Ammonia Uniformity to Predict NOx Reduction Efficiency in an SCR System

Wardana, Muhammad Khristamto Aditya,Shahariar, G. M. Hasan,Oh, Kwangchul,Lim, Ocktaeck Springer-Verlag 2019 International journal of automotive technology Vol.20 No.2

"Lepet": Indonesian traditional food for Eid Al-Fitr celebrations

Wardana Ata Aditya,Setiarto R. Haryo Bimo,Wigati Laras Putri 한국식품연구원 2023 Journal of Ethnic Foods Vol.10 No.29

Indonesia, a country with diverse cultures, possesses a rich variety of cultural heritage. The aim of this review is to discuss the culture of lepet considering its ethnic perspective, preparation and consumption, nutritional and functional properties, safety, and future outlook aspects. Lepet, a traditional Javanese dish, consists of sticky rice, grated young coconut, coconut milk, cowpea, and salt. It is wrapped in young coconut leaves with a specific pattern, boiled, soaked, and then hung to cool and dry. The persuasive technique employed by Sunan Kalijaga, which combines Javanese cultural traditions and Islamic religious teachings, symbolizes lepet for the Javanese people. This method facilitated the spread of Islam by emphasizing the importance of purity and refraining from committing further mistakes after apologizing during the Eid Al-Fitri tradition. Lepet is rich in carbohydrates and some protein. It is gluten-free and offers benefits for bone and skin health due to its contribution of antioxidants, vitamins, and minerals. Proper handling and storage of lepet are vital to prevent the growth of harmful bacteria and extend its shelf life. Given the rising worldwide acknowledgment of Indonesian gastronomy, advancements in technology and distribution, creative adaptations, and a surging demand for convenience, the prospects for lepet appear bright in the future.

Determinant Factors of Young People in Preparing for Entrepreneurship: Lesson from Indonesia

WARDANA, Ludi Wishnu,HANDAYATI, Puji,NARMADITYA, Bagus Shandy,WIBOWO, Agus,PATMA, Tudung Subali,SUPRAJAN, Sandy Eka Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.8

This study examines the determinant factors affecting young people in preparing entrepreneurship in Indonesia. This study involved several variables, including the need for achievement, risk perception, locus of control, entrepreneurial attitude to predict entrepreneurial intention, and preparation for entrepreneurship among young people. The approach utilized in this study was a quantitative research design using a survey model. The participants of this study were recruited from young people in East Java, Indonesia. Structural equation modeling with Partial Least Square (SEM-PLS) was implemented to test the hypotheses and the relationships between variables. The findings of this research showed that the attitudes toward entrepreneurship and entrepreneurial intention of young people in Indonesia are determined by several variables such as the need for achievement, risk perception, and locus of control. The correlation between variables showed one positive direction in which all independent variables can influence dependent variables. Additionally, the result of this study confirms a robust relationship between the attitude toward entrepreneurship and preparing for entrepreneurship among young people. Lastly, this study showed a positive correlation between entrepreneurial intention and preparation for entrepreneurship. This study suggests that government institutions and universities need to be concerned about entrepreneurial programs to promote young entrepreneurs.

Antecedents and Consequences of Intention to Become a Customer: A Case Study of Islamic Banks in Indonesia

Miko Andi WARDANA,I Ketut RAHYUDA,I Putu Gde SUKAATMADJA,I Gusti Ayu Ketut GIANTARI 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4

The aim of the study was to examine the effect of trust, awareness, attitude, subjective norms, and behavioural control on intention and examine the mediating role of trust in the relationship between awareness and attitude. The population was Muslims in Bali Province, with a sample of 150 respondents. Quantitative analysis is used based on multivariate analysis using the SEM model with a variance-based PLS. The results are as follows: (1) knowledge has a significant positive effect on attitude. (2) Awareness has no significant effect on attitude. (3) Awareness has a significant positive effect on trust. (4) Trust has a significant positive effect on attitude. (5) Attitude has no significant effect on intention. (6) Subjective norm has a significant positive effect on intention. (7) Behaviour control has a significant positive effect on intention. (8) The role of trust is a conscious mediation that impacts attitude. The study provides insight into Islamic bank managers to meet prospective customers’ expectations and identify their intention to become customers through managing trust, awareness, attitude, subjective norms, behavioural control, and intention in one unified whole as internal resource. This study enriches empirical evidence on the Theory of Planned Behaviour, which examines knowledge, awareness, and belief.

