bluuebunny/crossref_metadata_2025 huggingface dataset:
Gasdynamic Structure of Dispersed Flows in Two-Stage Air Purifiers
Authors: Enikeev I H
Published: December 2019

The work deals with numerical modelling of four-phase flows in a nozzle of two-stage air purifier. The aerodynamic structure of a gas-dispersed flow is studied in a wide range of determining parameters. The flow regimes are considered in the first stage nozzle with a high dust concentration.
Analysis of interphase heat and mass transfer in suspension plasma spraying using air
Authors: Gulyaev Igor
Published: December 2019

A theoretical model of interphase interaction “suspension particle - plasma flow” is proposed. The model assumes several successive stages of the evolution of liquid material: 0) entry into the plasma stream and break-up of the liquid into droplets; 1) heating the droplet to the evaporation temperature of the carrier fluid; 2) evaporation of the liquid, accompanied by convective mixing of the material; 3) evaporation of the liquid with the formation of a dry crust; 4) heating the solid material to melting; and 5) evaporation. Based on the analysis of the intensity of the processes of interfacial heat transfer, evaporation, diffusion and filtration mass transfer, relations are obtained for evaluating at each stage of the process duration, particle size, speed and distance passed in the flow. Demonstration calculations were performed for an aqueous ZrO2 suspension with a solid phase concentration of 20% injected into the air plasma stream at a flow velocity of 2000 m / s and a flow temperature of 5000 K.
Influence of copper on the phase composition and strength of laser-welded connections
Authors: Malikov A G , Orishich A M , Karpov E V , Bulina N V
Published: December 2019

This paper deals with the investigation of the influence of copper on the structure-phase composition and strength of laser-welded connections of aluminum alloys of the system Al-Cu-Mg, Al-Cu-Mg-Li, Al-Cu-Li. The microstructure, mechanical characteristics and chemical composition of the welded joints have been investigated. It is founded that the laser welding results in the reduction of copper concentration in the solid solution and growth of this concentration on the dendritic boundary.
Effect of inhibitor addition on the Markstein length in a distorted premixed dimethyl ether/air flame
Authors: Chernov A A , Shmakov A G , Korobeinichev O P , Toropetsky K V , Moskvin V N , Tatarenko V I
Published: December 2019

The paper presents the results of measuring the propagation velocity and Markstein length of pure and inhibited laminar axisymmetric dimethyl ether/air flames using the PIV method. Their dependence on equivalence ratio and the concentration of inhibitor is studied. Trimethyl phosphate is used as an inhibitor. The measurement results show a strong dependence of the Markstein length on the concentration of the inhibitor. This suggests the use of this parameter as a measure of inhibition effectiveness of turbulent flames.
Initiation of Richtmyer–Meshkov instability by a detonation wave
Authors: Kashkovsky A V , Kratova Yu V , Shershnev A A
Published: December 2019

As part of the HyCFS-R numerical code development, a module for the simulation of multiphase chemically reacting flows based on the Euler–Euler approach was implemented. The code was verified on simple 0D and 1D problems, such as constant volume explosion and 1D shock tube problem. For more comprehensive testing the numerical simulation of the Richtmyer–Meshkov instability in reactive heterogeneous media was performed. The comparison against the reference solution revealed that numerical method implemented in the HyCFS-R either introduce too much dissipation and suppress the detonation wave front instabilities or lead to numerical artifacts in the Richtmyer–Meshkov instability flow pattern.
Calculation of continuous spin detonation of a hydrogen-oxygen mixture in an annular combustor with oxygen ejection
Authors: Simonov E V , Zhdan S A
Published: December 2019

A closed mathematical model of continuous spin detonation in a H2-O2 mixture with oxygen ejection from the environment has been developed. The model takes into account the inverse effect of pulsation processes in the combustor on oxygen ejection. A numerical study was performed for a 10 cm diameter ramjet annular combustor with geometric dimensions corresponding to experiments. One-wave modes of continuous spin detonation were calculated and the flow structure was analyzed with variation in the specific hydrogen flow rate from 3 to 3.75 kg/(s·m2). Decreasing the flow rate of ejected hydrogen during continuous detonation in the combustor is found to lead to a monotonic decrease in the detonation velocity, wave front height, average static pressure, and equivalence ratio, but to an increase in the oxygen ejection coefficient. The results are validated against experimental data.
Shock wave and detonation flow regimes in gas suspension of reacting gases and inert particles
Authors: Tropin D A , Bochenkov E S
Published: December 2019

In this research, the interaction of shock waves (SW) with clouds of chemically inert solid particles of silica with a diameter of 100 μm in a hydrogen-air mixture is considered. Depending on the initial volume concentration of particles, three shock wave and detonation flow regimes are realized: 1. attenuation of the SW by a cloud of inert particles, 2. initiation of detonation behind the front of the SW reflected from the rigid wall, 3. initiation of detonation in a cloud of inert particles.
The correlation of the pulsations of flow in the settling chamber with the pulsations of supersonic flow
Authors: Afanasev L V , Kocharin V L , Yatskikh A A , Kosinov A D , Semionov N V , Yermolaev Yu G , Kolosov G L
Published: December 2019

