bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of nanocoating morphology on the signal of X-ray Photoelectron Spectroscopy
Authors: Afanas’ev V P , Lobanova L G , Selyakov D N , Semenov-Shefov M A
Published: December 2021

The paper considers the application of the traditional X-ray photoelectron spectroscopy (XPS) methodology: the Overlayer Thickness Determination for the analysis of coating parameters. In particular situations considered in this work, it is energetically favorable for the atoms of the coating to form clusters, but not be evenly distributed on the surface of the substrate material. The change in the XPS signal is analyzed in situations when the coating is not a plane-parallel homogeneous layer, but an island (cluster) structure. The mathematical model of the XPS signal formation is considered for the case of the cluster covering in the form of parallelepipeds. Photoelectron path distributions (in the coating material) analysis indicated a strong dependence of the signal on the viewing angle. For the purpose of analysis, experimental spectra were obtained for several samples: gold depositions of various thicknesses on a silicon substrate. The spectra were measured for different viewing angles of photoelectrons and interpreted within the Straight Line Approximation (SLA). It is shown that proposed simplest model of an island coating allows to describe the effect of a decrease in the value of the effective average coating thickness, determined in plane-parallel geometry, with an increase in the viewing angle, observed in XPS experiments with angular resolution.
Residual stresses in surface layers and coatings
Authors: Ashmarin A A , Lozovan A A , Betsofen S Ya , Moiseyev V S , Kubatina E P , Lebedev M A
Published: December 2021

Methods of measurement and mechanisms of formation of residual stresses in the surface layers of metal alloys after ion nitriding, as well as in heat-shielding and refractory coatings are considered. Examples of the application of a technique based on the peculiarities of elastic anisotropy for measuring residual stresses in heterogeneous surface layers, for which the standard technique of diffraction tensometry “sin2Ψ” is not applicable, are given.
Regularities and features of acoustic emission under plasma electrolytic oxidation of wrought Al-Mg alloy
Authors: Rastegaev I A , Polunin A V
Published: December 2021

The paper highlights the characteristic features of acoustic emission (AE) in the process of plasma electrolytic oxidation (PEO) of aluminum alloy, and also reveals the correlation of 4 main stages of PEO process with AE signals. The fundamental possibility to establish and detail the features of oxidation stages and to compare different PEO modes by AE signals was demonstrated. The results obtained substantiate the high potential of AE method as an instrument of in situ research, production monitoring and control, and evaluation of quality of PEO process on aluminum alloys.
Mechanical properties and fatigue of extruded D16 alloy profiles of the Al-Cu-Mg system after ion irradiation
Authors: Gushchina N V , Ovchinnikov V V , Shalomov K V , Vichuzhanin D I
Published: December 2021

The effect of 20-keV Ar+ ion irradiation on the mechanical properties andfatigue resistance of 6 mm thick hot-extruded profiles made of a D16 alloy (Al–Cu–Mg system) has been studied after natural aging. Irradiation at fluences of 2.1015 cm−2 and 1.1016 cm−2 has been revealed to increase the number of cycles to failure significantly at low load amplitudes σ/σu = 0.3. The maximum increase in the number of cycles to destruction 2.4 times is observed at a smaller fluence of ions F = 2.1015 cm−2.
Variation and adaptation of leaf water content among species, communities, and biomes
Authors: Wang Ruomeng , He Nianpeng , Li Shenggong , Xu Li , Li Mingxu
Published: December 2021

Leaf water content (LWC) is essential for the physiological activities in plants, but its spatial variation and the underlying mechanisms in natural plant communities are unclear. In this study, we measured the LWC of 5641 plant species from 72 natural communities in China, covering most terrestrial ecosystems, to answer these questions. Our results showed that LWC, on average, was 0.690 g g–1, and was significantly higher in forests and deserts than in grasslands. LWC was significantly different among different plant life forms, and ranked on averages in the following order: herbs > shrubs > trees. Interestingly, LWC decreased with increasing humidity and increased in dry environments. Furthermore, the variations of LWC in plant communities were higher in arid areas and those species with lower LWC in a plant community were more sensitive to changing environments. These results demonstrated the adaptations of plants to water regime in their habitats. Although, phylogeny has no significant effect on LWC, plant species both in forests and grasslands evolve toward higher LWC. Variations of LWC from species to community to biome represent the cost-effective strategy of plants, where plant species in drier environment require higher input to keep higher LWC to balance water availability and heat regulation. This systematic investigation fills the gaps on how LWC varies spatially and clarifies the different adaptation mechanisms regulating LWC across scales.
Impact assessment of the three gorges reservoir on the contribution rate for diversion through the three outlets
Authors: Chen M F , Li Y T , Li A Q , Yao W
Published: December 2021

