bluuebunny/crossref_metadata_2025 huggingface dataset:
Financial Analysis of The Purse Seine Fisheries Business in Panimbang Fishing Port
Authors: Irnawati R , Supadminingsih F N , Surilayani D , Nurdin H S , Susanto A , Hamzah A
Published: April 2021

A purse seine is one of the productive fishing gear catching pelagic fish. The feasibility of the purse seine business in Panimbang was needed to analyze after the tsunami disaster in late 2018. The research aims to analyze the financial aspect of purse seine fisheries business in Panimbang fishing port. The study was conducted from May to October 2019 using survey methods. The data were collected, including investment and operational cost, amount of catches and price, and fishing unit specification. Data analysis includes calculation of benefit, Revenue Cost Ratio (R/C), Net Present Value (NPV), Net Benefit-Cost Ratio (Net B/C), Internal Rate of Return (IRR), and Payback Period (PP). The result showed the vessel of purse seine based on Panimbang used 30 GT with the vessel’s engine 120 HP. The net of purse seine was 1,000 m in length and 50 m in depth. The benefit of purse seine business was IDR 1.2 billion; revenue was IDR 3.4 billion, R/C was 1.54, NPV IDR 3 billion, Net B/C 2.58, IRR 56.57, and PP when the business reaches in 1 year seven months three days. The entire financial of purse seine after the tsunami disaster in Panimbang is still profitable and feasible.
Economic Valuation of Mangrove Ecosystem Services in Sungai Apit District, Siak Regency, Riau Province, Indonesia
Authors: Warningsih T. , Kusai K. , Bathara L. , Zulkarnain Z. , Deviasari D.
Published: April 2021

The mangrove ecosystem is one of the ecosystems that has high productivity in coastal and marine areas, especially in supporting the productivity of fishery resources. This is due to the function of the mangrove ecosystem as ecological and socio-economic. Therefore, to determine the high level of mangrove utilization in the coastal area of Siak Regency, an economic assessment of mangrove ecosystem services is necessary. This research aimed to study quantified mangrove ecosystem services in Siak Regency, Indonesia. Methods for data collection included field survey and interview, performed between July - August 2020. The economic value assessment comprised valuation on following service groups, i.e. supporting, provisioning, regulating and cultural services. The results showed that the economic value obtained from all studied services reached IDR 29,180,852,208 per year, IDR 24,747,680,000 per year, IDR 90,291,590,933 per year and IDR 9,245,925,366 per year, respectively. In conclusion, a total amount of economic value for mangrove ecosystem services in Sungai Apit District, Siak Regency was IDR 153,466,048,507,014 per year, which was equivalent to IDR 300,090,044,0 per hectare per year.
Characteristics of Sea Waves Condition at The Northern and Eastern of Bintan Island within Period of 2015-2019
Authors: Suhana M. P. , Shafitri L. F. , Putra R. D. , Nugraha A. H. , Koenawan C. J. , Idris F. , Karlina I. , Febrianto T. , Anggraini R. , Apdillah D. , Nurjaya I. W. , Natih N. M. N. , Syakti A. D.
Published: April 2021

The objective of this research was to collect the comprehensive information about the characteristics of sea waves in the northern and eastern of Bintan Island Sea based on differentiation in oceanographic conditions between the north and east coast of Bintan Island. The north coast of Bintan Island faces the open seas directly with a potential high wave and cause several characters of coastal damage, including coastal abrasion. The characteristics of sea waves are obtained by forecasting, namely converting wind speed values using the SPM (Shore Protection Manual) method. The results of this study collected comprehensive information of sea waves on the north coast during the 2015-2019 period showed a dominant pattern with the direction of sea wave propagation from north and south, while for the eastern region the wave propagation trends prevailing from north and southeast. The maximum sea wave height in the northern of Bintan Island Sea reaches 3.32 m with a period of 8.70 s while in the eastern of Bintan Island Sea the maximum of wave height condition reaches 2.90 m with a period of 8.32 s. The maximum sea wave conditions on the north and east coasts of Bintan Island occur during the north wind season (December-February) and is directly proportional to the requirements of higher wind speeds. The minimum sea wave conditions occur during the east monsoon (March-May) where during that period the wind speeds that blow are very low condition. The results of this study indicate that wind speeds in northern Bintan Island are related to wave conditions. Our research proves that higher wind speeds form higher wave conditions.
Diversity of Epipelic Diatom in The Waters of Tanjung Pinang City Province of Riau Islands
Authors: Siregar S. H.
Published: April 2021

