Lanthanum Nickelates with a Perovskite Structure as Protective Coatings on Metallic Interconnects for Solid Oxide Fuel Cells

Nurhadi S. Waluyo,박범경,송락현,이승복,임탁형,박석주,이종원 한국세라믹학회 2015 한국세라믹학회지 Vol.52 No.5

An interconnect is the key component of solid oxide fuel cells that electrically connects unit cells and separates fuel from oxidant in the adjoining cells. To improve their surface stability in high-temperature oxidizing environments, metallic interconnects are usually coated with conductive oxides. In this study, lanthanum nickelates (LaNiO3) with a perovskite structure are synthesized and applied as protective coatings on a metallic interconnect (Crofer 22 APU). The partial substitution of Co, Cu, and Fe for Ni improves electrical conductivity as well as thermal expansion match with the Crofer interconnect. The protective perovskite layers are fabricated on the interconnects by a slurry coating process combined with optimized heat-treatment. The perovskite-coated interconnects show area-specific resistances as low as 16.5 - 37.5 m Ω·cm2 at 800oC.

A Simulation study of sea transport based fertilizer product considering disruptive supply and congestion problems

Nurhadi SISWANTO,Uly KURNIAWATI,Effi LATIFFIANTI,Ahmad RUSDIANSYAH,Ruhul SARKER 한국해운물류학회 2018 The Asian journal of shipping and Logistics Vol.34 No.4

Every company desires to have an ideal delivery system with no disruption and no downtime. In reality, disruption events cannot be avoided, especially when delivering products using maritime transportation. Such unwanted and uncontrolled events can include sudden factory downtime, vessel breakdown, jetty congestion at a port, and more. Due to the serious consequences, disruption needs to be subjected to considerable scrutiny because it may influence the performance of the company. Many studies have been undertaken regarding inventory routing problems in the maritime area. However, it is very rare that these studies have included disruption events in their model. This research examines supply and transportation disruptions and also develops several scenarios to recover from disruptions so as to increase the system performance. The method used to model this problem is a discrete event simulation, because this tool is capable of handling complex systems. The best alternatives were chosen by finding a compromise or tradeoff between the key performance indicators, specifically the service level and the cost of achieving the goals. Two parameters were tested in the sensitivity analysis to understand the behavior and how sensitive these parameters are to the performance criteria.

An Understanding for Industrial Internship Program Development for Preparing Employability Skills of Vocational Students in Indonesia

Didik Nurhadi,Dr. Nyan-myau LYAU 한국직업자격학회 2017 한국직업자격학회 학술대회 Vol.2017 No.10

The industrial internship program (IIP) has been widely recognized in many developed countries. This program has shown a contribution to the improvement of labor market outcomes for their country's economic development. This is demonstrated by the quality of job performance of vocational education graduates in the workplace. One of IIP successes is because it has implemented effectively by vocational education and industries supported by the government to provide employability skills to their students. Indonesia as one of the developing countries has also implemented IIP in vocational education both at the levels of higher education and high school, but this program indicated that the contribution of IIP was very minimal to provide work experience directly to the students. This is happening because of different understanding between education and industry how to develop IIP for preparing students' employability skills. Furthermore, to solve this issue, an understanding to develop sustainable IIP in Indonesia will be explained in this paper.

Lanthanum Nickelates with a Perovskite Structure as Protective Coatings on Metallic Interconnects for Solid Oxide Fuel Cells

Waluyo, Nurhadi S.,Park, Beom-Kyeong,Song, Rak-Hyun,Lee, Seung-Bok,Lim, Tak-Hyoung,Park, Seok-Joo,Lee, Jong-Won The Korean Ceramic Society 2015 한국세라믹학회지 Vol.52 No.5

An interconnect is the key component of solid oxide fuel cells that electrically connects unit cells and separates fuel from oxidant in the adjoining cells. To improve their surface stability in high-temperature oxidizing environments, metallic interconnects are usually coated with conductive oxides. In this study, lanthanum nickelates ($LaNiO_3$) with a perovskite structure are synthesized and applied as protective coatings on a metallic interconnect (Crofer 22 APU). The partial substitution of Co, Cu, and Fe for Ni improves electrical conductivity as well as thermal expansion match with the Crofer interconnect. The protective perovskite layers are fabricated on the interconnects by a slurry coating process combined with optimized heat-treatment. The perovskite-coated interconnects show area-specific resistances as low as $16.5-37.5m{\Omega}{\cdot}cm^2$ at $800^{\circ}C$.