The Dongting Lake distributes water and sediment of the Yangtze River through the three outlets. Influencing factors of the diversion capacity are complicated. In order to evaluate the influences of the operation of the Three Gorges Reservoir (TGR) on the diversion of the three outlets, this paper investigates systematically the variation process of the runoff at the three outlets based on substantially raw data and principles of variable control. By using comparative analysis and the calculation method of runoff reduction, the change magnitude of the runoff at the three outlets in different periods were quantified and the contribution rates of different influencing factors were estimated. Results show that (1) Inflow difference from the Yangtze River is the primary factor causing the runoff reduction of the three outlets. After the operation of TGR, the Yangtze River was in dry years. Therefore, over 60% of runoff reduction can be attributed to the variation of natural inflow discharge. (2) As the flow is retained by TGR, the runoff of the three outlets further reduced. From 2003-2008, the contribution rates of natural flow, sediment trapping and reservoir regulation to the runoff reduction at the three outlets were 76.19%, 13.49%, 10.32%, while their counterparts after optimal operation of TGR became 66.05%, 14.20% and 19.75% respectively. (3) Reservoir operation after the flood season showed the most significant impact on runoff of the three outlets, resulting in an increase in the number of shut-off days of the three-distributary channels from September to October, especially at Shadaoguan and Kangjiagang.
Recovery of cobalt and molybdenum from spent catalyst using citric acid
Authors: Nugroho M E C , Sutijan  , Prasetya A , Astuti W
Published: December 2021

Valuable metals play essential roles in various industrial sectors, such as petroleum, petrochemical, and steel industries. Potential secondary resources of these metals can be obtained from spent catalysts, which are a solid waste of the chemical and oil industries. Spent catalysts contain valuable metal compounds such as nickel (Ni), vanadium (V), cobalt (Co), molybdenum (Mo), rhodium (Rh), platinum (Pt), alumina (Al), etc. In this research, the recovery of cobalt and molybdenum from the spent catalyst of Pertamina Refinery Unit IV, Cilacap, Indonesia, was leaching using citric acid. Samples of spent catalyst were analyzed using EDXRF prior to the leaching process. Citric acid at various concentrations of 1.0, 1.5 and 2 M was used as a leaching agent. The leaching experiment was carried out for 300 minutes and sampling was undertaken at 1, 3, 5, 15, 30, 90 and 300 minutes. Each sample was separated between solid and liquid phases using a centrifuge at 400 rpm for 10 minutes. For analysis, 2 ml of the liquid phase was taken and the cobalt and molybdenum concentrations were analyzed using ICP-OES. It was found that at higher the citric acid concentration and temperature, the recovery of cobalt and molybdenum was also higher. The best leaching condition is obtained at a citric acid concentration of 2 M and 60ºC, where recovery of cobalt and molybdenum were 17.35% and 2.27%, respectively.
Synthesis of Al(OH)3 nanoparticles from Indonesian bauxite and tomato waste extract as chelating agent for nanofluids applications
Authors: Hardian A , Nirmalasari C , Budiman S , Murniati A , Kusumaningtyas V A , Yuliana T , Syarif D G
Published: December 2021

This study aimed to determine the effect of calcination time on the properties of Al(OH)3 or gibbsite nanoparticles in the sol-gel process, which was then used as the basic material in the manufacturing of water-Al(OH)3 based nanofluids. Nanofluid is a mixture of basic fluids such as water with solid nanoparticles. Al(OH)3 nanoparticles have been successfully synthesized from Indonesia local mineral bauxite using the sol-gel method by utilizing tomato waste extract as a chelating agent at a calcination temperature of 700ºC for 1 hour, 3 hours, and 5 hours. The obtained calcined powders were characterized using X-ray diffractometer (XRD). The evaluation toward nanofluids application based on theirs stability based on visual observation and zeta potential. Based on XRD analysis, all calcined powders has single Al(OH)3 or gibbsite phase. Increasing the calcined temperature gave impact on crystallinity, crystallite size, and reorientation of crystal. The water-Al(OH)3 nanofluid was relatively less stable with a zeta potential value of -25.2 mV; -26.4 mV; and -17.4 mV for calcination time 1 h, 3 h, and 5 h, respectively.
Cu-Mn Co-doped NiFe2O4 based thick ceramic film as negative temperature coefficient thermistors
Authors: Hardian A , Greshela S , Yuliana T , Budiman S , Murniati A , Kusumaningtyas V A , Syarif D G
Published: December 2021

NTC (Negative Temperature Coefficient) thermistors are widely used as temperature sensors in industrial and medical applications due to their high-temperature sensitivity, durability, and low cost. Generally, NTC thermistors are made from spinel structured ceramics formed by transition metal oxides with the general formula AB2O4. One of the spinel structured ceramics that can be made for NTC thermistors is NiFe2O4 nanoparticles. This work aimed to prepare Cu-Mn co-doped NiFe2O4 based thick ceramic film using Jarosite mineral as a precursor. The synthesis method used was a simple coprecipitation method, while the technique used in making a thick ceramic film was a simple screen printing technique. The sintering temperatures used were 1000 °C, 1100 °C, and 1200 °C. Based on x-ray diffraction analysis, the thick films consist of spinel phase, hematite phase, and some unidentified phase. The constant thermistor values (B) for thick films obtained with 1000, 1100, and 1200 °C sintering temperatures were 4740 K, 5669 K, and 5731 K, respectively. These results showed that all obtained thick films had passed the minimum value in market needs (B ≥2000 K).
Synthesis of TiO2-NiFe2O4 nanocomposites using coprecipitation method as photocatalyst for methylene blue removal
Authors: Hardian A , Devikha  , Budiman S , Yuliana T , Sujono H , Murniati A , Kusumaningtyas V A , Syarif D G
Published: December 2021

