bluuebunny/crossref_metadata_2025_split huggingface dataset:
The antioxidant and antibacterial study of Canarium indicum L. latex extract
Authors: Indrianingsih A W , Rosyida V T , Apriyana W , Darsih C , Angwar M , Windarsih A , Batrisya  
Published: January 2021

Abstract
Recently, plant extracts are natural additives that are in great demand. Many biological activities of plant extracts in the fields of food and health, make research on plant extracts quite rapid. Canarium indicum L. is one of the most famous fruits in Indonesia. However, usually only the seed of C. indicum that was studied such as anti-inflammatory, antirheumatic, and hepatoprotective. In this paper, the antimicrobial and antioxidant activities of C. indicum latex were studied. The C. indicum extract were prepared by maceration method using ethanol for 48 hours. After the evaporation, the crude extracts were evaluated its biological activity. The antibacterial activity was performed using dilution method and the antioxidant activity was using DPPH assay. The scavenging activity of C. indicum latex extracts values in the range of 10.92 – 58.36% with the extract concentration of 100 to 800 ppm, respectively. The antibacterial activity of C. indicum latex extract was conducted against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). The inhibition zone C. indicum was 6.39±0.06 mm against S. aureus and 2.38±0.62 mm against E. coli at extract concentration of 10000 ppm. The results obtained indicate that C. indicum latex extract is favourable to be applied in the fields of medicine and health.
In vitro antioxidant activity of macroalgae Sargassum duplicatum and Palmaria palmata extracts collected from Sepanjang Beach, Gunungkidul, Yogyakarta
Authors: Darsih C , Indrianingsih A W , Poeloengasih C D , Prasetyo D J , Indirayati N 
Published: January 2021

Abstract
Marine macroalgae are considered as important sources for bioactive phytochemicals. In this research, two potential marine macroalgae, i.e. Sargassum duplicatum and Palmaria palmata taken from Sepanjang beach, Gunungkidul, Yogyakarta, Indonesia were explored as sources of phenolic compound, and their antioxidant activities were evaluated. Three different solvents, i.e. chloroform, ethyl acetate, and methanol were applied as extraction medium. For each species, its total phenolic content (TPC) and antioxidant activity were determined using Folin-Ciocalteu reagent and DPPH scavenging assay, respectively. The result showed that methanolic extracts exhibited the highest yield in both species. The highest TPC (726.54 mg GAE/g) was obtained from S. duplicatum extracted using ethyl acetate. The antioxidant activity from S. duplicatum and P. palmata have similar value with IC50 values of 790.34 µg/mL and 789.29 µg/mL. The scavenging activities of all extracts related to the total polyphenol content, whereas the polarity of solvent affected the resulted yield and TPC of the extracts. However, our results demonstrated that all extracts were inactive against DPPH radicals (IC50 > 250 μg/mL).
A comparative study on the degradation of 2,4-dichlorophenol and 2,5-dichlorophenol using DBD non-thermal plasma reactor
Authors: Diristiani Febri Monica , Khairunizzahra Badzlina , Suryo Samantha , Bismo Setijo 
Published: January 2021

Abstract
The dichlorophenol compound group (DCP) is one of the pollutants contained in industrial wastewater. This component is difficult to degrade in the environment, subsequently leading to hazards and a severe impact on human health. Based on the location of the chlorine atom in the aromatic ring, the variety present in some isomers ought to be removed from the water, in order to reduce the impact. Therefore, the technology adopted to eliminate the DCP concentration levels in wastewater includes the application of Dielectric Barrier Discharge (DBD) plasma reactor of high efficiency. This set up implements advanced oxidation processes (AOPs) by relying on highly active species, specifically ‧OH and O3. The aim of this study, therefore, is to compare the effectiveness of DBD reactors in the degradation activity on isomer 2,4-DCP and 2,5-DCP under acidic (pH 4) and alkaline (pH 10) conditions. The results showed the highest percentage removal (89.05%) after 120 minutes process of 2.5-DCP degradation, under the following conditions: pH 10; flow rate 50 mL/minute; airflow rate of 2.5 L/min; plasmatron voltage of 19 kV. Under similar circumstances, 2,4-DCP was reduced by 86.95%. In addition, the COD content in the waste material reached 46.88% and 46.14%, respectively.
Evaluation of uncertainties measurement in EDXRF for air filter analysis
Authors: Sari D K , Lestiani D D , Kurniawati S , Atmodjo D P D , Kusmartini I 
Published: January 2021