Degradation indicator of water quality can be seen from changes in water quality parameters. Diatoms are one organism that can be used as an environmental bioindicator. Diatoms are the primary producers in waters so they have a very important role in the food chain. Data was collected in situ in the Tanjung Unggat waters of Tanjung Pinang City. The method used in this study is a survey method, where data is obtained through observations and measurements in the field. The samples taken are then taken to the laboratory for analysis. Epiphyte diatom samples were taken from 4 stations with different activities. Based on observations of the identification of diatom epipelic that has been done, found 22 diatom genera, namely, Pleurosigma sp., Navicula sp., Diploneis sp., Achnanthes sp., Synedra sp., Nitzschia sp., Gyrosigma sp., Surirella sp., Coscinodiscus sp., Thallasiossira sp., Thallasionema sp., Pinnularia sp., Plagiotropis sp., Halamphora sp., Biddulphia sp., Melosira sp., Chaetoceros sp., Triceratium sp., Isthmia sp., Licmopora sp., and Rhizosolenia sp. The abundance of diatoms in epipelic samples, which ranged from 905277 - 599530 ind / cm2. The structure of Epipelic Diatom Community average diversity index ranges from 3.72 to 4.65 and the dominance index value ranges from 1.09 to 1.46 and the uniformity index value ranges from 0.95 to 1.21.Then based on the results of the Storet Index classification, getting a score of -52.75 on 8 parameters tested. This scoring means that around the category of Class D Tanjung Pinang Coastal waters with a score ≥ -31 are classified as Heavy Polluted waters with the determination of the status of the waters quality is limited to 8 parameters tested.
Antioxidant Activity of Astaxanthin Flour Extract of Mud Crab (Scylla Serrata) with Different Acetone Concentrations
Authors: Karnila R. , Edison  , Ramadhani N. R.
Published: April 2021

Mud crabis one of Indonesia’s economically valuable fishery commodities, the high demand for crab from world and domestic trade will have an impact on the resulting waste in the form of shell waste. Crab shells contain bioactive compounds that have the potential to be antioxidant astaxanthin. This study consisted of four stages, namely (1) astaxanthin extraction (2) yield (3) terpenoid test (4) antioxidant test (DPPH). The objectives of this study were (1) to determine the amount of astaxanthin yield, (2) to determine the terpenoid test, (3) to determine the potential for antioxidant activity in mangrove crabs. The data obtained were tabulated in the form of tables and graphs, which were analyzed descriptively. The results showed that the yield with different acetone concentrations produced the highest yield of A 65%, namely 4.46 g, A 50%, namely 3.36 g and A 80% in the amount of 1.71 g. The antioxidant activity showed that treatment with the concentration of acetone extraction was able to produce the IC value of50 lowestwith acetone concentration of 65% compared to the extraction concentration of 50%. The ICvalue50 of 805.837 ug / mL is still classified as having weak or inactive antioxidant activity.
Utilization of Fermented Salted Marine Trashfish Meal for Replacing Fishmeal in Nemurus Catfish (Hemibagrus nemurus) Diets
Authors: Hasan B. , Iriani D. , Sumarto  , Warningsih T.
Published: April 2021

This research was carried out to determine the substitution values of fermented salted marine trash fish (FSMTF) for dietary conventional fishmeal (CFM) on growth of nemurus catfish. Four isoproteic (34% crude protein) and isocaloric (3.15 kcal DE g−1) diets were formulated. One diet was a control diet (C) in which 44% CFM was included and no FSMTF. Other three diets were test diets in which CFM was substituted with FSMTF, 50% (FSMTF-50), 75% (FSMTF-75) and 100% (FSMTF-100). A commercial diet (COM) which composed of 31 % crude protein and 2.90 kcal DE g−1 was also tested as a comparison. Nemurus catfish, 47±3.94 g in weight were distributed into triplicate net cages (2x2x1.5 m), 40 fishes per m3 water, and fed experimental diets two times daily for two months. Total substitution of fishmeal with FSMTF (FSMTF-100) in the fish diet did not affect fish growth (weight gain, specific growth rate, survival rate), feed efficiency ratio, protein efficiency ratio and protein utilization as compared to control diet. Total substitution of CFM with FSMTF gave better feed efficiency ratio, protein efficiency ratio and protein utilization than commercial diet. FSMTF therefore can completely replace CFM in the diet of nemurus catfish.
Astaxanthin Extraction of Vanname Shrimp (Litopenaeus vanname) Using Palm Oil
Authors: Karnila R. , Hasan B. , Ilza M. , Leksono T. , Ahmad M. A.
Published: April 2021

Vanname shrimp is an important economic commodity that has carapace waste which is rich in the pigment astaxanthin. This study aims to determine (1) the chemical composition (proximate) of vanname shrimp carapace flour (2) the astaxanthin content of vanname shrimp carapace flour with different extraction times (3) Randemen of astaxanthin extract of vanname shrimp carapace flour. This research consisted of two stages, namely (1) Preparation and analysis of the chemical composition of vanname shrimp carapace flour (2) Extraction and analysis of the astaxanthin content of vanname shrimp carapace with different extraction times. Experimental research method with completely randomized design (CRD). The different extraction time treatments consisted of three tare, namely 120, 180, and 240 minutes. The data obtained were analyzed using Analysis of Variance (ANOVA). The results showed that carapace flour had a chemical composition of moisture content of 10.28%, ash content of 33.73% db, protein content of 38.82%db, fat content of 1.56%db, crude fiber of 25.9%db. Meanwhile, the highest astaxanthin content from this study was 5.0909 mg / g (240 minutes). the resulting levels were 2.6351 mg / g (120 minutes), 3.2569 mg / g (180 minutes) and 5.0909 mg / g (240 minutes), respectively. The yield of astaxanthin extract produced were 50.95% (120 minutes), 65.36% (180 minutes), and 78.92% (240 minutes), respectively. The highest yield of astaxanthin extract in the study was in the 240 minute treatment of 78.92%.
Fortification of Nano Calcium of Freshwater Mussel (Pilsbryoconcha sp.) Shell on Cookies Towards Proximate Composition and Calcium Content
Authors: Iriani D , Hutauruk S W
Published: April 2021

