bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of growth temperature and thermal annealing on optical quality of GaNAs nanowires emitting in the near-infrared spectral range
Authors: Stehr J E , Balagula R M , Jansson M , Yukimune M , Fujiwara R , Ishikawa F , Chen W M , Buyanova I A
Published: October 2019

We report on optimization of growth conditions of GaAs/GaNAs/GaAs core/shell/shell nanowire (NW) structures emitting at ∼1 μm, aiming to increase their light emitting efficiency. A slight change in growth temperature is found to critically affect optical quality of the active GaNAs shell and is shown to result from suppressed formation of non-radiative recombination (NRR) centers under the optimum growth temperature. By employing the optically detected magnetic resonance spectroscopy, we identify gallium vacancies and gallium interstitials as being among the dominant NRR defects. The radiative efficiency of the NWs can be further improved by post-growth annealing at 680 °C, which removes the gallium interstitials.
Mild stimulation improves neuronal survival in an in vitro model of the ischemic penumbra
Authors: Muzzi Lorenzo , Hassink Gerco , Levers Marloes , Jansman Maikel , Frega Monica , Hofmeijer Jeannette , van Putten Michel , le Feber Joost
Published: October 2019

Objective. In the core of a brain infarct, characterized by severely reduced blood supply, loss of neuronal function is rapidly followed by neuronal death. In peripheral areas of the infarct, the penumbra, damage is initially reversible, and neuronal activity is typically reduced due to ischemia-induced synaptic failure. There is limited understanding of factors governing neuronal recovery or the transition to irreversible damage. Neuronal activity has been shown to be crucial for survival. Consequently, hypoxia induced neuronal inactivity may contribute to cell death, and activation of penumbral neurons possibly improves survival. Adversely, activation increases ATP demand, and a balance should be found between the available energy and sufficient activity. Approach. We monitored activity and viability of neurons in an in vitro model of the penumbra, consisting of (rat) neuronal networks on micro electrode arrays (MEAs) under controlled hypoxic conditions. We tested effects of optogenetic and electrical activation during hypoxia. Main results. Mild stimulation yielded significantly better recovery of activity immediately after re-oxygenation, compared with no stimulation, and a 60%–70% higher survival rate after 5 d. Stronger stimulation was not associated with better recovery than no stimulation, suggesting that beneficial effects depend on a delicate balance between sufficient activity and available energy. Significance. We show that mild activation during hypoxia/ischemia is beneficial for cell survival in an in vitro model of the penumbra. This finding opposes the current common belief that suppression of neuronal activity is the cornerstone of neuroprotection during cerebral ischemia, and may open new possibilities for the treatment of secondary brain damage after stroke.
Intelligent Unmanned Aerial Vehicle for Agriculture and Agroindustry
Authors: Hartanto R , Arkeman Y , Hermadi I , Sjaf S , Kleinke M
Published: October 2019

Unmanned Aerial Vehicle has been adopted in various different areas starting from hobby photography to professional measurement techniques. This paper focuses on the potential of using UAV for agriculture and agroindustry to improve the overall productivity and reducing the overall product cost. It provides brief overview of available UAV systems on the market including their sensors and capabilities. More important is the software part and required algorithms for controlling the AUV in such way that it becomes intelligent. The more advanced the software the more intelligent is the AUV. Some of available algorithms and applications for this purpose are discussed in this paper.
Development of Jamu formula prediction system module of Ijah analytics based on pharmacology activity and particular efficacy target
Authors: Ramadhanti N S , Kusuma W A , Heryanto R
Published: October 2019

Indonesia is one of countries with abundant amount of herbal plant species. These plants have potential to be used as an ingredient of alternative medication, which is known as Jamu. There have been already many previous research related to the topic of formulating jamu efficacy using network pharmacology that construct link among plants and disease. Moreover, some researchers were more interested in predicting the interaction between chemical compound and protein to formulate Jamu. Commonly, Jamu formula contains four basics of pharmacology activities including analgesic, anti-inflammatory, antibacterial, and target pharmacology activity. Ijah has not implemented these four essential characteristics yet for predicting jamu formula. This research implemented new molecular Jamu formulation composed by some active compounds from plant with analgesic, anti-inflammatory, antibacterial and target pharmacology activity characteristic. The result of this study showed a list of plants which consisted of herbal compounds that could be used to formulate jamu as an alternative to synthetic medicine.
Environmental engineering and sustainability for smart agriculture: The application of UAV-based remote sensing to detect biodiversity in oil palm plantations
Authors: Moreno A , Bhattacharyya A , Jansen L , Arkeman Y , Hartanto R , Kleinke M
Published: October 2019