Abstract
Energy Dispersive X-Ray Fluorescence (EDXRF) is one of the nuclear analytical techniques that has been widely used for elemental analysis, especially for air filter analysis. EDXRF Epsilon 5 has been installed in BATAN Bandung laboratory, Indonesia. EDXRF Epsilon 5 is an analytical instrument that is used to determine trace elements in many kinds of materials, especially in air filter samples. Measurement conditions have to be set up to determine several elements. Uncertainty evaluation was different according to the instrument used in each laboratory. This activity is aimed to calculate and evaluate the uncertainty measurement associated with EDXRF Epsilon 5 for air filter analysis. Evaluation of uncertainties measurement in EDXRF Epsilon 5 was carried out following the guides to express uncertainty: JCGM 100:2008 and EURACHEM. The uncertainty evaluation focused on 10 elements: Na, Si, S, K, Ca, Ti, Fe, Zn, Br, and Pb that generally existed in airborne particulate samples. The uncertainties results for 10 selected elements measured with Epsilon 5 were in a good correlation, with % relative uncertainty were ranged from 2% to 32%.
Phytochemical properties and antioxidant activity of wild-grown and cultivated Ganoderma lucidum
Authors: Hayati Septi Nur , Darsih Cici , Rosyida Vita Taufika , Apriyana Wuri , Nisa Khoirun , Indrianingsih Anastasia Wheni , Wulanjati Martha Purnami 
Published: January 2021

Abstract
The most biologically active compounds of medicinal mushroom Ganoderma lucidum can be classified into polysaccharides and terpenoids. Most of these biological compounds are supposed to associate with its antioxidant activity. Both of wild grown and cultivated G. lucidum have been commercially in demand in Indonesia during the past years. Due to their different growing conditions, the wild-grown and cultivated G. lucidum may contain different levels of effective chemical components which affect their quality and medicinal efficacy. This present study was carried out to determine the differences between wild-grown and cultivated G. lucidum which might be useful in exploring the characteristic of chemical compounds of G. lucidum regarding its antioxidant activity. The physicochemical evaluation was determined using gravimetric method. The phytochemical evaluation includes water – soluble polysaccharides, phenolic, and terpenoids content. The antioxidant activity was evaluated by measuring the radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Cultivated G. lucidum from Godean has the highest water – soluble polysaccharides (29.86±2.42 GE, mg/g dw) and phenolic content (5.07±0.39 GAE, mg/g dw) among other studied samples. Whereas, cultivated G. lucidum from Gunung Kidul has the lowest water – soluble polysaccharides (21.65±2.45 GE, mg/g dw) and phenolic content (3.21±0.87 GAE, mg/g dw). Both of wild grown G. lucidum have higher terpenoids content compare to all of cultivated G.lucidum. The cultivated – Godean revealed the highest DPPH scavenging activity (the lowest IC50, 344.15±9.57 µg/mL) among of the studied samples. Hence, the results suggested that G. lucidum contained high metabolites compounds and has a potential natural source of antioxidants.
Determination of Ca, Na, Mg Impurities in Demineralized Water Bandung Triga 2000 Reactor using Flame Atomic Absorption Spectrophotometry
Authors: Adventini Natalia , Damastuti Endah , Ratnawati Neni , Indah Suciati Fuji Octa , Niken Syahfitri Woro Yatu 
Published: January 2021

Abstract
Demineralized water is commonly used as cooling water, neutron moderator and as a radiation shield in a nuclear reactor such as Bandung Triga 2000 Reactor. According to its function, demineralized water has to fulfilled some requirements as stated in Safety Analysis Report (SAR) of Bandung Triga 2000 Reactor. The requirements were impurities of Ca, Na and Mg, pH and conductivity electricity in demineralized water reactor. Determination of Ca, Na and Mg as impurities were carried out using Flame Atomic Absorption Spectrophotometry (FAAS). In this activity, instrument and method verification were carried out as quality control. Instrument verification determined were sensitivity, precision and detection limit of FAAS. Method verification was carried out by using spike demineralized water with Na, Ca, and Mg standard. Accuracy and precision of the method were in the acceptance criteria according to AOAC then implemented to determined impurities of Ca, NA, Mg in demineralized water reactor samples. Na and Mg in demineralized water using FAAS gave values less than 1 mg/L, pH values were in the range 5,5- 6,5 meanwhile conductivity electricity gave values were less than 3 µmho fulfilled the requirements in SAR. These results were indispensable to support the performance of Bandung Triga 2000 Reactor which needed by public and university for the development of science and its application in the industry, health, environment and other fields.
Nuclear analytical techniques for identification of elemental composition of fine and coarse airborne particulate matter Collected in Bandung, Indonesia
Authors: Santoso M , Lestiani D D , Kusmartini I , Sari D K , Kurniawati S , Damastuti E , Atmodjo D P D , Tjahyadi A , Windiandi W D 
Published: January 2021