(Mn,Cu)3O4-based conductive coatings as effective barriers to high-temperature oxidation of metallic interconnects for solid oxide fuel cells

Waluyo, Nurhadi S.,Park, Beom-Kyeong,Lee, Seung-Bok,Lim, Tak-Hyoung,Park, Seok-Joo,Song, Rak-Hyun,Lee, Jong-Won Springer-Verlag 2014 Journal of solid state electrochemistry Vol.18 No.2

Protective coating based on manganese–copper oxide for solid oxide fuel cell interconnects: Plasma spray coating and performance evaluation

Waluyo, Nurhadi S.,Park, Seong-Sik,Song, Rak-Hyun,Lee, Seung-Bok,Lim, Tak-Hyoung,Hong, Jong-Eun,Ryu, Kwang Hyun,Bin Im, Won,Lee, Jong-Won Elsevier 2018 Ceramics international Vol.44 No.10

<P><B>Abstract</B></P> <P>A solid oxide fuel cell (SOFC) stack requires metallic interconnects to electrically connect unit cells, while preventing fuel from mixing with oxidant. During SOFC operations, chromia scales continue to grow on the interconnect surfaces, resulting in a considerable increase of interfacial resistance, and at the same time, gaseous Cr species released from the chromia scales degrades the cathode performance. To address these problems, in this study, protective Mn<SUB>2</SUB>CuO<SUB>4</SUB> coatings are fabricated on metallic interconnects (Crofer 22 APU) <I>via</I> a plasma spray (PS) process. The PS technique involves direct spray deposition of molten Mn<SUB>2</SUB>CuO<SUB>4</SUB> onto the interconnect substrate and leads to the formation of high-density Mn<SUB>2</SUB>CuO<SUB>4</SUB> coatings without the need for post-heat-treatment. The thickness, morphology, and porosity of the PS-Mn<SUB>2</SUB>CuO<SUB>4</SUB> coating are found to depend on the processing parameters, including plasma arc power, gas flow rate, and substrate temperature. The PS-Mn<SUB>2</SUB>CuO<SUB>4</SUB> coating fabricated with optimized parameters is completely impermeable to gases and has high adhesion strength on the interconnect substrate. Furthermore, no resistive chromia scales are formed at the coating/substrate interface during the PS process. As a result, the PS-Mn<SUB>2</SUB>CuO<SUB>4</SUB>-coated interconnects show a very low area-specific resistance below 10 mΩ cm<SUP>2</SUP> at 800 °C in air and excellent stability during both continuous operation and repeated thermal cycling. This work suggests that an appropriate combination of the material and coating process provides a highly effective protective layer for SOFC interconnects.</P>

Public Opinion on Lockdown (PSBB) Policy in Overcoming COVID-19 Pandemic in Indonesia: Analysis Based on Big Data Twitter

Catur Suratnoaji,Nurhadi,Irwan Dwi Arianto 충남대학교 아시아여론연구소 2020 Asian journal for public opinion research Vol.8 No.3

The discourse on the lockdown in Indonesia is getting stronger due to the increasing number of positive cases of the coronavirus and the death rate. As of August 12, 2020, the confirmed number of COVID-19 cases in Indonesia reached 130,718. There were 85,798 victims who have recovered and 5,903 who have died. Data show a significant increase in cases of COVID-19 every day. For this reason, there needs to be an evaluation of the government policy of the Republic of Indonesia in dealing with the COVID-19 pandemic in Indonesia. An evaluation of policies for handling the pandemic must include public opinion to determine any weaknesses of this policy. The development of public opinion about the lockdown policy can be understood through social media. During the COVID-19 pandemic, measuring public opinion through traditional methods (surveys) was difficult. For this reason, we utilized big data on social media as research data. The main purpose of this study is to understand public opinion on the lockdown policy in overcoming the COVID-19 pandemic in Indonesia. The things observed included: volume of Twitter users, top influencers, top tweets, and communication networks between Twitter users. For the methodological development of future public opinion research, the researchers outline the obstacles faced in researching public opinion based on big data from Twitter. The research results show that the lockdown policy is an interesting issue, as evidenced by the number of active users (79,502) forming 133,209 networks. Posts about the lockdown on Twitter continued to increase after the implementation of the lockdown policy on April 10, 2020. The lockdown policy has caused various reactions, seen from the word analysis showing 14.8% positive sentiment, 17.5% negative, and 67.67% non-categorized words. Sources of information who have played the roles of top influencers regarding the lockdown policy include: Jokowi (the president of the Republic of Indonesia), online media, television media, government departments, and governors. Based on the analysis of the network structure, it shows that Jokowi has a central role in controlling the lockdown policy. Several challenges were found in this study: 1) choosing keywords for downloading data, 2) categorizing words containing public opinion sentiment, and 3) determining the sample size.