The United Nations strongly support the progress towards sustainable agriculture, food security, sustainable management of life on land in a simultaneous approach. Oil production, though on increasing demand, is causing severe loss of biodiversity in tropical areas, Indonesia being the country with the most environmental damage due to this crop. Geographical Information Systems (GIS) and Unmanned Aerial Vehicles (UAVs) for base-remote sensing are promising tools to help with environmental conservation in oil palm plantations and to improve production efficiency and quality of crops. While different UAVs exist in the market, multi-rotor UAVs have already been used for oil palm plantation monitoring. There are more than 100 different Vegetation Indices (VIs); the Normalized Difference Vegetation Index (NDVI) is often used in smart agriculture. Still, there is a huge need for algorithms that assess floristic diversity. To maintain some elements of the Indonesian biodiversity within oil palm plantations, experimentation with algorithms were carried out. The imagery shows great potential for future research.
Isolation of collagen from chicken feet with hydro-extraction method and its physico-chemical characterisation
Authors: Suparno O , Prasetyo N B
Published: October 2019

Chicken slaughterhouses generate a large volume of chicken feet as a waste or by product. Nowadays, the chicken feet have not been optimally utilised. One of the ways to increase added value of the chicken feet is to utilize collagen contained in it. The objectives of this study were to obtain the best treatments in pre-treatment and hydrolysis stages of collagen extraction from chicken feet using hydro-extraction method, and to characterise the physico-chemical properties of the isolated collagen. Collagen extraction consisted of three stages of pre-treatment, hydrolysis, and hydro-extraction. Pre-treatment stage used NaOH concentrations of 0.5, 1, and 2 M, and soaking times of 2, 4, 6, and 8 hours. The hydrolysis used CH3COOH concentrations of 0.1, 0.3, and 0.5 M, and soaking times of 1, 2, and 3 hours. The best condition of pre-treatment was 0.5 M NaOH concentration with 6 hours of soaking time, while the best condition of hydrolysis was 0.5 M CH3COOH concentration with 1 hour soaking time. FTIR spectroscopy showed that the isolated collagen amino acids consisted of amide A, amide B, amide I, amide II, and amide III groups. The dominant amino acid contents were glycine, L-serine, L-proline, L-glutamic acid, and L-alanine.
Development of KMS to support quality shoes production
Authors: Feta N R , Seminar K B , Hermadi I
Published: October 2019

PT. PAI is a manufacturing company of Tomkins brand shoes. The company produces four types of shoes such as a child, junior, women, and men, from every kind of shoe there are different shoe names and models. The information or knowledge that each employee has about how to produce high-quality shoes has not been appropriately managed and stored, plus the employee’s entry and frequent employee mutations due to shoe production in one of the stages of production, which results in a loss of knowledge. A lot of defective shoe production and reduce production targets. Therefore, this study aims to create a knowledge management system in the production section. The method in this study was Awad & Ghaziri using five main stages of Knowledge Management Life Cycle. Based on the research that has been conducted, a web-based knowledge management system has been successfully created. The system developed is in the form of knowledge sharing and knowledge transfer applications. On the main login page, there are three levels of access rights, namely experts, admin and employee. Based on a series of tests, this system concerning functionality has been by the needs of users in the company and has been built correctly.
Lean management in the rice industry; case study at Widasari, Indramayu district
Authors: Perdana T , Sadeli A H , Hermiatin F R , Ginanjar T
Published: October 2019

Rice is a strategic product in Indonesia development because it becomes an essential aspect of economic growth. The inefficiency of food agribusiness system becomes a crucial aspect of developing the sustainable industry. Those affected by the lack of using technology that impacts the high amount of waste and losses, the inefficiency of time, etc. It could impact the competitiveness, equity of value-added, unstable price and poverty. Some amount of rice grade materials rejected from the production line due to the unsatisfactory quality. This article aimed to analyze efficiency in the food industry as a preparation in the development of agricultural digital supply chain. The analysis shows that inefficiency in the rice industry due to a lot of manual activities that impact the time and expense efficiency (labor intensive rather than the use of technologies). Improving efficiency in the food industry is not only about time and cost management, but it becomes complex issues which are involved in several barrier factors. It should be anticipated with appropriate technology, improving skills, and also develop an integrated logistics system. Importantly, improving efficiency in rice industry needs to develop soft skill as the key success factors to improve efficiency in the digital supply chain for the rice industry.
Efficient mapping for fodder cultivation with commercial small drone
Authors: Pandjaitan N H , Rau M I , Sutoyo  , Karunia T U , Waspodo R S B , Mustikasari N
Published: October 2019

