bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of production 500 kg/batch polyaluminum chloride from aluminum hydrate
Authors: Mamby H E , Hidayat K N , Wahyudi A
Published: December 2021

Polyaluminum chloride (PAC) is commonly used as a chemical in the water treatment industry, deodorant and paper-making. The PAC is a complex inorganic substance between hydroxyl and aluminum ions that gradually takes place chlorination with its general formula of Alx(OH)yCl3x-y. It has the ability to coagulate suspended solid or dispersed colloid within water perform easily precipitated flock. The raw materials used for manufacturing liquid PAC consists of hydrated alumina (Al(OH)3), hydrochloric acid (HCl), sulfuric acid (H2SO4) and calcium carbonate (CaCO3). A pilot-scale experiment with a capacity of 500 kg/batch feed was conducted by reacting Al(OH)3 with HCl and H2SO4, then neutralized using CaCO3 to obtain liquid PAC and gypsum as a by-product. The variation of acid concentration as reactant and reaction time were conducted to determine its effect on the composition of PAC and the amount of gypsum produced. The optimum experiment produced liquid PAC with the highest Al2O3 composition of 11.96% and the lowest Cl− ion of 10.87% at 2 hours reaction time with a total acid concentration of 37.74%.
The performance of Pacitan Power Plant (pulverized boiler) toward the blending coal: an experimental
Authors: Rasgianti  , Cahyo N , Supriyanto E , Sitanggang R B , Triani M , Bakti D
Published: December 2021

Coal blending testing of medium rank coal (MRC) and low-rank coal (LRC) in the Pacitan power plant with pulverized boiler type was conducted to increase the use of readily available coal. It was necessary to ensure the impact of the blending coal on the boiler performance. Therefore, this study was aimed to examine the performance of the plant. There were two coal blending configurations in testing; a) Combo #1: 75% of LRC and 25% MRC; b) Combo #2: 60% of LRC and 40% MRC. Each combination was held in 4 schemes of load at 165 MW, 210 MW, 255 MW, and 300 MW. Heat rate calculation was determined with the heat loss method (energy balanced approach). As a result, compared to the commissioning test (2,270 kCal/kWh), the power plant performance decreased. The performance of combo #1 obtained 2,517 kcal/kWh; meanwhile, combo #2‘s performance showed 2,360 kcal/kWh.
Characteristics of polymetallic enrichment on oceanic red bed in Matano Formation, Baturubei, Central Sulawesi, Indonesia
Authors: Jati Widiatama Angga , Fahruddin Achmad , Dwita Santy Lauti
Published: December 2021

The Matano Formation on Sulawesi Island has Cretaceous oceanic red bed (CORB) facies, but there is no further research on the geochemical characteristics of the sedimentary rocks. This study aims to classify the CORB of the Matano Formation and reveal the polymetallic element enrichment in CORB by using the X-ray fluorescence (XRF) analysis method. Matano Formation in the research area consists of two different facies: radiolarites facies and red clay facies. Radiolarites facies grouped as Si-ORB, dominated by siliceous pelagic bioclastic and deposited under oxic environment. The red clay facies grouped as Al-ORB, the components dominated by hemipelagic material with a small amount of silica shelled pelagically and deposited under reduction environment. Red clay facies have higher enrichment elements Mn, V, Ni, Zn and La than radiolarites facies. Oceanic red bed facies of Matano Formation deposited in basin plain environment below carbonate compensation depth in a passive margin tectonic setting.
Technical analysis of shovel working time towards inter-burden production achievement in open-pit coal mine
Authors: Sandra Wulandari Vivi , Korra Herdyanti Mixsindo , Novi Hartami Pantjanita
Published: December 2021

Shovel production can be affected by several factors, such as shovel working time and working conditions. The shovel production for the inter-burden removal target did not achieve at mining operations in Melak, East Kalimantan. This study’s main objective is to find the causes of the inadequate production and the efforts to improve. In this case study, the high delay due to the waiting for truck maneuvering caused the lack of shovel production. Some corrections were needed on the width of the loading point, and the loading method required to be replaced with double-side loading. Changes in the width of the loading point and loading method have an impact on increasing shovel productivity. In addition, a digger working time simulation is performed based on secondary data. Calculation of total production achievement is based on the simulation of time categories with working, standby, and repair time variables.
Low density optimization of emulsion explosive to improve blasting quality (MNK Max70)
Authors: Manullang Panangian , Arbi Madinatul , Rachman Jaka Slamet
Published: December 2021

PT Multi Nitrotama Kimia is a mining service company engaged in providing blasting services and the largest sales of explosives in Indonesia. PT Pamapersada Nusantara jobsite Kideco Jaya Agung is one of the customers of PT Multi Nitrotama Kimia in the blasting service business unit. On a far more optimal side, the development of commodity price conditions and operational needs is a common concern. From these conditions, one of the best target cost controls for blasting and fragmentation is to make adjustments and improvement to the quality and quantity of the use of bulk products. The high use of bulk products at the Kideco Jaya Agung Jobsite is a particular concern, especially for rocks that require a high powder factor value, thereby increasing blasting operation costs. From this condition, PT Multi Nitrotama Kimia strives to optimize the bottom value of density product emulsion MNK Max70 using chemical improvement from the previous 1.15 gr/cc to 1.05 gr/cc. This improvement has brought good results, where optimization in terms of using bulks product and blasting quality such as fragmentation and Velocity of Detonation (VOD) values are still in accordance with product standards.
Modification of Cu2+ in polyphenol oxidase extract from purple eggplant for phenol degradation in coal wastewater treatment
Authors: Murniati A , Buchari B , Gandasasmita S , Nurachman Z , Kusumaningtiyas VA , Jasmansyah  , Budiman S , Hardian A , Herlinawati S , Ibrahim R M , Prajitno D H
Published: December 2021

