bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of fish gelatin with DNA biomarkers
Authors: Nurilmala M , Indarwati A R , Nugraha R
Published: June 2022

The utilization of gelatin for food and non-food processing is increasing, but there are many mislabeling errors of the origin of commercial gelatin raw materials. This mislabeling can harm communities related to religion or safety. Therefore, research on detection of fish gelatin with Polymerase Chain Reaction is very important as a source of halal gelatin. This study aimed to isolate DNA of fish gelatin and determine the proper primers to identify fish gelatin using the DNA-based method. DNA was amplified using universal fish F1 / R1 primers, Mini-barcode, cyt b Pangasianodon sp., fish collagen, cyt b bovine, and 12S rRNA-tRNA Val Sus sucrofa. The catfish meat and fish gelatin samples could be amplified at an annealing temperature 59°C with universal fish primers F1R1, while the mini barcode and cyt b Pangasianodon sp. primers were carried out at 54 °C. Ish collagen gene primer could not amplify DP (catfish meat) and GI (fish gelatin) samples. The sequence of the DP and GI DNA samples amplified with cyt b Pangasianodon sp. primers was identical to Pangasianodon sp.
Efficacy of anti-koi herpesvirus DNA vaccine in carp Cyprinus carpio fry by immersion method and hyperosmotic infiltration
Authors: Nuryati Sri , Soraya Siti , Alimuddin
Published: June 2022

Indonesian carp production has decreased due to mass mortality caused by herpesvirus koi infection. Safe prevention techniques can be applied en masse and are relatively inexpensive are needed. This study aimed to examine the effect of immunization using anti-koi herpesvirus (KHV) DNA vaccine at a dose of 1.3 × 108 cfu.mL-1 through immersion with different lengths of time after hyperosmotic infiltration for 2 minutes. There were six groups with three replications: vaccination with 60 minutes immersion (A), 90 minutes (B), 120 minutes (C), non-vaccinated fish but infected with KHV (positive control), non-vaccinated fish and not infected with KHV (negative control), control fishes soaked with whole bacteria (control bacteria without DNA vaccine). The results showed that vaccination for 60 minutes gave the highest relative survival (93.55%). Thus, vaccination by immersion and hyperosmotic infiltration effectively improves the survival and relative survival of fish, and this method can be an alternative in the early control of KHV infection in common carp and koi.
Effect of Drying Condition on Phenolic Content, Antioxidant Activity, and Sensory of Sargassum sp. Tea
Authors: Afifah Rufnia Ayu , Millenia Ade Caroline Ester , Poernomo Achmad
Published: June 2022

Sargassumsp. has been known as a natural source of antioxidants. In Indonesia,Sargassumsp. grows very well yet it has not been utilized optimally.Sargassumsp. could be utilized as herbal tea through the drying process. However, the process can affect its antioxidants; therefore, this study aimed to determine the effects of drying conditions on phenolic contents and antioxidant activity ofSargassumtea. FreshSargassumsp. was harvested from Lima Island, Serang, Banten, Indonesia. Upon arrival at the laboratory,Sargassumsp. was washed with tap water then soaked in 5% lime solution (1:8) for 6 hours. The Sargassum was then dried at three different conditions (sun drying, air oven at 40 °C and 55 °C). The driedSargassumsp. (2 g) was packed in the tea bag then brewed in 150 ml boiled water for 3 minutes for analysis; i.e., total phenolic contents, antioxidant activity, and sensory properties (color, taste, and flavor). The results showed that theSargassumtea dried at 55°C had the highest total phenolic content (1.57±0.04 mg GAE/g) and antioxidant activity (56.01±0.52 μmol FeSO4/g) compared to others (P<0.05). It also was the most liked infused tea based on overall sensory scores (P<0.05).
Bioconversion and bioeconomics of thorn stringray skin waste (Dasyatis sp.) as a commercial leather products
Authors: Sahubawa Latif , Pertiwiningrum Ambar
Published: June 2022

Stingray skin can be utilized and processed into commercial products with high economic value. The aim of the research is to maximize the use and increase the economic value of thorn stingray skin waste through the processing of commercial products (wallet and bracelets) that consumers prefer. The research method used product design & processing, added value, and consumer preferences. The number of stingray skins used for processing 1 (one) men’s/women’s wallet-bag is two skin sheets (IDR. 100,000). The commercial leather products produced are women’s wallets-bag (hanging model, type 3-in-1, maroon, moss green, light brown, pink) and men’s wallet-bag (handle model, type 3-in-1, black and light brown), with four pieces of pearl bracelet and two beaded bracelet. Based on the analysis results, it is known that the selling value of women’s wallet-bags is IDR 950,000 per piece & men’s wallet-bags is IDR. 1,500,000; pearl bracelet is IDR. 200,000 & beaded bracelet is IDR 150,000. The economic value obtained from processing 1 item of stingray leather wallet-bag (for women) is IDR 1,500,000 & added value is IDR 1,400% while for men is IDR 2,050,000 & added value 1,950%. The level of consumer preference of the main products is women’s wallet-bag are 85% very likes & 15% likes and men’s wallets are 90% very likes & 10% like. Derivative products are pearl bracelets (100% very like) and bead bracelets (87% very like & 13% like). The total economy value, added value & consumer preferences of the stingray leather product of men’s wallet are higher than women’s wallets.
Alternative Source of Nutrients for Microalgae Cultivation in a Photobioreactor System
Authors: Rifai Agus , Jamilah Siti , Admirasari Rahmania , Prayitno Joko
Published: June 2022