The relationship of the pulsations of flow in the settling chamber with the pulsations of supersonic flow in the test section of the T-325 wind tunnel of ITAM SB RAS was investigated. Experimental data on the correlation between flow pulsations in different sections of wind tunnel and efficiency of turbulence reducing system were obtained. The system of three-channel hot-wire measurements in subsonic and supersonic flows was tested.
Correction of inertance of temperature sensing devices in high-speed flow
Authors: Goldfeld M A , Pickalov V V
Published: December 2019

The influence of the thermocouple calibration method on the reconstruction of the real temperature in impulse wind tunnel with operation duration of up to 100 ms is presented. It is shown that in an impulse set-up allow obtaining a stepwise thermal load with long temperature plateau which enough to determination of instrumental function, necessary for temperature reconstruction. To this aim, the developed technique, based on the application of the solution of the convolution integral equation, was used. It was included the information on the instrumental function, which was obtained from the calibration measurements. In the deconvolution procedure, the signal was first smoothed by splines, the convolution kernel was extracted by the differentiation of smoothed function, and regularization was performed by Kaczmarz algorithm with relaxation parameter. A comparison is made of the temperature reconstruction in the regular mode of hot shot wind tunnel with two different methods for measuring the response of thermocouples to the temperature step: measurement behind the shock wave front and rapid immersion in aluminum melt. It is found that the use of the instrumental function obtained in a wind tunnel allows one to more reliably determine the position of the temperature maximum in real experiment, which corresponds to the physical structure of the flow.
Low-frequency waves produced by a package of laser plasma clouds in a magnetized background
Authors: Tishchenko V N , Berezutsky A G , Boyarintsev E L , Zakharov Yu P , Miroshnichenko I B , Posukh V G , Ponomarenko A G , Chibranov A A , Shaikhislamov I F
Published: December 2019

It was shown for the first time that in a laboratory experiment a train of laser plasma clouds makes it possible to increase the length of the whistler waves generated in the power tube of a magnetized medium. The intensity of waves is orders of magnitude higher than the level achieved by known methods.
Effect of side walls on the supersonic ramp flow structure
Authors: Trubitsyna L P , Zapryagaev V I , Kavun I N
Published: December 2019

The reattachment zone structure of a supersonic separated ramp flow was experimentally studied at M∞ = 6. Several ramp model configurations with and without side walls were considered. It was found that the geometric size of streamwise vortices in the reattachment zone increases due to the absence of transverse flow in the separation region. Moreover, flow separation regions were detected on the model side walls which interact with the ramp-induced separation region, forming corner vortex structures.
Ballistic facility for heavy bodies acceleration
Authors: Zvegintsev V I , Melnikov A Yu
Published: December 2019

This paper discusses the issues of creating a ballistic facility for use in laboratory conditions and achieving throwing speeds of up to 2000 m/s for massive objects. The design of the facility was proposed and the results of the analytical calculation of the achieved speeds were presented. The verification of the analytical calculation and the results of experiments on the prototype ballistic facility was done.
Numerical simulation of jet flows in homogeneous and heterogeneous media
Authors: Shevchenko A K , Strijhak S V , Yakovenko S N
Published: December 2019

Submerged jets at different Reynolds numbers (Re) with random perturbations added to the inlet velocity profile are simulated numerically by solving the Navier–Stokes equations. The effects of Re on flow behavior and the length of laminar jet region are studied. A natural gas jet flow emitting form the sea bottom is also simulated using the URANS and VOF methods, and forces acting on an object placed within the multiphase jet are evaluated.
Numerical analysis of flow structure behind a bluff body under conditions of unstable thermal stratification
Authors: Valger S A , Fedorova N N
Published: December 2019

In the paper, the authors describe some results of a numerical simulation of the air flow around a bluff body mounted on a flat plate taking into account the injection of a tracer gas through a hole located in the substrate behind the body. The aim of this paper is to describe flow structure in the vicinity of a prism taking into account unstable stratification of the boundary layer which is characterized by a negative vertical temperature gradient. The results of numerical simulation for an unstable thermal state were compared with those obtained for the case of stable stratification for the same geometry configuration.
Supersonic airplane engine jet influence on the intensity of tail shock wave of sonic boom waveform
Authors: Volkov V F
Published: December 2019

The paper presents the computational experiment results aimed at studying the influence of the aircraft propulsion system on the sonic boom parameters. As a result, at large distances from the disturbances source at jet temperature of 2400° K and velocity of 1700 m/s at the nozzle exit, the trailing shock wave intensity in the sonic boom profile was significantly reduced by 50% compared to the profile generated by the aircraft without considering the jet influence.
Satellites reveal a small positive yield effect from conservation tillage across the US Corn Belt
Authors: Deines Jillian M , Wang Sherrie , Lobell David B
Published: December 2019