To optimise land use, an overview regarding its topography of the proposed land is essential to be portrayed, especially to depict the slope, elevation, calculation of cut and fill, as well as planning for water supply. However, in practice, high-resolution topographic data are hard to obtain and are highly priced. As an alternative solution, commercial small drones could be utilized to improve the input for such data. Commercial small drones could be utilized as a photogrammetric approach to obtain detailed digital surface model (DSM). This study aimed to get high-resolution of topography condition using commercial small drones and evaluate the result comparing to terrestrial surveying. The approach was done using Drone DJI Phantom 3 Professional, where the ground control points (GCPs) were undertaken with GPSMAP 64s SEA. The study area was ±23 ha proposed for fodder cultivation, located at Ngantru Village, Bojonegoro, East Java Province in Indonesia. Outcomes obtained from the analysis were orthophoto, digital models, and contours. The results yielded an efficient approach for mapping compared to field/terrestrial surveying. The drone approach only cost IDR ±4,000,000, whereas terrestrial mapping (using electronic total station) was worth up to IDR ±25,000,000. As the expense altered significantly, the process of collecting data varied as well. The overall data acquisition using drone only took 2 hours to complete, while field survey may require up to 2 days of acquisition. Although results accuracies were also an issue, the output reliability for drone with errors from 0.5 to 6 m was somewhat acceptable. In conclusion, small commercial drones were one way to undertake efficient mapping (in terms of cost and time) compared to field/terrestrial survey.
A preliminary investigation of various signal phenomena generated by termite infestation
Authors: Nanda M A , Seminar K B , Nandika D , Maddu A
Published: October 2019

Subterranean termites are major urban pests in Indonesia and lead damage to wooden structures and buildings. Termite pest management involves two sections: prevention and control. The most crucial part of termite control is to detect termites; however, due to their cryptic behavior, the termite infestation evidence on wooden structures is difficult to detect visually. When termite infestation is active and wood damage is occurring, the distinction of various signal phenomena are released including moisture content, temperature and acoustic emission. The identification of these phenomena becomes the basic foundation for designing a future termite detection system. The aim of this study is to identify various signal phenomena generated by termite infestation. In this investigation, the pine wood, as the medium for termite infestation, was divided into two groups, i.e., the wood infested by 220 termites (‘infested’) and the normal wood as a control (‘uninfested’). Each signal phenomenon generated by termites was observed and analysed to produce six pieces of information, i.e., (a) moisture content; (b) temperature; (c) four information of acoustic emission such as energy, entropy, peak frequency and zero moment power. Based on statistical analysis of Duncan multiple range test (DMRT; two-way ANOVA, P ≤ 0.05), it was revealed that the information that can distinguish significantly between infested and uninfested wood are moisture content, temperature, energy, entropy and zero moment power. Finally, various phenomena (i.e., moisture content, temperature and acoustic emission) can be embedded and integrated in the sensing technology of termite detection.
Utilisation of fish skin waste as a collagen wound dressing on burn injuries: a mini review
Authors: Afifah A , Suparno O , Haditjaroko L , Tarman K
Published: October 2019

The fish processing industries produce wastes such as skin, fish scales, stomach contents, and bones. Those organic wastes has not been widely used. The biggest content of fish processing industry is collagen. Fish skin has the highest collagen content (5%-30%). Collagen has been widely used in pharmaceuticals, cosmetics, and food. One of the benefits of collagen is as a wound dressing on burn injuries. Collagen as the most abundant fibrous protein in fish is the main constituent of the extracellular matrix (ECM). ECM is a dynamic substance between cells in a tissue and has the ability to improve the tissue functions. Burn injuries are one of the types of wounds that has a long healing phase, which requires intensive treatment. Severe burn injuries could make people who experience it have traumatic and paralysis that affects the entire organ system. Collagen wound dressing was expected to be able to engineer tissue and accelerate cell regeneration to replace or regenerate damaged tissues. This paper will describe the potency of fish skin waste, problems in healing burn injuries, collagen extraction, and collagen application as wound dressing.
Potency of reef fishes in Tuhaha bay waters, Central Maluku Regency, Maluku Province, Indonesia
Authors: Sahetapy D , Retraubun A S W , Bengen D G , Abrahamsz J
Published: October 2019

The research aimed to provide data on taxa composition, density, standing stock and potency of reef fishes at Tuhaha bay waters in 2017. There were 35 families, 105 genera and 243 species of reef fishes found in Tuhaha bay. Four areas of coral reef at good until excellent categories and various habitat had high species richness of reef fishes. Species richness, density and standing stock of major reef fishes species were higher than target and indicator species. Potency (biomass) of economically food fish (target species) ranged from 1.65 - 5.59 tons ha−1 of coral reef (total 2.93 tons ha−1). Total potency, Maximum Sustainable Yield and Allowable Total Catch of economically food fish in 389,70 ha of Tuhaha bay coral reef area were 1,141.82, 590.91 and 456.73 tons, respectively. The status of reef fishes in two coral reef areas belonged to a high category, while the other nine areas had a moderate category.
A Broker: role and function in small pelagic fish marketing in traditional market in Ambon
Authors: Apituley Y M T N , Savitri I K E , Bawole D , Tuapetel F
Published: October 2019

