bluuebunny/crossref_metadata_2025 huggingface dataset:
Contamination and health risk assessment of heavy metals in soil surrounding an electroplating factory in Jiaxing, China
Authors: Liu Ting-ting
Published: September 2019

To investigate the heavy metals pollution degree of in the soil around an electroplating factory and evaluate the health risk caused by contaminated soil. Based on soil in the vicinity of an Electroplating factory in JiaXing, soil in different horizontal distance and depth below wind direction direction of research region were sampled, and the heavy metal content were measured. The heavy metal pollution status was analyzed by using index of Geoaccumulation and health risk assessment. The results showed that the average index of Geoaccumulation (Igeo) of the 7 heavy metal (Cr, As, Pb, Ni, Cu, Zn, Cd) in the region was higher than 5, and it was at the extremely serious pollution level. The content of As in the middle part soil (10～20 cm) reaches the maximum of 2109. 25mg/kg, As pollution is relatively serious, and the average value exceeds the limit by 119.39 times. Cd is the least contaminate, but still reaches a medium-pollution. EDI non-carcinogenic exposure to As was greatest in children when ingestion of oral food. Conclusion Health risk assessment indicates of As intake by oral food has far exceeded the warning value, and there exist a high Risk of cancer, while Ni has a potential Risk of cancer. Therefore, we should pay great attention to these two heavy metal. and prevention and treatment of the polluted soil.
Research on New Geothermal Cascade Utilization System Suitable for Rural Areas
Authors: Zhao Fei , Gong Xian , Sun Pengcheng , Zhang Binbin , Bi Wenxin , Liu Guodeng
Published: September 2019

Geothermal energy is a kind of sustainable renewable and clean resources. However, when using this energy source, there are serious problems such as excessive tail water discharge and insufficient utilization of geothermal energy. Especially in rural areas, how to use geothermal energy at low cost and efficiently is an urgent problem to be solved. The use of geothermal cascade can reduce the temperature of tail water to a certain extent, make full use of geothermal energy in each temperature section, and increase the utilization rate of geothermal energy. Based on the research status of geothermal cascade utilization at home and abroad, this paper proposes a new type of rural geothermal cascade utilization system, and attempts to analyse this system, and finds that this system can increase the utilization rate of geothermal energy at low cost.
Environmental Impacts and Countermeasures for Hydraulic Fracturing in Shale Gas Development
Authors: Li Wenjuan
Published: September 2019

Shale gas is a kind of clean and efficient energy resource and chemical raw material. Hydraulic fracturing is the popular technology for extracting shale gas from extremely tight shales by enhancing porosity and permeability. However, the environmental impacts of such technology have aroused public concerns, including earthquakes, water contamination and water consumption and so on. In this article, the author reviewed the main environmental impacts of hydraulic fracturing in the US and China’s shale gas development practice, and then analyzed the mechanism for such possible impacts and the facts in development practice. Furthermore, the author summarized the countermeasures for these environmental impacts and provided advice for shale gas development in environment-responsible manners. The author advised: (1) strengthening science and technology innovation for new fracturing fluids and waste treatment; (2) formulating laws, regulations and standards for evaluation and management; (3) optimizing supervision and management and popular science propaganda.
Analysis of water resources in the Li River Economic Zone
Authors: Zhu Yanguang
Published: September 2019

A series of water resources data (from 1991 to 2014) were obtained from Guilin Hydrological Station, on which the statistics of the annual average total water resources and the amount of available water resources in the Li River Economic Zone were calculated. Results showed that the annual average total water resources of the Li River Economic Zone were93.13 hundred million m3. Under the precipitation guarantee rates of 50%, 75% and 95%, there were 92.55, 68.40 and 65.21 hundred million m3, respectively. At the same time, the annual average available water resource the Li River Economic Zone was 47.57 hundred million m3, which were 47.01, 34.98 and 22.94 hundred million m3 under the 50%, 75% and 95% precipitation guarantee rates, respectively. The analysis results provide a theoretical basis for the effective use of water resources in Guilin.
Research progress in loess landslides forecast and prediction based on assimilating multi-source information
Authors: Bai Xuejiao , Sang Lingzhi , Bai Guichen , Kang Hongxia , Liu Zhen
Published: September 2019