Conservation tillage is a primary tenet of conservation agriculture aimed at restoring and maintaining soil health for long-term crop productivity. Because soil degradation typically operates on century timescales, farmer adoption is influenced by near-term yield impacts and profitability. Although numerous localized field trials have examined the yield impacts of conservation tillage, their results are mixed and often unrepresentative of real-world conditions. Here, we applied a machine-learning causal inference approach to satellite-derived datasets of tillage practices and crop yields spanning the US Corn Belt from 2005 to 2017 to assess on-the-ground yield impacts at field-level resolution across thousands of fields. We found an average 3.3% and 0.74% yield increase for maize and soybeans, respectively, for fields with long-term conservation tillage. This effect was diminished in fields that only recently converted to conservation tillage. We also found significant variability in these effects, and we identified soil and weather characteristics that mediate the direction and magnitude of yield responses. This work supports soil conservation practices by demonstrating they can be used with minimal and typically positive yield impacts.
Greater stability of carbon capture in species-rich natural forests compared to species-poor plantations
Authors: Osuri Anand M , Gopal Abhishek , Raman T R Shankar , DeFries Ruth , Cook-Patton Susan C , Naeem Shahid
Published: December 2019

Tree plantations and forest restoration are leading strategies for enhancing terrestrial carbon (C) sequestration and mitigating climate change. While it is well established that species-rich natural forests offer superior C sequestering benefits relative to short-rotation commercial monoculture plantations, differences in rates of C capture and storage between longer-lived plantations (commercial or non-commercial) and natural forests remain unclear. Using a natural experiment in the Western Ghats of India, where late-20th century conservation laws prohibited timber extraction from monodominant plantations and natural forests within nature reserves, we assessed forests and plantations for aboveground C storage and the magnitude and temporal stability of rates of photosynthetic C capture (gross primary production). Specifically, we tested the hypothesis that species-rich forests show greater temporal stability of C capture, and are more resistant to drought, than monodominant plantations. Carbon stocks in monodominant teak (Tectona grandis) and Eucalyptus (Eucalyptus spp.) plantations were 30%–50% lower than in natural evergreen forests, but differed little from moist-deciduous forests. Plantations had 4%–9% higher average C capture rates (estimated using the Enhanced Vegetation Index–EVI) than natural forests during wet seasons, but up to 29% lower C capture during dry seasons across the 2000–18 period. In both seasons, the rate of C capture by plantations was less stable across years, and decreased more during drought years (i.e. lower resistance to drought), compared to forests. Thus, even as certain monodominant plantations could match natural forests for C capture and storage potential, plantations are unlikely to match the stability–and hence reliability–of C capture exhibited by forests, particularly in the face of increasing droughts and other climatic perturbations. Promoting natural forest regeneration and/or multi-species native tree plantations instead of plantation monocultures could therefore benefit climate change mitigation efforts, while offering valuable co-benefits for biodiversity conservation and other ecosystem services.
Simulation-based framework of bonus zoning to provide public space in Bandung city
Authors: Sugiana E , Hasan T S D , Zulkaidi D , Prilandita N
Published: December 2019

Bonus zoning is a zoning regulation tool that allows developers to get more density in exchange for public facilities improvement or provision. Bandung already has designated areas for Bonus Zoning within their Local By-law No.10/2015 on Detailed Spatial Plan and Zoning Regulation. This research aims to identify potential public space through zoning regulation tool along with the accompanying compensation. We simulate the formula of the provision of compensation on several areas in Bandung, within city/sub-city center and outside city/sub-city center. The compensation value is depending on land price and its location relative to the city center in the designated area. The average compensation in the city/sub-city center is higher compared to compensation outside the city/sub-city center. When applied correctly, bonus zoning can balance the intensive development and improved livability of its area.
Study on roadside greenery in Yogyakarta City towards development of productive urban landscape
Authors: Sarwadi A , Irwan S N R , Utami R N , Raya A B
Published: December 2019

Yogyakarta City has carried programs in developing green urban open spaces however those are still needed to be improved continuously. This paper aims to identify the type of trees in three roadside types. Field observations have been carried out in three types of road, i.e. secondary arterial road, secondary collector road, and local street. This paper also shows the identification of problems in developing a productive landscape of roadside greenery. Survey results were analyzed by descriptive statistics. 26 road samples were identified in relation to the tree species based on three road types. The survey results showed that secondary arterial roads consisted of 28.76% angsana trees (Pterocarpus indica) and 17.20% tanjung trees (Mimusops elengi). Secondary collector roads were dominated by tanjung trees (58.31%), and local streets consisted of 23.44% tanjung trees and 18.86% glodogan trees (Polyalthia longifolia). The survey also recognized that edible plants at roadside greenery were only 14.7%. Some problems were related to the trees such as inappropriate trees, less roadside space, less planting media, and less maintenance. 160 urban community also were interviewed. The interview results showed a lot of people disagreed to plant fruit trees at roadside greenery because of the unsafe feeling of fruit falling for walking at pedestrian under the trees and problems of intensive maintenance.
The aspect role of building maintenance on architectural design works (case study: a College Building in West Jakarta)
Authors: Rilatupa J
Published: December 2019