Cracking coal-forming organic compounds during the gasification process produces liquid waste containing phenolic compounds that require special handling based on their toxicity. As one of the components, there is liquid waste resulting from the coal gasification process. The purpose of this research was to study the activity of polyphenol oxidase (PPO) on phenol after the addition of Cu2+ to purple eggplant (Solanum melongena L.) extract and its potential to work more effectively in phenol biodegradation for coal wastewater containing phenol. Enzyme activity and phenol determination were carried out spectrophotometrically. The results showed PPO activity of 25.90-38.10 U/mL; 4.0 mM phenol and the activity of PPO-Cu2+ was 21.58-46.32 U/mL; 2-10 mM CuSO4; 2.0-4.0 mM phenol. Based on Michaelis Menten’s graph, the initial rate of PPO-Cu2+ was 0.015 mM/min and the initial rate of PPO was 0.15 mM/min using 2 mM phenol as a substrate. Lineweaver-Burk’s graph shows the KM of PPO-Cu2+ = 6.92 mM, which is lower than KM of PPO = 13.05 mM. Its means that the phenol response has a higher affinity for PPO-Cu2+ than PPO. The application of PPO-Cu2+ in purple eggplant extract works effectively as much as 46.7% for artificial coal liquid waste containing phenol.
A sustainable development strategy for mining industries in Citatah karst area in Bandung Basin
Authors: Rohaendi Nendi , Sukiyah Emi , Muslim Dicky , Cipta Athanasius
Published: December 2021

Citatah karst area is located in the western margin of Bandung Basin, as the only mining area within the basin. However, the pressure from environmentalists to preserve the karst area and change the use of land to become a conservation area or geopark is very high. The study aims to define the strategy to manage karst land in urbanizing areas to support sustainable development. The method of study includes policy and stakeholder analyses. Further analysis will be based on Spatial Multi Criteria Evaluation to apply land suitability analysis to seek the possibility of the Citatah karst area as geotourism and mine tourism. Karst area is an environmental complex system. Broad research to understand human-altered karst landscapes, karst ecosystems, karst disturbance, karst hydrology and also to manage karst lands in urbanizing areas in sustainable manners are needed. The provincial government agency has a master plan to develop the Citatah karst areas like agriculture, tourism, home industry, etc. The research result will support the plan on how to develop an assessment of the geosite and mining site present in Citatah karst area using multi criteria evaluation.
Techno-economic analysis study of coal gasification plant into various strategic chemicals
Authors: Tetrisyanda R , Wiguno A , Wibawa G
Published: December 2021

The abundant amount of coal reserves in Indonesia has a great potential to be used as a source of raw materials and energy for industry. However, the use of coal in meeting domestic needs is not optimally utilized, as indicated by the high number of raw coal exports abroad. In addition, the low quality of coal is also one of the reasons for its low utilization. The processing of coal into synthetic gas (syngas) opens the way downstream of coal-derived chemical products, namely dimethyl ether (DME), methanol, ammonia and synthetic natural gas (SNG). The integration of various chemical products is expected to maximize the potential of Indonesian coal. The plant capacity was 11540 tpd (tons per day) low-rank wet coal producing DME 2000 tpd, methanol 2500 tpd, ammonia 600 tpd and SNG 25 MMSCFD (million standard cubic feet per day). These chemical production technologies have been proven and are commercially available. Based on the results of the process and economic simulations, it is found that the establishment of a coal gasification plant into various integrated chemicals is feasible to be established with an internal rate of return (IRR) of 12.46% and a payback period of 6 years and 5 months.
Techno-economic analysis of producing low heating value underground coal gasification gas in Indonesia
Authors: Huda M. , Salinita S. , Zulfahmi  , Madiutomo N , Handayani E
Published: December 2021

Indonesia is currently reviewing the use of underground coal gasification (UCG) technology to utilize deep-seated coal. UCG may exploit the coal deposit that is not feasible for open-pit mines due to its great depths. In this study, the UCG plant in two coal mines, the Kideco Jaya Agung (KJA) and the Indominco (IMM) coal mines, will be compared their economics in producing low heating value gas with a capacity of 170,000 MJ/hour. The UCG plants implement the linking vertical well (LVW) technique combined with reverses combustion linking (RCL). The discounted cash flow (DCF) method is used for financial analysis to determine the minimum selling price of UCG low heating value gas. The study aims to understand the economic feasibility of applying UCG technology to Indonesia’s different characteristics of coal deposits. The results show the minimum prices of the low heating value UCG gas of KJA and IMM UCG plants are USD 3/MMBTU and USD 3.57/MMBTU, respectively. The operating cost of the IMM UCG is higher than that of the KJA UCG plant due to its thinner and deeper coal seams.
Domestication Strategies of Tinfoil Barb Barbonymus schwanenfeldii (Bleeker, 1854): Potential Candidate for Freshwater Aquaculture Development
Authors: Kusmini I I , Gustiano R , Radona D , Kurniawan K
Published: December 2021