Photobioreactors are used to produce microalgae biomass for many purposes in industries and agriculture. This research was aimed at investigating alternative source of nutrients with lower cost to produce a sustainable microalgae biomass production in a photobioreactor system other than using F2 nutrient medium, the most commonly microalga nutrient compositions used in laboratories. Firstly, two nutrient sources were used to cultivate Chlorella sp. in the laboratory, i.e., a commercial fertilizer (GrowMore™) and a common fertilizer (NPK) having nitrogen equals to 12.3 mg/L. Chlorella sp. biomass grown in the medium containing the commercial fertilizer or NPK was not significantly different to that of F2 medium, as well as when the dose of the commercial fertilizer was doubled. The commercial fertilizer was then selected as a source of nutrients in the cultivation of microalgae in 135 litre photobioreactors. Chlorella sp. biomass grown in the photobioreactors for 14 days using F2 medium was 0.80 mg/L, while using the commercial fertilizer was 0.75 g/L. Cost analyses of microalga production using these commercial fertilizers showed that it was 80% less than the cost of using F2 nutrient composition. These results showed that the commercial fertilizer could be used as alternative nutrient source for microalgae cultivation in photobioreactors.
Decision Model for Determining the Feasibility of Rice-Based Bioenergy Supply Chain Development Area with Fuzzy Logic-AHP Approach
Authors: Krisnaningsih Erni , Arkeman Yandra , Hambali Erliza , Marimin
Published: June 2022

Decision on location determination for rice-based Bioenergy Agro-industrial area is one part of the efforts to develop the bioenergy supply chain. The development location is selected based on the criteria set by the government. This study aims to plan the model of determining the location of agro-industrial supply chain development area of Rice-based bioenergy as well as evaluate the important criteria that need to be considered in the selection of the location of a bioenergy agro-industry so that alternative locations can be obtained from several potential locations that are targeted for rice-based bioenergy agro-industry development areas in Banten province of Indonesia. By using the fuzzy logic-AHP method approach, it is expected to obtain a decision model based on multi-criteria with a hierarchical process. The result of this study is the most optimal district used as the location of development of rice-based bioenergy agro industry area in Banten Province is Lebak Regency with the highest weight value 0,4328. Based on the results of research proposals for further research this method can be applied to the development of other bioenergy agro-industry, taking into account the criteria of spatial aspects based on geographical factors as well as appropriate alignment in an industrial area.
Evaluation Land Use Cover Changes Over 29 Years in Papua Province of Indonesia Using Remote Sensing Data
Authors: Letsoin Sri Murniani Angelina , Herak David , Purwestri Ratna Chrismiari
Published: June 2022

Land use/cover change (LUCC) observation and determination have been extensively discussed in natural resources management, biodiversity and ecosystem preservation, land management also climate changes studies. An evaluation of the LUCC in Merauke, the easternmost city of Indonesia, was conducted to gain relevant information in agriculture and forestry based on historical data from remotely sensed land cover data. To obtain the historical dynamics of the LUCC, a supervised classification algorithm was implemented to the Landsat images of 1990, 1996, 2009, 2015, and 2019 as well as statistical analysis Wilcoxon signed-rank. This study aims to investigate and analyze the LUCC over a period of 29 years. The results show a significant decline in the forest area by around 7% in 2019. As compared to the LUCC in 1990, agriculture sectors such as dry-land agriculture, shrub-mixed dry land and paddy field gained an area higher than 50%, while the area of the water body is a declined by 0.61 % over the period. The evaluation of LUCC will help government development plans in the protection of commodities in this Province and the promotion for biomass and bioenergy resources.
Determination of Diffusion Coefficient of Palm Oil in n-Hexane Using Laser Deflection Method and Image Processing
Authors: Aman Mohamad , Handoko Djati , Sudarmaji Arief , Handoyo  , Soedarmawan Levin
Published: June 2022

Determination of diffusion coefficient using the Wiener method has shown a high level of agreement with literature in previous studies, particularly for liquids with a mass of less than hundreds of amu and a small molecule-sized order of Angstrom (atomic mass unit). This method involves a laser beam deflection and refraction phenomenon on the inter-diffusion zone of two fluids with different refractive indexes. Palm oil, vegetable oil with a composition and structure that is quite complicated and size relatively large molecule, has abundantly available and has become one of the primary raw materials for biodiesel production and cooking. This study used the method to examine the diffusivity of palm oil in n-hexane, which is still rare and hard to find, so challenging to be studied. A camera is used to catch the trace of a deflected laser beam on a screen after it passes through a diffusion cell in the measurement. This image was then corrected, made grey, and digitized to extract the laser image coordinate data. An averaging window algorithm is used in digitizing. The digitized results are then processed to calculate the diffusion coefficient. Measurements were made three times to test the consistency of the results. Camera and digitizing techniques are used here to speed up and facilitate measurement. The measured value of diffusion coefficient of palm oil in n-hexane is 2.18×10-4 ± 5.05×10-5 cm2/minute. The results showed consistency in measure, i.e., precision with a maximum error range of 10.6%, but not good suitability value with literature data, i.e., accuracy was less than 10%. These results found that the measurement system that applied the laser deflection method and the image processing of averaging window could not measure the diffusion coefficient of large molecules and complexes such as palm oil quite well.
Effect of low percentage methanol blends in gasoline RON 90 on fuel volatility characteristics and spark ignition engine performance
Authors: Pratama Ravi Farkhan , Wibowo Cahyo Setyo , Fathurrahman Nur Allif , Hartulistyoso Edy
Published: June 2022

