bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of making coal water slurry with lignite Pendopo coal
Authors: Rahmanta M A
Published: December 2021

The Coal Water Slurry (CWS) technology increases the calorific value and changes the phase of coal from solid to liquid. The CWS Plant with a coal capacity of 1.4 t/hour located at Karawang, West Java converts lignite coal to CWS. Coal undergoes pulverizing, upgrading, and slurry-making processes to become CWS. Pulverization is the process of refining coal size into 200 mesh. The upgrading process is through reducing the moisture content in heat exchangers (HE). It occurs in HE where the coal is pressurized to 15 MPa and the temperature is maintained at 330 0C for 30 minutes. The research objective was to determine the CWS characteristics of the South Sumatra Pendopo lignite coal. The method used is through testing where the Pendopo coal is converted into CWS at the CWS Plant. The result shows that Pendopo coal which has a heating value of High Heating Value (HHV) 2,725.00 kCal/kg As Received (AR) has an increase in HHV heating value of 3,218.00 kcal/kg AR when it becomes CWS. The total moisture content of Pendopo coal has decreased from 49.36% to 44.58% when it becomes CWS. The fixed carbon content of Pendopo coal increased from 19.78% AR to 24.01% AR.
Fitting the variogram model of nickel laterite using root means square error in Morowali, Central Sulawesi
Authors: Anggara Benny , Marwanza Irfan , Ahmad Azizi Masagus , Dahani Wiwik , Subandrio
Published: December 2021

Abstract. The nickel commodity is getting popular due to its role as one of the raw materials for battery manufacture. It is estimated that this trend will continue for the next 2 - 3 years and reaching its peak when the factories that process the raw material for electric vehicle batteries are established. For this reason, the nickel mining companies are competing to explore new nickel deposits. The research location is a nickel mine in Sulawesi. The purpose of this study was to determine the most suitable Nickel variogram model based on root means square error (RMSE). To obtain an accurate number of resources, it is necessary to apply an accurate and validated estimation method to gain data that are in line with the actual conditions. Therefore, this study uses a geostatistical method that takes into account the spatial relationship of each data using a variogram which is validated by the cross-validation method and RMSE. From the results of the RSME analysis, the most suitable variogram model for nickel content in the limonite and saprolite layers is the exponential variogram model. In addition, the values of root mean square error for nickel content in the limonite and saprolite layers were 0.022 and 0.098 respectively.
The planning of mine drainage system at PT Perkasa Inakakerta, East Kutai Regency
Authors: Dewi M C , Anggara R , Hidayatullah R , Nurhakim I
Published: December 2021

This research located in Beruang Block Kalimantan. The purpose of the mine drainage planning system is to control runoff water. Therefore, an excellent drainage system is needed without interfering with mining activities such as runoff water pollution, which could cause contamination in the surrounding area and outside the mining sites. Based on the analysis of rainfall data of 2009-2020, the precipitation plan was 341.67 mm/day; the concentration time was 2.37 h, the rain intensity was 41.06 mm/h, and repeated rain periods were 2-years. The extensive catchment area was 1.52 km2 because the runoff entering the sump was 44.38 m3/h. To prevent the water from entering the mining area, an open channel was made around the mine openings, and the water flows naturally into the sump. The water pumped into the settling pond with the pump type Allight HL 150MHD-IT at 50 m/s for 3-days with a single rain, resulting in total water volume of 17,556.5 m3/day. A trapezoidal shape was designed for a sump with dimensions of 3.96 m in length and width at the surface, 1.79 m length and width at the base, and 1.03 depth.
Slope stability and bearing capacity analysis of disposal in open-pit coal mining
Authors: Sirait Bagaraja , Zulfahmi
Published: December 2021

Open-pit mine is a mining method by excavating overburden strata to get coal seam near the surface. One of potential hazard often occur in mining area is slope failure. The hazard can be prevented by performing geotechnical study. The study is required to provide recommendations regarding safe design of slope geometries in both open-pit and disposal sites. This paper produce information related to the results of slope stability analysis especially on the disposal embankment. The analysis is performed by using the limit equilibrium method. It is also produce the bearing capacity analysis of subsurface strata in disposal site. The analysis is carried out to determine the ability of the strata to burden the load of disposal embankment above. The location was selected in a site of open-pit coal mine in Indonesia. The results will become consideration for management in designing slope disposal and choosing the location of disposal facilities.
Removal of mercury ion from wastewater using natural zeolite: effect of humic acid to adsorption isotherm
Authors: Prasakti L , Utami F N , Prasetya A
Published: December 2021

