Fungal GlcN hydrochloride was reacted with 1-napthyl isothiocyanate (1-NITC) as the derivatizing agent to enhance the sensitivity of GlcN and so to achieve high resolution. This method was specific for quantification of GlcN hydrochloride at the wavelength of 230 nm. The standard deviation and relative error of the analytical results were less than 5%. By using microwave heating, the reaction time of hydrochlorination process was shortened from 24 h to 3 min. Thus, the overall time needed for analyzing GlcN from fungal sources was reduced from 5 h (thermal method) to 2 h (microwave method). A rapid method for the determination of fungal glucosamine (GlcN) from Aspergilus BCRC 31742 was developed. The hydrochlorination process using microwave effectively reduced reaction time needed for GlcN analysis. The analytical method consisted of two steps: (1) hydrochlorination of fungal cells and (2) derivatization process. Fungal GlcN hydrochloride was reacted with 1-napthyl isothiocyanate (1-NITC) as the derivatizing agent to enhance the sensitivity of GlcN and so to achieve high resolution. This method was specific for quantification of GlcN hydrochloride at the wavelength of 230 nm. The standard deviation and relative error of the analytical results were less than 5%. By using microwave heating, the reaction time of hydrochlorination process was shortened from 24 h to 3 min. Thus, the overall time needed for analyzing GlcN from fungal sources was reduced from 5 h (thermal method) to 2 h (microwave method).

Weighted averaging fusion for multi-view skeletal data and its application in action recognition

Azis, Nur Aziza,Jeong, Young-Seob,Choi, Ho-Jin,Iraqi, Youssef IET 2016 IET computer vision Vol.10 No.2

<P>Existing studies in skeleton-based action recognition mainly utilise skeletal data taken from a single camera. Since the quality of skeletal tracking of a single camera is noisy and unreliable, however, combining data from multiple cameras can improve the tracking quality and hence increase the recognition accuracy. In this study, the authors propose a method called weighted averaging fusion which merges skeletal data of two or more camera views. The method first evaluates the reliability of a set of corresponding joints based on their distances to the centroid, then computes the weighted average of selected joints, that is, each joint is weighted by the overall reliability of the camera reporting the joint. Such obtained, fused skeletal data are used as the input to the action recognition step. Experiments using various frame-level features and testing schemes show that more than 10% improvement can be achieved in the action recognition accuracy using these fused skeletal data as compared with the single-view case.</P>

Suitability of Palm Based Oil as Dielectric Insulating Fluid in Transformers

Norhafiz Azis,Jasronita Jasni,Mohd Zainal Abidin Ab Kadir,Mohd Nazim Mohtar 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

Mineral oil has been widely used as dielectric insulating fluid in transformers due to its excellent performance in-service. However, there are few issues with mineral oil such as it has poor biodegradability and could contaminate the environment if a spillage occurs. With the increasing tight regulation on safety and environment, alternative fluids for mineral oil are currently being investigated and among the suitable candidate is the vegetable oil. There are different types of vegetable oils and one of them is the palm based oil. At the moment, extensive research works are carried out to examine its feasibility to be applied in transformers. This paper will review the previous research works that were carried out to examine the suitability of palm based oil as dielectric insulating fluid in transformers. The physical and chemical properties of palm based oil are studied based on viscosity, acidity, oxidation stability and flash point. Next, the electrical characteristics of palm based oil are examined based on AC breakdown voltage, relative permittivity, dissipation factor and partial discharge.

A Boundary Integral Equation Formulation for an Unsteady Anisotropic-Diffusion Convection Equation of Exponentially Variable Coefficients and Compressible Flow

Mohammad Ivan Azis 경북대학교 자연과학대학 수학과 2022 Kyungpook mathematical journal Vol.62 No.3

The anisotropic-diffusion convection equation with exponentially variable co efficients is discussed in this paper. Numerical solutions are found using a combined Laplace transform and boundary element method. The variable coefficients equation is usually used to model problems of functionally graded media. First the variable coeffi cients equation is transformed to a constant coefficients equation. The constant coefficients equation is then Laplace-transformed so that the time variable vanishes. The Laplace transformed equation is consequently written as a boundary integral equation which in volves a time-free fundamental solution. The boundary integral equation is therefore employed to find numerical solutions using a standard boundary element method. Finally the results obtained are inversely transformed numerically using the Stehfest formula to get solutions in the time variable. The combined Laplace transform and boundary element method are easy to implement and accurate for solving unsteady problems of anisotropic exponentially graded media governed by the diffusion convection equation.

Collaborative Digital Storytelling-based Task for EFL Writing Instruction : Outcomes and Perceptions

Yek Amin Azis,Husnawadi 아시아영어교육학회 2020 The Journal of Asia TEFL Vol.17 No.2

Despite a myriad of studies documenting the educational benefits of digital storytelling (DST) on EFL learners’ language mastery, the majority of the research is not grounded in the theory of L2 instruction, say task based language teaching (TBLT). To fill this void, this action research involving 28 students investigated the efficacy of collaborative DST-based task in an Indonesian EFL writing classroom. Anchored in collaborative TBLT methodology instruction of Willis (1996) that met a set of task criteria coined by Ellis (2009), this study aimed to unveil the effect of collaborative DST-based task on the students’ writing skills; how the students perceived the use of the learning approach; and the challenges they encountered. The statistical evidence indicates that there was a significant difference on the students’ pre- and post-writing scores, which indicates that the use of collaborative DST-based task significantly improved students’ writing skills. The writing students perceived that the learning design could promote their English Language skills Development, engagement, motivation, and interpersonal relation. Another finding revealed that the students found the technological and pedagogical circumstances were their challenges. This study offers implications and recommendations for future research and practices for marrying TBLT and technology in ELT classrooms.

Sol-gel TiO₂/Carbon Paste Electrode Nanocomposites for Electrochemical-assisted Sensing of Fipronil Pesticide

Maulidiyah, Maulidiyah,Azis, Thamrin,Lindayani, Lindayani,Wibowo, Dwiprayogo,Salim, La Ode Agus,Aladin, Andi,Nurdin, Muhammad The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.4

The unique study of TiO₂ sol-gel modified carbon paste electrode (CPE) nanocomposites have been developed for electrochemical sensor detecting fipronil pesticide compound. We develop the easy synthesized TiO₂ via a sol-gel method and modified in CPE which applied electrochemical system as cyclic voltammetry (CV) because the concentration is proportional with current peaks. We discover the TiO₂ optimal mass used of 0.1 g which is compared with 0.7 g carbon and 0.3 mL paraffin. It has high-current anodic (Ip_a) of 1.13×10³ μA and high-current cathodic (Ip_c) -0.96×10³ μA in scan rate of 0.5 V/s. The limit of detection (LOD) of fipronil has been determined of 34.0×10^-5 μM in percent recovery of 0.8%. Its high-stability for lifetime TiO₂-CPE nanocomposites was expressed for 13 days which mean that can be used for detecting fipronil pesticide.