Methanol is one of the promising alternative fuel for gasoline that can be made from renewable sources. Methanol has high octane number, which can increase octane number of gasoline. Methanol is also an oxygenate and contain less carbon content than gasoline, so combustion emission can be reduced. Blending methanol with gasoline influences the volatility characteristics of the fuel blend where it could influence engine performance. Fuel used in this study were gasoline RON 90 blended with methanol in percentage of up to 20%. In this study, distillation and Reid vapor pressure were measured, and then engine performance tests were performed using those fuel blends. The obtained result showed that the vapor pressure was increasing with addition of methanol up to 15% with maximum vapor pressure of 74.75 kPa and started to decrease at 20% methanol blends. The distillation curve showed that increasing methanol addition to the fuel blend flattened the distillation curve below the methanol boiling point. Engine performance test results revealed that addition of methanol in fuel blend resulted in decrease of torque, changes in specific fuel consumption, and reduced CO and HC emission.
Comparative Study on the Effect of Catalyst to The Yield of Biodiesel from Kemiri Sunan (Reutealis trisperma) Oil
Authors: Hartulistiyoso E , Farobie O , Rholanjiba S
Published: June 2022

Biodiesel is an alternative fuel substitute for fossil fuel, which is produced from the trans-esterification and esterification process of vegetable oil and animal fats. One of the potential materials to be processed to biodiesel is kemiri sunan (Reutealis trisperma), due to its high oil content and inedible amount of toxic. Study based on literature review has been done to identify and analyze the effect of catalysts to the yield of biodiesel from kemiri sunan (Reutealis trisperma) oil. The acquired data on the catalyst used on the experimental trials was categorized as KOH with concentrations of 0.2%, 0.4%, 0.5%, 0.6%, 1.0%, 1.5% and 2.0% and NaOH with concentrations of 0.5%, 0.75%, 1.0%, 1.25%, 1.5% and 2.0%. Based on the data analysis, it was found that the biodiesel that meets the Indonesia National Standard (SNI) requirements was the biodiesel treated with 0.2% KOH and processed in two stages of trans-esterification. Further experimental studies on the multi stages trans-esterification and catalyst treatments are still needed to explore the potential of kemiri sunan for biodiesel production.
Astaxanthin production in Xanthophyllomyces dendrorhous grown in medium containing watery extracts from vegetable residue streams
Authors: Brands B , Kleinke M
Published: June 2022

Xanthophyllomyces dendrorhous DSM 5626 is a basidiomycetous yeast [1]. It produces the carotene Astaxanthin, which is used in fish farming and gives the flesh a characteristic salmon colour [2–5]. Astaxanthin has antioxidative properties and is said to have anti-inflammatory properties [6] and potential in human health [7]. Currently, in the industry astaxanthin is isolated from the algae Haematococcus pluvialis. Recent studies have shown that the yield of astaxanthin in X. dendrorhous can be increased by optimizations in the medium composition [8–10]. In the BIVAC project, several vegetable residue streams were analysed for their composition. Many of them contained sugars and proteins, which could have a positive influence on the production of astaxanthin in X. dendrorhous, so we analysed the astaxanthin levels in X. dendrorhous after cultivation in media with different watery extracts of these residue streams; these results are presented here. The process could contribute to the utilization of surplus biomass and provide a possible path to sustainable biomass use in a rapidly changing world.
The effect of woven oil palm empty fruit bunches (OPEFB) filler fiber on the mechanical properties of natural and synthetic rubber
Authors: Nikmatin Siti , Irmansyah  , Indro Muhammad Nur , Cifriadi Adi , Farhan Muhammad , Nurwinda Yulisa Aviani
Published: June 2022

Oil palm empty fruit bunches (OPEFB) are biomass from palm oil (CPO) processing which can be produced into long lignocellulose and made of yarn as raw material for woven textiles for sandwich biocomposite applications. The purpose of this study was to obtain a biocomposite sandwich variation of natural rubber, butyl, and silicone reinforced with OPEFB woven fibers at optimum filler concentration by studying mechanical properties. The biocomposite of rubber sandwiches with OPEFB fiber reinforced with concentrations of 14, 20, and 28 sheets with a size of 10 x 10 x 1 cm. The methodology used was layered printing with constant pressure and heat using a hot press. The best fiber concentration based on mechanical properties was a composite with a fiber concentration of 28 sheets on 70 shore A hardness natural rubber. This was because the fibers in the composite functioned as load bearers, where this containment was carried out by the distribution of stress. The more fiber concentration, the more effective and uniform distribution of stresses will be, so that an increase in the mechanical properties of the composite occurs. The mechanical properties of rubber have been shown to increase with the addition of fiber as a reinforcing material, the ratio of the impact strength of rubber (control) and fiber-reinforced rubber was lower than that of fiber-reinforced rubber. The natural rubber had an impact strength of 48 kJ/m2, while natural rubber with fiber reinforcement had a higher impact strength value of 321.40 kJ/m2.
A suitable design of metal hydride cartridge for a fuel cell assisted bicycle in consideration of heat transfer performance
Authors: Hara Daisuke , Miao Shan , Shimogawa Junnosuke , Katayama Noboru , Dowaki Kiyoshi
Published: June 2022