As Indonesia possessed a considerable amount of gold deposit, many golds mining activities, including the small-scale one, is commonly found. A simple mining technique (amalgamation) that utilizes mercury (Hg) will generate mercury-containing wastewater. One of the prospective Hg removal methods from wastewater is adsorption. In addition, it is also possible that metal contained in the wastewater interacts with other substances, such as humic acid. This experiment was aimed to examine the adsorption process of Hg2+ ions in the wastewater using natural zeolite. The effect of the presence of humic acid, which might be found in sewage, toward the adsorption capacity of Hg2+ onto natural zeolite was investigated. The natural zeolite, which contained several types of minerals, was obtained from Klaten, Central Java. The experiment was conducted using ten mg/L HgCl2 as the initial concentration and ten mg/L humic acids. A comprehensive study that includes isotherm and the kinetic study was carried out. Experimental results showed that the presence of humic acid was found to reduce the capacity of Hg2+ adsorption on natural zeolite. Freundlich isotherm model was found to be more suitable to represent equilibrium adsorption data. Kinetic examination revealed that the pseudo-second-order model was able to produce a better agreement with experimental data.
Prospect of coal-based methanol market in Indonesia
Authors: Suseno T , Umar D F
Published: December 2021

Coal is one of the commodities in the mining sector which is currently being pushed to strengthen the structure of the upstream petrochemical industry, including methanol as a raw material for various derivative industries, most of which are still imported. Currently, Indonesia has only one methanol plant with a production capacity of 660,000 tons. During 2023-2035, Indonesia needs an average of 1.77 million tons of methanol per year. If, until 2035, Indonesia does not add and build a methanol plant, then Indonesia will always import 1.51 million tons per year. Results indicate that the methanol plant, through coal gasification, can support the growth of the methanol-base industry to reach domestic needs and reduce imports. It can also as an export commodity to generate foreign exchange.
Business analysis of implementation of UCG technology in Indonesia
Authors: Kurnia Hudaya Gandhi , Huda Miftahul
Published: December 2021

There is a deep-seated coal potency with a depth more than 100 meters below surface in Indonesia that has not been exploited yet. Underground Coal Gasification (UCG) is an unconventional technology that can become the solution to exploit the deep-seated coal potential by extracting coal into in-situ gas that can be converted to electricity or chemicals. Based on business analysis, this paper aims to analyze the implementation of UCG technology in Indonesia, whether it is potential or not. Data are collected from literature and analyzed using Porter Five Forces and PESTLE Analysis. The Porter Five Forces analysis shows that the implementation of UCG in Indonesia is still potential as an industry because the only threat will come from substitute products. PESTLE analysis shows that almost all the factors, except for technology, are very supportive of implementing UCG commercial plants in Indonesia. Based on both studies, it can be concluded that the UCG project is very potential to be developed in Indonesia. However, it needs full support and control from the government because it will become a pioneer project with financial and environmental risk still has not quantified ideally.
Automation Design of Kentongan Sound for The Feeding Process of Vaname Shrimp Farming in Pond
Authors: Waryanto W , Zulkarnain R
Published: December 2021

Feeding on vanamei shrimp culture in pondsis carried out on average 4 to 5 times a day. In aquaculture activities with a large number of ponds, the sound of kentongan becomes a time reference for the operator in providing feed. The purpose of this article was to describe the process required to turn the kentongan sound into a command input for an automatic feeder. The sound of kentongan will be used as input data (commands) for the microcontroller is translated as a command for the feeder to carry out its activities of feeding. The methodology used the following points: first, field observations of the use of kentongan sounds as a sign of the feeding process for feed operators; second, literature study covering sound frequency and sensor system; third, the creation of a chart in the form of step by step logic from input in the form of kentongan sounds to the process of feeding using an automatic feeding device; fourth, the design of the hardware that will be used and the creation of the software in the form of a command flow chart. The result was realized in the form of a chart from input in the form of kentongan sounds to the process of feeding using an automatic feeder. This includes hardware and software design. There were two important things in automation design. The identification process of kentongan sounds becomes a function of frequency against time, where this frequency had certain characteristics which were expressed by graphs that have certain equation values. This kentongan sound with a certain frequency will be the input for the microcontroller to carry out its task of giving orders to the feeding device to provide feed for vanamei shrimp in ponds.
Quality Improvement of Water Hyacinth (Eichornia Crassipes) Leaf Meal Fermented with Aspergillus Niger as Fish Feed Ingredient
Authors: Suharman I , Lukistyowati I , Ramayani S , Caipang C M A , Adelina A , Aryani N
Published: December 2021

An experiment was conducted to investigate the nutrient quality of water hyacinth leaf meal (WHLM) fermented with different doses of Aspergillus niger as fish feed ingredients. This study utilized a completely randomized design (CRD) with five treatments and three repetitions. The doses of A. niger supplemented in WHLM were 0; 6; 8; 10; and 12%. Results of this study showed that nutrient quality of WHLM with A. niger supplementation significantly affected the reduction of crude fiber and increase of crude protein (P<0.05). Addition of 12% A. niger is the best treatment for improving protein and fiber quality of water hyacinth leaf meal.
Prevalence of Aflatoxigenic Aspergillus sp. in Dried Salted Fish from Traditional Market in Bandung City, Indonesia
Authors: Kusmarwati A , Novianti D A , Yennie Y
Published: December 2021