China’s one-third western region disseminated in Qinghai, Ningxia, Shaanxi, Gansu and other provinces witnessed landslide disasters in recent decades over loess and loess-like soils with special composition and properties. Loess landslides occur more frequently with serious constrained in the development of regional economy following the sharp increase in human engineering activity, especially from the launch of China’s Grand Strategy of Developing the West region of china. Therefore, the loess landslide forecasting and prediction is a hot topic in the study of environmental geology. This research demonstrates the situation and progress of the landslide forecasting and prediction motivated by the theoretical methods and technological means of landslide forecasting and prediction, the study of remote sensing survey of landslides, the study of multi-source information fusion and the study of loess landslide forecasting and prediction, followed by the prediction model for loess landslide based on assimilating multi-source information with its specific technology route anticipation based on assimilating multi-source information.
Visual Assessment of Landing-site Geography on Landing Feasibility
Authors: Jin Zhang , ShuJun Li , FanJun Meng
Published: September 2019

The primary problem and critical procedure that must be considered for landing operations is landing-site geographic environmental elements. Based on the impact of various geographical factors on landing, such as submarine slope, submarine characteristics, tides, tidals and waves, this paper simultaneously applied the methods of mathematical description, quantitative evaluation, three-dimensional visualization, and integration analysis of multiple factors. Taking dynamic changes of geographical elements into consideration, a visual measurement for landing alternatives on account of geographic environment background was hypothesized, and the dynamic comprehensive evaluation was displayed. Experiments verify the effectiveness and superiority that mentioned, and can provide reference for the probability of landing.
Analysis of seafloor reverberation related characteristics based on sea trial data
Authors: Wang Meina , Feng Jintao , Sun Chao , Bian Gang
Published: September 2019

Ocean reverberation is one of the main factors affecting sonar performance. Studying the spatio-temporal correlation statistical characteristics of reverberation is of great significance for sonar detection and suppress reverberation, and is a problem that sonar designers have always been concerned about. This paper first gives an overview of the sea trial test; and analyzes the signal strength of the reverberation signals with different frequencies under different terrain conditions, which proves the reliability of the sea trial data. By processing the time-space correlation characteristics of the seabed reverberation data, the relationship between time-space correlation characteristics of the seabed reverberation data and the frequency and form of the transmitted signal and the seabed topography is obtained, which provides a theoretical reference for reverberation suppression and application.
Suitability Evaluation of County Construction Land under the Constraint of the Key of Ecosystem Services
Authors: Qi Ma , Xiaohe Ma
Published: September 2019

As the early stage of land planning and resource management, the evaluation of land use suitability provides a scientific basis for rational and effective use of limited land resources. This paper takes Chang’an District of Xi’an City, Shaanxi Province as an example, and the key of ecosystem services was taking as an important factor for developing the evaluation system of the suitability of construction land.The results show that the area of the highly suitable construction land in Chang’an District is 766.03km2, accounting for 48.18% of the total study area. The forbidden construction area is 585.00km2, accounting for 36.79%. Moderately suitable and low suitable construction regions account for 15.03%. The suitable construction regions are concentrated in the northern part of Chang’an District, which is suitable for large-scale development of cities and towns. The moderately and low suitable regions are mainly distributed along the northern foot of the Qinling Mountains. The Qinling Mountains have importance level of ecosystem services, which mostly are forbidden construction regions. The research results will provide a scientific reference for regional construction and development.
Comparison and Analysis of Evaluation Indexes regarding China’s Eco-industrial Parks
Authors: Fu Yun , Zhu Yi , Lin Ling , Gao Dongfeng , Ma Yan
Published: September 2019

