bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Sr substitution on electrical polarization of Ba1-xSrxTiO3 (x = 0.0, 0.2, 0.6, and 0.8) perovskite materials
Authors: Yeceu E , Laysandra H , Triyono D 
Published: January 2020

Abstract
This study aims to investigate the electrical polarization of Ba1-xSrxTiO3 (x = 0.0, 0.2, 0.6, and 0.8) perovskite materials. The materials were synthesized using mechano-synthesis. The structural behaviour was assessed using X-ray diffractometer (XRD), revealing that all samples have a tetragonal perovskite structure with a lattice parameter that decreases with an increase in Sr. The electrical polarization was investigated using an electrometer, showing decreasing spontaneous and saturation polarizations as more Sr is substituted into the Ba sites of (Ba,Sr)TiO3. The decreasing lattice parameters and spontaneous and saturation polarizations in these materials indicate that the crystal structure changes from tetragonal to cubic as more Sr is added.
Analysis of satisfaction and loyalty level of online taxi bike customer
Authors: Pratiwi M N , Setiadi R , Siswantining T 
Published: January 2020

Abstract
Customer satisfaction in marketing research was defined as happiness and awful that was got from someone by comparing perceived performance with perception and expectation. Therefore, customer satisfaction was explained by application quality, driver’s quality and motorcycle quality. Customer loyalty in marketing research was defined by responses that reflected by continue purchasing. All component of application quality, driver’s quality and motorcycle quality is a latent variable that was measured by indicators. The purpose of this research is to know about correlation between loyalty level and satisfaction level depend on sample that was gotten by stratified random sampling. In each stratum, sample has got by systematic sampling. This research used Partial Least Square (PLS) method to find correlation between customer satisfaction and loyalty satisfaction. The results showed that there is positive correlation between satisfaction and loyalty level.
Estimation of variance of random effect in small area model with Spatial Empirical Best Linear Unbiased Prediction (SEBLUP)
Authors: Siswantining T , Naima M G , Soemartojo S M 
Published: January 2020

Abstract
Survey sampling is one of the sampling methods of an object to provide information estimation of population parameters that became the focus of research. One of the methods that used to estimate population parameters is direct estimation method. However, when the direct estimation is used it will cause a large standard error. To handle that problem in small area we add information about the same parameters in other small areas which has similar character, or the value of the variables that are related to the variables being observed, this method is known as the small area estimation (SAE). In this mini thesis, small area method that we use consider spatial correlation between area, spatial Empirical Best Linear Unbiased Prediction (EBLUP). The estimator of spatial EBLUP depends on the variance component and spatial correlation, but in practice they are unknown. Therefore, to get the spatial EBLUP estimator it is necessary to first estimate the variance of random effect and correlations between area. In this mini thesis we use maximum likelihood method and scoring algorithm to estimate the variance of random effect and correlations between area.
Effect of cobalt supported on the hierarchical Ni/HZSM-5 catalyst in hydrocracking of Sunan candlenut oil (Reutealis trisperma (Blanco) airy shaw)
Authors: Marlinda L , Al-Muttaqii M , Roesyadi A , Prajitno D H 
Published: January 2020

Abstract
The effect of cobalt supported on the hierarchical Ni/HZSM-5 on conversion, n-paraffin/aromatic selectivity, the degree of hydrocracking and polymerization in hydrocracking of Sunan candlenut oil was investigated. The hierarchical HZSM-5 was obtained through desilication with 0.2 M NaOH solution. The cobalt (Co), nickel (Ni) and Co-Ni supported on hierarchical HZSM-5 catalysts were prepared by incipient wetness impregnation. Desilication and metal impregnation did not change the crystalline structure of HZSM-5 catalyst. Hydrocracking of Sunan candlenut oil into gasoil-range hydrocarbon was tested with the catalysts at a temperature of 400 °C, and a reactor pressure of 15 bar for 2 h under initial hydrogen pressure in a pressured batch reactor. All catalysts reached conversion almost 100 %. Non-catalytic hydrocracking contained large amounts of undesired compounds (50 %), N-containing compounds around 1 area% and a small amount of compound containing oxygen including ketone (2-heptadecanone) and alcohol (<1%). The addition of cobalt supported on the hierarchical Ni/HZSM-5 improved C15/C16 ratio up to 11, the n-paraffin selectivity up to 78% and decreased polycyclic aromatic hydrocarbons (2-3.7 %). Then, N-containing compounds were not detected. The degree of hydrocracking decreased from 0.28 to 0.23. These results indicated that cobalt could control hydrogenation ability of nickel. The presence of cobalt in the hierarchical Co-Ni/HZSM-5 catalyst increased catalytic activity in decarboxylation route to produce the most abundant n-paraffin, i.e. pentadecane (n-C15) and heptadecane (n-C17). Overall, the monocyclic aromatic hydrocarbons selectivity produced for hierarchical pore structure based HZSM-5 catalyst were 15-18 %.
Investigation of metalloporphyrin in maltenes phase of crude oil Duri
Authors: Suwarno A C , Yulizar Y , Haerudin H , Kurniawaty I , Apriandanu D O B 
Published: January 2020