Methylene blue, a basic dye that is important in the coloring process in the textile industry. However, the use of the dye Methylene blue is hazardous for the skin, the eyes, and swallowed. Three composition types of TiO2-NiFe2O4nanocomposites (75:25, 50:50, and 25:75) had been synthesized using a simple coprecipitation method. The photodegradation and adsorption performance of the nanocomposites were also evaluated. Based on X-ray diffraction analysis, both the titania anatase and nickel ferrite spinel phases appeared in each nanocomposite’s diffraction pattern. The average crystallite size of the nanocomposites was 38 nm, 33 nm, and 41 nm for compositions 75:25, 50:50, and 25:75, respectively. The optimum photodegradation activity of TiO2-NiFe2O4nanocomposites was achieved at composition 75:25 %mol with >99% methylene blue degraded during 120 minutes of UV irradiation time. However, all nanocomposites also have adsorption capability toward methylene blue with an optimum percentage of 98%. Therefore, TiO2-NiFe2O4nanocomposites can be used either as photocatalysts or adsorbents for methylene blue removal in an aqueous solution.
Critical raw materials enrichment in bauxite laterite: a case study of diverse parent rock types
Authors: Nugraheni R D , Riyandhani C P , Apriniyadi M , Sunjaya D
Published: December 2021

High demand in utilizing the mineral and metal for industrial manufacture, which is unequal to the resources, has caused a vulnerable disruption. To compensate stocks in the global market, exploration of raw materials should be carried out for by-products. This study aims to elucidate the enrichment mechanism of Sc, Ga, and Nb elements from the bauxite weathering profile and sediment residue. An observation has been conducted using petrography, mineragraphy, x-ray fluorescence spectroscopy (XRF), x-Ray diffraction (XRD), inductively coupled plasma combined with mass spectrometry (ICP-MS), and scanning electron microscope - energy dispersive spectrometry (SEM-EDS). The results indicate that bauxite ores (gibbsite) hold the metal compounds of Ga, while some iron minerals of goethite and hematite are present as Sc-bearing minerals, and Nb is highly concentrated within saprolite of bauxite. The maximum enrichment of Ga and Sc is observed from the bauxite sample and sediment residue derived from microdiorite pyroxene, which makes up 24.2 - 42.1 ppm and 39.9 - 55.4 ppm, respectively. By contrast, Nb enriched about nine-fold higher in the saprolite zone relative to bauxite produced by weathering of granitic parent rocks. It suggests that metal concentration in the lateritic products depending immensely on the precursor rock types.
Impact of coal pile leachate on soil geochemistry: case study of PT Bukit Asam Tbk. Tarahan Port Unit and its surroundings
Authors: Farishi B A , Iqbal M , Candany M , Radityo D , Natalia H C , Erica T F , Hassan M A A
Published: December 2021

Surface runoff that flows through the coal stockpile and penetrates the ground can be a source of trace elements that can damage the environment. The trace elements possessed by coal in significant amounts can affect the geochemistry of soil, groundwater and human health, and it has become the concern of PT Bukit Asam Tbk. Port Units. This research aims to identify the effect of coal stockpiles on trace elements in the soil. The method was to take the soil sample around the research area and then performed X-ray fluorescence (XRF) analysis. The data obtained was then displayed in a distribution map of elements which has an anomaly. Based on the XRF test results, six elements, including K, Mn, Cr, Zn, Pb, and Cu, were exceeded the threshold. Based on further analysis, it could be concluded that there were several sources of these elements, including plant fertilizers, ash, and stockpile. The presence of the elements was directly related to stockpiles are Mn, Cr, Zn, Pb, and Cu.
Performance and boiler efficiency using low-grade coal on 400 MWe coal-fired power plant: case study of Suralaya Power Plant Unit 2
Authors: Supriyanto Eko , Cahyo Nur , Sitanggang Ruly , Rasgianti  , Triani Meiri , Bakti Dheka
Published: December 2021

In a coal steam power plant, changes in coal quality significantly affect plant performance, especially in its boiler. A coal-fired power plant with a capacity of 400 MWe had been commissioned using coal with a calorific value of 5,242 kCal/kg. This study aims to determine the effect on unit performance and boiler efficiency due to changes in fuel use with the typical calorific value of 3,520 kCal/kg, 34,17% lower than the initial design. The performance tests were conducted using the heat loss method at loads: 50%, 65%, 75%, and 100%. The test result showed that using low-grade coal reduces boiler efficiency by 6.26%. There were four dominant boiler losses: heat loss due to moisture in dry flue gas, heat loss due to combustible in refuse, heat loss due to moisture in fuel, and heat loss due to hydrogen burning. Furthermore, the gross plant heat rate using low-grade coal was increased from 2,120 kCal/kWh to 2,718 kCal/kWh; however, the electric price becomes cheaper from 1.99 cent-USD/kWh becomes 1.31 cent-USD/kWh.
Preparation of carbon anode sheet precursor using raw Air Laya–Bukit Asam coal and its application for battery
Authors: Mursito A T , Listiyowati L N , Arifin D N , Santoso D B , Wicaksono M D S
Published: December 2021

