Prima University of Indonesia
Medan, Indonesia

Time filter

Source Type

Chuang K.-T.,National Taiwan University of Science and Technology | Abdullah H.,National Taiwan University of Science and Technology | Abdullah H.,Prima University of Indonesia | Leu S.-J.,Taipei Medical University | And 5 more authors.
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2017

To broaden the application of antibacterial catalysts, ZnO/Ag2O composite thin films with different Ag2O contents have been successfully synthesized on non-woven fabric at room temperature by radio frequency (RF) sputtering with a single ceramic target formed by hot pressing ZnO/Ag2O nanocomposite powder in Ar atmosphere at 180 °C for 30 min. The composite thin films were also sputtered on glass substrates for characterizations. The best sputtering condition was found with the Ar/O2 gas flow ratio at 7:1 to obtain pure Ag2O thin film. The deposition of Ag2O nanoparticles on commercially available ZnO particles was also confirmed by HR-TEM prior to hot pressing for synthesizing ceramic targets. In this work, an appropriate amount of Ag2O incorporated in the composite film was endeavored by forming p–n junction to lower the cost without decreasing bactericidal ability of composite film. The amount of 45 wt% Ag2O in composite thin film to provide bactericidal effect was found to be as good as pure Ag2O. The feasibility in bactericide is due to the light sensitization of low bandgap Ag2O and the formation of nano p–n heterojunction between p-type Ag2O and n-type ZnO for efficient photo carrier separation. The dependence of antibacterial effect of ZnO/Ag2O thin films on the Ag2O content is demonstrated and elucidated in this work. © 2017 Elsevier B.V.

Abdullah H.,National Taiwan University of Science and Technology | Abdullah H.,Prima University of Indonesia | Gultom N.S.,National Taiwan University of Science and Technology | Kuo D.-H.,National Taiwan University of Science and Technology
Journal of Materials Science | Year: 2017

Indium oxysulfide nanosheet (In2(O,S)3 NS) had been successfully synthesized by a solution-based process at 90 °C. To further study some properties of photocatalyst, the 90 °C-prepared In2(O,S)3 NS was annealed at 350, 400, and 450 °C in air for 2 h. It was found that the nanosheet structure at 90 °C changed to nanoparticle at higher temperature. All the as-prepared and annealed photocatalysts were carefully characterized and examined toward photocatalytic hexavalent chromium (Cr(VI)) reduction. Among the photocatalysts, 90 °C-prepared In2(O,S)3 NS exhibited the greatest photocatalytic reduction of Cr(VI) without using any hole scavenger reagent under 150 W visible light illumination. After the Ag deposition on In2(O,S)3 NS, the photocatalyst could produce nearly 400 μmol/g hydrogen gas in ethanol solution under 150 W Xe-lamp irradiation for 5 h. The great performance of 90 °C-prepared In2(O,S)3 NS was due to the high surface area of nanosheet morphology and the formation of solid solution which significantly increased the visible light absorbance. The photocatalytic activities and their mechanisms of 90 °C-prepared In2(O,S)3 NS were evaluated and elaborated in this work. © 2017 Springer Science+Business Media New York

Florenly,Prima University of Indonesia | Fachrial E.,Prima University of Indonesia | Zein R.,Laboratory of Environmental Chemistry
Der Pharma Chemica | Year: 2016

The present study investigated the effect of Cr(VI) in the kidneys of experimental rats and the protective effect of Dimocarpuslongan peel fruit as renal protector. Administration of 1 mLCr(VI) 1000 mg/L in experimental rats intraperitoneally increased all the biochemical parameters that were observed, including: MDA, urea, creatinine, SGOT and SGPT. Histologically, administration of Cr(VI) leads to swelling of tubule and severe necrosis in kidney. Pre-treatment with D.longan peel fruit antidote reduced the levels of biochemical parameters and oxidative stress parameters. The decreased levels of MDA, urea, creatinine, SGOT and SGPT were 51, 74%; 30,26%; 31,37%; 26,74% and 67,19% respectively. The pre-treatment with D.longan peel fruit also reduced the damage in kidney tissue, although there was still swelling in the tubules.