Abstract
The presence of metals and organometals in heavy crude oil is interesting research to study. The most abundant heavy metals and undesirable presence of heavy metals in crude oil are nickel and vanadium. Organometals such as metalloporphyrin can inhibit the catalyst performance in cracking process. Crude oil is classified into asphaltenes and maltenes phases. In this study, isolation of metalloporphyrin in maltenes was perfomed by column chromatography using eluent of n-heptane: ethyl acetate (8.5:1.5) (v/v). The isolated metalloporphyrin was characterized using Ultraviolet-Visible (UV-Vis) spectrophotometry, FTIR (Fourier Transform Infrared), and Liquid Chromatography-Mass Spectrometry (LC-MS). UV-Vis spectrophotometry characterization showed the presence of metalloporphyrin at the maximum wavelength of 480–700 nm. FTIR characterization showed the existence of pyrrole rings vibration, which described as porphyrin compound at the wavenumber of 800 cm−1. LC-MS characterization showed the presence of vanadium bound at porphyrin in maltenes with the molecular formula of C39H36N4VOS.
Discovery of novel drug candidates based on herbaric acid derivates as potential inhibitors of the hedgehog signaling pathway in cervical cancer therapeutics
Authors: Nasution M A F , Parikesit A A , Tambunan U S F 
Published: January 2020

Abstract
Cervical cancer ranks as the second most deadly cancer in women worldwide and as the most deadly in developing countries. However, there is currently no effective treatment for this disease. Therefore, it is necessary to find improved drugs for cervical cancer treatment. Cervical cancer is caused by human papillomavirus (HPV) infection, which has E6 and E7 proteins that may activate the Hedgehog (Hh) signaling pathway and regulate the proliferation, survival, and migration of cervical cancer cells. In this study, a novel series of herbaric acid derivates were designed and developed as potential inhibitor candidates of the Sonic hedgehog (Shh) signaling pathway. All of the potential inhibitors were analyzed and compared with Shh inhibitors, such as robotnikinin, through molecular docking simulations. Molecular docking simulations of 6310 ligands were performed using the Accelrys Discovery Studio 2.5 software according to the LibDock method. After the analysis of the ligand–Shh protein complex interaction in the docking simulation, it was found that Sd32, Sa32, and Wc34 ligands were best at inhibiting the Sonic hedgehog protein.
Preparation of nitrogen-doped TiO2 nanotube deposited with gold nanoparticles for photocatalytic phenol degradation under visible light
Authors: Hadiputra R , Gunlazuardi J 
Published: January 2020

Abstract
One of the many functions of TiO2 photocatalysts is degrading organic compounds. TiO2 photocatalysts have a band gap of 3.2 eV, which is equivalent to the energy of ultraviolet (UV) photons with a wavelength of 388 nm and allows them to be effectively activated only by UV light. However, they are less effective under visible (Vis) light. Researchers have developed many ways to use the photocatalytic properties of TiO2 under visible light via nitrogen doping. Further, the photocatalytic activity of N-doped TiO2 can be improved via surface plasmon resonance. In this study, N-doped TiO2 nanotubes (N-TiO2 NTs) are prepared and deposited with Au nanoparticles (Au/N–TiO2 NTs) via electrodeposition. The TiO2 NTs and Au/N-TiO2 NTs are characterized using UV-VIS spectrometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), field emission scanning electron microscopy, energy dispersive spectroscopy (EDS), and linear sweep voltammetry (LSV). The photocatalytic test under tungsten lamp illumination of a 20-ppm phenol solution in a batch reactor shows a phenol degradation of 60 %, whereas a 20-ppm bisphenol A (BPA) solution is degraded by 40 %.
Polymerization of the tannin extract from the leave of Acacia mangium and its application as an adsorbent for the removal of lead
Authors: Laksmi M P , Nurani D A , Rahayu D U C 
Published: January 2020