Architecture design needs to be completed with design criteria and standard knowledge of building maintenance in order to estimate a design quality related to shape and building materials selection. Similarly, a design criterion needs knowledge of building operations, including its maintenance aspects. Building maintenance needs to be done, in order to building lifetime can be extended by making periodic repairs, because utilization of each building component is not the same. Generally after building implementation, began to emerge problems with degradation in quality function of each component, utility and utilization of maintenance costs that were not proportional to the building lifetime. This research was conducted at one of the college buildings in Jakarta. This study aims to observe changes in building structures conditions, determine failure location, both in terms of architecture and maintenance; and an improvements inquiry that have been made to construction components. The method used based on BRE Digest 268. Based on an investigation obtained category value reliability and condition of college building is 86.9 with good treatment condition.
Comparative study of community-based composters, a case study in West Bandung Regency, West Java – Indonesia
Authors: Afifah N H , Juwana I , Satori M
Published: December 2019

Organic waste is the most dominant waste produced; the reduction of this type of waste has the potential to significantly reduce waste entering a landfill. Composter can reduce organic wastes at the source. This research aims to compare the performances of 3 types of aerobic composters available in Waste Bank Sahdu which are brick overlay, drum, and takakura. The types of wastes are used food and yard waste. The performance of each composter is determined by its capacity, performance, and the quality of composts produced. The capacity of a composter is obtained from the quantity of waste reduced. The performance a composter is assessed based on the composter’s ability to process organic waste into compost. The quality of compost is the result of laboratory test for the following parameters temperature, ratio C/N, water content, pH, zinc, copper. The results showed that the capacity of brick overlay, drum and Takakura are able to treat waste per day from 456, 210 and 20 households respectively. Their performances are able to treat 53.45%, 48.27% and 56.01% of organic waste into compost, respectively. The compost quality that produced by all composter has met the standard quality, except for pH of the drum. Based quality of compost produced from all composters is suitable for use. The Takakura included of individual composter, while brick overlay and drum included of communal composters.
Food security index and livelihood assets of Pandaan District, Pasuruan Regency, Indonesia
Authors: Prayitno G , Safitri N , Subagiyo A , Riska B
Published: December 2019

Food security is a situation that exists when everyone has physical, social and economic access to healthy, nutritious food that meets his/her dietary needs and dietary preferences, as well as active and healthy life. The data needed to measure the level of food security index are the availability of food, access to food, and the use of food. In addition to measuring the level of food security, this study also measured livelihood assets owned by the community. The data needed to measure the livelihood assets of the community are human assets, social assets, and economic assets. The method used in this research was descriptive quantitative with the result of the vulnerability index, CFA analysis (confirmation factor analysis) with the result of the subsistence asset building factors, and SEM analysis with the result of the relationship of latent variables between livelihood assets. The purpose of this study is to determine the level of food security, the factors that constitute livelihood assets, as well as the relationships between each component of livelihood assets. The results of the analysis showed that there are six villages in the food insecurity category. Livelihood assets in Pandaan consist of three assets, namely human assets (health, education, skills), social assets (relations between citizens and the intensity of conflicts) and economic assets (possession, savings, economic conditions and type of work). SEM’s results from Mplus analysis showed that each component of livelihood assets supports and maintains mutual relationships.
Role of land cover change to landslides susceptibility in agricultural catchment
Authors: Satriagasa M C , Suryatmojo H , Dewi H N
Published: December 2019

Physical and hydrometeorological properties of Karangkobar Catchment combine with poor land management cause landslide is commonly occurred in Karangkobar Catchment. This research is aiming to proof the role of land cover change to landslide susceptibility in Karangkobar Catchment. We use LULC change detection and landslide susceptibility analysis in this research. Main data use in this research is Landsat imagery from 1990 to 2018. LULC change detection is done using supervised classification to divide the land cover in the research area. Landslide susceptibility analysis was done using overlaying parameters then the landslide susceptibility analysis divides into 3 classes of susceptibility. Land cover in the research area tends to shift from agroforestry land to agricultural area or built up land. This affected the landslide susceptibility, it shifted from medium in 1990 to high susceptibility for almost 3 decades later. This analysis is proof of the role of the land cover change to landslide susceptibility in the research area. Furthermore, this phenomenon should be a warning to maintaining the land better and reducing the landslide susceptibility in the future.
Landslide risk assessment: human activities influence on an agriculture catchment
Authors: Dewi H N , Suryatmojo H , Ngadisih  , Satriagasa M C
Published: December 2019