Turnip A.,Indonesian Institute of Sciences | Soetraprawata D.,Indonesian Institute of Sciences | Turnip M.,Prima University of Indonesia | Joelianto E.,Bandung Institute of Technology
Internetworking Indonesia Journal | Year: 2016

The paper considers a non-invasive brain computer interface uses EEG-SSVEP signals over visual cortex to control electronic wheelchair movement (i.e., forward, backward, left, and right). The main goal of the paper is to help people with severe motor disabilities (i.e., spinal cord injuries) and to provide them with a new way of communication and control options. In this paper, offline analysis of the data collected is used to make the user able of controlling the movement of the electronic wheelchair. The data are collected during a session in which four subjects with age about 25±1 years were tested. The adaptive-network based fuzzy inference system algorithm is then applied for the classification method with some parameters. In the offline analysis, the implemented method shows a significant performance in the classification accuracy level and it gives an accuracy level of more than 90%. This result suggests that using the adaptive-network based fuzzy inference system algorithm can improve real time operation of the current BCI system. © 2016 IIJ.

Pardede J.,National Institute of Technology Bandung | Turnip M.,Prima University of Indonesia | Manalu D.R.,Methodist University of Indonesia | Turnip A.,Indonesian Institute of Sciences
ARPN Journal of Engineering and Applied Sciences | Year: 2015

In recording the EEG signals are often contaminated by a large of signals called artifacts such that the brain activity (source) difficult to estimate. There are different kinds of artifacts such as power line noise, electromyogram, electrocardiogram and electrooculogram. In this research, an adaptive recurrent neural network (ARNN) for estimation of source and reduction of noise from recorded EEG signals is proposed. In the experiment, the EEG signals are recorded on three conditions, which is normal conditions, closed eyes, and blinked eyes. After processing, the dominant frequency of the EEG signal is obtained in the range of 12-14 Hz either on normal conditions, closed eyes, and blinked eyes. The experimental results show that the ARNN method was effectively estimated the brain activity according to the given stimulus and remove the artifacts from all subjects. © 2006-2015 Asian Research Publishing Network (ARPN).

Putera A.,University of Pembangunan Panca Budi | Putera A.,Prima University of Indonesia | Siahaan U.,University of Pembangunan Panca Budi | Siahaan U.,Prima University of Indonesia | Rahim R.,Jl. Sekip Simpang Sikambing
International Journal of Security and its Applications | Year: 2016

Genetic algorithms can solve complex problems, including the problems of cryptography. What problems often occur on the Hill Cipher is the waste of time to determine the numbers that are used in the encryption process. In the encryption process, it is not a problem if the key is derived from any number. However, the problem is ciphertext cannot be returned to the original message. The key that is used must have the determinant is 1. To find the value of it is something that takes time if it must be done manually. Due to the entered value to the Hill Cipher is random, Genetic algorithms can be used to optimize the search time. By using this algorithm, the determinant calculation will be more accurate and faster. The result achieved is the program can specify some combination of numbers that can be used as the encryption key Hill Cipher and it can reject the unnecessary numbers. © 2016 SERSC.

Sitinjak R.R.,Prima University of Indonesia | Pandiangan D.,Sam Ratulangi University
Agrivita | Year: 2014

The aim of this study was to evaluate the effect of plant growth regulator triacontanol to the growth of cacao seedings (Theobroma cacao L.). A completely randomized design was applied using non-factorial pattern on the treatment triacontanol growing regulator substance to level: 0.0 ml/L, 0.1 ml/L, 0.5 ml/L, 1.0 ml/L and 2.0 ml/L replicated 5 times. The result shows that the given of tria-contanol significantly affected the growth of cacao seedings at the age of 14 weeks. The best tria-contanol concentration was 1.0 ml/L, which was effectively able to increase the growth of cacao seedlings; high seedlings, number of leaves, lenght of leaves, and diameter of stems respectively reached 26.21%; 3.70%; 42.28%; and 10.42% higher than the control. Plant growth regulator triacontanol was efective to increase the growth of cacao seedlings. © 2014, Agriculture Faculty Brawijaya University. All rights reserved.