This research was aimed to determine the effect of nano calcium of freshwater mussel (Pilsbryoconcha sp.) shell on cookies towards proximate composition and calcium content. Cookies were prepared by fortified with nano calcium of freshwater mussel shell consist of 4 levels of treatment: 0%, 0.5%, 1%, and 1.5%. Cookies were evaluated for proximate analysis (moisture, ash, protein, fat, and carbohydrate content), calcium, phosphorus content, and consumer acceptance. Findings it was observed that fortification of nano calcium of freshwater mussel shells significantly increased the calcium (Ca) and phosphorus content (P) of cookies when compared to the control treatment, with the highest value of calcium (6.91%) and phosphorus (1.36%) of 1.5% fortification treatment. Meanwhile, based on consumer acceptance that 1% fortification of nano calcium of freshwater mussel shell on cookies was most preferred with calcium content 5.97%, phosphorus content 1.24%, and proximate content of moisture, ash, protein, fat, and carbohydrate content was 3.26%, 2.26%, 10.12%, 29.32%, and 55.33%, respectively.
Characteristics and community perception on mitigation of Human-Tapanuli Orangutans conflict around Dolok Sipirok Natural Reserve, South Tapanuli
Authors: Kuswanda W , Harahap R H , Alikodra H S , Sibarani R
Published: April 2021

The frequency of human-tapanuli orangutan (Pongo tapanuliensis) conflict has been increased with the widespread on degradation and fragmentation at Batangtoru Forest, South Tapanuli Regency. Orangutans often come on community lands to look for food, especially while the durian fruit season. This study aims to obtain information on socio-economic characteristics and public perception index to mitigate on human-tapanuli orangutan conflict around the Dolok Sipirok Nature Reserve, South Tapanuli Regency. Data was collected using a questionnaire distribution, interviews and descriptive observations, starting from October 2019 to January 2020. Respondents were selected by purposively sampling method, i.e. people had met and interacted with orangutans as many as 61 respondents from three villages. Data analyzed using frequency tables, likers scale and spearman rank correlation. The results showed that the community is Muslim majority, productive age, education below senior high school, farmers and income below IDR. 4,000,000. The public perception has declared orangutans as animals that consume community plants. They will drive away the orangutans found in processed land. The perception of conflict mitigation has strongly agreed with the program that must be done including providing compensation for losses, increasing patrol programs, developing local wisdom and building corridors in state forests. The characteristics were a significant (α <0.01) influence on the perception index assessment i.e. the level of education, household member and family income.
Ecological risk of coastal ecosystem: A perspective of mangrove ecological sensitivity in small islands, case in Anambas Archipelago District at Natuna Sea
Authors: Yonvitner  , Rakasiwi G , Wahyudin Y , Kamsari
Published: April 2021

The ecosystem sensitivity in the coastal and small islands is dependent on the vulnerability and resilience level of that ecosystem. Mangroves are one of the primary ecosystems in coastal areas, also high vulnerability and sensitivity due to natural factors such as waves, pollution, and due to the impact of human activities. Based on this reason, the study of vulnerability and sensitivity was needed for mitigation plans and other actions in reducing the risk due to the pressure by a coastal manager. This study was carried out around small islands in Anambas District, especially in Matak Island. The results showed that the level of mangrove vulnerability was relatively high at all locations; the condition of the ecological status was classified as moderate. The status of the social and economic index was classified as medium to high vulnerably. The assessment of the sensitivity level, known as the condition of mangrove ecosystems, is moderate to very sensitive. The areas with the highest sensitivity level are Peninting and Ayerbadong. The high sensitivity in both locations is due to the influence of the economic index, which indicates that the region is economically sensitive and potentially vulnerable.
Potential phosphate solubilizing bacteria from the rhizosphere of Cotylelobium melanoxylon tree
Authors: Elfiati D , Susilowati A , Modes C
Published: April 2021

Microorganism have important roles in soil cycles and plant living activities. Phosphate solubilizing bacteria is one of the microorganisms in the soil that plays a role in helping provide phosphorus nutrients that are not available to plants. The purpose of this study was to obtain potential phosphate solubilizing bacteria from the rhizosphere Cotylelobium melanoxylon plants. Soil samples were taken in a composite at a depth of 0-20 cm from the rhizosphere area of C. melanoxylon plants in the village of Bona Lumban, Tukka District, Tapanuli Tengah Regency, North Sumatra. Isolation of phosphate solubilizing bacteria using the dilution plate technique with Pikovskaya medium. Phosphate solubilizing bacterial isolates were selected qualitatively by measuring the ratio of the clear zone. Selected isolates are identified up to species molecularly. The isolation results obtained were 16 isolates of phosphate solubilizing bacteria with a clear zone ratio varying between 1.03 to 1.68. Four isolates were selected with the highest clear zone ratio. Based on molecular identification, the four isolates included Pseudomonas aeruginosa species.
Application of Aspergillus fumigatus from Rhizophora mucronata leaves that have decomposition in various salinity levels in Belawan
Authors: Yunasfi  , Rakesya N , Desrita
Published: April 2021