The industrial park plays a significant role in fueling the economic growth, expanding the foreign trade and promoting the industry cluster. However, due to the blind investment attraction, and the poor perspectiveness and systematicness of the planning, the industrial park also becomes the centralized pollutant emission area. Chinese government has implemented many meaningful explorations in promoting the ecological development of the industrial parks, successively introduced the demonstration eco-industrial park, circular transformation of industrial park, and green park construction, and separately established the evaluation index system and policy guarantee system. This paper reviews the ecological greening development course of China’s industrial parks, thoroughly introduces the evaluation index system of demonstration eco-industrial park, circular transformation index system of the industrial park, and the green park evaluation index system, and compares and analyzes the commonalities and differences of such three sets of index systems from the theoretical basis, target positioning, index requirements, index universality, evaluation methods and many other dimensions, based on which this paper proposes the policy suggestions regarding the ecological greening development of China’s industrial parks.
Research and Application of Water Pollution Control Technology
Authors: Xueqing Wang
Published: September 2019

The rapid development of the modern economy has also brought huge impacts on water resources. So far, the water pollution situation in China has been serious. The water that meets the drinking water hygiene standards only accounts for 10%, and the national water resources has been polluted up to 50%. Moreover, the types of modern water pollution are increasing, and the degree of water pollution is gradually deepening. Faced with the above situation, this paper starts the analysis and preliminary treatment methods of the status quo, grade, and pollution types of water pollution, and takes a representative of activated sludge method and biofilm method as an example to carry out in-depth introduction and analysis, providing theoretical reserve for water pollution control and construction projects for the future.
Construction and Case Study of Rural Environmental Value-added Evaluation System Based on Emergy Theory
Authors: Wan Ajun , Tu Runqiu , Yue Weidong , Liu Yixuan , Wu Yunpeng
Published: September 2019

In order to solve the problem that the current rural environment value-added benefits are difficult to estimate, based on the emergy theory, this paper built a rural environmental value-added evaluation system with resources, development, space and environmental protection as the main elements, including 18 sub-indicators. This study also quantitatively evaluated the value-added situation of ecological environment in Queshan Village, Shanxi Province, from 2010 to 2015, and put forward development strategies. It is found that from 2010 to 2015, the resource factor decreased from 0.02 to 0.00, the development factor decreased from 0.16 to 0.06, the space factor increased by 0.19 from 0.07, the environmental protection factor decreased from 0.21 to 0.05, and the composite index decreased from 0.61 to 0.31. The results show that the ecological environment of Queshan Village was negative in the evaluation period, and the development showed an imbalance law and an unsustainable development trend. This method constructs a quantitative analysis system for rural environmental value-added evaluation, and has certain theoretical and practical value in rural planning guidance and evaluation.
Towards Eco-Vitality Pedestrian Street: Research on the Design of Traditional Commercial Street Oriented by Green Energy and Thermal Comfort
Authors: He Meiting , He Wenting
Published: September 2019

This paper attempts to take the thermal comfort model and the concept of green energy conservation as a new perspective to study the traditional commercial pedestrian street, trying to make the transformation of the traditional pedestrian street achieve the goal of ideal comfort, taking the traditional West Street in Jiading District of Shanghai as an example. Firstly, through cases study of traditional commercial streets in southern China, the traditional wisdom of vernacular buildings and spaces in responding to regional climate is analysed in detail. Secondly, according to the detailed information of the project, combined with the field thermal imaging survey, the performance of simplified models of different spaces is simulated by dynamic simulation tools (such as Ladybug, Honeybee and Butterfly based on Rhino-Grasshopper). The multi-objective performance simulation optimization aims at thermal comfort, wind and sunshine environment, and compares thermal comfort at different spatial levels and at different times. Considering the thermal comfort and activities of commercial streets in the research project, it is found that there will be great differences in thermal comfort performance under different space forms, and the micro-environment design will effectively improve the comfort of the area, which is conducive to creating an eco-friendly and lively street environment.
Effects of mulching with hyperaccumulator straw on soluble sugar content of accumulator Perilla frutescens
Authors: Wang Xun , Xiang Gang , Lin Lijin , Liao Ming’an
Published: September 2019