Abstract
Pollution of heavy metal ions in water is a hazardous environmental problem that requires specific methods for handling lead ion contamination. One of these methods involves the use of tannin adsorbent. Tannin adsorbents exhibit renewability, biodegradability, and natural abundance. In this study, the extract from the leaves of Acacia mangium was used as the raw material for the adsorbent. The tannin extract was polymerized by the addition of concentrated H2SO4 because the adsorbent was insoluble in water. The resin obtained from the polymerization of the tannin extract (hereafter referred to as PET) was characterized qualitatively by Fourier transform infrared spectroscopy and quantitatively by total organic carbon measurements. To determine its ability as an adsorbent, we estimated the adsorption parameters of PET. The optimum adsorption capacity of PET was 5.261 mg/g at a pH of 7 and a contact time of 120 min.
Development of nitric-oxide-sensor-based gold (Au) and platinum (Pt) metals on screen-printed electrode modified graphene
Authors: Nurkhasanah S , Setiasih S , Wibowo R 
Published: January 2020

Abstract
Nitric oxide (NO) plays an important role in physiological processes. NO measurement accuracy is important to understand the essential functions of NO but attaining these levels of accuracy is difficult due to NO’s short half-life. NO concentrations can be determined using an analytical method that has fast response and high sensitivity and is simple and practical. In this study, gold and platinum metals are deposited onto a screen-printed electrode (SPE) surface in a solution mixture of HAuCl4 in 0.05 M H2SO4 and K2PtCl6, in 0.05 M H2SO4, which has been modified with graphene to detect NO. Experiments that varied the deposition concentrations of the Au/Pt onto the G/SPE are conducted to obtain an optimal deposit concentration ratio between AuPt and G/SPE. NO detection tests are conducted at +0.878 V against Ag/AgCl. Deposits of AuPt/G/SPE that have 1:1 concentrations form high-performance sensors due to its high sensitivity at 23029.92 μA mM−1 cm−2, a low detection limit of 2.2 × 10−3 mM, and the best linearity, R2 = 0.9943. No is detected using the Griess Saltzman method. Based on the linearity results from the NO detection measurements, we observe that the electrochemical method provides significant improvements over the Griess Saltzman method.
The growth of Synechococcus sp RDB001 at temperature of 30 ± 5 °C and 50 ± 5 °C: a comparison study of cell density and chlorophyll content
Authors: Prihantini N B , Anggriary R D , Kusmadji L R 
Published: January 2020

Abstract
Research on comparison of cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C has been carried out. Synechococcus sp. RDB001 was isolated from hot spring water samples in the area of Rawa Danau-Banten with a water temperature of 50 °C which grown in MA medium (pH 6). The research aims to determine the comparison of the average cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C in incubation cabinets. The research results are useful for understanding the physiological tolerance limits and adaptation of Synechococcus sp. RDB001 ex-situ. Culturing of Synechococcus sp. RDB001 was carried out in cabinets with the incubation temperature of 30 ± 5 °C and 50 ± 5 °C for 16 days, from day 0 (t0) until day 16 (t16). Each treatment was done in 16 replicates. Non-parametric statistical analysis using the Mann Whitney test (α = 0.05) and the Spearman test (α = 0,01). The results showed there were significant differences (α = 0.05) in cell density of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C. The highest average of cell density of Synechococcus sp. RDB001 at a temperature of 30 ± 5 °C occurred at t12, (24.2075 ± 5.33926 x 106 cells.mL−1), while at a temperature of 50 ± 5 °C occurred at t14 (1.21313 ± 2.92573 x 106 cells.mL−1). There was no correlation (α = 0.01) between cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C. The research showed that increasing the cell density of Synechococcus sp. RDB001 is not always followed by an increase in chlorophyll content of Synechococcus sp. RDB001.
Seasonal effect on the spatial distribution of macro debris in Tunda Island, Banten
Authors: Maharani A , Yuliadi L P S , Syamsuddin M L , Ismail M R 
Published: January 2020