Analyze, design, develop, implement, and evaluate approach to develop a pelvic floor muscle training guidebook to treat stress urinary incontinence in women

Surahman Hakim,Budi Iman Santoso,Harrina Erlianti Rahardjo,Siti Setiati,Widjajalaksmi Kusumaningsih,Erwinanto,Joedo Prihartono,Nurhadi Ibrahim,Wresti Indriatmi 대한산부인과학회 2024 Obstetrics & Gynecology Science Vol.67 No.3

Objective Stress urinary incontinence (SUI) is a common problem that affects the quality of life of women worldwide. Pelvic floor muscle training (PFMT) is an effective conservative first-line treatment for SUI. However, low compliance with PFMT is one of the main reasons for therapeutic failure. Indirect supervision using a guidebook may improve PFMT outcomes. To develop a PFMT guidebook using the analyze, design, development, implementation, and evaluation (ADDIE) method. Methods A guidebook was developed from July 2020 to April 2021 using the ADDIE method. This prospective study used mixed methods, namely qualitative analysis, focus group discussions, and in-depth interviews, and involved various experts from urogynecology, urology, medical rehabilitation, and physiotherapy departments. A pilot study was conducted on patients with SUI to evaluate the effectiveness of the guidebook. Results The ADDIE method was successfully implemented to develop the PFMT guidebook. The formative evaluation of the ADDIE steps mainly focused on the PFMT technique, content clarity, illustration, design, and color choice of the book. After the pilot study, the guidebook significantly improved Incontinence Impact Questionnaire, Short Form, 1-hour pad test, and perineometer scores. However, the pilot study showed no significant improvement in Urogenital Distress Inventory, Short Form scores. Conclusion The PFMT guidebook developed using the ADDIE method improved outcomes in patients with SUI.

Double Pedicle Artery Rotation Sigmoid Vaginoplasty for Vaginal Aplasia Management

Adeodatus Yuda Handaya,Nurcahya Setyawan,Nuring Pangastuti,Marijata,Agus Barmawi,Imam Sofii,Muhamad Nurhadi Rahman,Ida Ayu Setyawati,Hamzah Muhammad Hafiq 대한대장항문학회 2020 Annals of Coloproctolgy Vol.36 No.3

Sigmoid vaginoplasty has been popular for neovagina reconstruction in vaginal aplasia. The most common surgical complication was vaginal stenosis caused by inadequate vascularization and tension because of graft length. Therefore, ischemia ensued and disrupted wound healing. The selection of double pedicle artery rotation sigmoid vaginoplasty is expected to reduce this problem. Five patients from April to December 2016 were diagnosed with vaginal aplasia; 4 had history of neovagina stenosis. These patients underwent sigmoid vaginoplasty with double pedicle artery rotation. No complications occurred during or after the procedure. Assessment postsurgery was conducted at 1 year. These results suggest that double pedicle artery rotation sigmoid vaginoplasty is a safe and acceptable technique for management of vaginal aplasia. The procedure decreased tension inside vascular pedicles as a result of maintaining abundant vascularization supply. Consequently, this procedure could avert graft necrosis, leakage, and severe stenosis. All of the patients exhibited regular menstrual cycle and satisfactory sexual activity. The outcomes were excellent with remarkable anatomical and functional results.

Correcting of pronated feet reduce skeletal muscle injury in young women with biomechanical abnormalities

Maria Regina Rachmawati,Angela B. M. Tulaar,Suzana Immanuel,A. Purba,Muchtaruddin Mansyur,Ratna Darjanti Haryadi,Ismail Hadisoebroto,Amin Husni,Nurhadi Ibrahim 대한해부학회 2016 Anatomy & Cell Biology Vol.49 No.1

Biomechanical abnormalities of pronated feet accompanied by functional leg length disparity may increase the risk of skeletal muscle injury. Objective of the study is to prove that correction of pronated feet by the foot orthoses will reduce the creatine kinase-MM (CK-MM) concentrations as the muscle injury indicator. The design study was double blind randomized clinical trials with control. Research subjects were divided into two groups, group 1 used the foot orthoses while group 2 did not used the foot orthoses. The whole subject examined the concentrations of the CK-MM enzyme before, and 24–72 hours after the walking test. The walking test was conducted 15 minutes with maximum speed. The concentration of the CK-MM enzyme before walking test on treatment group was 70.07±15.33 International Unit (IU), similar with the control group was 69.85±17.03 IU (P=0.971). The increased in CK-MM enzyme concentrations 45 hours after the walking test was lower in the treatment group (7.8±9 IU) than the control group (22.0±11.5 IU) (P=0.001). The CK-MM enzyme concentrations continued to decline in the treatment group after the second walking test (77.21±17.47 IU), and after the third walking test (69.86±11.88 IU) (P=0.018). The foot orthoses for correcting the pronated feet on the young women with biomechanical abnormalities is able to reduce the degree of the skeletal muscle injury after walking activity.