Abstract
Air pollution has received serious attention from both the government and the public in Bandung, Indonesia. Nuclear analytical techniques (NAT) such as X-ray fluorescence (XRF) have been implemented for the quantification of environmental pollutants, especially airborne particulate matter (APM). Sampling for fine APM (PM2.5) and coarse APM (PM2.5-10) have been conducted in Bandung using a GENT sampler, once a week for 24 hrs from 2015 to 2017. The samples were then analyzed for their mass, black carbon (BC), and elemental composition using gravimetric, smoke stain reflectometer, and ED-XRF, respectively. The results obtained indicate that the annual average of PM2.5 is in the range of 17.85-20.90 µg/m3 which has exceeded the Indonesian annual standard (15 µg/m3). While for PM10 it is still below the standard. Compared to PM2.5 and PM2.5-10 in 2002-2004, the concentration has increased by around 35% and 29%, respectively. This situation needs serious attention especially because of the adverse effects of PM2.5 on human health. The average BC fraction at PM2.5 is around 19%. In this paper, chemical composition, annual concentration trends, and correlations between elements will be discussed in detail including the advantages and disadvantages of the NATs method. For the next stage, this information can be used to identify sources of pollutants.
The Screening of Antidiabetic Activity and The Cultivation Study of Local Marine Microalgae
Authors: Priatni S , Ratnaningrum D , Kosasih W 
Published: January 2021

Abstract
Microalgae are rich source of primary and secondary metabolites which have potential bioactive compounds for application in the pharmaceutical industry. The study of antidiabetic activity from microalgae have been carried out because it can be cultivated in a small area and efficient in light capturing. This study aimed to screen the local marine microalgae which potential as the antidiabetic source. Five microalgae strains (Chlorella sp A and B, Nanochlropsis sp, Porphyridium sp, and Skeletonema sp were screened according to their growth rates, antidiabetic activity (α-glucosidase inhibition) and biomass yield. Results showed that Porphyridium sp cells were grown very active compared to other strains. After 8 days of cultivation, the cells’ number of Porphyridium sp was 345x103 cells/ml. The highest activity in α-glucosidase inhibition was detected in Porphyridium sp biomass (12.63%). The biomass yield of Porphyridium sp (6.71 g) was obtained after cultivated at 5 L scale production. The exponential growth rate of Porphyridium sp which cultivated with aeration pump system (Rexp = 0.177, TD = 3.8 days) was higher than cultivated with shaker incubator system (Rexp = 0.045, TD = 15.4 days). We concluded that Porphyridium sp is the best microalgae compared to other microalgae both its productivity and antidiabetic activity. The cultivation of Porphyridium sp by using aeration pump system is much recommended.
Antibacterial activities of Solo garlic
Authors: Setiyoningrum F , Herlina N , Afiati F , Priadi G 
Published: January 2021

Abstract
Solo garlic, either in fresh form or its black garlic has a lot of bioactive compounds, such as flavonoids and polyphenols. The aim of this research was to evaluate the antibacterial activity of organic solvents extract’s solo garlic inside the fresh and black garlic form against pathogenic bacteria such as Escherichia coli and Staphylococcus aureus, by using agar diffusion and dilution methods. The diffusion test shown that BG4 had the highest inhibitor activity comparing the other treatments. Concentration of BG4 1 mg/ml, either in isopropanol or ethyl acetate was able to inhibit the growth of E. coli and S. aureus. Based on that results, solo black garlic especially 3 or 4 weeks-fermented solo black garlic could be considered as a therapeutic agent.
Toxicity and Total Phenolic Content of Saurauia vulcani Extracts from Cultivation
Authors: Pasaribu Gunawan , Budianto Emil , Cahyana Antonius Herry 
Published: January 2021