The effects of mulching with four hyperaccululator plants Youngia erythrocarpa, Galinsoga parviflora, Gnaphalium affine and Crassocephalum crepidioides straws on the soluble sugar content of P. frutescens under cadmium stress were studied by a pot experiment. The results showed that the straw-mulch C. crepidioides and G. affine increased the soluble sugar content of P. frutescens. But, the straw-mulch Y. erythrocarpa and G. parviflora decreased the soluble sugar content of P. frutescens. The soluble sugar content in shoot of P. frutescens for the treatments of mulching with straw of C. crepidioides and G. affine were 5.18% and 25.83% higher than control. In conclusion, the treatment of G. affine is the best, followed by C. crepidioides.
Research on Green and Low-carbon Development Strategy of Chinese Circulation Industry
Authors: Guo Haihong
Published: September 2019

In recent years, with the continuous development of social economy, Chinese circulation industry has developed rapidly, and has become one of the important industries causing pollution in China. In order to build an ecologically civilized country, China needs to develop the circulation industry into a green and low-carbon industry. This paper analyses the problems in the development of green and low-carbon circulation industry in China. Based on the problems existing in the development of circulation industry, this paper puts forward some pertinent suggestions on the low-carbon development of circulation industry from two aspects of circulation enterprises and the Chinese government.
Slow Strain Waves in Rocks as Potential Precursors to Seismic Hazard
Authors: Bornyakov S A , Salko D V , Shagun A N , Dobrynina A A , Usynin L A
Published: September 2019

The article reports on instrumental monitoring of rock deformation in the South Baikal geodynamic test site. Based on the analysis of the time series of data sets, two groups of strain components are distinguished by differences in their origin and wave properties. Strain components in the first group are caused by external factors, such as lunar-solar tides and atmospheric pressure variations. The second group includes non-periodic, random and periodic (constant) components generated by internal tectonics. Non-periodic components are manifested as single deformation impulses that differ in intensity and form, and are related to slow displacements along large active faults, which occur outside the monitoring sites. Besides, non-periodic components are related to fast displacements at block interfaces within the monitoring sites. The periodic (constant) component is related to the India-Eurasian collision. It is represented by slow strain waves, which lengths amount to 400–500 m, with amplitudes of few microns, and periods of (1-3)·10−4 Hz. The strain wave directions and rates of their migration in space vary with time. The identified trends of changes of the wave parameters in the South Baikal geodynamic polygon can be related to the preparation of a strong earthquake.
Electromagnetic soundings of the earth crust and deformation processes in geosphere of the Bishkek geodynamic polygon (BGP)
Authors: Sychev V N , Bogomolov L M , Sycheva N A
Published: September 2019

A new processing of materials on variations of seismicity of the Bishkek geodynamic polygon (BGP) under effect of electromagnetic (EM) soundings of geological medium has been carried out. The revision of these materials is topical due to following issue. During the period of 1983-1989 the disharges of the capacitor battery (so-called cold runs) were used for supply for EM soundings in addition to the MHD generator launchs (hot, or fire runs). Moreover, alternative source of EM soundings by bipolar current pulses (namely, the ERGU-600-2 equip) was used in the times of 90s. But previous studies paid low attention to electric injection to Earth Crust besides MHD generator hot runs. Motivated by such state of the art we have analysed temporal dependence of Benioff strain on the territory of the BGP in the overall period of EM soundings (from 1983 up to now). The alterations of EM soundings sources and operational modes have been taken into account. But our approach has reveal no no noticeable change seismic regime (by the Benioff strain data) during the nineties in close surrounding of the injecting dipole.
The modulation of the eigen oscillation in the harbours by tide
Authors: Kovalev P D , Kovalev D P , Zarochintsev V S
Published: September 2019