This research was conducted in Pasar Mardika-Ambon, on June to July 2018. Five of the ten brokers in that market were taken as samples and observed as well as interviewed in depth. The results show that the role of the Brokers in the fresh fish marketing process, especially in that market, which is known as the main traditional market in Ambon is very large. It can be seen from the percentage of fish passing through them. Approximately 90% of the fishermen’s catch (especially purse seine) must pass the brokers for further distribution to consumers through retailers. For this job, they will earn 10% of fishermen’s sale, both those distributed to retailers and those sold to Cold Storage. Some fishermen argue that the existence of broker is very helpful in the marketing process, but some fishermen also complain about their presence in the market. When fishermen experience problems and need assistance (money), the broker will immediately reach out to help. The assistance must still be returned by the fishermen but the return time is flexible.
Numerical simulation of tidal bore in Kampar river: a preliminary study
Authors: Abdullah F A R , Ningsih N S , Rachmayani R
Published: October 2019

Tidal bore is a very rare natural phenomenon, in which the flow of the river goes upstream. It usually happens close to the estuary. In Indonesia, it happens at Kampar river, Riau province. Some factors that cause this phenomena are tides waves and water bottom topography. In this paper, we simulated the propagation of tidal bore in the Kampar river based on shallow water equations (SWE). We used the staggered grid conservative scheme to discretize the SWE. Next, we apply bottom topography of Kampar river and tides elevation profile there into our scheme. Finally, we present numerical simulation of tidal bore propagation along the Kampar river. The result shows that the river discharges have a quite significant effect on increasing bore elevations. The friction coefficient has an important role on wave attenuation of tidal bore propagation.
Species identification and spawning of sea turtle at Meti Island North Halmahera Regency
Authors: Rupilu K , Fendjalang S N M , Payer D
Published: October 2019

Sea turtles are large, air-breathing reptiles that inhabit tropical and subtropical seas throughout the world. With long lifetimes and wide-ranging migration patterns, sea turtles are exposed to many sources of danger both in coastal area and in the open sea, including environmental accidents. Sea turtles are most endanger and threaten with extinction, many are listed in the IUCN Red List or at CITES list. The objective of this study was to identify sea turtles species in Meti Island, their nesting area and its characteristics. Data on nesting area obtained from direct observation and interview with the local community. The result showed that there are three species of sea turtles found in Meti Island i.e. Chelonian mydas, Eretmochelys imbricata, and Lepidocheys olivacea. There are two locations of nesting area i.e. the coastal area of Meti Island and Pasir Timbul Island The characteristic of the substrate at nesting area was medium sand, fine sand, and coarse sand. The slope of the coast of nesting area is approximately 350 at Meti Island while the upper side at Timbul Island was steeper with approximately 400. Marine flora at the nesting site is dominated by seagrass and sargassum which is suitable for nesting area for sea turtle. Shore vegetation at Meti Island consist of Hernandia nymphaeifolia, Scaevola taccada, Thespesia populnea, Pandanus sp, Guettarda speciosa, Terminalia catappa, Crinum asiaticum, Millettia pinnata, Cycas circinalis, Thuarea involute, Cardia subcordata while shore vegetation of Pasir Timbul Island consist of Ipomoea pes-caprae, Wedelia biflora, Spinifex littoreus, Scaevola taccada, Argusia argentea, Terminalia catappa, Pandanus sp, Hernandia nymphaeifolia, and Cocos nucifera.
Investigation of fuel consumption on an operating ship due to biofouling growth and quality of anti-fouling coating
Authors: Hakim M L , Nugroho B , Nurrohman M N , Suastika I K , Utama I K A P
Published: October 2019

This article will look into to the environmental and economic issues in the maritime sector that arise due to biofouling. For the shipping industry, biofouling is known to increase hull roughness that would lead to an increase in friction resistance and fuel consumption. Here we present a short review regarding ship-hull roughness due to biofouling and its associated increase in skin friction drag, and analysis of fuel consumption from an operating ship with two different anti-fouling coating. The data shows that a higher quality antifouling would result in a low biofouling attachment on the hull surface, resulting in a lower fuel consumption.
The effect of joints model to the vibration characteristics of wood
Authors: Lekatompessy D R , Zubaydi A
Published: October 2019