Salted fish is an important source of protein and income in Bandung City, Indonesia. Meanwhile, salted fish products that are contaminated with aflatoxin-producing molds can pose a considerable hazard to consumers’ health. This study aims to determine the presence of aflatoxigenicAspergillussp. that contaminates salted fish products. A total of 8 samples of dried salted anchovy and 7 samples of dried salted cotton fish from 8 retailers in traditional market were analyzed for fungal contamination, sample physicochemical factors, and prevalence of aflatoxigenicAspergillussp.. This research was divided into 4 stages, namely, total mold calculation, identification of molds through morphological observations, isolation, screening, and molecular identification of aflatoxin-producing molds. Using internal transcribed spacer (ITS),Nor-1, andOrd1primers, 8 out of 66 mold isolates from salted fish samples were isolated and identified.The results showed that the dominant genera in dried salted anchovy and cotton fish areAspergillussp. (36.8% and 53.6%), followed by other genera (36.8% and 28.6%) andPenicilliumsp. (26.3% and 17.9%). The total fungal counts in the dried salted anchovies and cotton fish ranged from 2.50 × 102to 4.00 × 102cfu/g, and 5.00 × 100to 1.40 × 102cfu/g. The prevalence of dried salted anchovy samples was 13.16% (3 of 28) and in the dried salted cotton fish sample was 12.12% (5/38). In general, the characteristics of positive aflatoxigenic samples have a temperature of 26.3 to 38.0°C, relative humidity of 44% to 59%, salt content of 3.06% to 16.06%, aw 0.71 to 0.79, and pH 6.13 to 8.75. The presence of aflatoxigenicAspergillussp. in salted fish sold in the Bandung market poses a potential hazard to consumer health.
Innovation Technology on Catfish Fillet By-Product as Raw Materials for Food Industry
Authors: Dewita D , Syahrul S , Sidauruk S W , Hidayat T
Published: December 2021

Kampar Regency is one of the national catfish cultivation development clusters, and there are many catfish processing industries, especially fish fillet processing. The processing of catfish fillets always left by-products in the form of small pieces of meat, skin, bones, and abdominal fat, which amounts to around 50% – 60%. The by- products are mostly disposed to the environment around the industry, causing pungent odor pollution, as the byproducts contain protein, fat, minerals and crude enzymes which are suitable habitat for the growth of spoilage microbes. Therefore, it is very possible for these by-products to be processed further in order to obtain new products in the form of industrial raw materials that have economic added value. The objectives of this research are (1) Optimizing the utilization of by-products from fish fillet processing starch into raw materials for food industry that have economic value; and (2) understanding the characteristics of organoleptic quality and the proximate composition of the food industry raw materials produced. The research method used is an experimental method, namely experiments on processing by-products into raw materials for the food industry in the form of fish meal, fish oil and bone meal. The results showed that the number of by-products produced from processing the catfish fillets was arround 60% with, consisted of head, tailbone and fins by 37%, small pieces of meat 5%, viscera 10% and abdominal fat 8%. Furthermore, that raw materials having organoleptic quality and proximate composition that meet the SNI standards.
Impact of the COVID-19 Pandemic on Marine Tourism Derawan Island, Berau Regency, East Kalimantan Province
Authors: Simarangkir O R , Tawang F , Irwan I , Utami P B , Nani N , Ricky  , Kodiran T
Published: December 2021

The COVID-19 pandemic has had a tremendous impact on various aspects of life today. The tourism sector is one of the sectors affected by COVID-19, especially by the policy of social restrictions and foreign tourist visits. Derawan Island is one of the leading tourist destinations in East Kalimantan which has been affected by the COVID-19 infectious disease. The purpose of this research is to find out the impact of the COVID-19 pandemic on marine tourism on Derawan Island. The research was conducted in December 2020 – March 2021, using survey methods based on primary and secondary data. COVID-19 causes changes in habits, visit patterns, and the number of visits to Derawan Island marine tourism. The number of tourist visits decreased by 58% from the previous year, even as of December 2020, diving tourism actors are the parties most affected by COVID-19 due to the absence of diving tourists since the reopening of the leading tourist destination Derawan Island. The decline in tourist arrivals causes a decrease in income in the tourism sector, especially the income of tourism actors on Derawan Island.
Efficiency of Different Traps and Baits for Catching Freshwater Prawn Macrobrachium Spp. for Broodstock Development
Authors: Pacho J D , Avillanosa A L , Avillanosa A P , Caipang C M A , Dagaraga R S , Valencia R V , Montaño B S , Limbaga L A , Garganta G P
Published: December 2021

Catching of wild freshwater prawns in Palawan is done by using different fishing gears, including baited traps. However, there are only limited studies related to the efficiency of these traps on catching freshwater prawns. In this study, the efficiency of four different traps (traditional plastic traps, bamboo traps, modified traps, and rattan traps) and three baits (low-valued fish, grilled coconut, and octopus) was tested in catching live Macrobrachium spp. from the rivers of two localities in the Barangay Bagongbayan, Roxas and Sitio Catama, Dumaran, Palawan at two sampling events with 12-hr intervals along the river bank. Each trap was deployed randomly 5-8 meters apart in the collection site late afternoon and retrieved the following day. The highest catch was obtained using plastic traps with low-value fish as bait. All samples from the different traps were collected alive. Modifications are underway to improve the design of these traps to improve catch efficiency. Regulating the collection of Macrobrachium from the wild by developing it into broodstocks will support the sustainable aquaculture industry using hatchery-produced seedstocks instead of sourcing it from the wild.
Dynamics Water Quality in Koto Panjang Reservoir, Indonesia
Authors: Budijono B , Suharman I , Hendrizal A
Published: December 2021