Abstract
Saurauia vulcanii plant has been widely used to treat a variety of diseases suffered by villagers as antidiabetic and digestive problems’ remedy. The Forestry Research and Development Agency has cultivated this plant at Forest Area for Specific Purpose in Northern Sumatra. The aims of this study were to determine the toxicity and total phenolic content from n-hexane, ethyl acetate and methanol Saurauia vulcani extracts. The toxicity was carried out using the Brine Shrimp Lethality Test (BSLT) method and Folin Ciocalteu method is used for total phenolic content. The result showed that the toxicity of n-hexane, ethyl acetate and methanol extracts i.e. LC50 values of 365.19 ppm, 715.28 and 225.77 ppm, respectively. The total phenolic content of hexane, ethyl acetate and methanol extracts were 7,155 mg GAE/g, 13,702 mg GAE/g and 16,560 mg GAE/g, respectively.
The analysis of several types of catalysts for ozone decomposition
Authors: Luvita Veny , Bismo Setijo , Sugiarto Anto Tri 
Published: January 2021

Abstract
There has been rapid technological development in the aspect of water and wastewater treatment, including the application of ozone technology, commonly known as Advanced Oxidation Processes (AOPs). This involves the use of ozone gas converted to oxygen and OH● radicals, which possess the capacity to degrade the unwanted compounds present, although there is need for performance optimization to enhance the ease of formation and decomposition. This process is faced with serious problems that require immediate attention, particularly the presence of excess ozone, which is harmful to the health of living things, especially humans. Ozone decomposition uses an MnOx active core catalyst with a nominal loading of 0–2%. As a comparison used catalyst supports such as Zeolite Alam Lampung (ZAL), Granular Activated Carbon (GAC) and Green Sand (GS) with diameter 18–100 mesh. However, the challenge is comprehensively attenuated by using catalysts possessing the capacity to degrade the excesses, and promote procedure optimization, subsequently enhancing conversion and decomposition. Furthermore, previous studies have demonstrated the potential to elevate the production of OH radicals, and it was also established that catalysts from natural origin are less expensive, easy to operate, highly selective and difficult to damage under various conditions. The result of this study is GAC is more effective and efficient compared to others for decomposition.
Tribo-behaviours of textured point contacts lubricated with low and high consistency lithium greases under reciprocating motion
Authors: Chaudhary Rameshwar , Pandey R K , Mazumdar S K 
Published: January 2021

Abstract
Tribo-behaviours of grease-lubricated textured point contacts were experimentally explored at heavy loads (characterized in term of Hertzian pressure, P

H
= 1.5–3.0 GPa) and relatively low sliding speeds (0.2 and 0.4 m s−1) under the linear reciprocating motion employing lithium-based low and high consistency greases. Two contacts (grounded plate versus lapped ball & grounded textured plate versus lapped ball) were employed for the comparative investigations of friction coefficient, specific wear rate, and contact potential. Effects of grease consistency on the greases’ rheological behaviours have also been found at two temperatures 25 °C and 80 °C using controlled stress rheometer. Overall, textured concentrated contacts yielded a low coefficient of friction (reduction up to 24.6%), reduced specific wear rate of the ball (decrease up to 89.5%) and better development of contact potential in comparison to conventional contacts. The transmission electron microscopy (TEM) of used greases collected from textured contacts revealed less degradation in soap fibres. Moreover, the x-ray photoelectron spectroscopy (XPS) revealed the formation of ferric oxide (Fe2O3) and ferrous-ferric oxide (Fe3O4) protective chemical films on the worn surfaces of balls of the conventional and textured contacts.
Tribological properties of dithiocarbamate triazine and its competitive adsorption behavior compared to T701 on the corrosion inhibition of Q235 steel
Authors: Zhu Mengyue , Rao Sainan , He Zhongyi , Hu Jianqiang , Xiong Liping , Zhang Renhui , Han Sheng , Li Lili 
Published: January 2021

Abstract
The triazine dithiocarbonate (CDMS) was synthesized from the reactions among diethanolamine, carbon disulfide and 2-chloro-4,6-dimethoxy-1,3,5-triazine. The synthesized CDMS showed excellent anti-wear and friction-reduction properties and outstanding corrosion inhibition for the investigated systems. Besides, the synergy-inhibition effect of the CDMS and T701 compound-inhibitor was investigated compared to the inhibition effect of CDMS, which showed that the inhibition effect of CDMS was superior to that of compound-inhibitor. The DFT and molecular dynamics simulations results showed that it existed competitive adsorption behavior between CDMS and T701, led to the inhibition effect of the compound inhibitor lower than that of CDMS.
Reconfigurable optical memory based on MoS2/QDs mixed-dimensional van der Waals heterostructure
Authors: Sun Yilin , Ding Yingtao , Xie Dan , Sun Mengxing , Xu Jianlong , Yang Pengfei , Zhang Yanfeng , Ren Tianling 
Published: January 2021