The One piece of the wooden beam has different vibration characteristics compared to the two pieces of wood with a joint. One of the parameters measured is the dynamic stiffness of wood. The method used is a technique in which the vibration excitation test using a hammer with a rubber head. The wood used in this study is Gofasa (vitex cofassus). The Properties of wood was using the data from previous studies. Vibration characteristic of a piece of wood was used for comparison purposes. Two pieces of wood have joined and secured by bolts. Cantilever beam model has used with the knock in a perpendicular direction to the wood fibres. The joints model used to excitation test is the plain scarf, hooked scarf, half lap splice, and tabled splice. All of these models were tested to determine the characteristics of vibration. The results showed the different vibration characteristics for each model. The results are used as a recommendation of the best models in distributing the vibration from the vibration source.
Study on development of shipyard type for supporting pioneer ship in Indonesia
Authors: Pratama P , Fadillah A
Published: October 2019

Abstract— Based on the geographical conditions of Indonesia, especially the eastern region of Indonesia, a national sea transportation system is needed that can be a bridge for remote, isolated and undeveloped islands using pioneering sea transportation. The problem is when the pioneer ships carry out maintenance and repairs, where the pioneer ship population of 82% operates in the eastern part of Indonesia and 18% operates in the western region of Indonesia, while 70% of shipyards are located in Western Indonesia and the remaining 30% are located in Eastern Indonesia. The purpose of this study is to determine the appropriate type of shipyard. The methods used in this study were the fishbone and SWOT methods. As many as 11 locations in Indonesia are selected for surveys. Construction of shipyards for pioneer ships takes into account shipyard availability in the area of operation, the number and type of vessels operating. The results show that the best shipyard location to support the operation of pioneer ships is located in the Bitung Region or in the Sorong Region with the type of shipyard in the form of a slip way.
Antimicrobial activity of fungi isolated from the marine sponges collected from Sekotong Beach Lombok, Indonesia
Authors: Julianti E , Singgih M , Ikram M R , Naufal A , Putra M Y , Hadi T A
Published: October 2019

The search for new antibiotics from a variety of sources that have the potential to produce bioactive metabolite compounds is essential to solve the increasing problem of microbial resistance. Recently, one of the most widely studied for new antimicrobial sources is marine derived fungi. The aims of this study were to isolate endophytic fungi of marine sponges collected from Sekotong Beach Lombok, Indonesia and determine their antimicrobial activity. Fungi isolation were conducted in yeast extract, peptone, and dextrose (YPD) agar medium and each pure fungi was fermented for 21 days in YPD broth medium. Culture media and mycelium were separated by filtration method. The culture media was extracted by liquid liquid extraction and mycelium was extracted by maceration method using ethyl acetate. The dried extracts then tested for their antibacterial activity against Escherichia coli ATCC8739, Staphylococcus aureus ATCC6538, and Candida albicans ATCC 10231 using paper disk diffusion method. Extracts which showed antimicrobial activities on 250 ug/disk content were determined their minimum inhibitory concentration (MIC) and minimum bactericidal or Fungicidal concentration (MBC or MFC). The results of this research were obtained 12 fungi isolates that were coded as FSKT1 until FSKT12. The lowest MIC and MBC value against E. coli was showed by mycelium extract of FSKT10 with concentration of 128 and 256 ug/mL, respectively. The lowest MIC and MBC value against S. aureus was showed by medium extract of FSKT9 with concentration of 64 ug/mL and against C. albicans with concentration of 128 and 512 ug/mL, respectively. The antimicrobial activity observed in this research indicates that the endophytyc fungi of the marine sponge could be considered as new sources of antibiotics.
A hybrid wavelet neural network (HWNN) for forecasting rainfall using temperature and climate indices
Authors: Ghamariadyan M , Imteaz M A , Mekanik F
Published: October 2019

Rainfall forecasting plays an important role in water resources management and also for controlling the unusual events related to the rainfall. This study aims to forecast monthly rainfall from antecedent monthly rainfall, temperature and climate indices using a hybrid wavelet neural network (HWNN) model. The discrete wavelet transform is used incorporation with a conventional ANN model. The skilfulness of the proposed model is compared with the observed rainfall and the ANN model. The results show that the HWNN model provides a good fit with the observed rainfall data particularly in facing the extreme rainfall. The decomposed sub-series obtained by wavelet transform can extract invaluable information which is enormously useful for future rainfall prediction. The results confirm that the hybrid model considerably improves the neural network ability to predict future rainfall.
Dynamic characteristics of liquid sloshing in cylindrical tanks filled with porous media
Authors: Tsao W H , Hwang W S
Published: October 2019

The dynamic characteristics of liquid sloshing in cylindrical tanks filled with porous media are analyzed in this paper. As the tank is subjected to the small external excitations, the flow is assumed to be in Darcy’s flow regime, and then the porous medium can provide damping effect linearly proportional to the fluid velocity. Based on the pore flow theory, the linear equivalent mechanical model with the damping effect due to porous medium is established. This equivalent model consists of a rigidly fixed mass and infinite sets of mass-damping-spring systems, which can exert the same total dynamic force as the linearized actual fluid field. The equivalent system can explain the dynamic characteristics of each modal response of sloshing in a cylindrical porous-medium tank. Therefore it is more convenient to analyze the sloshing behavior from the structural dynamic analysis point of view. By this model, the natural frequency and damping ratio of the cylindrical porous-medium tank are revealed. Both parameters are related to the tank dimensions, porosity and permeability of the porous medium.
Foam glass from municipal waste as a lightweight aggregate for cement mortar
Authors: Wattanasiriwech D , Nontachit S , Manomaivibool P , Wattanasiriwech S
Published: October 2019