Riau Province has the Koto Panjang reservoir which is generated from the damming of the Kampar River flow for hydroelectric power generation and other utilization activities. The increase in community activities in reservoir waters and on land causes water quality dynamics that can affect fish farming activities. The purpose of this study was to determine the dynamics of reservoir water quality. The survey was conducted in March – August 2021 at seven sampling points, where water samples at each sampling point were taken at a depth of 1 m as much as 1 liter using a van dorn water sampler and preserved and analyzed according to standard methods. Data from measurement and analysis were tabulated and analyzed descriptively including temperature, pH, turbidity, TSS, TDS, DO, nitrate, ammonia, total nitrogen, BOD5, COD, and total phosphate. The results obtained indicate that the values of temperature, turbidity, TDS, TSS, pH, DO, ammonia, nitrate, and phosphate are still below the quality standard, except in the range of BOD values of 4.30 – 5.75 mg/L and COD of 17.90. – 23.73 mg/L is an indication of organic matter originating from other activities on the reservoir land, such as plantations, agriculture, settlements, tourism, apart from floating net cage cultivation activities.
Abundance of Phytoplankton and Physical Chemical Parameters as Indicators of Water Fertility in Lekok Coast, Pasuruan Regency, East Java Province, Indonesia
Authors: Herawati E Y , Darmawan A , Valina R , Khasanah R I
Published: December 2021

The Lekok Coast is part of Pasuruan Regency which has various community activities. The condition of the waters is influenced by natural and anthropogenic factors which receive a lot of input loads from the mainland. These input load can come from human activities such as aquaculture, industry and domestic waste that enters through rivers and then empties into the coasts. These conditions can affect the fertility of eutrophic, mesotropic or oligotropic waters. This study aims to determine the conditions of the waters based on the abundance of phytoplankton and the physical and chemical parameters of the waters to see the fertility status of the waters. The descriptive method is the method used in this study and the determination of the sampling point uses the purposive sampling method, the research was conducted in April – May 2019. Based on the results of the abundance of phytoplankton in the coastal waters of Lekok, it is classified into waters that have oligotrophic fertility levels. The results of observations and measurements of physical and chemical parameters in the coastal waters of Lekok showed that several parameters that support the growth of phytoplankton are less than optimal, such as temperature, brightness and nitrogen elements.
Mapping of Water Quality as Aquaculture Media, Comparative Study on Three Rivers in Riau Province
Authors: Harjoyudanto Y , Asiah N
Published: December 2021

Kampar River, Siak River, and Rokan River have different watersheds, and the water from these rivers is not interconnected. The results of this study can be used as a basis for managing aquatic resources in the Kampar River, Siak River, and Rokan River, Riau Province, Indonesia. This research was conducted in April 2017 – March 2018. The collection and measurement of water quality for each river consisted of three stations which were carried out based on SNI through the survey method twice, namely in the dry season and rainy season. The observed water quality parameters include physical, chemical, and biological parameters. The results of the next analysis are calculated using the STORET method using a value system from the United State-Environmental Protection Agency (US-EPA) which is adjusted to the Class III Water Quality Standard based on PP. 22 of 2021. The results of the analysis of the rain index value in the highest dry season is a score of -44 on the Rokan River, classified as class D with a score of -31 heavily polluted. The STORET score in the Kampar River and Siak River obtained -24, each classified as Class C, is included in the moderately polluted category. Meanwhile, in the rainy season the pollution index with the same pattern is highest in the Rokan River -40, then Kampar River, and Siak River each -20. The water quality standard used in this study is class III because it still supports fish farming activities. Based on Government Regulation Number 22 of 2021 concerning water quality standards, class III is water whose designation can be used for freshwater fish aquaculture, animal husbandry, and gardens irrigation. The Storet method is carried out by collecting water quality data and measuring data from each water parameter compared to the value of class III water quality standards.
Distribution and Abundance of Macrobrachium Populations in Palawan
Authors: Dagaraga R S , Avillanosa A L , Caipang C M A , Avillanosa A P , Pacho J D , Valencia R V , Montaño B S , Limbaga L A
Published: December 2021

Nothing is known about the population dynamics of Macrobrachium spp. or freshwater decapods in Palawan that hence received little attention to conservation studies that are imperative to establish sustainable management proposals. Thus, this paper provides information on the natural distribution and abundance of Macrobrachium spp. in Palawan to address threats to their survival. Preliminary findings through key informant’s interviews suggest the distribution and abundance of these species in Palawan’s river system. Generally, Macrobrachium spp. are present in all river systems in the province. However, the respondents observed that the population started to decline during the late 1990s attributed to the rampant use of organic pesticides/insecticides for agricultural purposes and intensive quarrying activities stretched along with the river systems in some of the municipalities in Palawan. Results also annotated that the local populations use these animals as food without official regulations, which may be additional pressure on freshwater prawns. The abundance of the Macrobrachium spp. is affected by human interventions and the destruction of their natural habitat and populations. Management measures should be considered from the economic conditions of freshwater prawns for effective management strategy and conservation efforts for future generations.
Biodiversity of Associated Megabenthic Invertebrate of Corall Reef Ecosystem of Petong Island Batam Indonesia
Authors: Siregar Y I , Nasution S , Kurniawan R
Published: December 2021