This paper discussed domestication strategies of Tinfoil barb from different populations for evaluation of potential fish candidate for freshwater aquaculture development. Collection and maintenance of wild-caught adult fish was the first step in domestication strategies followed by characterization of fish, broodstocks selection and maturation, control of fish reproduction, and larval rearing. The Tinfoil barb presented an excellent performance to adapt to the new environment. This was indicated by survival rate of the fish acclimated in the captive environment of about 69.28 ± 19.64% for five weeks. Phenotypic characterization revealed that Tinfoil barb collected from Borneo, Java, and Sumatra have different morphological characters. Based on genetic characters, polymorphism percentage and heterozygosity of the Borneo tinfoil barb population provided the highest performance followed by Java and Sumatra. The growth model of all Tinfoil barb populations was allometric negative indicating a faster increase in length than in weight. Reproductive performance presented that the fecundity of Tinfoil barb female from Borneo was the highest (2795-5099 eggs/gram) followed by Sumatra (1822-2976 eggs/gram) and Java (2210 eggs/gram). The artificial reproduction performance of broodstock from Borneo also presented more excellent performance than other population after hormonal treatment. Fertility rate and hatching rate were 94,33+0,29 % and 77,44+1,03%, respectively. Java Tinfoil barb had fertility rate 93+0,05% and hatching rate 73,67+3,15%, while it was no fertility rate and hatching rate obtained from Sumatra brood-stock group. Wild-caught adult Tinfoil barb from Borneo population presented the best performance used for potential brood-stock regarding genetic characters, reproductive performances, and response to artificial reproduction. Future studies need to be concerned with the acceleration of gonad maturation and the improvement of larval rearing technology for improvement of domestication strategies of Tinfoil barb as a potential candidate for freshwater aquaculture development.
Effect of Fermented Rice Bran used as Feed Ingredient on Apparent Digestibility Coefficient of Tilapia (Oreochromis niloticus) Feed
Authors: Putra A N , Rohayati D , Syamsunarno M B , Mustahal
Published: December 2021

This study aimed to investigate the effect of fermented rice bran used as a feed ingredient on the apparent digestibility coefficient (ADC) of tilapia feed. The fermentation process was conducted under aerobic conditions using 2% Aspergillus niger for 24 hours. Moreover, three different types of feed were prepared with 3 replicates and these include treatment A (reference feed), B (unfermented rice bran feed), and C (fermented rice bran feed). These treatments were provided for the tilapia for 30 days. Meanwhile, the tilapia used had an average weight of 5 g/fish and reared using a recirculation system with a density of 16 fish/aquarium. The results showed that the value of ADCenergy (78.11%) in treatment C was significantly highest (P<0.05) compared to other treatments, while the lowest was in treatment B with 72.24%. The values of ADCdry matter (67.56%) and feed efficiency (64.20%) in treatment C were also higher (P<0.05) compared to treatment B with 57.02% and 54.74% respectively. However, there was no significantly difference (p>0.05) in the value of ADCprotein, ADClipid, and SGR among the treatments. These results indicate the rice bran fermented using A. niger is potential to be used as a raw material ingredient for tilapia feed.
Performance and Energy Consumption of Paddle Wheel Aerator Driven by Brushless DC Motor and AC Motor: A Preliminary Study
Authors: Fauzi Ahmat , Handoyo W T , Hakim A R , Hidayat F
Published: December 2021

Energy demand for paddle wheel aerator in a shrimp pond is high and brings to second highest cost of operational behind feed supply. Most of wheel aerators are driven by electric motors than diesel engines as their easy operations. The electric motors need high electrical energy to drive wheel aerators along day and night. The common type of motor used is Alternating Current (AC) or induction motor, however Brushless Direct Current (BLDC) motor has potential electrical energy saving which need to be explored. This study objectives to find out performance of BLDC and AC motor as paddle wheel aerator driver. The motor’s performances were compared in term of operation of paddle wheel at various static loads. Both motor also challenged by On/Off running every 5 minutes, the treatment goal was to determine their reliability. Parameters observed included consumption of power, wheel rotary, torque, and efficiency, motor temperature as well. Results showed energy consumption of BLDC motor 51% lower than AC motor, and BLDC motor attained 89.99% of maximum efficiency while AC motor efficiency had 73.16%, however rotary wheel and torque both of them were similar. The On/Off treatment caused rising temperature of AC motor but did not affect the temperature of BLDC motor. Therefore, applied BLDC motor as paddle wheel aerator driver could be alternative way to reduce energy consumption without reducing its performance.
The Effectiveness of the Growth of a Consortium of Bacillus cereus Bacteria with Different Protein Sources
Authors: Feliatra F , Batubara U M , Mukti P R , Feliatra V A , Efendi I
Published: December 2021

One of the benefits of probiotic bacteria is to become a source of protein that can be used as a product in the field of biotechnology with high use value. Proteins derived from bacteria are less widely used compared to animals and fungi. The aim of this study is to analyze the composition of the media and the optimal time for the growth of a consortium of Bacillus cereus bacteria. The experimental method used is a consortium of B. cereus bacteria isolates (5 Strains) six treatments in each B. cereus consortium, namely the addition of a different protein source (eggs and skim milk, the same carbohydrate source, namely Sago) and 3 different concentrations in each protein source (8%, 10%, and 12%) so that the treatment obtained was 6 treatments with 3 replications in each treatment. Measurement of bacterial culture growth was carried out every 6 hours for 24 hours using two methods, namely the TPC method and bacterial cell biomass. Optimal growth was found in sago media which was added in different concentrations, namely 12% due to growth in this medium which was close to the same results as growth in positive control. Growth on biomass measurements showed similar results to the growth pattern similar to TPC. While in milk sago media, the growth is less because the exponential and stationary phases are shorter.
The Dynamic of Fishermen’s Income and the Influencing Factors on the West and East Coasts of Sumatra Island
Authors: Hidayati D , Widayatun W
Published: December 2021