Research has been carried out on manufacturing carbon electrode thin sheets used as anode for solid battery cells. The material used is raw coal carbonized at 800 and 1000oC, polyvinylidene fluoride (PVDF), and N-Dimethylacetamide (DMAC) as a solvent. Observation of crystal structure by X-rays diffraction method shows a diffraction pattern where crystallites in all product samples have an intermediate structure between graphite and amorphous known as a turbostratic structure or a random layer lattice structure. The distance between the crystallite structure’s aromatic layers (d002) is in the range 3.52-3.62 Å. Aromaticity (fa) is in the range 0.42 - 0.48 for all samples. The high value of d002 indicated that the crystallinity or level of graphitization obtained by all samples was still low. Manufacturing technique using a Doctor Blade-based tape casting method. The discharge capacities of the samples reach about 60 and 18 mAh.g-1, while their charge capacities at the first cycle are 50 and 16 mAh.g1, respectively. Cyclic voltammetry (CV) was performed using anodes resulted at 0.1 to 2.3 volt. During the forward scan, CV curves of the sample reveal a reduction current starting from around 1.2 V and exhibiting two-reduction waves, between 1.2 and 0.6 V.
Mitigation in erosion control and management of ex-mining water through revegetation and sustainable environmental management technologies
Authors: Istiqomah E , Aryanto R , Purwiyono T T
Published: December 2021

In the open-pit mining system that is being carried out by a company in the mining sector with gold and silver commodities, PT Citra Palu Minerals, land clearing can cause soil erosion which can lead to soil sedimentation, increased turbidity of water that will be released into the environment and potential entry soil eroded into the tailings pond at the Dry Tailing Management Facility (DTMF). Therefore, further action is needed to control erosion and sedimentation as well as water management so that the water to be released into the environment is following environmental quality standards that have been set by the government. Before determining and controlling erosion, it is necessary to know the rate of erosion that occurs at the research location, in this study the USLE (Universal Soil Loss Equation) method was used to predict the rate of erosion with the results obtained, namely 17.07 tonnes/ha on the North DTMF slopes and 21.04 tonnes/ha for DTMF South slopes. To reduce the rate of erosion, it is necessary to control erosion by revegetation of the land, create a water drainage system to the sedimentation pond and treat the collected water using biophytoremediation of land with the use of chemicals to accelerate the deposition process, constructed swamp forest to the latest sustainable technology recommended by the Indonesian Academy of Sciences (LIPI).
Quality of coal seam D of Muara Enim Formation, Central Palembang Subbasin
Authors: Purnama A B , Yudha S S , Surono W
Published: December 2021

Coal seam D belongs to Muara Enim Formation in Central Palembang Subbasin, South Sumatera Basin, which ages of Middle Miocene to Late Miocene. This study aims to determine the quality of the coal, especially sulphur content and form, ash content and composition, and trace elements of heavy metals. Those are important to know as a reference in suitability in the use of this coal. Methods of analysis is proximate, total of sulphur, form of sulphur, SEM-EDS, ash composition, and trace element. The coal is categorized as low rank coal or lignite with a very low total sulphur max 0.25%, dominated by the organic sulphur formed during the peatification and coalification process (syngenetic). The coal has a safe ash composition. It shows from a very low metal oxide content that causes slagging and fouling at low temperatures process. Likewise, the trace element content of the coal such as chromium (Cr), cadmium (Cd), manganese (Mn), lead (Pb), nickel (Ni) is still far below the threshold for trace element content in coal.
The application of “line drilling” and “buffer holes” methods to reduce blasting vibration
Authors: Pradatama Dhion , Pradasara Chani , Syafiq Isnaya M.
Published: December 2021

PT Multi Nitrotama Kimia is one of the largest mining service companies that provide blasting services and sales of explosives in Indonesia. PT Putra Perkasa Abadi Jobsite Borneo Indobara is one of PT Multi Nitrotama Kimia’s customers who is facing challenges in optimizing blasting activities. Currently, blasting activities at PT Putra Perkasa Abadi Jobsite Borneo Indobara are carried out within 500 m of the active slope, so that the blasting distance is optimized. In optimizing the blasting distance, it is necessary to maintain slope conditions (no underbreak / no overbreak) and to consider the vibration of blasting results on the slopes. The line drilling method was chosen for the blasting trial stage. In the observation activity, an analysis of the resulting blasting and fragmentation vibrations was carried out. Precise planning and good control in field operations play an important role in this experimental process. Based on the results of the blasting trial, no damage was found in the area 25 m – 100 m from the blasting location and a 10% - 20% reduction in blasting vibration results (Peak Vector Sum) was obtained when compared between normal blasting designs with controlled blasting designs.
Characterization of potential mercury contamination in the ASGM area of Mandailing Natal, North Sumatera
Authors: Astika H , Handayani S , Damayanti R , Surono W , Maryono  , Suciyanti M , Octaviano H A
Published: December 2021