A disaster is an event that can cause damage, loss of human life, or environmental damage. One of the disasters that often occurs in the upstream area is landslides. Karangkobar is one of the regions in the upstream area that had experienced a major landslide at 2014 which is resulted in 105 houses buried in land and 95 people were dead. The landslide disaster that has occurred in the Karangkobar catchment area is caused by the topography of the hills, high slopes, thick soil solum, soil texture is clay, cropping pattern and treated land that is inconsistent with conservation rules. This shows that landslide in the Karangkobar catchment area not only caused by natural conditions, but also human activities have an influence on the land. This research aimed to analyze the risk of landslide disaster based on hazard, vulnerability and capacity aspects in the Karangkobar catchment area. Assessment of risk analysis made by overlay between Hazard, Vulnerability, and Capacity is then given scores and weights. Overlay created with Arc Gis 10.4.1, scoring is given to assigning values to each parameter disaster. Weighting was analyzed by Analytical Hierarchy Process (AHP) with pairwise method and Expert Choice V.11 software, Weighting determined based on AHP scale. The result showed that the percentage of landslide risk based on human activity in the Karangkobar catchment are 41,16 % high risk, 38,04 % medium risk, and 14,47% low risk.
Identification of Pest and Disease in The Plant Conservation Center - Bogor Botanical Garden (PKT-KRB) Ecological Park Cibinong, Bogor, West Java, Indonesia
Authors: Muttaqin Z , Hartantri H , Meiganati K B , Hidayat I
Published: December 2019

The purpose of this study were: (1) to determine the pests and diseases infestation of plants in the Plant Conservation Center - Bogor Botanical Garden (PKT-KRB) Ecological Park area in Cibonong, Bogor Regency, (2) to determine the extent of damage that has been attacked by the pests and diseases. Sampling method was made by creating sample plots of 20m x 50m size with sampling intensity of 10% in the selected area at bioregion of Sumatera and of Kalimantan. The result of study showed that plants damage in those areas were dominated by hollow leaves caused by caterpillar pests i.e. at bioregion of Sumatera (37,84%) and of Kalimantan (40,23%). In addition, it was found that the secondly dominated infestation was alga leaf spot (Cephaleuro virescens) that has caused spots on leaf. Infestation intensity of the disease was of 35,14% at bioregion of Sumatra and of 28.74% at of Kalimantan, while the intensity of plants damage at bioregion of both were 36.00% and 42.44%, respectively. The scale of damage in both bioregions was included as score 2, which was the mediun category (⩾26-50%).
Arthropod Diversity on Forest Stands in South Sumatra, Indonesia
Authors: Utami S , Kurniawan A , Muslimin I
Published: December 2019

Arthropods have an important role in the forest ecosystem. Arthropods play a role in food webs as herbivores, carnivores, and detritivores. This study aims to analyze the diversity and abundance of arthropods in different forest stands, namely Pelawan (Tristaniopsis merguensis), Cajuput (Melaleuca cajuputi), and Sungkai (Peronema canescens). The research was carried out in the Forest Research Station of Kemampo belonging to the Environment and Forestry Research and Development Institute of Palembang, South Sumatra, Indonesia; through an observation approach with sweep nets, then taken to the laboratory for selection and identification. Research results showed that the levels of arthropod diversity in Pelawan, Cajuput, and Sungkai were relatively low. Those arthropods belong to 8 families with the highest number of the individual dominated by Pelawan stand, followed by Cajuput and Sungkai stands. Arthropod families consisted of Formicidae, Lycosidae, Elateridae, Scarabaeidae, Crabronidae, Chrysomelidae, Scolitidae, and Entomobryidae. The diversity index of arthropods under Pelawan, Cajuput, and Sungkai stands were 0,68; 0,31; and 0,3, respectively. The dominance index of arthropods on Cajuput stand was higher than in Pelawan, and Sungkai stands.
Bird Diversity and Its Association in Mangrove Habitats of Teluk Bintuni Regency, West Papua
Authors: Cita K D , Budiman M A K
Published: December 2019

Birds are one of the most essential components to maintain the stabilization of the ecosystem. Mangroves are one of the most biologically diverse ecosystems providing shelter and feeding sites for many species, but mangrove habitats are under severe land-use pressure through the world including Indonesia. The aim of this study was to identify the diversity of birds and their association with vegetation in Mangrove Habitats of Teluk Bintuni Regency. In this study, we assessed bird species diversity within six mangrove habitats that are Weriagar, Tanah Merah, Irarutu, Amutu, Kalipotong, and Muara Retui. This research was conducted in March 2019 with the rapid assessment method. According to our estimate, there were 54 bird species with 28 families which were dominated by Laridae in all sites. Tanah Merah was the location that had the highest number of species diversity (H’2.95). It is caused by diverse vegetation in Tanah Merah. This information could be useful for sustainable development of mangrove habitats.
The Diversity of Endophytic Fungi in Kemaitan (Lunasia amara Blanco)
Authors: Istikorini Y , Hartoyo A P P
Published: December 2019

All plants in natural ecosystems appear to be symbiotic with fungal endophytes. Endophytes are especially little known in tropical forest trees, which their abundance and diversity are thought to be greatest. This research aims to identify the diversity endophytes fungal in the shoots, leaves and stem of Kemaitan (L. amara). There are 180 endophytic fungi were isolated using a modified Photita’s method, by isolating in their shoots (34 isolates), leaves (70 isolates), and stems (76 isolates), which categorized in 37 morphospecies. The number of morphospecies endophytic fungi found on stem was higher (24 morphospecies) than on shoot and leaf (22 morphospecies). The index value of endophytic fungi on Kemaitan’s stem (3.050) was considered as high diversity, while on shoots (2.966) and leaves (2.911) were classified as moderate diversity. The index value dominance of endophytic fungi was categorized as low criterion. The evenness levels on stem, leaf, and shoot of Kemaitan were categorized into high level. The level similarity if endophytic fungi is categorized as low similarity.
Rhizophora mucronata Lamk Seedlings Growth Model with Guludan Planting Technique in Angke Kapuk, Jakarta Coastal Area
Authors: Haris AM , Kusmana C
Published: December 2019