Abstracts

Global warming and climate changes were of the main environmental concern of marine scientist in the last three decade. As a biodiversity hotspot, marine coastal ecosystem faced an environmental threat because of increasing sea surface temperature (SST) and land base effluent, which in turn had an impact on the biodiversity of megabenthic faunal on coral reef community. The present paper studied the current condition of reef ecosystem as well as biodiversity of megabenthic community in Petong Island, a core zone of Batam Marine Management Area (BMMA), Riau Archipelago Province. Gradual changes of physical and chemical properties of seawater originated from coastal activities presumably has caused an effect on benthic faunal community structure. It revealed that benthic lifeform coral cover account for 30,53%, categorized into fairly good, whereas abiotic sand cover of 16,53%. The lifeform consists of Acropora (AC)1.73% and non-Acropora 28,80%. Death coral with algae (DCA) account for 40,40% and death corall (DC) 2,80%, Soft Corall (SC) 1,20%, fleshy seaweed (FS) 0,07%, other fauna (OT) 1,47%, and rubble (R) 7,00%. Apparently, only 4 of target species megabenthic fauna from eight, were eccounterred including; seaurchin (Diadema sp.), topshell (Drupella sp.), giant clam (Tridacna sp.), trochus (Trochus sp.), with density of each megabenthic fauna calculated 5929, 1857, 71 and 71 ind/ha, respectively. It appeared that sea urchin were the highest density and followed by topshell (Drupella sp). Sea urchin were noted as a bioindicator of reef ecosystem health. High density of sea urchin may indicate that reef in unhealthy state. The presence of Diadema Sitosum indicate that dead coral were present and it feed on algae growing in dead coral. High density of sea urchin may indicate that reef in unhealthy state
Species Diversity of Marine Bivalves from the Strait of Rupat Island Riau Province, Indonesia
Authors: Nasution S , Effendi I , Nedi S , Mardalisa M
Published: December 2021

A survey of marine bivalves for species diversity was conducted at five locations in the current study; Three stasiun at Dumai city beach those are Silensing, Bandar Bakau, Basilam Baru, Sri Tanjung, and Pulau Payung beach of Rupat Island Strait, Riau Povince. Indonesia. The goal of this study was to learn more about the marine bivalves that live in the Rupat Island strait. From July to August 2020, marine bivalves were collected during spring low tides from intertidal zones and shallow coastal waters. From the Strait of Rupat Island, 13 bivalves belonging to 11 genera, 11 families and 8 orders were discovered. During the research, bivalves from the families Pectinidae, Placunidae, Arcidae, Trapezidae, Veneridae Ostreidae, Corbiculidae, and Psammobiidae were recorded during the study. The number of bivalves in each family reveals that two species belongs to the Arcidae family and two to the Cyrenidae family. Corbiculidae, Placunidae, Trapezidae, and Psammobiidae each had one species reported. The abundance of each species found was extremely low, it is not feasible to be presented quantitatively. The most common species encountered in the strait were Anadara granosa, Polymesoda erosa, Polymesoda expansa, and Pharella acutidens. The anthropogenic activities of Dumai city and Rupat Island, such as the discharge of industrial wastes, residential sewage, overfishing, habitat loss, overharvesting and tourism, could cause variations in bivalves abundance in the Strait of Rupat Island.
The Stock Status of Skipjack Tuna (Katsuwonus pelamis) in Tomini Bay and Its Surrounding Areas, Indonesia
Authors: Mardlijah S , Pane A R P , Panggabean A S
Published: December 2021

Skipjack tuna (Katsuwonus pelamis) is an essential part of tuna, skipjack tuna, and mackerel tuna trades in Indonesia as the species is an economic commodity with export value. Tomini Bay is one of the areas in Indonesia with intensive skipjack tuna exploitation activities using purse seine fleets. Such a high fishing rate requires management efforts to maintain the species population’s sustainability. This study was conducted in April 2018–December 2019 at a fish landing site in Gorontalo City with a total sample of 8,833 skipjack tunas. The population dynamics, recruitment, and utilization rate were analyzed using FISAT II application and ELEFAN program. The results showed that the length at first capture (Lc) was 31.8 cmFL (in 2018) to 32.2 cmFL (in 2019) at around 1.3 year old. The fish recruitment occurred all year long, peaking in May at 16.12%. In addition, the utilization rate (E) of the species was 0.47, meaning that the species was already moderate to fully exploited. The suggested practical management efforts to maintain the population of the skipjack tunas in the area are to stop the fishing efforts from growing and control the size of the mesh for fishing.
Palmarosa essential oil encapsulated in chitosan nanoparticles by ionotropic gelation: formulation and characterization
Authors: Nguyen G H , Le X T
Published: December 2021