EFFECTS OF UREA INJECTION TIMING ON PREDICTING NOX CONVERSION IN SCR SYSTEMS

Muhammad Khristamto Aditya Wardana,Kwang Chul Oh,Young Jae Lee,우영민,임옥택 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.1

The most undesired diesel engine pollutants are nitride oxide (NOx), particulate matter (PM), carbon monoxide (CO), and unburned hydrocarbon (HC). Selective catalytic reduction (SCR) with ammonia (NH3) has been successfully employed to remove NOx from diesel emissions via chemical reactions to yield steam (H2O) and nitrogen (N2). However, the ammonia homogenization process is usually incomplete and difficult to mix with NOx. This reaction affected from the urea injection process in the system when the condition is not suitable for urea decomposition process. Therefore, a study on the effects of urea injection timing to predict the NOx reduction efficiency was needed in order to identification the suitable condition based on temperature, flow mass, pressure, etc. In this study, the experiments and simulations were conducted to obtain constant and stable conditions in the SCR system, as constant conditions can optimize the uniformity of ammonia distribution in the system. The engine conditions in the experiment were computed from turning an engine on to determine the desired temperature and airflow, and the simulation was performed using a commercial code of STAR-CCM+. The temperatures used for processing ammonia uniformity in diesel SCR systems were investigated with operation at ambient temperature (298 K) and inlet gas temperature (686 K). Numerical results were validated using the experimental results of ammonia concentration distribution.

Do Creativity and Intellectual Capital Matter for SMEs Sustainability? The Role of Competitive Advantage

SRIKALIMAH, Srikalimah,WARDANA, Ludi Wishnu,AMBARWATI, Diana,SHOLIHIN, Ustadus,SHOBIRIN, Rizky Arief,FAJARIAH, Nuraidya,WIBOWO, Agus Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

SMEs as an organization to succeed and to be sustainable must have the most essential and strategic capital, namely creativity, competitive advantage, and intellectual capital. This study aims to explore how creativity and intellectual capital determines SMEs' sustainability as well as examine the emerging role of competitive advantage in supporting this relationship. A quantitative method was applied to gain a better understanding of the relationship between variables undergoing Structural Equation Modeling with Partial Least Square (SEM-PLS). This study collected data from 123 SMEs in East Java of Indonesia using an online survey. The approach adopted in this study is a convenience random sampling method, which is widely used in entrepreneurship and SMEs' sustainability research. The findings showed that intellectual capital positively affects both competitive advantage and SMEs' sustainability. Additionally, the result of this study confirms a robust relationship between intellectual capital and SMEs' sustainability. However, partially, creativity failed in explaining SMEs' sustainability. Furthermore, this study confirmed that competitive advantage has successfully mediated both the influence of creativity and intellectual capital to SMEs' sustainability. Although this research only involved participants in East Java, this study can be the first step for relevant research of SMEs' sustainability, in particular, in Indonesia.

Paramagnetic Zn_(1-x)Mn_xO (0.00≤x≤0.06) Nanoparticles Prepared by The Coprecipitation Method

Harsono, Heru,Wardana, I Nyoman Gede,Sonief, Achmad As'ad,Darminto, Darminto The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.1

The Zn1-xMnxO ($0.00{\leq}x{\leq}0.06$) samples have been synthesized in the form of powder by the coprecipitation method at low temperature using $Zn(CH_3COO)_2$. $2H_2O$ and $Mn(CH_3COO)_2$. $4H_2O$ powders, as well as HCl and $NH_4OH$ solutions as starting materials. Characterization was conducted using XRD, TEM, XRF, FTIR and VSM. The result shows that the $Zn_{(1-x)}Mn_xO$ ($0.00{\leq}x{\leq}0.06$) nanoparticles have the wurtzite phase with a hexagonal structure and particle sizes ranging from 17.48 to 118.83 nm. In a qualitative analysis of XRF, the peaks that confirm the existence of the manganese element in Mn-doped ZnO samples were observed. Meanwhile, FTIR test result shows that there are peaks at around $500cm^{-1}$ and $400cm^{-1}$ in the FTIR spectra for Mn doped ZnO samples which clearly reveal the existence of the (Zn, Mn)-O strain mode. The (Zn, Mn)-O absorption peak positions have shifted to a lower wave number with increasing Mn doping content. The peak intensity is also lower if compared to that of the ZnO sample without doping. From the VSM test, it is shown that $Zn_{(1-x)}Mn_xO$ ($0.00{\leq}x{\leq}0.06$) nanoparticles are all paramagnetic having monotonically increased susceptibility as increasing Mn content.