Municipal waste glass has long been a problem because of its difficulty in disposal. In Chiang-rai province alone, it was approximated that improperly treated glass waste amounts to 20,000 kg per annum. Foam glass is a porous insulating material which provides the advantage of low-thermal conductivity, low density and fire resistance. This research aimed to prepare foam insulating glass using waste glass collected from local municipality. The glass was first cleaned and then crushed using a hammer mill. Further grinding using ball milling technique was done until glass powder was obtained. With the use of proper amounts of foaming agent, calcium carbonate (CaCO3), and binder, cassava gel, glass foams could be prepared at the temperature of 750 °C. Microstructure was observed using an optical microscope, while density was measured using water replacement. The obtained foam glass has a bulk density of 0.535 g/cm3 with approximated porosity of 77%. To observe ability as a lightweight aggregate, cement mortar with different amounts of glass foams was prepared. It was found that thermal conductivity linearly decreased while compressive strength increased when the amount of the foamed glass was increased. Compressive strength and thermal conductivity of the foam glass were estimated to be 2.43 MPa, of 0.23 W/m.K, making it a new economically promising lightweight aggregate for cement mortar.
Evaluation of high performance cementitious grouts for connecting precast concrete bridge deck panels
Authors: Yang Z F , Brown H J
Published: October 2019

The use of full-depth precast concrete panels for rehabilitation of bridge decks allows fast installation and all-weather construction. Typically, precast panels are prefabricated in a well-controlled environment, resulting in strong and durable products. Undoubtedly, they will perform well under the traffic loading and weathering. However, the panel joints that are closed later with grout pour may degrade prematurely, leading to a less desirable composite action. Obviously, the lack of overall system performance causes concerns that limit the wider application of this innovative construction method. Conventionally, cementitious grouts, epoxy mortars or polymer concretes are used for the closure pour. In general, epoxy mortars or polymer concretes have extremely low permeability and dry shrinkage, as well as good adhesion with the substrate; but they are difficult to mix and clean, very sensitive to moisture variations, and incompatible with the substrate under thermal and mechanical loads. As a result, deficient bonding may occur, particularly when longitudinal post-tensioning is not provided, causing leaking and rusting. Oppositely, cementitious grouts are easier to mix and more compatible with the concrete substrate; however, they are more prone to shrinkage. More recently, advances in cementitious materials resulted in the development of Ultra-High Performance Concrete (UHPC). While this material has demonstrated exceptional performance when used for the closure pour; it requires special mixing to well disperse the particles and careful attention must be paid to the construction and curing practices to achieve enhanced mechanical and durability properties. As a result, testing of various types of grout materials is essential to establish the quality and serviceability of these materials. It is the intention of this paper to evaluate the performance of different cement-based grouting materials and to provide bridge engineers with useful database as to what materials are preferred for a specific project.
The analysis of influential factors for urban water supply system considering causality with time-series data
Authors: Ryu J W , Park H K
Published: October 2019

Recently, the research on critical infrastructures have been extended its boundary and some previous research analysed interdependency between infrastructures tried to suggest operation and management policy of the infrastructure. This highlighted the importance of systemic approach such as System Dynamics. But there still exist the limit to select the modelling component in terms of causality. In this study, convergent cross mapping was applied to time series variables in Songpa-gu and Gangdong-gu in Seoul, South Korea. Selected variables include operating variable of water supply system, floating population and meteorological variables and 330 observations were collected. The result shows that daily average temperature and floating population that are equivalent to mobile population influences to the daily water supply, and vice versa. Other weather factors such as average precipitation and wind speed showed little causality with the daily water supply. The influential factors of water supply system can be investigated with convergent cross mapping and the result can be utilized for the pre-process of other methodology such as LSTM in short-term water demand prediction. It is expected to collect more available data to improve this study further.
Water quality risk assessment for drought conditions: A case study of the Korean Nakdong River basin
Authors: Kim J -S , Lee J -H , Park S -Y , Chen J , Chen H
Published: October 2019