In this study, chitosan nanoparticles containing palmarosa essential oil (PEO-CNPs) were formed by ionotropic gelation, consisting of two parts: emulsion preparation followed by ionotropic gelation encapsulation with tripolyphosphate ions (TPP) as a crosslinker. The encapsulation method was optimized by varying three parameters, including chitosan concentration, initial oil loading in the emulsion and TPP concentration. The effects of these parameters on the encapsulation efficiency (EE) and loading capacity (LC) were analyzed. EE had an initial increase followed by a decrease in the range of three parameters. However, LC rose with varying initial oil content while it reduced with changing polymer and TPP concentration. The optimum experiment with the highest EE (10.0 g/L of chitosan, 5.0 g/L of TPP and 30.0 g/L PEO) was chosen to analyze the particle size using Dynamic Light Scanning method (DLS). With DLS measurement, the z-average diameter was 235.3 nm, and the particle size distribution was in the range of 100 – 500 nm.
Simulation of temperature distribution in refrigerated container 40 feet
Authors: Sim Vo Van , Phung Le Thi Kim , Viet Tran Tan
Published: December 2021

This study shows the method for predicting the temperature distribution and air flow in the box of a refrigerated container 40 feet, for two configurations (open and closed) of the rear door. Computational Fluid Dynamics – CFD (Computational Fluid Dynamics) is decoupled and used when the truck door is fully closed. The temperature, velocity vector and heat flow are simulated based on the finite element method. The simulation results are compared with the experimental data.
The Influence of Meshing Strategies on The Numerical Simulation of Solar Greenhouse Dryer
Authors: Tran Viet. T. , Duong Yen. H.P. , Le Tan M.
Published: December 2021

In the present study, we conduct the numerical simulation for solar greenhouse dryer performance by Ansys Fluent software. The numerical simulations compared the meshing strategies for the dryer and show the effects on both temperature distribution and relative humidity distribution of air inside the dryer. Unstructured meshes were used in the numerical simulation employing hexahedral meshing and tetrahedral meshing for mesh generation. The meshing strategies were evaluated through 2 size of cell i.e., 0.1 m and 0.05m. The results indicated that the size of cell have strong effect than the mesh type on the temperature profile and humidity of air inside the dryer. Thus, the results gave the engineers more options to select the optimum conditions for meshing and simulation the dryer.
Simulation of shell and tube heat exchanger using COMSOL software
Authors: Nguyen Trung Kim , Ba Tuan Nguyen , Ngoc Pha Bui , Embong Abdul Mutalib , Thi Nhu Ngoc Nguyen , Xuan An Nguyen Si , Trung Ngon Hoang , Abdul Kadir Nurul Ashikin , Nguyen Tuan-Anh , Huy Phuoc Pham Loi Hoang
Published: December 2021

The aim of this paper is to propose a model to simulate the behaviour of water flows in shell and tube heat exchanger. Particularly, the continuity equation, the general heat transfer equations and the energy equation in COMSOL Multiphysics software were implemented in the numerical modelling. Besides, the experiment was also conducted to validate the proposed COMSOL model. The water temperature at locations close to the inlet and outlet of the shell side was respectively predicted at 31.5°C and 34.6°C in the simulation, and it was respectively measured at 31.5°C and 35°C in the experiment. These findings showed that the simulation results had a good agreement with the experiment. Next, this model was extended to simulate the overall heat coefficient and the pressure drops of the water flows in such heat exchanger. The overall heat coefficient was at 736.62 W/m2K. The pressure drops at the inlet/outlet areas of the shell and tubes were at 849.93 Pa and 6255.50 Pa, respectively. Conclusive evidence showed that the proposed model is a reliable method for studying the heat transfer behaviour of the shell and heat exchanger.
A review on Extraction of alkaloid from Nelumbo nucifera Embryos and Leaves for Production of Dietary Supplement
Authors: Nguyen Hanh H T , Lam An T , Pham Tuyen N V , Le Tien X , Le Phung K
Published: December 2021

Lotus (Nelumbo nucifera Gaertn.) commonly distributed in low-lying and flooded areas like Southern Vietnam provides flowers, leaves, seeds, embryos, and edible rhizomes. All parts of the plant show good pharmacokinetic properties, especially lotus embryos and leaves. Studies have shown that lotus plums and leaves have many bioactive compounds such as alkaloids, flavonoids, triterpenoids, and polyphenols, in which alkaloids are one of mainly bioactive compound kinds. So that, there are many studies investigating extraction methods that increase the amount of alkaloid from lotus leaves, embryos. There are some conventional extract methods such as soak, heat reflux, Soxhlet, etc… and some modern extract methods as microwave, ultrasounds, enzyme assisted, supercritical fluids (S-CO2). At present, lotus leaves, embryos and their bioactivities can have application potential in the supplementary food such as protect-liver, anti-neurotic, etc.. The aim of this paper is to review a variety of develop methods used in the alkaloid extraction from lotus embryos, leaves. Besides, this study also introduces some pharmacokinetic properties of alkaloid which can use in functional foods.
Efficient reduction of methylene blue in aqueous solution using a Fenton-like catalyst of Fe3O4/Cu
Authors: Luong Huynh-Vu-Thanh , Dang Huynh-Giao , Tran-Nguyen Phuong-Lan , Phan-Thi Diem-Trang , Dao Lam-Gia-Hao
Published: December 2021