Abstract
The small island coast is an area that is vulnerable to environmental problems. Debris problems occur in some areas of Tunda Island with low human activity, due to current and wind factors that can distribute the debris. The speed and direction of wind and currents in Indonesia are influenced by the seasons, so the seasons have an influence on the accumulation of debris in a place. This study aims to determine the effect of the season on the distribution of debris and potential sources that influence the presence of debris on the coast of Tunda Island, Banten. This study uses MIKE 21 software to determine current and wind patterns and movement of macro debris particles. Based on season research, it influences the pattern of macro debris distribution in this area. In the east season, the increase in the litter is 9 kg from the weight of the debris in the west season. Also, there is an increase in debris in several categories including the most likely to find items, fishing gear, packaging material, small pieces trash, and base wood materials. The potential source that affects the presence of debris on the coast of Tunda Island, Banten is Muara Ciujung.
Effect of regional oceanographic processes to the distribution of radionuclides in the coasts of Kalimantan
Authors: Prihatiningsih W R , Suseno H , Makmur M , Muslim M , Yahya M N 
Published: January 2020

Abstract
The present status of marine radioecology condition at the coastal of Kalimantan was determined based on monitoring of the radionuclides concentration in marine compartment of West, South and East Kalimantan. The characteristicof Pacific Ocean contribute to the distribution of radionuclide in Kalimantan from the Indonesian Through Flow (ITF) that passes through the Makassar Strait. The aim of this research is to determine the concentration of radionuclides and regional oceanographic effects on the distribution of radionuclides in the coasts of Kalimantan. Gamma radionuclides activity concentration were measured using High Purity Spetrometer Gamma Detector (HPGe) that is integrated with Genie 2000 software analysis. Modelling processes and field observation from previous study become reflelction of Kalimantan regional sea characteristic. The result of this research shows that the baseline data that represented natural and antrophogenic radionuclides are comparable with other regions in Indonesia. The concentration of natural radionuclides in the sediments showed that there are no contamination of Naturally Occurring Radioactive Material (NORM) and 137Cs.
Variation of seawater properties on tidal-scale in the entrance of Padangbai Lombok Strait Indonesia
Authors: Suteja Y , Atmadipoera A S , Natih M N , Wattimena M , Masoleh V , Pranoto Y , Adhyatma D , Widiastuti P , Deswanti S R , Triwahyuni A , Watari H , Hastuti A W , Mamun A , Vladoiu A , Chonnaniyah  
Published: January 2020

AbstractDuring Marine Science Summer Course 2017, a continuous 24-h conductivity-temperature-depth (CTD) “yoyo” measurement has been carried out at the entrance of Padangbai Lombok Strait to investigate seawater properties variations on semidiurnal tidal-scale which is dominant in the strait. The SBE CTD 19 plus is equipped with optional sensors such as pH, turbidity and chlorophyll-a derived-fluoro. During 24-h field observation, 15 CTD casts from sea surface to about 60 m depth have been acquired. It is shown that observed seawater properties fluctuate strongly four times a day, following semidiurnal-tide period with two flood-tide and two ebb-tide conditions. During flood-tide, water mass is derived from open strait with colder, saltier, denser and low dissolved oxygen characteristics. In contrast, during ebb-tide, local water mass is recirculated back from the inner bay to the open strait. It is interesting to note that fluctuation of chlorophyll-a indicates a diurnal signal. In addition, fluctuation of pH, turbidity and dissolved oxygen showed a weak semidiurnal signal.
Indonesian short fin eel Anguilla bicolor (Mclelland, 1844) swim bladder as important organ for reflecting acoustic wave
Authors: Hananya A , Pujiyati S , Hasbi S M , Retnoaji B 
Published: January 2020