Indonesia is known as a ‘Paradise under the Sea,’ with the richness and beauty of its coral reefs. This ecosystem is an important asset that has high economic value and a potential source of community income. However, this wealth has not been utilized optimally by coastal communities, especially fishermen. This is backed by their poor economic conditions. This paper discusses the dynamic of fishermen’s income and the influencing factors on the West and East Coasts of Sumatra Island. The fishermen’s income on both coasts is dominated by income from capture fisheries, which fluctuates throughout the year. The income of east coast fishermen is higher and more varied than west coast fishermen. This paper identifies three factors that influence the differences: 1) technological capacity of the fishermen’s fleet and fishing gear, 2) fish marketing and seasonal variations throughout the year, along with the degradation of coastal resources, and 3) policies and programs for fishermen’s empowerment and development in coastal areas. This paper uses quantitative and qualitative methods from the assessment of social aspects of coral reefs conducted by the COREMAP LIPI team. The authors also utilize secondary data from related documents, research results, papers and books.
Potency and Strategy of Aquaculture Development in Rokan Hilir Regency, Province of Riau, Indonesia
Authors: Effendi I , Elizal E , Zargustin D , Listihana W D , Wiyati R , Arizal N
Published: December 2021

Rokan Hilir Regency is situated east coast of Sumatera in Riau Province. Fish production of the area dominated by capture fisheries (80.67%) compared to aquaculture production (19.33%), however, there is a demand for strengthening the role of aquacuture. This study aimed to analyze the prospects and strategies for developing aquaculture in this area. Primary data was obtained by measuring of water quality, observations of aquaculture objects and other supporting facilities. Interviews and discussion were conducted with fish farmers, community leaders, the fishing industry, local government officials and other stakeholders. Secondary data were obtained from government and private institutions. This area has the potential for freshwater aquaculture of 102.80 ha, brackishwater aquaculture of 3,049.25 ha, and marine aquaculture of 118.330 ha. In 2019, aquaculture only utilized an area of around 2,879,107 ha, including 47,107 ha of freshwater (ponds), 10 ha of brackish, and 2,822 ha of shellfish ponds. Aquaculture production in 2019 was 15,006.34 tons consisting of fish production from ponds (blood clams and shrimp) 9,009.34 tons which was the main production, followed by fish production from ponds of 5,997 tons. In coastal waters, it is recommended to cultivate blood cockles and Pacific white shrimp (Litopenaeus vannamei). While in inland waters, the recommended fish culture included tilapia (Oreochromis niloticus), striped catfish (Pangasianodon sp), kissing gouramy (Osphronemus sp), and African catfish (Clarias gariepenus), both in ponds and floating net cages. The recommended development strategies include; training on aquaculture human resources, training on making their own feed, building seed and brood centers, and providing business stimulants in the form of seeds, making ponds and floating net cages as well as sustainable guidance from the fisheries industry and the government.
Impact of the Covid-19 Pandemic on Activities Socio-Economic Floating Net Cages (FNC) Business in the Koto Panjang Hydropower Reservoir, Riau Province
Authors: Hendrik H , Hendri R , Yolandika C
Published: December 2021

The purpose of the study was to analyse the impact of social activities related to cultivation and outside the cultivation business as well as economic activities before and after covid-19. The method used in this research is a survey method. Data collection was carried out on 20 farmers, three fish seller, and two fish feed sellers. Data analysis was carried out quantitatively and qualitatively. The results showed that before the pandemic, 80% of FNC cultivators’ social activities were done face-to-face and after the pandemic, only 40% were face-to-face and the rest were through mobile phones. Social activities outside the FNC such as worship, marriage and other attendance frequency is reduced by 5% - 25% after the pandemic. The economic activity of aquaculture has decreased after the Covid-19 outbreak by 50% in 2020 and 37.5% in 2021. In 2021 cultivators have made a profit but it is lower than the profit before the covid-19 pandemic. The economic activity of aquaculture has decreased after the Covid-19 outbreak by 50% in 2020 and 37.5% in 2021. In 2021 cultivators have made a profit but it is lower than the profit before the covid-19 pandemic. The economic activity of aquaculture has decreased after the Covid-19 outbreak by 50% in 2020 and 37.5% in 2021. In 2021 cultivators have made a profit but it is lower than the profit before the covid-19 pandemic.
Mitigation Strategy for Fishermen’s Households as a Result of Covid-19 Pandemic Social Engineering in Sungai Kayu Ara Village
Authors: Fitriansyah P , Darwis  , Amrifo V , Ramadona T
Published: December 2021