to compare the anti-malarial effect among sambiloto extract, chloroquine and artemisinin-only as well as those of their combination. the study was conducted in Central Biomedical Laboratory, Faculty of Medicine, Brawijaya University, Malang, Indonesia from January to February 2006. Malaria culture used Plasmodium falciparum of Papua strain (2300) that was obtained from Namru-2 Jakarta. Five drugs applied in this test; those were chloroquine, artemisinin, the extract of sambiloto, the combination of sambiloto and chloroquine, and the combination of sambiloto and artemisinin. Parasite density was determined by counting the number of Plasmodium falciparum infected erythrocyte in 5,000 erythrocytes of the culture. Single drug (Chloroquine-only or artemisinin only) and either combination with sambiloto at dose 0.5 ug/ml had killing-effect against the parasite, measured by the appearance of "crisis form" on the infected erythrocytes. This killing-effect was dose dependent, and reached its optimum effect of 200 ug/ml. treatment of single sambiloto extract with dose 0.5 ug/ml increased the density of the parasite, however after every 1ug increasing dose of sambiloto extract, the killing effect also increased. The reduction of the parasite density was also seen by increasing the Sambiloto dose in the group of combination of sambiloto-chloroquine as well as the group of combination of sambiloto and artemisinin. Statistically, there was no difference in the anti-malaria efficacy among of five test drugs (p=1.00). The correlation between the reduction of the parasite with the increasing of dose in all groups is statistically significance (p=0.001). the extract of sambiloto in a single dose or in a combination evidently has the effect of anti-falciparum malaria.

Karo-Karo U.,Prima University of Indonesia
International Journal of Pharmacy and Technology | Year: 2016

Noninfectious desease became a problem in health which must be solved seriously. The risk general factor that noninfectious desease was hypertension, high blood sugar, unnormal fat embolism and obesity. Hypertension becomes interested desease caused it caused of death. The number of the persons who have hypertension was rising from year to year. It was caused of factors. There were low potash, high natrium, les nutrition, commonly consumme animal grease, stress, smoking, and less excercising. It used quantitative research. It has been Done since March until April 2015. The object of research was police. It used systematic sampling. The collecting data was done with questioners and to measure blood pressure was done by nurses. The research finding was shown that 28% of smoking persons had high hypertension, vise versa the lowest smoking persons shown that 36.6% normal. Responden who had floaty activity was 26.8%. Medium with normal blood pressure was 32.9%. The conclusion of this research was there were relationship between smoking persons and ecercising activity with hypertension. To solve the problem above was the pearsons must be done more execises than smoking. © 2016, International Journal of Pharmacy and Technology. All rights reserved.

Sitinjak R.R.,Prima University of Indonesia
Journal of Chemical and Pharmaceutical Research | Year: 2016

The aim of this research was to evaluate the somatic embryo of meristem culture of ginger (Zingiber officinale Rosc.) through morphological analysis. This research used descriptive methode. Friable embryogenic callus, obtained from meristem culture, was cultured on proliferation medium. Cultured tissue fragments containing several globular embryoids were observed by microscopy to follow development of ginger embryoids. Based at morphology analysis, at first week it grew into somatic embryo. Somatic embryo that rise from embriogenic cells were another contach via a route spesific. The somatic embryo formed was consist of an apical region, a basal region and a suspensor region. On the fourth week, however, the morphology of somatic embryo was founded on the shape of globular. It’s consist of an apical region and a basal region. © 2016, Journal of Chemical and Pharmaceutical Research. All rights reserved.

Loading Prima University of Indonesia collaborators
Loading Prima University of Indonesia collaborators