Rhizophora mucronata leaf litter is a source of organic material for several organisms found in mangrove forest ecosystems. Leaf litter that falls on the forest floor will undergo a process of decomposition by biological agents within a certain time period. One effort to accelerate decomposition process is the use of fungi Aspergillus fumigatus. The purpose of this study was to measure the rate of decomposition and to measure the levels of carbohydrates and proteins contained in R. mucronata litter with different levels of salinity in the mangrove area of Hamparan Perak District. Carbohydrate and protein analysis is carried out at the Medan Industrial Research and Standardization Center. The average decomposition rate (k) of R. mucronata leaf litter at the 0-10 ppt salinity level is 10.89, the 10-20 ppt salinity is 7.74 and the 20-30 ppt salinity is 7.81. The Leaf Litter of R. mucronata experienced a decrease in carbohydrate levels. The highest carbohydrate content was found in Observation I station 3 which was 12.2% while the protein content in R. mucronata litter had increased. The highest protein content was found in observation VI of station 3 which was 6.78%. The decomposition rate in Belawan waters shows that productivity is good.
Community structure of shorebirds (Charadriiformes: Scolopacidae) in Percut Sei Tuan District, North Sumatra
Authors: Jumilawaty Erni
Published: April 2021

A study on the community structure of sandpipers (Charadriiformes: Scolopacidae) has been conducted from February to March 2014. Scolopacidae is a large family of shorebirds inhabiting the mudflat of Percut Sei Tuan district. The site was also documented as a transitory habitat during migration in each year during September and April. The aim of this study was to obtain the community structure and population of Scolopacidae species in the area. The method used to calculate the shorebirds was the concentration count and block method to estimate the number of population. The study documented 16 species and 2573 individuals, all dispersed within three sub-sites namely Bagan Percut, Pematang Lalang, and Tanjung Rejo. The total Shannon’s diversity index (H’) was obtained lower (1.672) in this study than the previous report in 2012 (1.865). The species,Numenius madagascariensiswas the dominant population with a number of 1,156 individuals.
Increasing added-value of styrax resin through post-harvesting techniques improvement and essential oil based product innovation
Authors: Kholibrina C R , Aswandi A
Published: April 2021

Styrax resin is a major non-timber forest product from North Sumatra, Indonesia. However, thousands tons of raw resin are sent abroad, while various styrax oil-based products worth US millions dollars are imported annually. Limited harvesting and processing technology are some of root of causes the lack of styrax oil-based industry development in Indonesia. The objective of this paper was an overview of styrax forest management in North Sumatra, efforts to increase the added-value both quality and quantity of resin, and an alternative processing of raw material into a perfume innovation. Benzoin resin is produced by the injured inner epithelial bark of styrax tree. Therefore, tapping of bark is the best effort to harvest the resin. But, styrax forest management has been carried out traditionally, including harvesting techniques. One of scheme to increase added-value is resins processing into a perfume products with high economic value. The innovative products begin from extracting a solid styrax resin into pure essential oil. There are two methods used, namely (a) extraction with solvent, and (b) distillation method. The amount of yield of benzoin oil produced by solvent method is influenced by incense grade from 23.9 to 34.6% and higher than another method. But distillation method also produces high quality and quantity of hydrosol (side product) with a distinctive aroma. Combined with various essential oils from Indonesia’s tropical forests, the styrax oil becomes a fixing agent for a signature perfume that formulated by considering the gradation of aroma in accordance with release of constituent essential oil particles. Processing resin into an essential oil increases the added-value of styrax resin. Innovation of styrax resin based products will explore the fragrance formulation of this commodities therefore reduce our country dependence on imported perfume and raw materials used for various personal cares.
The effect of sikkam (Bischofia javanica) leaf extract on blood sugar levels and islet of langerhans in alloxan-induced diabetic rats
Authors: Rumahorbo C G P , Hutahaean S , Ilyas S
Published: April 2021

Diabetes Mellitus is a metabolic disease characterized by hyperglycemia, occurring due to abnormal insulin secretion or insulin action. Alloxan induces diabetes by damaging pancreatic cells and initiating hyperglycemia. One of the plants that has the potential to decrease blood sugar is leaves of sikkam (Bischofia javanica), because it contains quercetin and gallic acid compounds which are classified as an antioxidant group. The objectives of this study were (1) to analyze the effect of sikkam leaf extract on the reduction in blood sugar levels of Wistar rats and improved the histology of langerhans islet and (2) determine the dose of sikkam leaf extract which has the most effective effect in reducing rat blood sugar levels. The design used is a non factorial complete random design. The samples used were 30 Wistar rats which were divided into 6 treatment groups and 5 repetitions, namely K0 (negative control), K1 (positive control), K2 (dose of ethanol extract of sikkam leaf (EESL) 300 mg/Kg BW), K3 (EESL 600 mg/kg BW), and K4 (EESL treatment 900 mg/kg kg) and K5 (Glibenclamid 4.5 mg). Data analysis used One-way ANOVA followed by LSD test. The results showed that there was an EESL effect on the reduction in rat blood sugar levels and improved the histology of Langerhans islet. EESL which has the best antidiabetic effect is on administering a dose of 900 mg/kg BW.
The genetic variant of GSTP1 and immune response of immunoglobulin A (IgA) on nasopharyngeal carcinoma patients
Authors: Farhat F , Sari M I , Chrestella J , Syari R P
Published: April 2021