A large amount of Hg is used for gold extraction through the amalgamation process in the Mandailing Natal derived from artisanal and small-scale gold mining (ASGM) area located in the North Sumatera Province, Indonesia. The objective of this work was to characterize the potential contamination of total Hg in water, sediments, and soil in this ASGM area. Sampling was done in two locations in West Panyabungan and Huta Bargot Districts using grab sampling method. Results showed that accumulation of Hg in the studied soils and sediments was the highest, but Hg in aquatic solution was below the detection limit of the analytical method of the studied community wells and rivers. The highest concentration of Hg was found in the river sediments of the Saba Padang irrigation (1,63 mg/kg), and in the soil of the plantation area of Huta Bargot (1,62 mg/kg) respectively. These concentrations may pose a serious problem for aquatic and land life, related ecosystems, and human health. For further study, there is a need to study Hg availability in riverine biota to better understand the cycling of Hg in this ASGM area. Understanding the ecological impacts can assist in the prioritizing of impact mitigation efforts.
Utilization of Tephrosia vogelii in post-mining land reclamation
Authors: Kusumaningtyas V A , Murniati A , Budiman S , Hardian A , Ruhaniyah H , Melina M , Juliawaty L D , Syah Y M
Published: December 2021

Reclamation is an effort to repair the damaged mining sector to provide optimal benefits. This review article aims to propose a natural product technology approach to the reclamation of post-coal mining land by increasing the content of soil organic matter so that the post-mining land becomes fertile and can be used for agricultural land. The method used is an observation and literature study. Literature searches were using them ScienceDirect, Scopus, PubMed, and Google Scholar databases. Land-use change of post-mining site to agricultural land provides prospective economic value to the community. However, the land quality of the post-mining area should be improved before food crop production.Tephrosia vogeliiis a member of the Papilionoideae subfamily is important for land revegetation. They can fertilize the soil because of mutualistic symbiosis with the bacteria Rhizobium sp. which is capable to fix nitrogen in the soil and hence provide available nitrogen. Thus, the use of post-mining land as agriculture can improve the economy and sustainability as well as protect life and the environment with natural product technology.
Legalization of illegal small-scale mining, as a policy of business guarantee and environmental management
Authors: Sugiarti S , Yunianto B , Damayanti R , Hadijah N R
Published: December 2021

Small-scale mining has a very long history, and the majority operated without permits: coal and almost all kinds of minerals they cultivate. The area of operation covers most of Indonesia. There are grab licensed mining areas. The number of illegal miners is estimated at more than 3.6 million people, about 1.4 million gold miners. This activity has been going on for years, never be solved. The Negative impacts of illegal mining, include the loss of potential state revenue, environmental damage and mercury pollution, mining accidents, social vulnerabilities, conflicts with licensed companies, and no resource conservation. It is time for this issue serious attention of the government to be resolved. Legalization by granting permits can be a business guarantee that will grow responsibility for regulations and become the basis for environmental management. This research is socio-legal research. The role of local governments, associations, and the state-owned company is required in technical guidance on mining and the environment, institutions, business management, and product markets. If the activities can be managed and developed, the negative impacts can be overcome. So, the benefits of their business can become a forum for people’s activities in the mining sector, and state revenues can be collected.
Utilization of Sodium Bicarbonate as Anesthetic During Routine Husbandry Activities in Ornamental Fish
Authors: Caipang C M A , Deocampo J E , Pakingking R V , Suharman I , Fenol J T , Onayan F B
Published: December 2021

The tropical ornamental fish industry requires the stock to be reared in captivity before being sold; thus, exposing them to various handling- and transport-related stressors. A number of commercially available anesthetics are used during fish husbandry procedures, but these products are expensive and not readily available to small-scale ornamental fish operators. The use of sodium bicarbonate as an inexpensive anesthetic during routine husbandry activities in molly, Poecilia sp., a freshwater ornamental fish was assessed in terms of its effect on sedation, recovery and survival post-exposure in three independent experimental runs. Juvenile molly were exposed to sodium bicarbonate at a concentration of 100 g L−1 and the time to sedation and recovery were monitored. It took longer for the fish to be fully sedated than their recovery. Survival of the fish a week post-exposure ranged 40-60%. Simulated transport of fish for 6 hrs in water containing 1 g L−1 of sodium bicarbonate showed survival ranging 70-100% a week after transport. These findings demonstrated that sodium bicarbonate could be potentially used as a low-cost anesthetic during handling and short-term transport of ornamental fish. Future studies shall focus on discovering the underlying physiological mechanisms in fish following sedation with this chemical.
Growth of Bacillus toyonensis in Tofu Wastewater
Authors: Nursyirwani N , Yoswaty D , Oktavia D A
Published: December 2021

Bacillus toyonensis has been isolated in Dumai mangrove ecosystem of Riau Province. One of factors affecting the growth of the bacteria is growth substrate. Tofu wastewater is rich in nutrition which can be used as substrate for bacterial growth. This research aimed to observe the growth of B. toyonensis in different concentration of tofu wastewater. The bacteria was grown in tofu wastewater at concentrations 8%, 10% and 12% was supplemented with 0.1 g K2HPO4, 0.15 g KH2PO4, 0.15 g NaCl and 0.5 g vitamin B12 in 100 mL distilled water. The bacterial growth was observed by using spectrophotometer at λ 610 nm and by analysis the total plate counts on plate count agar (PCA) at 0, 24, 48, 72 and 96 hour cultivation. Spectrophotometric observation showed that the highest bacterial growth of all tofu wastewater treatments indicated by the addition of 12% tofu wastewater, although the absorbance value was lower than culture in tryptic soy broth (TSB) as control. Exponential growth occurred between 0-24 hour incubation, and the highest growth indicated in substrate contained 12% tofu wastewater. Similarly, total plate count (TPC) analysis indicated that the highest bacterial growth of all treatment occurred at 24 hours incubation, and the highest count was also indicated by treatment of 12% tofu wastewater (2.42±0.06×108 CFU/mL). In conclusion, tofu wastewater can be an alternative substrate for the bacterial growth.
Analysis of The Texture Profile and Sensory Quality of The Jelly with The Addition of Liquid Cork Fish (Channa striata)
Authors: Basmal J
Published: December 2021