Mangrove seedlings planted using the guludan technique are considered to produce optimal growth. Mangrove planting using guludan is an alternative for mangrove rehabilitation in former pond areas with deep water pools (more than 1 m). This study aimed to analyze the growth model of Rhizophora mucronata seedlings (growth in stem diameter and height, number of leaves, number of internodes, number of stilt roots) planted with guludan technique in Angke Kapuk, Jakarta Coastal Area. Measurements were made in the Angke Kapuk Mangrove Forest Area, Jakarta, in January 2019-April 2019. A total of 20 individuals from the 2018 planting year group were chosen as individual samples, were planted with Rhizhopora mucronata with a spacing of 0.5 m × 0.5 m. The data taken were the growth of stands, which include stem diameter, height, number of leaves, number of internodes, and number of stilt roots in the guludan. The results showed that the growth of stem diameter and height of R. mucronata seedlings for 12 weeks of observation formed a positive exponential equation. During the observation period (12 weeks) of the 20 R. mucronata seedlings seen, there were 380 leaves, 53 internodes, and four stilt roots growth.
Application of Silviculture Techniques to Improve Productivity of Binuang Bini Plant (Octomeles Sumatrana Miq.) as an Alternative Plant in Community Forest
Authors: Bogidarmanti R , Darwo
Published: December 2019

Currently the type of wood in community forests on Java Island is dominated by sengon species. However, this type faces problems with attacks of gall rust diseases One of the potential species as a substitute for light construction wood is binuang bini (Octomeles sumatrana Miq.). To increase stand productivity, it is necessary to apply the right silvicultural techniques. The purpose of this study was to find out the right silvicultural technique in order to increase the productivity of the binuang bini stands. The study design used a split plot design. The results showed that the organic fertilizer dose had a significant effect on the growth of the diameter and height of binuang bini stands. Fertilizing used bioactive compost charcoal with a dosage of 4 kg / planting hole can increase the growth in height and diameter of binuang bini plants was twice that of control treatment at the age of 30 months after planting. The pattern of binuang bini planting can be mixed with the other species such as Mindi (Melia azedarach L.) and/or Trema (Trema orientalis L.)
Characteristics of the cement board from parring bamboo (Gigantochloa atter)
Authors: Taskirawati Ira , Agussalim  , Baharuddin  , Sanusi Djamal , Suhasman
Published: December 2019

As a non-timber forest product, bamboo is widely used as a craft material, construction, and food (bamboo shoots). Bamboo as a lignocellulose material can also be used as a raw material in the manufacture of cement boards. This research was conducted to compare the characteristics of the cement board derived from bamboo paring with various treatments. The type of bamboo used is bamboo parring (Gigantochloa atter), while the cement used is Portland Cement Composite (PCC). The cement board was made using conventional and CO2 injection methods with the addition of additives (CaCl2, MgCl2, and Ca(OH)2). The characteristics of the cement board were tested based on JIS A 5417-1992. The results showed that the addition of CaCl2 using the CO2 injection method significantly improved the physical and mechanical properties of the cement board.
Ulin (Eusideroxylon swageri T.et.B) seed cleavage, fast way of germination in Sambas Regency, West Kalimantan
Authors: Sudarmono  , Efendi M
Published: December 2019

Ulin (Eusideroxylon swageri T.et.B) or Ironwood has never been cultivated by the people in Sambas, West Kalimantan. As the limited duration of the germination and growth of ironwood trees need to breakthrough propagation techniques. Forests in Sambas Regency are beginning to lose the ironwood trees because of the wood that is strong and durable (including the strong class I and durable class I), so that it is widely used for building houses and bridges. This study aims to propagating of ironwood seeds through propagation techniques. The seed coat treatments and cleavages used for this experiments in Sajingan Besar of Sambas Regency. Sowing seeds regular of Ironwood takes 9 months and can accelerated to be 3 months but the seed coat must be peeled first. The characteristic of ironwood seed has a polyembryonic seed, so that used treatments of cutting the seeds to be 2 and 3 parts of seed. The results that the ironwood seeds can grow faster after 4 weeks planting if peeled the coat and cutting seeds into two part of seeds. The quantitative analysis explained and showed in this paper.
Numerical Study on Cavitation Characteristics of High Speed Fuel Centrifugal Pump
Authors: Li Xiaoyu , Ji Yunguang , Liu Xiaolan , Cui Hongbin , Xue Shuqi
Published: December 2019