Covid-19 had a major impact on people’s lives, including the fishing community. Mitigation strategies are needed in order to reduce the impact of Covid-19. This research was conducted in March 2021 at Sungai Kayu Village. This village is one of the coastal villages located in Sungai Apit District, Siak Regency, Riau Province. The purpose of this study is to identify structural and non-structural mitigation and analyze the mitigation strategies carried out by fishing households in Sungai Kayu Ara Village. The method used in this study using the Survey Method. The population was fishing households totaling 48 households. The technique of determining the respondents is by census, which takes all the population as respondents. Data was collected by means of observation, in-depth interviews, documentation, literature studies, and online searching of data and information. The data that used: qualitative descriptive analysis and Analytical Hierarchy Process (AHP). Structural and non-structural Covid-19 mitigation in Sungai Kayu Ara Village, Sungai Apit District, Siak Regency is more focused on implementing government policies stipulated by the Regent’s regulation on handling infectious diseases and the Regent’s regulation on the application of administrative sanctions for the enforcement of health protocols in handling infectious diseases. Mitigation strategies for fishermen households in Sungai Kayu Ara Village, Sungai Apit District, Siak Regency due to the main social engineering of the covid-19 pandemic are: Selling fish caught by fishermen online, receiving protection fund and empowering fishermen, owning a plantation business (alternative business), receiving social assistance and have saving and emergency fund.
Morphoanatomy of Pangasionodon hypopthalmus Reared Under Controlled Photoperiod
Authors: Windarti  , Amin B , Simarmata A H
Published: December 2021

Fish morphoanatomy is affected by environmental condition such as photoperiod duration. A research on the effects of shortened photoperiod on the morphoanatomy of Pangasionodon hypopthalmus has been conducted. There were 3 treatments applied, namely, 24 hours dark (24D), 18 hours dark (18D) and natural photoperiod (control). The fish, 8 cm total length (TL) and 4 gr body weight (BW) were reared in circular plastic tanks filled with 100 L freshwater and completed with aerators and circulation pumps, 30 fishes/tank. The fish was reared for 8 weeks and fed with commercial fish feed pellets, twice/day, at satiation. The dark condition was created by placing the tanks under dark tarp tents. Morphoanatomy data were studied by the end of experiment. Results shown that the survival of fish was 100%. The growth of fish reared in 24D and 18D was better, more than 20 cm TL and 85 gr BW, while that of the control was 18 cm TL and 72 gr BW. The condition factor as well as the liver condition of fish in all treatment was not different, it was around 1.2. The liver was reddish brown color, smooth and oily in which hepatosomatic index (HSI) value 0.023 in 24D; 0.027 in 18D and 0.048 in control. The visceralsonatic index (VSI) was 0.090 in 24D; 0.70 in 18D and 0.161 in control. In most of fishes reared in 24D and 18D, the gonad were in the 1st maturity stage (gonadosomatic index; GSI 0.0058 to 0.0068), while the gonad of some control fishes were in the 2nd maturity stage (GSI 0.0080). Data obtained shown that the morphoanatomical data (HSI, VSI and GSI) of the fish reared in lengthened dark were lower, but the growth data (TL and BW) was higher than those of the control, indicated that the fish reared in dark condition may allocated more energy for growing.
Study of Physicochemical of Rivers in DKI Jakarta Province
Authors: Prihatinningtyas E , Jasalesmana T , Novianti R , Nafisyah E
Published: December 2021

Most of inland water in DKI Jakarta Province are highly polluted caused by the increase in urbanization, industrialization development and reclamation process. This research intend to conduct an initial characterization of the water quality in Jakarta. The survey was conducted in 9 location namely Kali Sunter 1, Kali Sunter 2, Cakung Drain, POM Vyle Pluit, Waduk Pluit, Museum Bahari, WTC Mangga Dua, Mookenvart and Pesanggrahan. Based on the level of salinity, the rivers are categorized into fresh water (Cakung Drain, WTC Mangga Dua, Mookenvart and Pesanggrahan) and brackish water (Kali Sunter 1, Kali Sunter 2, Pluit Village, Waduk Pluit, and Museum Bahari). The physicochemical measurement using Water Quality Checker reported turbidity and Total Dissolved Solid (TDS) concentration were very high at all sampling locations. The Oxidation Reduction Potential (ORP) value can be used to determine the pollution status. Pesanggrahan is the only river with a positive ORP value of 22 mV. It can be said that the pollution level of the Pesanggrahan is very low. The other rivers have a negative ORP value and the largest is in Kali Sunter 2. Serious efforts need to be made in dealing with inland waters pollution located in Jakarta.
Water Quality and Its Relationship to Tides and Ebbs on the Sail River, Pekanbaru City, Riau Province, Indonesia
Authors: Yuliati Y , Sumiarsih E , Efawani  , Fauzi M , Suryo G
Published: December 2021

The Sail River flows through the Pekanbaru City area which functions as a hydrological reservoir and main drainage channel. This river is affected by tides. Development along the Sail River Basin may affects the aquatic ecosystems. The research was conducted to determine the quality of the Sail River water and how it relates to the tides. Sampling was carried out two times during June-July 2021 in high and low tide conditions. The water quality parameters measured were temperature, TSS, pH, dissolved oxygen, BOD, COD, oil and fat, and Pb metal. Results showed that the temperature, COD, and Pb were significantly different at high tide and low tide conditions. On the other hand, during low and high tides condition, the value of TSS, pH, dissolved oxygen, BOD, oil, and fat were not significantly different. Dissolved oxygen levels during high and low tide ranged from 2.00 -3.00 mg/l and 1.00 -1.70 mg/l respectively. The Pb content during high and low tides ranged from 0.12-0.16 mg/l. In the present study, the values of dissolved oxygen and Pb content does not meet the water quality standards of Government Regulation No. 22/2021 (Class III).
Clustering Lakes in Kampar by Using Morphometry Data and Machine Learning Analysis
Authors: Hendrizal A , Plaimo P E , Harjoyudanto Y , Fauzi M
Published: December 2021