GSTP1 polymorphism is one of the genetic factors contributed to (NPC). The polymorphism alters its function in detoxifying carcinogen and inhibits oxidative stress. Oxidative stress induces EBV lytic reactivation and enhances IgA response. This study was aimed to analyze the association of GSTP1 polymorphism and serum IgA levels in NPC patients. The study was analytic research with a cross-sectional design. The samples were the blood of NPC patients who underwent PCR-RFLP-electrophoresis and ELISA method to identify GSTP1 polymorphism and IgA level. We found 21 (72.4%) patients with Ile/Val genotype, 6 (20.7%) patients with Ile/Ile, and 2 (6.9%) patients with Val/Val. Patients with elevated IgA levels were 21 (72.4%) patients. In this study, there was no significant association of GSTP1 polymorphism and serum IgA level. We found the GSTP1 polymorphism and serum IgA elevation in nasopharyngeal carcinoma patients, but there was no significant association between them. Future research with the inclusion of environmental risk data is needed as well as larger samples. The study may help to determine effective prevention, treatment, and monitoring therapy of nasopharyngeal carcinoma.
The bioinformatics of projected acetyl-CoA carboxylase genes in Hevea brasiliensis
Authors: Pratomo B , Lisnawita  , Nisa T C , Basyuni M
Published: April 2021

This study clarified the variation and role of physical and chemical characteristics of the H. brasiliensis projected acetyl-CoA carboxylase genes. The detectable similarity and joining projected acetyl-CoA carboxylase genes of H. brasiliensis in the dendrogram may be the outcome of tropical environmental. Six projected acetyl-CoA carboxylase genes from H. Brasiliensis collected from NCBI. The NCBI locus number of the protein sequence utilized in this study was determined. The physical and chemical properties of acetyl-CoA carboxylase from H.brasiliensis. The factors were calculated the designate number of protein, number of amino acids, molecular weight, theoretical isoelectric point values, the total number of atoms, extinction coefficients, estimated half-life, instability index, aliphatic index and grand average of hydropathicity.
Numerical Simulation of Blast Loads of Building with and without Glass Window
Authors: Zhou Xiaoqing , Xie Licheng , Yan Junjie
Published: April 2021

A typical building model with and without glass windows has been constructed in the present paper using LS-DYNA to calculate the blast loading acting on it. For the without glass window case, the window is assumed to be an opening and there is no glass. Scaled distances of 0.5 m/kg1/3, 1.0 m/kg1/3 and 2.0 m/kg1/3 are considered. The peak value of the overpressure at some typical positions inside the building are obtained and compared. The peak pressure distribution of each wall surface and the ceiling are obtained, and the influence of glass on the explosion load under different scaled distances is attained. It is found that the smaller the scaled distance, the less obvious the blocking effect of glass, and the glass can be ignored in the simulation. As the scale distance increases, the barrier effect of glass becomes more obvious. At this time, simply ignoring the glass may cause error.
An Investigation on the Mechanical Properties of Cement Mortar under Axial Loading Conditions at High Temperature
Authors: Gao Zhifei , Wang Linbing , Yang Hailu
Published: April 2021

Concrete preloaded during heating always shows higher compressive strength than that unloaded, and the reason was confused. As one of the main components of concrete, cement mortar has an important impact on the performance of concrete at high temperatures. However, few studies have conducted on the stressed mechanical properties strength of mortar at high temperature. In this paper, a series of mechanical tests were conducted to investigate the mechanical properties of cement mortar specimens under axial loading conditions. Seven temperatures (20 °C, 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, 600 °C) and three pre stress ratios (0.2, 0.4, 0.6) were set during the in-door laboratory tests. Test results showed that temperature and pre-stress have significant influences on the compressive strength and the failed mode of cement mortar specimens at high temperature. The compressive strength of mortar under stressed condition was even higher than that at room temperature which might be a reason for the improvement of stressed compressive strength.
Study on Preparation and Performance of Fly Ash Used in Clay Fluidized Backfill Materials
Authors: Kong Xianghui , Yu Xiaohua , Zhao Yanna
Published: April 2021

The problem of insufficient compaction of traditional fillers is difficult to solve in the backfilling project. It is a new solution to prepare backfill materials with self-leveling and self-compacting properties by using excavated clay, cement and water as raw materials. Adding fly ash to the backfill materials to replace part of the cement can effectively improve the utilization of industrial waste. Through a series of laboratory tests, the fluidity, bleeding and compressive strength of the mixture were studied respectively, and the influence of fly ash content on the performance of the mixture was preliminarily grasped. The test results show that the increase of fly ash content can reduce the fluidity of the mixture. Compared with the strength of the mixture without fly ash, when the amount of fly ash replacing cement is less than 10%, the strength of the mixture increases, and when the amount of fly ash replacing cement is more than 15%, the strength of the mixture decreases.
Application Analysis and Problem Prevention of Cast-in-Situ Beamless Hollow Floor Construction Technique in Large Deep Foundation Pit
Authors: Ou Yazhou , Chen Gang , Xing Cheng , Jin Shulou
Published: April 2021