Metal hydrides (MHs) can store hydrogen produced from biomass at low pressure and high volumetric energy density. However, the endothermic reaction that occurs during hydrogen discharge decreases the hydrogen flow rate, which prevents the generation of sufficient power for fuel cell (FC) devices. Because a previous study reported that the hydrogen capacity of MHs would drop by approximately 20% due to the hydrogen sulfide contained in hydrogen from biomass, the utilizable amount of hydrogen in MHs should be enhanced. In this study, MH utilization for an FC-assisted bicycle in consideration of waste heat recovery from MH to FC was investigated. The results show that the MH-based hydrogen storage system can weigh 8 kg or lower for the FC bicycle to travel twice the distance of a lithium-ion-battery-derived bicycle. Using the mathematical model of hydrogen discharge from the MH, the heat transfer of a small MH cartridge for the FC bicycle was investigated. The center of the cartridge cooled by approximately 20 K from the initial temperature, indicating the necessity of heat injection into the MH cartridge even if the initial and boundary temperatures were high. It was also concluded that 83% of the hydrogen charged in the MH could be utilized to maintain the hydrogen flow rate to run a 220 W FC.
Decreased in Paddy Yield (Oryza sativa L.) as a Response to Plant Bioaccumulation of Chromium
Authors: Taufikurahman Taufik , Purnamawati Rizka , Rahmawati Andira
Published: June 2022

In leather tannery industry such as a case in Sukaregang, Garut, untreated or poorly treated wastewater which contain chromium has been severely polluting nearby river. The polluted river water (PRW) has been used by local farmers to irrigate their paddy fields. In this study we planted Sarinah variety (Svar) and Rojolele variety (Rvar) of paddy in soil and watered with PRW, K2Cr2O7 solutions with concentration of 50 and 100 mg/L and clean water as a control, for a period of four months. Chromium solutions were added gradually to the soil until reached final concentrations of 50 and 100 mg/L. The result showed that the treatment with PRW and Cr solutions reduced plants weight, shoot length and paddy production. Treatment with Cr solutions significantly decreased plants fresh and dry weight by 26.53% and 36.69% for Svar, 32.14% and 19.74% for Rvar. Paddy yield also decreased as higher Cr concentration was accumulated in plant tissues. The amount of filled grains decreased by 33.05%, while empty grains increased by 50.21% in Svar. In Rvar the amount of filled grains decreased by 21.44% and empty grains increased by 31.95%. Chromium treatment by gradual increase allowed plant to survive at an exposure of 100 ppm Cr, although the plant reduced its growth, biomass and yield.
Review of Biodiesel Policy in Indonesia
Authors: Widrian Adil Fajar , Arifianto Budiawan Sidik , Nurbaiti  , Sasongko Nugroho Adi
Published: June 2022

Indonesia is known as an energy-rich country, both fossil and renewable. In 2019, the national energy supply still relied on oil, coal and natural gas, with a total proportion in the primary energy mix of 91.5%. Import dependency on petroleum and the high burden of the state budget for fuel subsidies are why the Indonesian Government implements biofuel policies in Indonesia. Biofuel development in Indonesia has been implemented from 2006 with Presidential Regulation No. 5 of 2006 to Regulation of the Minister of Energy and Mineral Resources No. 41 of 2018. Since 2008, the Government has issued a mandatory policy for using biodiesel with a mixture content of 2.5%. The Government gradually encouraged increasing biodiesel content to 7.5% in 2010, 10% in 2011, 15% in 2015, and 20% in 2016. By 2020, biodiesel mandatory is targeted to be 30%. Over the years, the biodiesel industry has shown an increase in quantity and capacity. Using biofuels has many positive impacts, such as reducing diesel import and CO2 emission and increasing CPO and labour’s added value. On the other hand, the mandatory biofuel policy negatively impacts the environment due to the possibility of land expansion. This study aims to review biodiesel policies in Indonesia since 2006 and analyze the problems and outputs in each policy and challenge for future biodiesel development.
Combined evaluation of quality and eco-burdens of the hydrocarbon refrigerant GF-08 in tomato greenhouse air conditioning
Authors: Oki Akihiro , Kanemura Takuma , Dowaki Kiyoshi
Published: June 2022