As the frequency of drought from climate change increases and the severity of drought become worse, it is imperative to prepare appropriate countermeasures against severe droughts. Despite the severe impacts of droughts on coupled humans and environmental systems, we do not fully understand the consequences of severe droughts affecting the environment. Therefore, the present study proposed a quantitative assessment index for water quality risk for extreme droughts to improve the safety of water environment management by providing flows to areas vulnerable to the drought. The application of this study is the Nakdong River basin in Korea, which has assessed the vulnerability of water quality to severe droughts as water quality deterioration problems continue to be experienced event after the river restoration project was completed. The results of this study are expected to provide scientific environmental drought monitoring information in a changing climate.
Research on the differential settlements of mat foundations
Authors: Ma C-M , Chen Y-Y
Published: October 2019

Mat foundation is a very commonly used foundation type. There are many advantages in adopting mat foundations including the effects of loading compensation, full utilization of underground space, lowering foundation settlements and increasing the factor of safety of bearing capacity for foundations etc. In addition, because of the high stiffness of the mat foundation and foundation girders the differential settlements could be effectively decreased, which would in turn increase the safety of structures. The differential settlements of the foundation will produce extra stresses in the structure. At the worst it will make the structure members failure. There are many factors which would affect the differential settlements of the foundation, which include the uneven distribution of structure column loading, the subgrade reaction of foundation soils (or so called soil spring coefficient), the combined stiffness of the foundation plate and foundation girders, the shape and size of the mat plate etc. The main objective of this research is to use the finite element method to simulate the interactions between the mat foundation and the underneath soils. It will focus on the systematic research on all possible factors affecting the differential settlements of mat foundations. The influence of each factor on the differential settlements will be studied and identified. The influence charts for the differential settlements for each individual factor will be proposed. Finally a reliable method using these influence charts to predict the differential settlements of mat foundations will be developed, which will be verified by practical examples.
A prediction model of bubble size from experimental factors and fluid properties using multiple linear regression algorithm
Authors: Park G B , Park H K
Published: October 2019

In a clean water test, the bubble diameter coming out through the circular diffusers was measured by photographic method and binary image analysis. Strong correlation was found between bubble diameter and superficial velocity. The depth of water has been added to existing experimental factors that include pore size and superficial velocity. By using dimensional analysis and multiple linear regression algorithm, a prediction model of bubble diameter was developed considering fluid properties and experimental factors including the depth of water. The developed model(EF-Model) was compared with the existing bubble diameter prediction models for the sample data. As a result of estimating the bubble diameter for the superficial velocity, the EF-Model has a lower RMSE and higher accuracy result than the existing models.
Development of waste expanded polystyrene flexible coating material in concrete waterproofing
Authors: Hsu K -L
Published: October 2019

How to deal with the waste polystyrene and rubber has become a key research topic recently. This research attempted to process the waste rubber and waste polystyrene with chemical additives to produce the flexible coating material for concrete waterproofing. Based on the best guess on the configuration of the coating constituents by the grid-point method, the design experimental levels (3 levels) for different coating constituents could be decided by introducing the golden-section ratio. Then, the orthogonal experimental design method L27(313) was adopted by choosing surface-drying time, viscosity, water permeability, tensile strength, pull-elongation rate as orthogonal indicators. Through orthogonal experiment design method, the most influential coating constituents on different indicators were experimentally investigated. The results of the water permeability test showed that the water permeability of the coating was 0 mL and the water resistance was good. The analysis results of the orthogonal table showed that the material factors and levels affecting the tensile strength of the waste EPS flexible waterproof coating were: plasticizer (10.09%), polystyrene (17%), rubber powder (14%) and curing agent (5.1%), and the material factors and levels affecting the elongation of the waste EPS flexible waterproof coating are: plasticizer (2%), curing agent (5.1%), rubber powder (11.91%) and EPS (17%). This result can be used as a reference for adjusting the proportion of waste EPS flexible waterproof coating in the future.
Sub-urban land classification using GF-2 images and support vector machine method
Authors: Cui H S
Published: October 2019

Remote sensing classification is an important part in the process of extracting effective image information and research the foundation of land cover change. While traditional remote sensing image classification methods have some problems on low accuracy and uncertainty, machine learning algorithms are gradually applied to remote sensing classification. In this paper, support vector machines (SVM) method with high training speed and low computation burden is adopted to classify land cover based on GF-2 image, which is the domestic optical remote sensing satellite with high spatial resolution. The results show that: The overall classification accuracy by SVM is achieved 72.59% and the coefficient of Kappa is 0.65. The classification map is highly consistent with the original image, especially higher classification accuracy of cropland and tree. Partial regions were misclassified as shadow that didn’t reflect the real land objects. As a whole, there is favorable classification quality using SVM method and GF-2 multispectral bands.
Study of parametric pump performance curve based on surface fitting
Authors: Yuan Y , Xu X D , Li J D
Published: October 2019