Cast-in-place concrete beamless hollow floor is more and more widely used in engineering, especially in basement engineering, due to its characteristics like increase of the structure height, enhancement of heat preservation, heat insulation, noise reduction, rapid construction speed and others. Based on engineering practice, the application of cast-in-situ beamless hollow floor cover in large deep foundation pit is studied. In order to improve the construction quality, the deformation and stress state of long-span hollow plate are analyzed by finite element simulation. By optimizing and improving the process and comparing the results, the process method which is helpful to improve the quality of finished products of beam-less floor under this condition is extracted.
Risk Analysis of Project Construction under the New Crown Epidemic Situation
Authors: Luo Xing
Published: April 2021

The aim of this paper is to avoid construction project losses based on the normalized situation of prevention and control new crown epidemic. This paper takes an example of Shu Xiang Garden project in Anhui. An early warning system of epidemic risk based on was constructed and applied to risk analysis. Index system and expert survey were conducted to identify the risk factors and divide them into major risk and general risk. In addition, this paper carried out a special assessment of interpretative structural modelling to directly reflect the influence factors of the cost risk. The results show the overall risk belonging to level III is extremely high risk and risk management is the most critical factor to reduce the cost risk. The paper concludes with recommendations from four aspects of epidemic control, balanced progress, information technology and risk transfer to reduce risk and provides a theoretical basis for epidemic risk management.
Study on the Mechanical Properties and Durability of Carbon Fiber Reinforced Lime-Based Mortar
Authors: Xu Wen , Jalal Mostafa , Zakira Umme , Wang Linbing
Published: April 2021

In this study, the changes in mechanical properties and durability of Portland cement lime-based mortar due to the addition of chopped carbon fibers (CFs) have been studied. Compressive strength (CS), split tensile strength (STS) and flexural strength were determined in relation to the volume of CFs, water to binder ratio and SP dosage. Additionally, the durability, i.e. immersion water absorption (IWA) and capillary water absorption (CWA), has also been investigated. The results show that the CS, STS, IWA and CWA of the mortar with 1 vol.% CFs are increased by 11.24%, 3.69%, 5.41% and 46.50% respectively, comparing with that of the mortar with 0.5 vol.% CFs. The lime mortar with 1 vol.% fiber shows 6.59% higher energy absorption than that with 0.5 vol.% fiber in aspect of flexural strength.
Numerical Analysis and Application of Uncoupled Coefficient of Water Sealed Blasting on Blasting Effect
Authors: Liu Jiangchao , Gao Wenxue , Zhang Shenghui , Xu He
Published: April 2021

To study the influence of axial and radial uncoupling coefficient on blasting effect when air and water are used as spacer in surrounding holes of tunnel water seal blasting, and the optimal charge coefficient is determined for construction. Combined with numerical simulation and field test, the research results show that: (1) When the air and water are used as the interval medium in the peripheral hole for multi-hole blasting, the optimal value range of axial uncoupling coefficient is 2.2∼2.5. The optimal value range of radial uncoupling coefficient is 1.5∼1.6. (2) The concept of composite uncoupling coefficient is proposed, and the optimal decoupling charge coefficient is determined. Finally, the axial decoupling coefficient is 2.2 and the radial decoupling coefficient is 1.6, which can meet the blasting requirements. (3) The simulation results are verified by field test. It is proved that the axial decoupling coefficient is 2.2 and the radial decoupling coefficient is 1.6, which is better than the research results of axial decoupling coefficient of 2.07 and radial decoupling coefficient of 1.5 used in conventional blasting. The results show that the air and water media used in engineering construction can improve the blasting effect and reduce the explosive unit consumption.
Characteristics for Microstructure Changes of Unsaturated Coal-bearing Soil under Dry-Wet Circulation
Authors: Fan Yakun , Zheng Mingxin , Wu Junhua
Published: April 2021

The macroscopic mechanical properties of soil are essentially determined by its microstructure, which is a comprehensive manifestation of the external microstructure of soil. This paper conducts microscopic tests on coal-bearing soil with different moisture content under dry-wet circulation conditions, and uses Image-Pro Plus software to preprocess and image the SEM images of coal-bearing soil samples to characterize the size and orientation of coal-bearing soil particles and pores. The microstructure parameters of average diameter and orientation frequency of shape and orientation are quantitatively analyzed, revealing the change rule of the microstructure parameters of unsaturated coal-bearing soil under dry-wet circulation.
Research on Static and Dynamic Load Test of Suspension Bridge with Univalent Hyperboloid Space Cable System
Authors: Xu Jinfa , Xu Wenping , Zhu Guangchuan
Published: April 2021

In this paper, a new model of univalent hyperboloid space cable system suspension bridge is proposed, and a comparative test model of 15 m space suspension bridge and parallel suspension bridge is made. Vertical load test, horizontal load test, partial load test and moving load test were carried out. The results show that compared with the parallel and space cable suspension bridge, the vertical stiffness of the suspension bridge increases slightly, the lateral stiffness is greatly improved and the torsional rigidity is tremendously improved. The space suspension bridge has good wind resisting stability.
Dynamic Finite Element Analysis of the Interaction of Rubber-Soil Foundation and Structure
Authors: Wang Fengchi , Zhao Hengliang , Lu Shan
Published: April 2021