This study focuses on a combined evaluation of GF-08, a non-CFC hydrocarbon refrigerant, to maintain the quality and reduce the environmental impact of tomatoes during air conditioning (cultivation stage) and during cold storage (storage stage). Past studies have shown that power consumption can be reduced by replacing the conventional refrigerant R410A with GF-08 for air-conditioning in a tomato farm. In addition, the CO2 intensity of GF-08 was extremely low compared to that of R410A. Regarding the air conditioner for the cultivation technology, the relationship between the energy-saving performance and the nutritional and freshness preservation of agricultural products has not been discussed. This study examined the effects of temperature and CO2 gas controls on nutritional value and freshness preservation of a tomato facility based in Kesennuma City, Miyagi Prefecture, Japan. The energy consumption and the characteristics were analyzed for the use of GF-08 and compared to the conventional refrigerant R410A. The effect of storage temperatures on the tomato quality was estimated and the energy consumption and eco-burdens were analyzed based on the LCA methodology. This combined data was further used to determine the relationship between the eco-burdens and quality of the tomato produce.
Analysis of university infrastructure and recognition of reward and punishment system on College Students’ garbage classification behavior – a case study of Wuhan University of Technology
Authors: Xia Zixuan , Xu Luhua , Zheng Bowei , Wang Zitong , Li Yuhong , Liu Yu , Shen Lei
Published: June 2022

Only a few college students can realize the garbage classification under the background that the garbage classification policy has already been issued. In order to explore the factors that influence garbage classification behavior, this paper puts forward five hypotheses based on Behavioral Science Theory, and explores the influence of internal and external factors on garbage classification behavior of Wuhan University of Technology Students. It provides a reference for improving college students’ consciousness of energy conservation and environmental protection and implementing college garbage classification.
In vitro antifungal activity of essential oils against Botrytis cinerea of postharvest grapes
Authors: Xie Yongdong , Zhu Jiawen , Liu Hanyang , Lian Huashan , Liu Ji
Published: June 2022

Botrytis cinerea is a widespread pathogen that infects a wide variety of plants. Postharvest grape infects with B. cinerea results in fruit rot and drop. In this study, the inhibitory effect of 30 kinds of plant essential oils on B. cinerea was investigated through in vitro experiments, and the types and concentrations of essential oils with the best inhibitory effect on B. cinerea of postharvest grapes were screened. The results showed that 10 essential oils completely inhibited the growth of B. cinerea when the concentration of essential oils was 1000 μL/L. After reducing the concentration of these 10 essential oils to 500 μL/L, 5 essential oils showed continuous fungistasis effect on B. cinerea. The concentration of these five essential oils dropped to 250 μL/L, and only garlic essential oil showed long-lasting antifungal benefit. But which showed no long-lasting antifungal benefit at 125 μL/L. Therefore, garlic essential oil higher than 125 μL/L has sustained antifungal effect on B. cinerea, which can be used for postharvest preservation and storage of grapes.
Study on enhanced nitrogen removal of caprolactam production wastewater
Authors: Ling Wenhua , Zhou Yangyuan , Zhao Jianfu , Yao Guodong
Published: June 2022

Caprolactam (CPL) is widely used in polymer material and engineering plastics synthesis. The CPL production wastewater is difficult to treat due to high chemical oxygen demand (COD) and ammonia nitrogen (NH3-N), complex components and poor biodegradebility. The common treatment method for this wastewater is biochemical treatment combined with physicochemical pretreatment. Though the NH3-N of effluent can decrease to 1 mg/L, total nitrogen (TN) usually is above 100 mg/L. Herein, the enhanced nitrogen removal way was studied. The results showed TN was mainly composed of nitrate nitrogen which the concentration was approximately 90 mg/L via traditional A/O process. A simulated A/O/A process with methanol addition was investigated and TN of the effluent was below 20 mg/L, indicating this process with carbon source is efficient for advanced nitrogen removal.
A new water treatment technology—Hybrid ozonation-coagulation process: A review
Authors: Wei Lelan
Published: June 2022

Hybrid ozonation-coagulation (HOC) process is an integrated water treatment process of simultaneous ozone and coagulation processes. This paper introduces the origin, performance, reaction mechanism and influence of coagulant in HOC system. Compared with traditional air flotation and pre-ozone-coagulation, HOC system shows more advantages in removal of organic pollutants. It is attributed to abundant pathways for reactive oxygen species (ROS) generation in HOC process, which not only transfers pollutants to flocs but also synchronously degrades some organic pollutants.
Bibliometric analysis of related literatures on sludge disposal technologies
Authors: Liang Yuting , Lin Ye , Yue Bo , Meng Bang-bang , Yuan Xusheng
Published: June 2022

In order to understand the research hotspots and development status of sludge disposal field at home and abroad, the Web of ScienceTM core collection was used as the data source to retrieve the articles on sludge disposal published in the 15 years from 2006 to 20 20. Using visual metrological analysis software CiteSpace and bibliometrics to draw the knowledge map of sludge disposal field, and analyze the research country, institution, discipline layout and keyword emergence, etc. The results show that in the past 15 years, the international sludge disposal field has shown an overall growth trend. The research hotspots in sludge disposal field can be divided into two stag es. The research focus of sludge disposal can be divided into two stages: land utilization and energy utilization from 2006 to 2010; Adsorption studies were added from 2010 to 2020. The impact of land use and sludge on the environment, the characteristics analysis of personal care products and heavy metals in sludge, and the environmental impact assessment of sludge disposal may become the main research trends in the future.
Research on the shaft orbit of hydropower units based on convolutional neural network and the fine-grained indicators
Authors: Pan H , Luo Z L , Xu J J , Feng F
Published: June 2022