Lakes have an important role in hydrological and biochemical cycle. It also has some other crucial role such as domestic and industrial water use as well as irigation. The monitoring and management of this aquatic resources is crucial. But with many numbers of lakes, it is very challenging to manage them all. Clustering lakes can provide the answer so the management of the same cluster lakes may be done efficiently. Within this study, morphometry data of 6 lakes in Kampar Regency, Riau Province, were analyzed by using one of artificial intelligence branch which is machine learning. Morphometrical data are collected by using information geographic system. These data then categorized by using python language. This categorization based on data mining categorization algorithm named K-means. Based on the K-means machine learning clustering, the optimum cluster based on Elbow methid is k=3. But there is a possibility to look around for k=2. Based on K=3, cluster 3 is defined as the lowest values of all atribute. Based on k=2, the lowest value of morphometry data wiil be in the cluster 1.. These data will not only provide basic data such as total area, shape, width and length, but also help to understand the large scale hydrological models.
Acceleration of Sago Food Diversification in Improving the Welfare of Sago Farmers in Riau Province
Authors: Pramana A , Adhianata H , Zamaya Y , Nopiani Y , Alvionita P
Published: December 2021

There have been many efforts to increase agricultural productivity as a step to improve farmers’ welfare, one of which is through food diversification. Processing sago into various kinds of processed food products is a strategic to accelerate sago diversification. The market potential for sago starch in Riau Province is quite growing along with the local food products development. The purpose of this study was to analyze practical steps as an acceleration of sago food diversification so that opportunities could be identified in improving the welfare of sago farmers in Riau Province. This study used a survey method through interviews and direct observation regarding raw materials and processing methods for sago-based food products and the development of sago diversification products. As a support, secondary data is used through documents and reports related to local processed food in Riau Province, nutritional aspects, community and farmer empowerment, as well as increasing added value of products as supporting economic aspects. It was analyzed through a comparison between the increase in population and the potential for sago production. The existing diversified sago food products have good consumer acceptance and nutritional aspects.
Adsorption of chromium (VI) ion using zeolite NaA/Fe3O4 composite derived from rice husk ash
Authors: Ngoc Mai Ngo Truong , Anh Thu Nguyen Thi , Bao Trang Ngo Truong , Phu Pham Quoc , Hong Thien Doan Van , Vu Thanh Luong Huynh , Ngoc Hanh Cao Luu
Published: December 2021

In this study, zeolite NaA was fabricated from rice husk ash before combining with Fe3O4 to form a magnetic NaA/Fe3O4 composite. NaA/Fe3O4 composite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Brunauer Emmett Teller (BET). The surface area and the pore size of zeolite NaA/Fe3O4 was 24.11 m2.g−1 and 23.04 Å. In addition, batch adsorption studies were carried out for the removal of chromium (VI) ion in aqueous solution. The effects of adsorption parameters, including pH solution, initial concentration of Cr (VI) ions, mass of adsorbent, and contact time were investigated. The maximum equilibrium adsorption capacity of zeolite NaA and NaA/Fe3O4 was 22.554 mg.g−1 and 13.722 mg.g−1, respectively. The pseudo-first order kinetic model fitted well to the experimental data. The regeneration of the adsorbent was also investigated for three cycles.
Facile preparation of lotus seedpod-derived magnetic porous carbon for catalytic oxidation of Ponceau 4R
Authors: Nguyen Minh-Hung , Nguyen Thi-Linh , Nguyen Thi-Kim-Linh , Lam Hoa-Hung , Tran-Thuy Tuyet-Mai , Nguyen Quang-Long , Nguyen Van-Dung
Published: December 2021

In this research, magnetic porous carbon was directly synthesized through one-step pyrolysis of FeCl3– lotus seedpod mixture. Properties of the obtained material were analysed by X-ray powder diffraction, SEM image, nitrogen adsorption isotherm and vibrating sample magnetometer. The results showed that magnetic Fe3O4particles were successfully formed over material template in 1 hour. The magnetic porous carbon possessed the specific magnetization of 7.13 emu/g, high specific surface area of 288 m2/g and total pore volume of 0.18 cm3/g. The material was subsequently applied as a potential catalyst for Ponceau 4R degradation by H2O2. Parameters including pH, H2O2concentration, and different types of catalysts were investigated. At pH 3, 200 ppm H2O2, and 0.40 g/L magnetic porous carbon, 83% Ponceau 4R 50 ppm was removed after 120 minutes treatment. Moreover, the catalyst powders were separated from the treated mixture easily by a magnet. Summarily, magnetic porous carbon can promise to be an efficient catalyst in decomposition of Ponceau 4R.
A Study of Cordierite Ceramics Synthesis From domestic kaolin
Authors: Tuan Kim , Phong Dinh Huu , Lam Minh Tam , Nguyen Viet Thai , Le Minh-Vien , Luan Van Hoang
Published: December 2021