Variations in the concentration of cork fish liquid in jelly were used in the investigation of the effect of cork fish liquid on the quality of jelly products. To establish the textural profile and level of preference of the panelists, the jelly was blended with the Cork fish juice. The different concentrations of Cork fish juice, such as K (0%), A (5%), B ( 10%), C (15%), and D (20%) v/v. After being mixed with Cork fish liquid according to the procedures, the jelly was packaged in plastic cups with a capacity of 50 ml each and refrigerated at a temperature of 10-15oC overnight. The purpose of this experiment was to see how cork fish juice affected the texture and sensory quality of jelly. The results reveal that panelists are willing to eat jelly mixed with Cork fish liquid, but that the more the concentration of Cork fish liquid added, the lower their preference level. Treatment A produced the best results among the cork fish liquid treatments, with a panelist preference value of 5.60, which was similar to syneresis 10.80, elasticity 0.83, cohesiveness 0.57, gumminess 419.50, elasticity 339.40, resilience 0.23, hardness 847.30, and gel strength values of 534.85 g/cm2, respectively.
Anti-bacterial Activity of Alginate Based Edible Coating Solution Added with Lemongrass Essential Oil Against Some Pathogenic Bacteria
Authors: Irianto H E , Marpaung D B , Ggiyatmi  , Fransiska D , Basriman I
Published: December 2021

Edible coating is a thin layer that can be made of several materials, one of which is polysaccharides, such as alginates, carrageenan, agar, chitin, chitosan, pectin, starch, cellulose derivatives, and gums. The application of food products with edible coatings has been widely carried out and has been proven to improve quality and extend the shelf life of the product. Antibacterial agent can be added to improve the performance of edible coating. This study was aimed to explore the potential of lemongrass essential oil as an antibacterial agent in alginate based antibacterial edible coating solutions, especially against pathogenic bacteria. Edible coating is made of alginate powder, modified cassava flour (Mocaf), beeswax, glycerol and antibacterial agent. The additional levels of lemongrass essential oil into edible coating formula were 0.25, 1.50 and 0.75%. The antibacterial activity of the edible coating solution produced was tested againstEscherichia coli, Staphylococcus aureus, Salmonella, andPseudomonas aeruginosaby employing a disk diffusion testing method. Antibacterial agents used in previous studies to develop alginate-based antibacterial edible coatings and potential applications of the developed alginate-based edible coatings incorporated with lemongrass essential oil were identified by browsing through the internet. The results showed that various antibacterial agents have been explored to improve the performance of alginate based edible coatings. An antibacterial activity study exhibited that the highest antibacterial activity was found in the edible coating with the addition of 0.50% lemongrass essential oil, except forS. aureusat the addition level of 0.75%. This study suggests that the addition of lemongrass essential oil for the manufacture of alginate based edible coating solution is 0.50%. The potential uses of edible coatings made from alginate with the addition of lemongrass essential oil are to coat various animal and plant based food products.
Isolation and Characterization of Cellulolytic Bacteria Diversity in Peatland Ecosystem and Their Cellulolytic Activities
Authors: Batubara U M , Mardalisa M , Suparjo S , Maritsa H U , Pujianto E , Herlini M
Published: December 2021

Peatlands are terrestrial wetland ecosystems formed from piles of organic matter that decompose into organic deposits. Peat soil has a high potential to produce cellulose which, can be reused by cellulolytic bacteria. This study aims to find out the potential strain of cellulolytic bacteria isolated from peatland ecosystems. The method used was experimental, sequentially, the stages are isolation and screening for cellulolytic bacteria, quantitative testing of cellulolytic activity, characterizing the morphology and physiology of bacteria, and the identification of bacteria based on Bergey’s Manual of Determinative Bacteriology. The screening results obtained seven isolates of cellulolytic bacteria capable of hydrolysed cellulose on 1% Carboxy Methyl Cellulose (CMC) Agar Medium, namely SPS1, SPS2, SPS 3, SDG1, SDG 2, SPW1, and SPW4. Three of seven isolates obtained the highest cellulolytic index sequentially, namely SPS2 of 2.82, SPS3 of 2.65, and SDG1 of 2.47. The cellulolytic activity was indicated by the value of a halo zone around the colonies on 1 % CMC medium after being dripped with Congo red. The halo zone is an early indication to determine the ability of bacteria to decompose cellulose. Based on Bergey’s Manual of Determinative Bacteriology showed that the three isolates had the same characteristics as the genus Bacillus, Lactobacillus and Corynebacterium.
The Impact of Covid 19 on Fisher and Fish FarmerTerms of Trade
Authors: Suryawati S H , Damanti R R , Rahadian R
Published: December 2021