Abstract
Indonesian shortfin eel, Anguilla bicolor (McClelland, 1844) is one of fish that have swim bladder to assist swim and doing migration. Every fish has different shape, gas volume, dimension, and length ratio of swim bladder, which can play role in the difference in backscattering of acoustic energy. This study aims to determine the shape, dimensions and ratio of Anguilla bicolor’s swim bladder and their effect on target strength (TS) values. The research was conducted in two places, in the Acoustic lab, Department of Marine Science and Technology, Bogor University and Laboratory of Histology and Embryology, Faculty of Biology, Universitas Gadjah Mada. Retrieving data using the EK-15, Frequency 200 KHz tool and also the X-ray photo. The results show the shape of the swim bladder of Anguilla bicolor is elongated and consists of 1 room which is generally called a closed swim bladder. Acoustic detection results show that fish with large swim bladder volumes have large TS values and conversely fish with small swim bladder volumes have a small TS value.
Freshwater intrusion during ebb and flood tide in the Balikpapan Bay
Authors: Benita I , Naulita Y , Nurjaya I W 
Published: January 2020

Abstract
The Balikpapan Bay waters is influenced by freshwater discharge from many rivers and its distribution is affected by tidal current. This study aims to estimate seawater intrusion during flood and ebb tides, using the box model and freshwater fraction methods. The data used in this study for calculating freshwater fraction and its transport volume were 45 conductivity- temperature-depth CTD casts and single moored ADCP current measurement, carried out between 17 and 25 May 2018. The budget of the box model system is calculated using evaporation and precipitation data. The results show that estimated freshwater fraction and transport volume during flood tide vary between 16.92 and 36.26%, and between 2.048 and 9.661x109 m3day−1, respectively. Near the entrance of the bay, seawater flux urges freshwater westward with surface salinity budget of -95.352x106 psu.m3day−1. Furthermore, during ebb tide, freshwater fraction and transport volume are estimated to be 19.33 – 34.5% and 2.048–9.661x109 m3day−1, respectively. Near the mouth of estuary, freshwater pushes seawater toward east side of the bay with salinity budget of -186.187x106 psu.m3day−1. During flood tide (ebb tide) estimated surface salinity budget in transect 5 that came out from the system is about -135.512x106 psu.m3day−1 (-143.794x106 psu.m3day−1) toward the southern bay.
Coral disease at Mansuar Island, Raja Ampat, Indonesia
Authors: Subhan B , Arafat D , Rahmawati F , Dasmasela YH , Royhan Q M , Madduppa H , Santoso P , Prabowo B 
Published: January 2020

Abstract
Coral reef has been facing rapid destruction nowadays. Raja Ampat Islands in Papua has one of the highest coral reef diversities and is located within the Coral Triangle area. The coral condition in Raja Ampat is still categorized as healthy. However, it started to show some of the habitat degrading signs. Coral disease is one of the main causes in coral reef ecosystem decline. This study aims to measure the level of coral disease based on coral disease category prevalence observation at Mansuar Island in Raja Ampat, Papua. The method used in data sampling is by using 5 x 50 m Belt Transect. The results show that as many as 28 coral genera were found from all of the observation sites with Fungia being the most abundant. There are 7 coral health categories, dominated by Tissue Discoloration Non-White. There are 5 coral diseases found namely Yellow Band Disease, White Syndrome, Brown Band Disease, Atramentous Necrosis, and Ulcerative White Spots.
Ocean wave measurement and wave energy calculation using overtopping power plant scheme
Authors: Vidura A , Nurjaya I W , Iqbal M , Jaya I 
Published: January 2020

Abstract
Indonesian seas have not been used as a source of electricity yet. One of the potential and abundant sources of energy from the sea is ocean waves. This study describes the measurement of the wave characteristics and calculates its spatial and temporal energy in Pari Island which can be utilized as electrical energy using overtopping ocean wave power plants scheme. The energy that can be harvested from ocean waves is calculated by wave energy converter using the Wave Dragon WEC. This converter is the terminator type. Sea waves on the Pari Island are classified as the smooth sea with 0.16-0.51 meters significant wave height and 2–4 seconds period. The calculated WEC can produce energy up to 28 Mega Joules and power up to 6 Mega Watts. Based on this calculation, Wave Dragon which is an overtopping WEC is able to meet the electricity needs on Pari Island with two options, The first one is using 35 units of WD 1 on the Pari Island Coast with a 500 m distance from the settlement, or the second one is using 6 units of WD 2 which is located in the northeast region of Pari Island waters with 18 Km distance from the settlement of Pari Island.