This work aims to study the effect of chlorine ion on the formation of the cordierite phase (2MgO.2Al2O3.5SiO2) from domestic kaolin at various calcined temperatures.. The cordierite phase was synthesized by a solid-state reaction technique from the mixture of kaolin, aluminum nitrate nonahydrate (Al(NO3)3.9H2O), and magnesium chloride hexahydrate (MgCl2.6H2O) which was designed to the stoichiometric composition of cordierite in the absence and presence of chlorine ion (NH4Cl). The structure and formation of cordierite phase were characterized by X-ray diffraction (XRD) and thermogravimetric - differential thermal analysis (TG-DSC). Phase composition of samples calcined at various temperatures was calculated by using Match! (Version 3.7.0) software. It is noteworthy that the presence of chlorine ion in the mixture declined the formation temperature of cordierite by 50 °C. The cordierite phase was calculated to be 61.3 wt.% and 5.5 wt.% at 1150 °C for the present and absent chlorine ion, respectively. The presence of chlorine ion affected the cordierite formation rate and suppressed the temperature of formation. Cordierite phase could be obtained up to 89.6 wt.% at 1250 °C and 30 wt.% NH4Cl. This investigation found that cordierite ceramic could be synthesized from domestic kaolin at lower temperature by using NH4Cl additive.
Defluoridation of water by Ce-Ti hybrid oxide nanoparticles
Authors: Dang-Bao Trung , Lam Hoa-Hung , Dang Thi-Hoai-Linh
Published: December 2021

In the present work, Ce-Ti and Ce-Ti/Fe3O4 hybrid oxides were prepared by co-precipitation method and then characterized by X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and scanning electron microscope (SEM) techniques. The nano-adsorbents were applied to remove fluoride (with the concentration range of 10–30 mg L−1) from aqueous solution, reaching the adsorption equilibrium within 30–60 minutes. Practically, the fluoride removal onto both nanomaterials was efficient at the neutral pH (pH 5–7) and obeyed the Langmuir adsorption isotherm with the maximum adsorption capacities of 22.78 mg g–1 (Ce-Ti) and 20.28 mg g–1 (Ce-Ti/Fe3O4) at room temperature.
Activation of ordered mesoporous carbon nitride prepared via soft-template for CO2 adsorption
Authors: Nguyen Van-Dung , Nguyen Thi-Thanh-Tuyen , Tran-Thuy Tuyet-Mai , Lam Hoa-Hung , Nguyen Quang-Long
Published: December 2021

A mesoporous carbon nitride material (MCN) was nanocasted by using a soft-template of triblock surfactant Pluronic F127, a carbon resource from resol and dicyandiamide (DCDA) as a nitrogen precursor. The obtained MCN was activated to improve its porous channel (AMCN). A reference sample of mesoporous carbon (MC) material was also prepared in the same protocol without DCDA. The tunable mesostructures (p6m symmetry) was proved by X-ray diffraction, transmission electron microscopy images and nitrogen adsorption-desorption isotherms. Fourier transformation infrared spectroscopy and energy dispersive X-ray spectroscopy presented about 3.1 wt% of doped-nitrogen in the obtained MCN. In comparison to the MC, a significant increase of BET surface area (333 m2/g for MC, 414 m2/g for MCN and 951 m2/g for AMCN) and an enlargement of pore volume (0.23 cm3/g for MC, 0.25 cm3/g for MCN and 0.33 cm3/g for AMCN), which contributed to a noticeable enhancement of the room temperature CO2 uptake from 1.8 mmol/g (for MC) to 3.7 mmol/g (for MCN) and 4.1 mmol/g (for AMCN). This work emphasized that the assistance of DCDA and further activation resulted in enlargement of both pore volume and BET surface area promising a feasible application of MCN and AMCN in adsorption technology.
Identification of multi-antibiotic resistant bacteria isolated from Vietnamese climbing perch (Anabas testudineus) on fish farms in Ho Chi Minh City, Vietnam
Authors: Nguyen Thanh Luan , Tran Kien Cuong , Thi Thu Nha Nguyen , Nguyen Lan Phan-Hoang , Thi Nga Tran , Ngan Huyen Mai Thi , Pham Minh Quan , Tran Quoc Toan , Pham Quoc Long , Bach Long Giang , Thi Hai Ha Pham
Published: December 2021

Climbing perch (Anabas testudineus) is considered a cultured species with high economic value and is widely distributed in several Asian countries, including Vietnam. In climbing perch aquaculture, antibiotic and antibacterial agents have been overused, leading to the emergence of antibiotic-resistant bacteria or genes in the aquatic environment as well as in the seafood products. These antibiotic-resistant bacteria and/or genes can then be spread to human through the food chain, generating detrimental consequences for public health and environment. In this study, 14 bacterial strains were isolated from Vietnamese climbing perch collected from various fish farms in Ho Chi Minh City which possess abnormal symptoms on the outside and in their organs. These bacterial strains were then subjected to several biochemical tests to characterize their colony morphologies. Besides, gene sequencing was performed and as compared to the 16S rRNA, 4 bacterial strains were identified with a high percentage in similarity, including Pseudomonas aeruginosa (99.7%), Aeromonas caviae (99.93%), Kosakonia sacchari (100%), and Edwardsiella ictaluri (99.44%). Additionally, these bacteria showed high levels of antibiotic resistance against beta-lactam, tetracycline, and others. Taken together, these results showed that the four identified bacterial strains isolated from Vietnamese climbing perch circulated in fish farms in Ho Chi Minh City. Their current status of multi-antibiotic resistance indicates further alternative sources of antimicrobial agents, for example, natural compounds, to overcome antibiotic resistance. It is then crucial to identify fish diseases, the associated pathogens, and the new alternatives for antibiotics to protect aquatic ecosystems and water resources.
Towards ergonomics working - machine learning algorithms and musculoskeletal modeling
Authors: Suess Franz , Melzner Maximilian , Dendorfer Sebastian
Published: December 2021