In the port harbors there are reoccurring a reciprocating movements of water, which a connected with strong waves at sea. Threatening the safety of ships and berthing facilities, these movements, called harbor oscillations, are caused by the infragravity waves. They occur when their periods are close to the periods of eigen resonant oscillations of the water area. As a result of the observations, it was found that the seiches modulated with the frequency of tidal waves. This phenomenon cannot be explained by analogy with the modulation of infragravity waves. Observations show that the primary reason is an enhancement of energy loss over the low-tide surfzone bottom profile, while in the port harbour significant currents are observed only in the harbor entrance zone. It is shown that the reason of modulation is a change in the water level in the harbor, which occurs nonlinearly. Using the Duffing equation, the dynamics of a nonlinear dynamic system a liquid oscillating in a port under the external excitation by tidal waves and swell, is analyzed. It is shown that under the influence of swell at the harbor entrance can lead to chaotic vibrations in the harbor, which can be dangerous for ships.
On the problem of geochemical signatures of mud volcanoes and sediment-hosted hydrothermal systems
Authors: Ershov V V , Nikitenko O A , Perstneva Yu A , Bondarenko D D , Ustyugov G V
Published: September 2019

The present paper is a comparative study of geochemical characteristics of the emissions of the Yuzhno-Sakhalinsky mud volcano and the sediment-hosted hydrothermal systems Salton Sea and Lusi. The comparative analysis was performed using the data on the content of Cl, Br, SO4, Li, Na, K, Ca, Mg, B, Ba, Sr, Si, oxygen-18 and deuterium in the discharged fluids, as well as on the content of CO2, C1-C5, carbon-13 in CO2 and CH4 in the released gases. It showed the absence of any distinct systematic differences in geochemical parameters between mud volcanoes and sediment-hosted hydrothermal systems. This suggests, inter alia, a need for a detailed geochemical classification of mud volcanoes, which to this day has not been elaborated.
Thermal springs of the Ushishir volcano (Russia)
Authors: Zharkov R V
Published: September 2019

The article presents the results of researches of thermal waters of South-Eastern solfataric field of Ushishir volcano (Yankicha Island, Central Kurile Islands) in 2007 and 2015. Detailed studies of the physicochemical properties of the hydrothermal springs of the volcano were begun in 1950-60 years. Modern studies have confirmed the stability of physical and chemical parameters of hydrotherms. Modern thermal waters (temperature up to 100 °C), as before, can be attributed to acidic (pH 2.8-3.6), highly mineralized (TDS 23-36 g/l), sodium chloride. The chemical composition and ratio of the main macroelements of hydrotherms are close to the sea waters of the region. The uniqueness of these waters distinguishing them from other coastal hydrotherms of the Kuril Islands is their high acidity. The increased content of balneological elements (Br – 107 mg/l; B – 36 mg/l; I – 0.5 mg/l) in hydrotherms determines their high therapeutic value, which allows them to be used in the treatment and prevention of a wide range of diseases.
Rare earth elements in waters from the Yuzhno-Sakhalinsky mud volcano, Far East of Russia
Authors: Ershov V V
Published: September 2019

For the first time, data have been obtained on the concentrations of REE in the subsurface fluids of the Yuzhno-Sakhalinsky mud volcano, as well as in the spring at the foot of this volcano. It has been demonstrated that the REE concentrations in the waters of the studied volcano are significantly higher than in the waters of the mud volcanoes of Junggar Basin. It has been ascertained that the total concentration of REE in mud volcanic waters does not depend on their mineralization, yet it correlates with the concentration of Al. This is probably caused by the sorption of REE on the fine particles of clay suspension. The obtained ranges of REE have a high positive Eu anomaly, which is likely to be an artifact due to the relatively high concentration of Ba in the studied waters.
The destruction of rocky shores at high latitudes according to precision measurements data
Authors: Afanas’ev V V , Uba A V
Published: September 2019