This work aimed to investigate the efficient reduction of methylene blue (MB) by a heterogeneous magnetic nanoparticles/copper (MNs/Cu) Fenton-like catalyst. The MNs/Cu was successfully synthesized in the presence of Citrus aurantifolia extract. The characterizations showed an effective fabrication of Cu onto the surface of MNs. The reduction of MB by the MNs/Cu Fenton-like catalyst presented an efficiency of 99.5% at the optimum conditions, including MNs/Cu dose of 0.1 mg, temperature of 25°C, contact time of 75 min, pH 4.0, and 20 mL H2O2 30%, MB initial concentration of 25 mg/L. The reduction kinetics was well fitted to pseudo-second-order with reaction rate constant of 0.0029 g/mg.min. The main mechanism of the MB reduction due to active oxygen species was pointed out. The decrease of reduction yield at high pH, catalyst dose and MB concentration was elucidated in this study.
Study on the synthesis of 1,3,5-triazinane derivatives on copper-ferrite nanoparticles catalyst
Authors: Pham Thao Xuan , Pham Minh Tuan , Cao Hai Thuong , Nguyen Bich Ngoc , Nguyen Quang Ha , Trang Bui Thuy
Published: December 2021

A high efficient method for the synthesis of 1,3,5-triaryltriazinane derivatives is developed by the condensation reaction of amines and formaldehyde followed by spontaneous cyclotrimerization using CuFe2O4 NPs as an environmentally benign catalyst at room temperature. The copper ferrite was easily separated, reused in good repetitive catalytic performance by simple filtration or external magnet. This process was efficient and compatible with wide range of amines to afford a direct access to nitrogen containing compounds in excellent yields up to 99% and high selectivity.
Quantification of total sugars and reducing sugars of dragon fruit-derived sugar-samples by UV-Vis spectrophotometric method
Authors: Lam Hoa-Hung , Nguyen Thi-My-Thuong , Do Thi-An-Sa , Dinh Tuan-Hoang , Dang-Bao Trung
Published: December 2021

In the present work, the phenol-sulfuric acid method and the 3,5-dinitrosalicylic acid (DNS) method were developed with the aim to quantitatively analyze total sugars and reducing sugars, respectively. In regard with the phenol-sulfuric acid assay, 1.0 mL of sample was treated with 1.0 mL of 5% phenol, 5.0 mL of concentrated H2SO4 and measured at 485 nm, with the linearity range of 10–100 ppm for total sugars. The DNS method was performed on 2.0 mL of sample, using 1.5 mL of DNS at 80 °C for 10 minutes and measured at 510 nm, with the linearity range of 50–400 ppm for reducing sugars. The sugar contents of white dragon fruit-derived sugar-samples (extracted from species in Binh Thuan province, Vietnam) were also estimated by the above measured methods, exhibiting the total sugars of above 90% and the reducing sugars of above 5%. The methods were well-performed with the acceptable relative standard deviations of repeatability in accordance with the Association of Official Analytical Chemists (AOAC).
Alternative concept in structural analysis education-AxisVM® X6 FEM software
Authors: Kovačević Dušan
Published: December 2021

One short review on the preferable concept in Structural Analysis education by use of finite element method (FEM) software is given. It is generally accepted that good “educationally aided” FEM software includes a pre-processor with intuitive graphically user interface that enable simple and efficient geometrical modelling of structural topology, powerful solverprocessor with sophisticated numerical modelling possibilities, post-processor with various types of analysis results presentation, as well as benefit of fast, easy training and satisfaction of use.

Hungarian software company “InterCAD” developed FEM software AxsVM® that satisfies mentioned conditions and much more performances in professional and scientific area. Therefore AxisVM® is embedded in a curriculum of subject “FEM Modelling in Structural Analysis” on Department of Civil Engineering and Geodesy, Faculty of Technical Sciences, University in Novi Sad, Serbia.
Melt electrospun fibrous architectures with target geometries
Authors: Mijović Budimir , Jelić Josip , Brać Petra , Kirin Snježana
Published: December 2021

In the melt electrospinning technique, the polymer melt is stretched under high voltage and the cooled to form microfibers structures with a fibre diameter in the tens of micrometres range, although some studies have reported values ranging from hundreds of nanometres to hundreds of micrometres. In this respect, this technique has significance in the biomedical field, where tissue engineering scaffolds with bimodal (nano and micro) fibrous structures are preferred in regard to cell adhesion, spreading and infiltration to final tissue reconstruction. This paper gives a review of recently reported melt electrospinning devices, especially those based on the direct writing principle, and of their comparison with the new melt Spraybase electrospinning device. The Spraybase device provides high precision melt jet deposition into 2D and 3D programmed architectures, with versatile translation speeds of the collector plate in the X-Y and the melt head in the Z direction. The melt spun fibrous architectures are designed depending on the types of tissue cells used in scaffold development.
Mechanical properties comparison of PLA, tough PLA and PC 3D printed materials with infill structure – Influence of infill pattern on tensile mechanical properties
Authors: Pandzic Adi , Hodzic Damir
Published: December 2021