Reflecting the level of welfare of the fishers and fish farmers, terms of trade index (namely NTN/NTP) is believed to have decreased as the result of the Covid 19 outbreak. And, recognizing the important role of fisheries in the economy, understanding what have occured to the index is relevant. This paper aimed to: (i) analyze the impact of the outbreak on NTN/NTPi and (ii) identify what changes in variables have significant contribution to the NTN/NTPi decrease. The analytical method used is descriptive quantitative. The primary data consisted of: (i) fisher and fish farmer terms of trade as published by the Central Bureau of Statistics, (ii) variables that compose the price index received by fishermen / fish farmers and the index of prices paid by fishermen / fish farmers. The results showed that the decline in NTN and NTP occurred in all provinces in Indonesia. For fishers and fish farmers, variables of received price index that had the most significant effect on the decline is basic need cost such as food, drinks, cloth and transportation while variables of paid price index that had the most significant effect on the decline is capital goods.
Women’s Role in Smoke Fish Processing Business in Koto Mesjid Village XIII Koto Kampar Kampar District, Riau Province
Authors: Firdaus E , Andrikasmi S
Published: December 2021

Koto Mesjid Village, XIII District Koto Kampar is a long-known smoked fish-producing village in Kampar Regency. The large potential of smoked catfish resources in Koto Mesjid village has led to high public interest in processing fish as an effort to improve the family economy. This study used sociological juridical research method, namely field research. Data collection techniques used the method of observation, interviews and purposive sampling. The purpose of this study was to find out what are the roles of women in the smoked fish processing business in area, what are the inhibiting factors and efforts to increase the role of women in the smoked fish processing business. The results showed that the role of women in the smoked catfish business in Koto Masjid Village, was very important. Starting from the process of availability of raw materials, provision of equipment and processing materials, washing, fish division, involving the role of women, but still done traditionally.
Food Security Level of Fisherman Household in Bandar Lampung, Indonesia
Authors: Yolandika C , Anggraini N , Berliana D
Published: December 2021

The condition of fishermen’s households that are less food secure can be triggered by poverty. As a developing country, Indonesia still has a fairly high poverty rate of 34.96 million people, of which 63.47% are people living in coastal areas. According to the Food Consumption Survey of Lampung in 2017, 2018, and 2019 conducted by the Food Security Agency of Lampung Province, it is known that the amount and level of energy consumption of fishery households in Bandar Lampung City has decreased from 1,815.1 kcal/cap/day or by 93, 1% in 2017 to 1,666.4 kcal/cap/year or 84.0% in 2018, and decreased again to 1,568.0 kcal/cap/day or 75.1% in 2019. This study aims to analyze the level of food security of fishermen’s households in and the level of energy and protein adequacy of fishermen’s households in Teluk Betung Selatan District. This research was conducted in Teluk Betung Selatan District, Bandar Lampung. The research was conducted on March to July 2021. The sample of fishermen in this study was 50 fishermen from 1,207 fishermen in Teluk Betung Selatan District. Sampling was done by simple random method. The results of this study are (1) the food security of fishermen’s households in Teluk Betung Selatan District is mostly in the food security category (78%), while the remaining 22% are in the food insecurity category; (2) the level of energy adequacy of fishermen’s households in Teluk Betung Selatan District is mostly in the poor category (52%), but the level of protein adequacy is mostly.
Port Dickson Surface Water Quality Status: A Year with COVID-19 Pandemic
Authors: Kamarudin N A , Mohamat-Yusuff F , Zulkifli S Z , Zainuddin A H , Ali M Y , Ekhsan N F M , Hassan M Z , Aris A Z , Md Yusoff F
Published: December 2021

The COVID-19 pandemic has become a planetary concern that affecting the sustenance of the human population all around the globe. The effective measured has been taken in Malaysia to control the virus transmission by limiting the human vitality which unsurprisingly propitious to the environment. A monitoring study was conducted to assess the water quality status of surface seawater along the Port Dickson coast based on the Malaysian Marine Water Quality Index (MMWQI) and Malaysian Marine Water Quality Standards (MMWQCS) with an interval period of a year (March 2020-March 2021). In situ, water quality parameters incorporate temperature, pH, salinity, conductivity, dissolved oxygen (DO), and total dissolved solids (TDS) were measured at 14 sampling sites to evaluate the biochemical characteristics of water. Surface water samples were collected from the same sites and transported back to Universiti Putra Malaysia for nitrate (NO3-), ammonia (NH3), phosphate (PO4), biochemical oxygen demands (BOD), fecal coliform (Escherichia coli), and total suspended solids (TSS) analyses. The MMWQI showed the status of surface water from the Port Dickson coast was classified as moderate quality (50.41 - 64.05) for both sampling events. However, there are some indexes that showed significant decreases (p< 0.05) in the latter year. The concentration of nutrient pollution such as phosphate, nitrates, ammonia, fecal coliform as well as oil and grease, was decreased by 11.12%, 77.39%, 82.4%, 90.26%, and 99.9% respectively. The water parameters namely TDS, pH, and BOD levels were significantly decreased by 1.77%, 20.73%, and 77.16%. Certain parameters listed in the MMWQS such as temperature, pH, ammonia, fecal coliform, oil and grease were classified as Class 1 in March 2021. These occurrences recorded were greatly influenced by the reduction of the substantial human activities around the recreational beach of Port Dickson followed by the declaration of Movement Control Order (MCO) in Malaysia.
Community Awareness on Domestic Waste Disposal Towards Its Impact to the Sustainability of Mangrove Forest in Kuala Selangor
Authors: Mazelan N A , Yusuff F M
Published: December 2021