Shaft orbit is one of the most representative characteristics of vibration signals which reflect the healthy and breakdown status of hydropower units. However, the traditional pattern recognition methods consisting of feature extraction and classifier could not been able to identify the kinds of faults and the degree of severity effectively. In this paper, a novel intelligent method based on convolutional neural network (CNN) and the fine-grained indicators is proposed for auto-diagnosis of faults with different severity levels in hydropower units. Firstly, four fine-grained indicators have been put forward to describe the severity of four kinds of common shafting faults. Secondly, a CNN fault diagnosis model is designed to extract high discriminative features and identify fault categories. Twelve kinds of shaft orbit samples were input into the model with the same size of 64×64.Through reaction of two convolution layers and two pooling layers in feature extraction module, the graphic features were extracted. The faults of hydropower units were identified after the fully connected layer and the SoftMax classifier. The experimental results show that the accuracy of the proposed approach for the fault with different severity is 98.33%, which is better than the traditional learning method. The proposed method retains the pattern information in the axis trajectory to the maximum extent and has the ability to accurately capture features of various severity faults.
Assessment of Hydro cyclone Separator for Sediment Laden Hydropower Plants
Authors: Kayastha A , Shakya N , Thapa B S , Thapa B , LEE Y H
Published: June 2022

Sediment management is particularly essential for run-of-river hydroelectric facilities and initiatives such as upstream sediment traps or watershed management can lower sediment yield downstream. It can prevent early failure of turbine runners and associated equipment at facilities which otherwise would cause significant problems in operation and sustainability of hydropower plants. The yearly operational and maintenance costs are typically represented as a percentage of the annual capital outlay per kW, with prominent figures ranging from 1 to 4 percent. Amongst many methods, hydro cyclone separators like a pre-filtering system can be implemented to reduce the inflow of sediment partially or completely. This paper focuses on the analytical design of hydrocyclone for hydro power plants. The theoretical calculations on the size, efficiency and number of hydrocyclones required for hydropower plants, on the basis of their operational parameters, have been presented in this paper. The basic parameter for the design of hydrocyclone is its cut size which influences all of its geometrical and operational variables. The analysis for hydrocyclones, ranging from 30 to 100 inches in diameter, has been conducted at pressure drops from 4 psi to 8 psi. The cut sizes and its underflow efficiency for afore mentioned sizes of hydrocyclones has also been calculated. A case design for Jhimrukh hydropower plant has been presented, on size and number of hydrocyclones required for the plant, to put purpose of this study into perspective.
Effects of Inlet S-duct on Inducer Performance and Cavitation Instability
Authors: Yoon Youngkuk , Song Seung Jin
Published: June 2022

To investigate the effect of inlet flow distortion on two-bladed inducer performance and cavitation instability, the s-shaped duct was installed at the inlet of the inducer to induce secondary flow. Inducer cavitation performance with and without s-duct were compared while varying the cavitation number. Also, the effect of s-duct on the occurrence of alternate blade cavitation was investigated using unsteady casing pressure measurement and high-speed camera visualization. It was shown that the s-duct decreases the strength of alternate blade cavitation and lowers the head breakdown cavitation number without considerable head loss by reducing the tip leakage vortex cavitation.
Investigation of sediment erosion in low head Francis turbines and its effect on the structural integrity
Authors: Bhattarai Aasma , Kunwar Prashant , Chitrakar Sailesh , Gautam Saroj
Published: June 2022

The geographical condition of Nepal has always challenged the hydropower plants in Nepal. The huge potential run-off rivers flowing through this terrain carry an immense amount of sediment. This sediment constitutes quartz particles with enough hardness, which corrodes the material of the hydraulic turbines and other components of the hydropower plant. The sediment erosion hindered the growth of hydropower plants as it significantly increased the maintenance cost and decreased the efficiency and life span of the plant itself. This paper takes this problem into account to investigate the structural integrity of one of the reference cases of eroded low head Francis turbine of Nepal by performing one-way FSI. CFD analysis was conducted on the single passage of the runner and structural analysis of the runner was conducted as well. For the structural integrity, the thickness of the blade at the trailing edge was decreased to 80 percent of its span. From the results of the structural integrity, the stresses imposed on the reference runner due to the erosion were observed to be within the allowable stress even in the extreme case condition.
Mass transfer rate effects on the cavitating vortex shedding flow around a circular cylinder at a low Reynolds number
Authors: Chen J , Escaler X
Published: June 2022

Cavitating vortex shedding is a flow phenomenon commonly encountered behind bluff bodies in hydraulic machinery and systems. The generated vapor bubbles significantly change the dynamic behaviors of the vortices. In addition, the collapses of the cavities become major sources of unwanted effects such as vibration, noise and material erosion. In this study, the numerical results of the cavitating vortex shedding behind a circular cylinder at a low Reynolds number have been compared and analyzed using different mass transfer rate values between the vapor and the liquid water phases. For that, the transport equation for the vapor volume fraction coupled with the source term based on the simplification of the Rayleigh-Plesset equation has been solved. Commonly, this source term that accounts for the mass transfer rate is a function of the pressure difference, the vapor volume fraction, and the empirical factors. To understand the effects of this rate, its has been gradually increased from its default value up to the infinite when the equilibrium assumption is satisfied. The current results show that as the rate increases, higher gradients of the vapor volume fraction and of the pressure near the interface between the vapor and the liquid phases are predicted. As a consequence, the frequency of the vortex shedding is also affected by the variation of the mass transfer rate.
Evolution and influence of high-head pump-turbine cavitation during runaway transients
Authors: Wu W D , Liu K , Li L , Hou X X , Zhang P C , Du C , Liu X Y , Cheng Y G
Published: June 2022