For centrifugal fuel pump operating at high speed, the flow passage components in the pump will be more prone to cavitation, which may lead to efficiency decrease and failure. A single-stage high-speed centrifugal fuel pump is taken as the research object in order to study the phenomenon and the law of cavitation flow in this paper. The influence of different blade inlet angles, rotating speeds and fuel temperatures on cavitation of pump is then studied using numerical method. The results show that properly increasing the blade inlet angle can improve the cavitation performance, and at different rotational speeds, the degree of cavitation is determined not only by NPSHr, but also by Speed C of cavitation, however fuel temperature has rather small influence on the cavitation performance of the fuel pump.
Comparison Research on the Sino-US Maritime Development in Marine Engineering
Authors: Li Feifei , Dang Kun
Published: December 2019

Marine engineering, applying engineering sciences, mostly mechanical and electrical engineering, to the development design, operation and maintenance of the vessels. China and the United States have made rapid progresses in the maritime development for decades, among which, the development in marine engineering between two countries is analyzed and compared through maritime education, training ships, etc in this paper. It is found that there are many differences in selecting the marine propulsion and transmission system, sea practice and ship types and so on.
The multi-level urban rail traffic safety based on fuzzy TOPSIS evaluation research
Authors: Chen Jiaxu
Published: December 2019

With the expansion of the scale of the urban rail transit network and the increase of the factors affecting the safety of the operation of the network, the operation risk of urban rail transit is also increasing. For urban rail transit network security problems, according to the statistical analysis of urban rail traffic accident, first constructed oriented network station, line, different levels of urban rail traffic safety evaluation index system, from the three levels of urban rail transit network security influence factors were analysed, and further improving the system of safety evaluation index; Secondly, TOPSIS evaluation method based on triangular fuzzy number is used in this paper to evaluate the safety risk of urban rail transit, which overcomes the disadvantage of subjective factors in AHP and FAHP evaluation methods. Finally, the model is calculated and analysed. This paper provides decision-making basis for the safety management department of urban rail transit, and has certain reference significance for improving the safety management level of urban rail transit.
Research on Route Search of Connecting Flights in International Airline Network
Authors: Ma Ruixin , Chen Xian , Liu Jian , Zhu Jinfu
Published: December 2019

With the development of global aviation industry, a huge international airline network has been formed. In order to solve the problem that the connecting path search method takes long time in global airline network, the objective of this paper is to find out all the target connecting flights paths fast between an OD pair. According to the features of the connecting path search in the schedule-based network, the solving method is divided into three stages. In the first stage, we build a time-space graph. In the next stage, three-step cutting is used to reduce the scale of graph. After that, we apply an algorithm which is combined with depth-first and breadth-first search algorithm to enumerate the paths. It can be seen that our algorithm is suitable for multi-constraints, big data and searching all paths.
Research on traffic zone partition method based on two-level partition theory
Authors: Li Yongchang , Yan Xuedong
Published: December 2019

As an important part of traffic planning, traffic zone division has drawn much attention for decades. Better than traditional methods of traffic zone division based on traffic surveys and road network structures, this paper proposes a two-level framework for dividing traffic zones by using massive car-hailing data from a big data perspective. Firstly, the grid model is established within the study area and massive travel data are matched into grids. Secondly, the Louvain community detection algorithm is used to divide the research area into different traffic medium zones (TMZs). Further, a K-prototype clustering algorithm based on partition is used to divide each TMZ into several traffic small zones (TSZs). Taking the Beijing Fifth Ring as an example, the study area is divided into 16 TMZs and 302 TSZs by using two-level partition theory. The proposed method of dividing traffic zones is proved to be efficient and accurate and can be easily applied to other areas, which helps planners to make more smarter traffic planning and city management.
Development of Rail Precision Cleaning Vehicle for Modern Tramway
Authors: Dong Hanjiang , Ma Wentao , Huang Jingwen , Li Haijian , Huang Yanming , Liu Xin , Li Jingui , Lin Zenan , Xie Yongjun
Published: December 2019

Supported by the Zhuhai Collaborative Innovation Project, we develop a Road-Rail Precision Cleaning Vehicle for the rail of the first modern tramway based on the Tram Wave system in China, which has been built in Zhuhai City. Development scheme of overall mechanical structure, electrical control and condition monitoring system and man-machine interface system has been realized. We also designed a target recognition algorithm based on OpenCV to control actuators like solenoid valve, electromagnetic clutch and air pressure regulating valve and so on.
Evaluation of Cloud Model for Public Transport Service Quality
Authors: Meng Zhang , Yi Zhang , Li Jinhui , Wang Xiaomin , Wang Zhixin
Published: December 2019

In order to practice bus city planning, it is of great significance to construct a reasonable urban bus service system. At present, there are various research models and methods, and a city bus service quality evaluation model is established based on the advantages and disadvantages of various methods. Analytic hierarchy process and coefficient of variation method were combined to form subjective and objective weights, and cloud model was established for comprehensive quality evaluation. The feasibility of the model is verified by the measured indexes of public transportation in Luoyang City, which proves the rationality of the evaluation method and provides reference for other cities.
Study on PSD of track irregularities of Beijing Metro Line
Authors: Feng Jin , Xiao Hong , Ling Xing
Published: December 2019