Mangrove forest in Kuala Selangor has seen to be depleting over the years. This study believes that domestic waste disposal is considered as one of the treats to mangrove forest. Local community must play their role in protecting the mangrove forest. This study aims to determine the level of knowledge of the community on the importance of mangrove, level of awareness on the impact of domestic waste disposal to mangroves and their level of practice on proper domestic waste management. Besides, this study aims to identify the correlation between community awareness with knowledge and practice. Structured questionnaire was used to collect data and analyzed using SPSS version 26 software. The finding shows that the level of knowledge of the community on the importance of sustaining mangrove forest is high (n=256, 85.3%), the level of awareness of community on the impact of domestic waste disposal is also high (Mean=4.48), while the level of community practice on proper domestic waste management is moderate (Mean=3.9). The correlation test showed that there was a negligible correlation between knowledge and awareness of community (r=0.14, <0.05, n=300) and also weak positive correlation between awareness and practice with (r=0.33, p<0.01, n=300. The finding suggests community with great knowledge does not necessarily have great awareness as well not necessarily with great awareness, community will practice good waste management to secure mangrove forests. Thus, this study recommends strictly enforcing all parties to comply/implementing control at source method, or develop appropriate management plans to reduce domestic waste disposal at mangrove areas.
Production of Rhizophora Mangrove Leaf Litter in The Sungai Bersejarah Mangrove Ecosystem, Siak Regency
Authors: Efriyeldi E , Amin B , Hersa T
Published: December 2021

The mangrove ecosystem is one of the coastal ecosystems that has important ecological roles and functions in supporting marine and fishery resources. Marine and fisheries resources are largely determined by the contribution of mangrove litter. The aims of this study was to determine the production of Rhizophora mangrove leaf litter in Sungai Bersejarah mangrove ecosystem, and to determine the value of environmental parameters related to litter. The research was conducted in January until March 2021 in Sungai Bersejarah mangrove area Kayu Ara Permai, Siak Regency. Line transect plot were used to calculate the density of Rhizophora. Rhizophora litter production was measured using the trap net method placed at three sampling site. Three litter trap nets measuring 1 m x 1 m are placed at each station. Rhizophora tree density ranges from 316 - 444 ind./ha. The production of Rhizophora mangrove leaf litter in Sungai Bersejarah mangrove ecosystem was 0.82 – 1.39 g/m2/day (3.00 – 5.09 ton/ha/year), average was 4.11 ton/ha/year. Analysis of variance test showed that there was a significant difference in Rhizophora leaf litter production between sampling points with different Rhizophora tree densities (p<0.05). Mangrove vegetation density has a moderate relationship (r=0.43) to the production of Rhizophora mangrove leaf litter. Environmental parameters indicate that the condition of the Sungai Bersejarah mangrove ecosystem is still good and can support the life of mangrove vegetation.
Dried fish in Indonesia: Problems and a Possible Solution, a Review
Authors: Dewi F R , Widiyanto A
Published: December 2021

Dried fish has become one of the favourite food for Indonesian. The drying technology has been passed down through generations especially in the coastal communities due to its simplicity. Despite the long history of dried fish in Indonesia, some problems need to be addressed. Maintaining the quality for both domestic and global markets in an integrated and sustainable manner is still standing as the major problem. Formalin residue had been found in some dried fish products in several areas in Indonesia. This safety matter is also drawn both researcher’s and policy maker’s attention. Several possible solutions are offered to iron out the issues. The development of new technology which easy to adopt and low cost is needed. A combination drying machine can be an alternative to solve the problems. The machine is designed to be able to operate using both electrical and solar sources. The machine can yield a good quality product which can be used throughout the year.
Manufacture of Toman Fish Protein (Channa micropeltes) Isolate with Different pH Methods using Star Fruit (Averrhoa bilimbi) Acid
Authors: Karnila R , Ilza M , Fakhriah S N
Published: December 2021

Toman fish (Channa micropeltes) is a type of freshwater fish that belongs to the genus Channa which is the largest size compared to the others and has high protein. This study aims to obtain the isolate of toman fish protein (Channa micropeltes) by the method of pH regulation using star fruit acid. Wuluh star fruit acid is used as a substitute for HCl in making fish protein isolates to reduce pH. This research method uses a Completely Randomized Design (CRD). The treatments consisted of (P1 = pH 4, P2 = pH 5, P3 = pH 6). The results showed that star fruit acid can replace HCl as a protein precipitant and P1 (pH 4) obtained the most isolates, namely an average protein content of 91.64% (db), a moisture content of 1.67%, ash content of 2.06 % (db), fat content of 2.74% (db), yield of 88.46%, and total amino acid composition of 61.30%, where the type of amino acid that dominates is glutamic acid (12.30%). Glutamic acid amino acid is the one that influences a lot in giving pH isoelectric point, in the treatment of P1 with pH 4 making isolates of toman fish protein to be the best treatment, because glutamic acid has an isoelectric point of 3.22 which is the closest to pH 4 plus also the pH of isoelectric point from other amino acids.