Pumped-storage hydropower stations (PSHSs) play irreplaceable roles in promoting the stability and flexibility of power grids. Runaway process is one of the most dangerous transients for PSHSs, and the cavitation in the pump-turbine seriously affects the stability and safety of the unit. However, the evolution and influence of pump-turbine cavitation during runaway transients are still unclear. In this study, the runaway transients of a high-head pump-turbine considering the cavitation effects were simulated by using the three-dimensional (3D) computational fluid dynamics (CFD) method. The results show that the cavitation cavities in the runner appear and disappear periodically, influenced by the backflows around the leading and trailing edges of the runner blades. The wedge-shaped cavities near the leading edges occur around the peak rotational speed moment when the pressure pulsations in the vaneless space show the peak magnitude. And the tongue-shaped shaped cavities near trailing edges appear around zero discharge moment when the hydraulic radial forces reach the peak. The two types of cavitation occur at dangerous moments, to which attention should be paid in the preliminary design stage of PSHSs.
Erosion wear in a double-suction centrifugal pump using an improved erosion model
Authors: Qian Zhongdong , Su Jiahui , Guo Zhiwei , Dong Jing
Published: June 2022

Prediction of erosion wear in double-suction centrifugal pumps is studied numerically using an improved erosion model (EM). Experiments are also performed to verify the improved EM’s prediction ability. In the experiments, painted layers of five colors are applied to the blade surfaces using spray guns to show the erosion wear distribution, where the colors and the order are selected based on the simulated results. In simulations based on the Oka model, the small-angle scratching effect is specifically added to the improved erosion model (called the Qian EM here). For the chosen double-suction centrifugal pump, the Oka EM and the Qian EM are used to predict erosion wear, including the wear area and intensity. Both EMs effectively predict the erosion areas of the leading edge, the suction side inlet part and the pressure side outlet part of the blade, but the Qian EM shows better ability to predict the erosion area of the outlet part on the suction side. Additionally, the erosion intensity seems more reasonable with the Qian EM. Inclusion of all different particle sizes in the numerical simulations is found to be necessary to predict erosion wear accurately because each single particle size may provide important information.
Experimental study of Crossflow turbine under different operating conditions
Authors: Shrestha O , Kapali A , Thapa B , Neopane H P , Lee Y H
Published: June 2022

In the present study, experiments were conducted to investigate the performance of Cross-flow turbines (CFT). A CFT runner with 16 degrees of angle of attack and a ratio of 0.67 inner to the outer diameter is selected for the experiment. The efficiency of the turbine was studied using a 3D printed runner with 30 blades at a constant head of 10m and varying rpm from 350 to 750 with an increment of 100 rpm and guide vane opening ranging from 10% to 100% with an increment of 10%. The results of the study indicate that CFT can be used effectively as it contains a flat curve that works well over wide flow conditions. CFT efficiency increases with increasing rpm to a certain point, after which it begins to decrease with increasing rpm.
Pressure pulsation analysis of runner and draft tube of pump turbine under different working conditions
Authors: Wang Dong , Li Zhenggui , Zhao Qing , Li Deyou , Deng Wanquan , Ji Lei , Shengyang Peng
Published: June 2022

As the core component of pumped storage power station, the pump turbine usually needs to adjust the operating condition point according to the electricity demand during operation. Pressure pulsation is an inevitable phenomenon in the operation of pump turbine, which affects the safe and stable operation of the unit. In this paper, the method of combining numerical simulation and experiment is adopted to carry out three-dimensional full flow channel numerical simulation of the pump turbine by using CFD. The flow pattern and pressure pulsation of the runner and draft tube of the pump turbine were analyzed at the three working conditions of PL (50% maximum load), BEP (70% maximum load) and HL (90% maximum load). It is found that under the three conditions, the pressure pulsation from the leafless area to the downstream of the draft tube shows a weakening trend. Because the flow pattern in the bladed area of the unit is poor, the pressure pulsation in the bladed area is the most obvious. From low load to high load, the pressure pulsation tends to weaken at first and then increase. Combined with flow pattern analysis and vortex analysis, it can be concluded that the number and scale of vortex flow are positively correlated with the pressure pulsation, and the vortex flow inside the unit is an important factor that causes the flow disorder inside the unit, and then becomes an important factor that affects the pressure pulsation inside the pump turbine unit.
Static Characteristics Analysis of Shaft Rotor of Vertical Long-Shaft Fire Pump Under the Connection of Different Shaft Lengths
Authors: Zhang J F , Yu X H , Jin S B , Yang Z J , Song H Q , Fu L H , Zhang W J
Published: June 2022