A more reasonable method of semi-infinite foundation analysis was realized in this paper through the introduction of viscous-spring artificial boundary to simulate the radiation damping and elastic recovery performance of the foundation. The viscous-spring artificial boundary is realized by Combine14 element in ANSYS finite element software to realize the real dynamic characteristics of complex rubber-soil foundation under dynamic loading. Firstly, the reliability of the method is verified by comparing the method with the example of numerical solution. Finally, the optimal tunnel shape is obtained by combining the rubber-soil foundation with different shapes of tunnels.
Comparison Thermal Insulation Effects of Different Thermal Insulation Materials for a Roadway Tunnel at Southeast Edge of the Qinghai-Tibet Plateau
Authors: Zhang Kun , Zhu Xiaoming , Yu Hong , Tian Zhizhuo , Mu Yanhu , Bi Guiquan
Published: April 2021

In seasonal frost regions, tunnels are affected by frost damage after excavation. At entrance and exit section of tunnels, thermal insulation layer (TIL) is widely used to mitigate this problem. In this study, a moisture-temperature coupled mathematical model was established. Based on field observed air temperature at entrance section of Altun mountain tunnel, the thermal regime of surrounding rocks was investigated. Moreover, a comprehensive evaluation method was established to evaluate the thermal insulation effects of seven thermal insulation materials. The results showed that, with increase in thickness of TIL, maximum frozen depths of surrounding rocks decreased almost linearly. At the vault (H1), arch hance (H2), foot (H3), and inverted arch (H4) of the tunnel, the thermal insulation effect was different. When the thickness of TIL reached to 5 cm, there would be no seasonal freezing process at the four points. Seven types of TIL were considered for the thermal insulation of the tunnel. The optimal thickness of them was 4.2, 11.0, 5.5, 6.3, 10.2, 12.8 and 8.5 cm. To ensure the surrounding rocks do not experience freezing process, rigid polyurethane foam would be the best choice. Considering the cost, dry process aluminum silicate fiber would be a better one.
Study on Optimization of Excavation Scheme of the Entrance Section of Hongjiaban Tunnel
Authors: Feng Haoran , Zhang Bang , Zhang Hong
Published: April 2021

The choice of excavation method is particularly important for small clear distance tunnel with short distance between two holes.The finite element software is used to simulate the excavation of Hongjiaban tunnel,which obtained a series of laws, such as the stress change of surrounding rock, the stress of supporting structure and the displacement of surrounding rock during the excavation of the tunnel with a small distance, which is helpful to better guide the construction.There are different excavation methods for tunnel excavation under different surrounding rocks. The rock mass of the entrance section of Hongjiaban tunnel is the Class V surrounding rock, and a variety of excavation methods can be used, such as full section method, reserved core soil method and CRD method. Through the numerical analysis of the above three methods, the advantages and disadvantages of each method are discussed, and the most suitable excavation method for Hongjiaban tunnel is optimized.
Research on High-Speed Train Load Spectrum and Bridge Load Effect Spectrum
Authors: Zhou Hongyu , Zhou Yun , Liu Yanan , Tang Qi
Published: April 2021

Based on ANSYS finite element analysis software, a dynamic model of the Beijing-Tianjin intercity railway car-track-bridge system is established to analyze the dynamic response of the bridge under the normal high-speed double-track traffic conditions. Combined with the statistics of actual train operation, the bridge load spectrum represented by wheel/rail force is obtained. With the aid of the rain-flow counting method, the stress data of the weak part of the bridge span is equivalently converted into variable amplitude stress amplitude and the corresponding cycle times are obtained. In this way, the stress spectrum of the Beijing-Tianjin intercity railway bridge in the use reference period is estimated, which provides a certain reference basis for the life assessment of the in-service bridge and the reinforcement of weak parts in the future.
Research on Seismic Performance of Switches with Different Types of Supporting Structure
Authors: Liu Wei , Li Hao , Dong Xinsheng , Li Sheng , Fu Guangzhi , Xue Yaodong
Published: April 2021

As an important type of porcelain-type electrical equipment, switches have been seriously damaged in many earthquake disasters. Studies have shown that different types of supporting structure of switches have significant impact on their seismic performance. This paper takes the medium-voltage and the high-voltage switches in a substation in the high-intensity area as the structural prototype, proposes six different types of supporting structure of switches, and explores the influence of the supporting structure on their seismic performance under different seismic intensities. In addition, the single column supporting high-voltage switch was found to have large displacement under 0.4 g earthquake input, and optimization design is needed for this kind of supporting structure. Seven different optimization schemes were proposed in this paper. It was found that single column supporting high-voltage switch with four bracing and single column supporting high-voltage switch with six bracing have excellent seismic performance in high intensity areas, which can be adopted in the optimization design of single column supporting high-voltage switch.
Seismic Performance of Steel Reinforced Concrete Column-Steel Beam Joints after Exposure to Fire
Authors: Li Junhua , Li Quanping , Zhang Xingqiang , Che Jinru , Ma Chao
Published: April 2021