By selecting the appropriate basis functions according to the variation of vane pump regulating performance curves, we analysed the relationship in blade angle, flow, and head (or shaft power) based on surface fitting, and we established a parametric model, proposed the solution of the problem. The calculation of the example shows that the model has a high correlation coefficient, and has a simple mathematical expression, which is helpful for further application and popularization.
Impact assessment of dredging on fish eggs and larvae: A case study in Caotan, South China
Authors: Yang Z F , Chen D , Xiao B P
Published: October 2019

Dredging can lead to an increase in suspended sediment concentration, which poses a threat to the survival of fish eggs and larvae.To assess the impact of dredging on fish eggs and larvae, Caotan Fishing Port in south China was chosen as a case in this paper. The threat to the survival of fish eggs and larvae, i.e. the increased suspended sediment concentrations, is identified through analyzing pollution sources in dredging operations; the number and species of fish eggs and larvae were obtained through on-site investigations; the concentration and influence range of suspended sediments are calculated by pollutant diffusion equations; the loss of fish eggs and larvae caused by suspended sediment during dredging is evaluated according to Technical Regulations for the Impact Assessment of Construction Projects on Marine Biological Resources (SC/T 9110-2007) in this paper. It can be preliminarily concluded that the suspended sediments produced during dredging and backfilling have an impact on the survival of fish eggs and larvae, and will reduce their quantity. Currently, loss analysis methods are based on empirical formulas, and more accurate quantitative analysis needs to be further studied.
Application of the internal substructure method for seismic wave input in structural dynamic analysis considering SSI effect
Authors: Bao X , Liu J B , Li S T , Wang D Y , Wang F
Published: October 2019

A new internal substructure method for seismic wave input in soil-structure systems was proposed very recently. This method simplifies the calculation of equivalent input seismic loads, and avoids the participation of artificial boundaries in the process of seismic wave input. In this study, we introduce the application of the internal substructure method in the structural seismic analysis considering soil-structure interaction (SSI). A typical frame structure is taken as the example, and the effect of SSI on the structural dynamic response is studied.
The influence of “night” factors on urban earthquake disaster prevention
Authors: Gu Y , Wu X Y , Lin J
Published: October 2019

Existing urban planning and urban disaster prevention measures are mostly based on urban space and crowd behaviour patterns during the day, ignoring the anti-disaster demand for urban space at night. Since people‘s perception of urban space is quite different by night and daytime, with behaviours patterns varying much accordingly, thus the consequences of urban disasters occurring at night are more serious than those occurring during the day, including the trigger of secondary disasters, which are more harmful. This paper collects and analyses the data collected from the target location, and finds that the night factor has a certain degree of impact and change on urban disasters. Through the construction and improvement of disaster prevention lighting facilities, it can guarantee the normal function of evacuation and avoidance paths and areas at night to a certain extent, and help the affected people to carry out effective self-rescue and mutual rescue at night, thereby reducing the impact of disasters and protecting the lives of personnel.
The Role of Muhammadiyah in Sustainable Development Through Community Empowerment Program
Authors: Ahmad M , Soemanto RB , Drajat TK , Edi W
Published: October 2019

Sustainable development is the development goal of every country, including Indonesia. The process of sustainable development has positioned the community as the subject with the main actor of the development is the community itself. Regarding this context, the process is performed through community empowerment approach. Muhammadiyah is the biggest non-governmental organization in Indonesia which engaged in religion, social community, economy, education, environment, and health sectors. This study aimed to discover the role of Muhammadiyah in the sustainable development of Indonesia. The method used in this study was mixed method as the combination of quantitative and qualitative approaches. The results of the research have concluded that Muhammadiyah has positive and significant roles in sustainable development of Indonesia, including from the evaluation results of the restoration program of tropical forest ecosystem in East Borneo Province and social-economic empowerment on vulnerable groups in Yogyakarta Province. The approach of Muhammadiyah through community empowerment program has been successful to improve the knowledge, change of attitude, and skills of the facilitated community. The community empowerment approach was implemented by Muhammadiyah to encourage public participation in sustainable development.
Simulation analysis of the influencing factors on the wind environment around the hilly terrain
Authors: Chen Q , Liu Y
Published: October 2019

The wind environment condition of hilly terrain is closely related to wind resources utilization. In this paper, based on Fluent numerical simulation method, the wind flow characteristics around the hill topography under the influence of varied slopes, incoming wind speeds, heights and roughness are analyzed and summarized. It can be drawn that for the range from the hillside to the top on the windward side, the slope has a significant effect on the wind speed. Within the 100m height above the ground, when the hill is steeper, the wind speed is significantly enhanced. At the top of the hill, the wind speed’s maximum increment is 1.5 times of the incoming value. When the wind goes across the hilltop, the factors including the slope, height and roughness, have great influence on the wind environment on the leeward side. When the slope is greater than or equal to 0.5, the phenomenon of eddies present and the range of influence extends downstream. The wind speed weakness trend can also be found when the height and roughness increase.