In this paper, a vertical long-shaft fire pump XBC18-178-240LC3 was taken as the research object to study the static characteristics of the pump rotor-shaft system under different shaft length connection. To analyse the influence of the length and number of the intermediate shaft section of the pump shaft on the deformation and equivalent stress of the shafting rotor, three shafting rotor models Z4(modified model), Z5(original model) and Z6(modified model) were designed, and then the static characteristics of them were analysed and compared under four operating conditions of 0.65Q
d(0.65 times design flow),1.0Q
d, 1.2Q
d and 1.4Q
d by numerical simulation. The results suggested that the changed rules of the three models' deformation and equivalent stress were basically the same. After the rated operating condition, the maximum deformation of the impeller of Z5 model was smaller than that of the Z4 and Z6 models. Under the four operating conditions, the maximum equivalent stress of the impeller of Z5 model was the smallest. This showed that the length and number of the intermediate shaft section affected the deformation and equivalent stress of the shaft rotor. Therefore, Z5 model was selected as the best rotor structure design scheme.
Determination of Generator Efficiency on Performance Test of Prototype Turbine
Authors: Cao Dengfeng , Zhang Peng , Zhou Ye , Zhang Xaocheng
Published: June 2022

As an essential parameter to be determined on performance test of prototype turbine, the output power of turbine is generally determined by measured active power and efficiency of generator. Determination method of generator efficiency on turbine performance test is discussed in this paper. A determination method is presented as generator efficiency could be determined by actual generator losses. Analysis results show that it is a better solution rather than reading from the generator efficiency curve. Furthermore, due to the location of active power measurement, excitation loss must be excluded from the generator losses in determining generator efficiency. And the copper losses of rotor and stator must be converted to the actual measured temperature on turbine performance test. Then correct generator efficiency and output power of turbine are determined.
Analysis of deformation characteristics of flood gates of runoff hydropower stations under different operating conditions in case of frequent floods
Authors: Shao S , Li Z G , Kong X Y , Kang J
Published: June 2022

The safety and reliability of flood gates of runoff hydropower stations in the basin are very important. There is no clear rule on the mechanical causes of flood gate deformation in runoff hydropower stations under frequent floods. Therefore, this paper takes a hydropower station as the research object, adopts the unidirectional fluid-solid coupling method, and investigates the stress displacement of flood gate under typical frequent flood conditions by using ANSYS and Fluent software. The results show that the maximum stress of the flood gate is located at the intersection of the bottom two sides of the gate panel and the gate pier, and the stress meets the stiffness requirement. When the gate is opened, the stress distribution range of the panel is shifted from the top to the bottom, and the stress decreases with the increase of the gate opening degrees. The maximum total displacement is concentrated at the bottom of the central axis in the direction of the panel span, and gradually decreases from the middle of the gate panel to the left and right sides, showing a fan-shaped distribution, and basically symmetrical along the central axis of the panel. The flood gate is mainly deformed along the downstream direction, with obvious depression characteristics.
Performance Analysis of Micro Francis Turbine Manufactured Locally in Nepal
Authors: Dahal D R , Kayastha A , Chitrakar S , Thapa B S , Neopane H P , Thapa B
Published: June 2022

The manufacturing of micro-hydro turbines, especially Cross-Flow, Pelton, Propeller turbine, has been carried for more than 50 years in Nepal. A prominent opportunity in the manufacturing of Francis turbines has been perceived in recent years as the requirements of turbines for future installations falls on the Francis turbine range and are above 60%. However, none of the manufacturers step forward to accept the challenges of manufacturing Francis turbines which may be due to the lack of know-how in design and the manufacturing technology of Francis Turbine as a whole. Nevertheless, many attempts have been put forward with the initiation of the Turbine Testing Laboratory, Kathmandu University, for the development of both the design and manufacturing methodology. In this paper, the performance analysis of two different Francis runners, manufactured using local technology of investment casting and pressing-welding method, was conducted. For making the manufacturing, installation and, operations of the turbine as simple as possible, the trapezoidal spiral casing with fixed guide vanes was implemented. In addition the leading and trailing edge modification had not been carried out so as to observe the efficiency rise after these modifications. A comparison of the efficiency for both the turbines indicates Francis turbines with fairly good efficiencies can be manufactured using locally available tools and technology.
Tunnel support practice in small hydropower tunnels in the Himalayas through observational approach
Authors: Karki Sujan , Chhushyabaga Bimal , Khadka Shyam Sundar
Published: June 2022

With the high mountains, steep terrain and fast flowing river, the Himalayan region has a great opportunity and potential for hydropower development. In Nepal, many hydropower projects have been constructed and many are under construction among which majority of the project are small to medium scale project. For such project, medium size tunnel provides an economic and safe route for water convergence. Squeezing and collapse have been observed in most of the hydropower tunnels, which have resulted in support failure, as the tunnel passes through weak rock mass under high in-situ stress during construction. Due to insufficient tunnel closure measurements, field-based observation has been conducted to study the installed support at different tunnels in the Himalayas. The observational approach is used for analysis and recommendations have been made for designing a stable and safe support system for tunnels. Through an analysis of a case study from Nepal, comparison has been made on the design and practiced support systems, and description of supports used in various case histories from Nepal have been provided.