Ergonomic workplaces lead to fewer work-related musculoskeletal disorders and thus fewer sick days. There are various guidelines to help avoid harmful situations. However, these recommendations are often rather crude and often neglect the complex interaction of biomechanical loading and psychological stress. This study investigates whether machine learning algorithms can be used to predict mechanical and stress-related muscle activity for a standardized motion. For this purpose, experimental data were collected for trunk movement with and without additional psychological stress. Two different algorithms (XGBoost and TensorFlow) were used to model the experimental data. XGBoost in particular predicted the results very well. By combining it with musculoskeletal models, the method shown here can be used for workplace analysis but also for the development of real-time feedback systems in real workplace environments.
Wood Surface Roughness Prediction Modeling Depending on Influential Cutting Variables
Authors: Hodžić Atif , Aldžić Elmasa , Hodžić Damir
Published: December 2021

Paper presents the design of experiment and determining mathematical model to calculate roughness parameter of wood planned surface. For design of experiment three different types of solid wood were taken and processed on the planner with three different displacements and three different cutting speeds. After measuring the roughness parameter Rz, experimental results were obtained on the basis of which the central composite plan of the experiment was made. Based on that, a model of roughness parameter Rz was made, which is adequate and with high accuracy. The significance of the model coefficients was determined using the R software and the results were presented using the Design Expert software.
Computing the heat flux required for warming up of frozen wooden prisms for veneer production in the beginning of their autoclave steaming
Authors: Deliiski Nencho , Angelski Dimitar
Published: December 2021

An approach for computing the heat flux required for warming up of frozen wooden prisms in the regimes for their autoclave steaming at limited heat power of the steam generator, depending on the dimensions of the prisms cross section, wood moisture content, and loading level of the autoclave has been suggested. The approach is based on the use of two personal mathematical models: 2D non-linear model of the temperature distribution in subjected to steaming frozen wooden prisms and model of the non-stationary heat balance of autoclaves for steaming wood materials. For numerical solving of the models and practical application of the suggested approach, a software program was prepared in the calculation environment of Visual FORTRAN Professional developed by Microsoft. Using this program computation and research of the non-stationary change of the processing medium temperature and heat fluxes in an autoclave with a diameter of 2.4 m, length of 9.0 m and loading level of 50% at a limited heat power of the steam generator, equal to 500 kW during the initial part of the steaming in it of frozen beech prisms with different moisture content have been carried out. The suggested approach can be used for computing and model based automatic realization of energy efficient optimized regimes for autoclave steaming of different wood materials.
Researching the change in the weight of split oak firewood due to different drying methods
Authors: Gačo Amina
Published: December 2021

In this paper, the influences of stacking methods and drying places of split oak firewood in winter conditions (Quercus cerris) have been experimentally and theoretically investigated, due to the great importance of use in heating with such wood. The research was conducted on a sample of 48 pieces of logs with bark made of freshly cut oak. The logs were obtained by mechanized technology with the help of grafting by a hydraulic splitter and a chainsaw. Each log was measured for a research length of 0.30 m, marked with numbers 1-24. On each log, the weight was measured on a scale of 5 kg with an accuracy of 0.5 grams. Drying of logs was performed in two places. The first drying place was in outdoor conditions, sheltered from the snow and ventilated. The second place was indoors, at approximately constant room temperature. The logs were stacked in a crossed way for better air circulation. They were dried between 15/12/2020 and 15/02/2021, a total of 62 days. The average initial weight of logs dried in the facility was 1130.3 g, in the dried state the average weight was 952.87 g, which represented 84.3% of the original weight. The average initial weight of logs dried in outdoor conditions was 1192.125 g, in the dried state 1076.37 g, which represented 90.29% of the original weight. The average initial water content in the logs dried in the facility was 37.9%, in the dried state it was 27.5%. For logs dried in outdoor conditions, the average initial amount of water was 36.6%, in the dried state the average amount of water was 31.2%.
Analysis of the dimensions of desks in primary schools in Aerodrom Municipality - Skopje
Authors: Jevtoska Elena , Gruevski Gjorgi , Antovska Ivana , Krstev Marija
Published: December 2021

Educational institutions are facilities where each person spends many years of their life. Desks used in these institutions are designed with specific features of shape, material and size. Long-term use of desks in educational institutions may be the cause of damage to the health of users if they are not carefully designed and dimensioned. In compliance with the prescribed rules and dimensions in the design of desks it is of great importance for proper development of the users that are in the stage of growth and development when using this type of desk. In this paper, the functional dimensions of real samples of desks taken from primary schools in the Municipality of Aerodrom – Skopje will be measured. The testing samples of desks will be designated to the group that they belong to according to the EN 1729-1:2006 standard, and all requested dimensions according to the standard will be measured. The purpose of this work is to show the real condition of desks in primary schools and whether the desks are with the requested dimensions of the EN 1729-1:2006 standard.