Track irregularities are the significant factor of vehicle vibration. In this paper, track spectrum is combined with the theory of finite element method. Dynamic responses of several track spectrums such as spectrums of the USA and Europe are compared with the field investigation result. The comparison prove that the spectrums which are mentioned above are not applied well to the construction and maintenance of the metro line. Using the method of wavelet theory and error removing algorithm, process the raw data which is measured by the track inspection car. And by using nonlinear least square method, get the track spectrum of the metro line, and constructed a FEM model for verification. The results say the spectrum we put forward has significant advantages compare with other track spectrum. Through this way, this work fills the blanks on field of metro line track spectrum.
Research on Calculation of Port Optimal Anchorage Demand Based on Queuing Theory
Authors: Huang Qingyve , Hu Liu
Published: December 2019

In view of the contradiction between the supply and demand of anchorage resources, the research on the optimal anchorage demand of the port is carried out. The M/M/c model is constructed by the queuing theory method combined with the main characteristic indicators and main parameter indicators. Taking the coal port area of the Huanghua Port as an example, the Matlab software is used to calculate and determine the optimal anchorage demand, which is 14, according to the restriction that the anchorage guarantee rate is greater than or equal to 95%. And the conclusion shows that the port anchorage resources are not tight. The calculation result shows that the model has certain application value in anchorage planning.
Analysis and Research on Aviation Power Operation Mode
Authors: Tang Guangrui , Qian Zhang
Published: December 2019

Aviation power operation can effectively improve the efficiency and safety of power grid operation and maintenance. It has become the trend of the world’s power operation field. Its operation modes are mainly divided into helicopter power operation and drone power operation. Helicopter power operation modes include helicopter power inspection operations, helicopter charged water flushing operations, helicopter live maintenance operations, helicopter infrastructure construction operations, and helicopter laser scanning operations. The drone power operation mode includes drone inspection work, drone clearing operation, and drone construction work. With the development of technology, the coordinated inspection mode based on helicopters and auxiliary aircraft will become the future development trend.
Characteristics of low-level wind shear in Qinghai Xining Airport
Authors: Xu Ting
Published: December 2019

Characteristics of low-level wind shear in Qinghai Xining Airport are analysed by using pilot reports and reanalysis data. It manifests seasonal and diurnal variation that the frequency is higher in spring and summer, and for diurnal variation, it is higher in afternoon and early night. The weather patterns of low-level wind shear can be roughly divided into four types. Their characteristics are also studied in this paper. And terrain effect is of importance to the cause of low-level wind shear, gorges and mountains lead to strong wind and variable wind direction.
Low Carbon Vehicle Routing Optimization with Multi-Energy and Multi-Vehicle Types under Traffic Restriction Conditions
Authors: Wang Heng , Wei Li , Wang Zhanwu , Xu Guangyin , Wang Zhenfeng
Published: December 2019

Aiming at the problem of automobile exhaust pollution and the measures of urban traffic restriction, this paper introduces the traffic restriction conditions into the vehicle path problem. Firstly, the speed characteristic models of different road conditions are established. Then, aiming to minimize the total cost such as carbon emission and distribution cost in the distribution process, a multi-energy and multi-vehicle hybrid vehicle path optimization model is constructed under traffic restrictions. Finally, an improved adaptive genetic algorithm is proposed based on the idea of simulated annealing. The effectiveness of the model and algorithm is verified by simulation experiments and examples.
A Quantitative and Comprehensive Evaluation of China’s Ecological High-speed Railway Development Based on DSR Model
Authors: Guo Jing
Published: December 2019

This paper evaluates the development status of China’s high-speed railway from 2010 to 2018 based on the DSR (Driving force, State and Response) model, and further evaluates the ecological development status of China’s high-speed railway in the future by using the analytic hierarchy process. The results demonstrate the overall trend of the development of ecological high-speed railway in China is good, but the driving force is insufficient, the proportion of state indicators decreases year by year, and the response indicators indicate an upward trend. According to the research and analysis, some suggestions are put forward for the development of ecological high-speed railway.
Numerical Analysis of Semi-rigid Asphalt Pavement Deflection under Dynamic Traffic Load
Authors: Yue Xuejun , Shi Jicun , Wang Junxiong , Zhang Qing , Li Zhongyu , Liu Tingguo
Published: December 2019

In order to detect dynamic deflection rapidly and continuously, a dynamic model under traffic load of asphalt pavement finite element was built, dynamic deflection with different traffic speeds and different point were studied; the dynamic deflection with different thickness of pavement layers and different dynamic modulus were also studied. Results show that the dynamic deflection is different with different traffic, the higher the speed the smaller the deflection, and the maximum deflection lags the peak traffic loads; road pavement thickness increased significantly reduced dynamic deflection, the order of thickness impact dynamic deflection was the surface layer, the base and subbase; the layers modulus increases the dynamic deflection reduced. Findings contribute to developing continuous and rapid dynamic deflection testing equipment based on dynamic deflection characteristics of the road surface.