Abstract
Optical memory unit with the ability to detect and store optical signals is increasingly becoming a crucial part of advanced data communication and image sensing technology. Despite great efforts devoted to develop high-performance optical memory devices based on two-dimensional (2D) material, the photoelectric conversion is still limited to defect-dominant photo-generated carrier trapping/de-trapping process at the interface of 2D materials. Here, a reconfigurable optical memory implanted with photonic programming/electric erasing operation is demonstrated based on MoS2/quantum dots (QDs) mixed-dimensional heterostructure. Unique photoelectric coupling effect between MoS2 and QDs leads to a continuous n-doping on MoS2 channel after light exposure removed, resulting in the generation of persistent photocurrent. Excellent optical memory characteristics such as high programming/erasing ratio, long retention time and stable operation cycles have been achieved and demonstrated to be gate-tunable. Besides, multi-level optical data storage with ten different states is also realized by applying a series of programmable optical signals. Owing to the unique dynamic response of mix-dimensional van der Waals heterostructure to optical and electric signals, our proposed optical memory transistor may pave up a new path to explore photoelectric conversion in low-dimensional system and develop high-performance optoelectronics for a broad range of applications.
Kinetic calculation analysis of Ga deposition on the morphology evolution of GaAs quantum ring
Authors: Lang Qi-Zhi , Guo Xiang , Luo Zi-Jiang , Ding Zhao 
Published: January 2021

Abstract
GaAs Quantum Ring (QR) was gained on GaAs (001) by Droplet Epitaxy (DE), and the microscopic morphology of the GaAs samples was observed by Scanning Tunnel Microscope (STM). The kinetic model of Local Droplet Etching (LDE) was mainly used to study the influence of Ga deposition on the morphology evolution from Ga droplets to GaAs QR. Comparing experimental data with the theoretical value, it can be seen that the increase of Ga deposition will cause the reduction of surface density of Ga droplets, but the volume, height and diameter of Ga droplets will increase. Geometric dimension of GaAs QR increased also with the increase of Ga deposition. In addition, it found that the rate at which the substrate was etched was affected by Ga deposition and As pressure from experiment. The more Ga deposition, the deeper GaAs nano hole. However, GaAs nano hole became shallower under high As pressure. These results are consistent with theoretical calculation analysis. Under high substrate temperature, GaAs double rings finally evolved into a single ring. Above all results have certain guiding significance for the preparation of patterned GaAs substrates and the controlled growth of GaAs QR morphology.
Effect of sintering temperature on the microstructure and mechanical properties of the Ti-2.5Zr alloy
Authors: Alhazaa Abdulaziz , Assaifan Abdulaziz , Hezam Mahmoud , Shar Muhammad Ali , Umeda Junko , Kondoh Katsuyoshi 
Published: January 2021

Abstract
Zirconium effectively became an emerging alloying element used for titanium in order to improve its mechanical properties by Ti grains refinement and solid solution strengthening effects. As a result, Ti-Zr alloy enhances its industrial applications. In this study the titanium powders were sintered after the addition of 2.5 wt% of Zr using Spark Plasma Sintering (SPS) technology. The original pre-mixed powder consists of pure Ti and ZrH2 particles. An applied pressure of 40 MPa and a short sintering time of 5 min were fixed in all experiments under a vacuum of 1 Pascal. EDS, XRD and XPS analysis showed that Zr dispersion as solid solution through α-Ti was homogenized for sintered samples at 1000 °C and 1200 °C while the agglomeration of ZrH2 was detected in the sample sintered at 800 °C. These agglomerated particles reduced the average Zr content through titanium matrix compared to an average of 2.3 to 2.7 wt% for samples sintered at 1000 °C and 1200 °C. The hardness increases with the increase in the sintering temperature. However, since the sample sintered at 1200 °C showed an excessive grain growth that reduced its strength, it was found that 1000 °C sintering temperature can be an optimum temperature for this process.