Low cyclic reversed loading tests of six steel reinforced concrete column–steel beam joints were conducted to study the failure mode, hysteretic character, and shear mechanism of joints that had been exposed to fire. Two test parameters, i.e. the duration of fire exposure and axial compressive ratio were taken into consideration. Test results showed that the failure mode of the joints after exposure to fire was basically the same as that of joints maintained at room temperature. Due to the shear resistance of the steel reinforcement, the maximum loading strength of the joints after fire exposure declined indistinctively, however displacement corresponding to the maximum loading strength increased notably. The rigidity, ductility and energy dissipation of the joints after exposure to fire decreased compared to the joints maintained at room temperature, and the extent of reduction was related to heating time and axial compressive ratio.
Rational Layout and Planning for Children’s Activity Places in Hongkou, Jingan and Xuhui Communities of Shanghai
Authors: Wang Mingming
Published: April 2021

“Shanghai Urban Developing Plan (2017-2035)” puts forward to construct a children friendly city. However, there are few studies focusing on the suitability of children’s activities in Shanghai, and the current situation of children’s activity places in Shanghai is still unclear. In this research, three districts with the largest population density in Shanghai: Hongkou, Jingan and Xuhui, were selected to investigate the current status of children’s activity places, and the problems existing in the districts which hamper the development of children’s activity places is identified. Then, using advanced theoretical and practical experience for reference, the optimization scheme of children friendly districts in Shanghai was put forward.
Preface
Authors: Solovev D B
Published: April 2021

International science and technology conference “Earth science” (ISTCEarthScience) it is a subsection of a big conference the International Scientific Conference “FarEastCon”.

The conference represents an informational platform for accumulation of expert opinion on projects and initiatives that are aimed at implementation of farsighted scientific research and development; it allows to present scientific and practical achievements to a wide circle of researchers.

Sections of the conference are of interest for the broad range of experts in the sphere of development of innovative solutions and organizing events that increase the efficiency of economic and innovative activities.

List of Organizing committee are availble in this pdf.
Research into Clarification Filtration through Synthetic Filtering Partitions
Authors: Salamatov V I , Fetisova S A , Salamatov O V
Published: April 2021

The research presents the results of the study of clarification filtration process of low-concentration sludge suspensions through mixed media filtration systems containing fabric filtering partitions made of synthetic and cotton fibres. It is the kinetics of the clarification process of rougher filtration solutions under study in the research, as well as the stages of the formation of the filtering layer of synthetic filtering partitions are determined; the filtration regime of clarification filtering is analysed; the rate of the increase in the total resistance of the filtering partition in the process of dehydration is evaluated. The data available from the experiments allow providing a mathematical expression for the filtration rate. The influence of structural components of filter fabric on the initial stage of filtration process is taken into account.
Hydrogeochemistry and Hydrogeological Model of CO2-rich Springs on Buryatia Territory (Russia)
Authors: Kharitonova N A , Aseeva A V , Lukanov D D
Published: April 2021

The work presents the results of isotopic-geochemical and hydrodynamic studies of CO2-rich springs of the Tunka Valley, Buryatia. The waters are remarkably diverse in terms of cationic composition, although the dominant anion is hydrocarbonate. In general, the springs studied are characterized by high concentrations of microcomponents. To form these springs, the presence of active deep-seated faults is necessary. Such fractured zones serve as channels bringing gas to the upper horizons of groundwater. The 2D numerical model presented convincingly proves that the Arshan field’s waters are meteoric waters of long-term water circulation (up to 220,000 years).
Simulation Model of Emergency Evacuation in Case of Fire in a Nightclub
Authors: Matveev A V , Maximov A V , Zadurova A A
Published: April 2021

The article is devoted to studying the problem of ensuring people safety and security in case of fires in nightclubs. It is proposed to use the agent-based modeling for estimating evacuation time period, which allows to take into account in the model the following factors: club visitors alcohol intoxication, as well as panic and crush accompanying evacuation process. Based on a Saint Petersburg club example, evacuation model was developed using the AnyLogic simulation modelling system. Two probable evacuation scenarios were considered to estimate time period required for the nightclub visitors evacuation. Results obtained showed that in the said nightclub high risk to human life and health was present.
Use Effect of Unconventional Feed and Mineral Additives on Animal and Poultry Productivity
Authors: Lushnikov N A , Alekseeva E I , Tovkalo M V , Pozdnyakova N A
Published: April 2021

The possibilities of increasing productivity of animals and poultry by using an additive containing selenium, rapeseed cake and complex mineral additive have been studied. An addition of the preparation “Kartsesel” in mixed fodder promoted the increase in digestibility of nutrients, the increase in erythrocytes, hemoglobin in blood, output of conditioned youngsters, profitability of production. Conditioned young growth was obtained more by 19-22 %. Inclusion in mixed fodder at cultivation of goose rapeseed presscake of Siberian selection positively affected the increase of live weight, yield of gutted carcass. Goose of the first experimental group surpassed the control group by live weight by 3.4%, and the second experimental group by 6.1%. Output of gutted carcass of goose receiving rapeseed meal and rapeseed meal in combination with rapeseed oil is 286.13 g and 388.48 g more. Complex mineral additive in the diet of bulls contributed to the increase of live weight of bulls in 15 months of age, slaughter output, profitability of production and improvement of meat quality. The live weight of the control group of bulls not receiving the feed additive made 459.50 kg, and the experimental group made 11.00 kg more. At the same time the level of profitability of production on steers of the experimental group receiving a mineral additive amounted to 13.77% instead of 10.24% in the control group.