One of the advantages provided by fused deposition modelling (FDM) 3D printing technology is the manufacturing of product materials with infill structure, which provides advantages such as reduced production time, product weight and even the final price. In this paper, the tensile mechanical properties, tensile strength and elastic modulus, of PLA, Tough PLA and PC FDM 3D printed materials with the infill structure were analysed and compared. Also, the influence of infill pattern on tensile properties was analysed. Material testing were performed according to ISO 527-2 standard. All results are statistically analysed and results showed that infill pattern have influence on tensile mechanical properties for all three materials.
Modeling of Influential Parameters on Bending Strength of Solid Wood Panels Perpendicular to the Grain
Authors: Hodžić Damir , Hurem Nedim , Hodžić Atif
Published: December 2021

The paper presents the results of modeling the bending strength of wood. During the experimental examination and definition of the model, solid wood was taken, where the bending was performed perpendicular to the grain. The experiment was done with thirteen replications and the input values that varied at three levels were wood density and board thickness. The thirteen-repetition experiment also involved four repetitions in the marginal areas, so two more wood densities and two board thicknesses had to be taken. The experimental measurement was performed in the laboratory of the Technical Faculty Bihać. Based on the experimental results, a sufficiently adequate mathematical model of the breaking force of a solid wood panel perpendicular to the grain is obtained.
Influence of furniture exploitation on the bending strength of final mountable-dismountable corner joints
Authors: Krstev Marija , Antovska Ivana , Jevtoska Elena , Gruevski Gjorgi
Published: December 2021

The aim of the researches presented in the paper is to show how the exploitation of furniture affect the strength of its connectors, more precisely the bending strength of the final corner dismountable joints for designed furniture – office desk. For studying this influence, 2 office desks were made (from chosen material OSB panels), joined by dismountable connectors, and also from the same material and the same type of connectors, reference test fixtures were made and their bending strength was the value of comparison. Office desks were tested according to European Standard for determining the stability of the structure (EN 527-3:2003 E) and that was simulated exploration of furniture. After that, the final corner compositions were cut off, and its bending strength was compared with the reference test fixtures strength. The research results showed that the exploiting of dismountable furniture has not a significant impact on their compositions strength.
Influence of accelerated aging on bending strength of particleboards
Authors: Talić Hasan , Ćehić Minka
Published: December 2021

Particleboards are used in the manufacture of furniture, as well as the furnishing of structures and prefabricated homes. Their quality dictates where they can be used and how long they can last. The boards’ characteristics deteriorate as they are used. To examine the change-degradation of the properties of the boards are exposed to the effects of the external climate (rain, snow, wind, sun) or regimes of accelerated aging. For this purpose, a degradation test of the properties of wood-based panels was performed, which aims to create a model that will describe the change in bending strength of the mentioned panels. The paper presents the results of bending strength and thickness swelling tests of 16 mm thick particleboards that were exposed to accelerated aging regimes, and the basic model of property degradation.
Application of genetic algorithm in solving the travelling Salesman problem
Authors: Kulenović Fatka , Hošić Azra
Published: December 2021

The Travelling Salesman Problem is categorized as NP-complete problems called combinatorial optimization problems. For the growing number of cities it is unsolvable with the use of exact methods in a reasonable time. Genetic algorithms are evolutionary techniques used for optimization purposes according to survival of the fittest idea. These methods do not ensure optimal solutions, however they give good approximation usually in time. Studies have shown that the proposed genetic algorithm can find a shorter route in real time, compared with the existing manipulator model of path selection. The genetic algorithm depends on the selection criteria, crosses, and mutation operators described in detail in this paper. Possible settings of the genetic algorithm are listed and described, as well as the influence of mutation and crossing operators on the efficiency of the genetic algorithm. The optimization results are presented graphically in the MATLAB software package for different cases, after which a comparison of the efficiency of the genetic algorithm with respect to the given parameters is performed.
Remote control and monitoring in smart homes using voice commands
Authors: Vojić Azra , Mujčić Edin , Drakulić Una
Published: December 2021

With the development of modern technology, smartphones have become a necessity for most people. Among other uses, mobile phones are increasingly being used in smart home systems. In smart homes, mobile phones are used to remotely control and monitor various systems such as simply turning on/off lights and household appliances, various monitoring systems, etc. Nowadays, sending coded messages or pressing application buttons is increasingly being avoided in process of developing smart systems. More and more frequently is used voice commands. The system which uses voice commands for remote control and monitoring smart home is described in this paper. In the implemented system, the user is able, using specific voice commands to remotely control the operation of various appliances in his home. An Android application was designed to control the implemented system. Using the designed Android application, the user controls the desired home devices with specific voice commands. Also, on the designed Android application are buttons that the user can use, in case the user’s voice is not recognized in the implemented system. For experimental work analysis, the model of the home is made with lights and different home appliances inside. The results of the experimental work analysis of the implemented system show this system is very simple to use and very efficient. Also, the latest technology for remote control and monitor smart systems is applied in the proposed smart home system.