The Shifting of Business Activities during the COVID-19 Pandemic: Does Social Media Marketing Matter?

PATMA, Tundung Subali,WARDANA, Ludi Wishnu,WIBOWO, Agus,NARMADITYA, Bagus Shandy Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

The implementation of physical or social distancing during the Covid-19 pandemic has an implication on the shifting of conventional to online business activities. This study aims to explore how financial support, perceived benefits, external pressure determine social media marketing as well as understanding the role of internet and e-business technology (IEBT) that occurs in this relationship. This study adopted a quantitative study with Structural Equation Modeling (SEM)-based variance Partial Least Square (PLS), which aims to enhance understanding of the relationship between variables. The surveyed population of this study came from 123 small- and medium-sized enterprise (SME) owners in East Java of Indonesia, using an online survey and selected with the convenience random sampling method. The findings of this study indicated that the perceived benefits and external pressure have a positive effect on the adoption of IEBT. However, financial support failed in explaining SMEs' adoption of IEBT. This study confirmed that the adoption of IEBT has successfully mediated the influence of financial support, perceived benefits, and external pressure on social media marketing. Despite the samples solely collected from East Java, this study is the first step in research related to the social media marketing in SMEs in Indonesia.

Investigation of urea-water solution spray impingement on the hot surface of automotive SCR system

Shahariar, G. M.,Wardana, M. K.,Lim, O. T. 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6

<P>Selective catalytic reduction is the most promising technique for NOx reduction from diesel engine exhaust emissions. The greatest challenge to implementing the system is solid deposit formation. Spray wall impingement of UWS was investigated in a constant volume chamber by numerical simulation using STAR CCM+ CFD code. The realizable k-epsilon two-layer approach together with standard wall functions and all y+ treatment was implemented for the modeling of turbulence flow. The two-phase flow was modeled by using Eulerian- Lagrangian approach. The heated wall temperature was maintained from 338 K to 573 K during the UWS spray wall impingement. The development of the spray after impinging on the heated wall was visualized and measured. UWS droplet size distribution, wall film formation and droplet evaporation rates were estimated, which are vital parameters for the system performance but not well researched. User-defined functions (UDF) were developed to input the Leidenfrost temperature limit in the calculation and to estimate the desired parameters. The investigation reveals that wall temperature is the most important parameter that significantly affects spray development after impingement, droplet size distribution, wall film formation and droplet evaporation. Increasing the wall temperature leads to longer spray front projection length, smaller droplet size, faster droplet evaporation and smaller film thickness, which are preconditions for urea crystallization reduction. The numerical model and parameters were validated by comparing with experimental data.</P>

Paramagnetic Zn(1-x)MnxO (0.00≤x≤0.06) Nanoparticles Prepared by The Coprecipitation Method

Heru Harsono,I Nyoman Gede Wardana,Achmad As'ad Sonief,Darminto 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.1

The Zn1-xMnxO (0.00≤x≤0.06) samples have been synthesized in the form of powder by the coprecipitation methodat low temperature using Zn(CH3COO)2. 2H2O and Mn(CH3COO)2. 4H2O powders, as well as HCl and NH4OH solutionsas starting materials. Characterization was conducted using XRD, TEM, XRF, FTIR and VSM. The result shows that theZn(1-x)MnxO (0.00≤x≤0.06) nanoparticles have the wurtzite phase with a hexagonal structure and particle sizes rangingfrom 17.48 to 118.83 nm. In a qualitative analysis of XRF, the peaks that confirm the existence of the manganeseelement in Mn-doped ZnO samples were observed. Meanwhile, FTIR test result shows that there are peaks at around500 cm-1 and 400 cm-1 in the FTIR spectra for Mn doped ZnO samples which clearly reveal the existence of the (Zn,Mn)-O strain mode. The (Zn, Mn)-O absorption peak positions have shifted to a lower wave number with increasingMn doping content. The peak intensity is also lower if compared to that of the ZnO sample without doping. Fromthe VSM test, it is shown that Zn(1-x)MnxO (0.00≤x≤0.06) nanoparticles are all paramagnetic having monotonicallyincreased susceptibility as increasing Mn content.