New high-precision data on the surface destruction rates of a co-seismically raised bench as a result of the Nevelsk earthquake in August 2, 2007, Mw = 6.2 in Nevelsk allowed to determine that the destruction of subvertical coastal cliffs occurs with the speeds nearly an order of magnitude larger, than the speed destruction of subhorizontal bench surfaces. The role of wave influence in the benches formation is mainly reduced to the mobilization and removal of debris obtained as a result of frost weathering at negative air temperatures. High-precision orthophotos and 3D models of high coastal ledge composed of volcanogenic-sedimentary rocks made it possible to identify the cliffs destruction mechanisms with non-uniform strength and to determine their quantitative parameters. It was found that the destruction occurs along structurally weakened zones, as well as during the collapse of large rocks blocks due to the formation of wave-breaking holes in rapidly destructing tuffs. Suffosion in tuffs and their contacts significantly weakens the solid characteristics of volcanogenic-sedimentary mountain massives. The retreat of the coastal scarp brow formed by volcanogenic-sedimentary rocks can reach several meters per year under these conditions.
3-D structure of the discharging zone of the Daginsky hydrothermal system (Sakhalin Island) according to the ground penetrating radar method and well logs
Authors: Yu Pavlova B , Zharkov R V , Delemen I F
Published: September 2019

The paper presents the results of a comprehensive analysis of GPR data and geophysical well survey data (gamma-ray logging and self-polarization potentials) to study the 3-D spatial structure of the Daginsky hydrothermal system discharging zone (Sakhalin Island) and its hydrogeological situation. According to the GPR method, the paleo-valleys were identified, the morphology of which indicates the presence of runoff hollows, the accumulation of sandy-aleurite-clay sediments covered with peat formations. It can be concluded that the caprock in this area consists of a pack of water layers and permeable zones. Based on the data of geophysical studies in wells, three zones can be distinguished, each of which is characterized by the corresponding values of gamma activity and changes in the potentials of its own polarization. All this helps in identifying permeable thermally conductive zones. The data obtained are of practical importance.
Risk assessment of dangerous Aeolian processes within the Baikal rift zone
Authors: Tyumentseva E M
Published: September 2019

Among dangerous natural processes in the Baikal region we emphasize aeolian processes of high intensity which is due to dust storms caused by hurricane winds. The factors of the process development were studied, and special attention was paid to the wind regime and seismic activity, as well as to the catastrophic consequences and damage. We analyzed the number and duration of dust storms, calculated the deflation potential of the wind and the energy of the air flows. The morphology of aeolian relief forms, both deflationary and accumulative was studied. We forecasted sand dune drifts based on the analysis of the charted sand rose. Differences in structure, mechanism, and intensity of the processes are revealed depending on the hydroclimatic conditions during the monitoring period. In connection with global climate change, which is manifested in the Baikal region by an increase in the number of arid years of observations (35%), and the frequency of emergency situations associated with natural processes increases. It is necessary to continue the monitoring of aeolian processes in order to create long-term and short-term forecasts to avoid catastrophic consequences.
The Effect of Sintering Temperature on Bilayers Hydroxyapatite Coating of Titanium (Ti-6Al-4V) ELI by Electrophoretic Deposition for Improving Osseointegration
Authors: Juliadmi Dian , Harlendri  , Hon Tjong Djong , Manjas Menkher , Gunawarman
Published: September 2019

Bilayers hydroxyapatite (HA) coating using electrophoretic deposition (EPD) method has been applied into a biocompatible metal, Ti-6Al-4V ELI, in order to improve bioactivity of the alloy and then to accelerate bone remodeling and osseointegration during implantation. Two steps EPD process wasconducted for obtaining based layer consist of HA nanoparticles using voltage 3 volt for 3 minutes. It was then followed by second layer formation consist of HA micro particles using voltage 5 volt for 5 minutes. The coated alloy was then sintered at temperatures of 700°C, 800°C and 900°C for each 10 minutes within vacuum tube furnace at the sintering rate 20°C/s. Surface morphologies were examined using optical microscope and scanning electron microscope (SEM). The result of this study showed that bilayers hydroxyapatite coating onto Ti-6Al-4V surface was produced through EPD with those parameters. Sintering treatment at temperature 800°C gives thin, dense, even and crack-free coatings. The Ti-6Al-4V ELI surface is almost fully covered by bilayers hydroxyapatite (with surface coverage 98.6%) with adequate bonding (without lost weight of coating layers). An improper coating layer is obtained for lower (700°C) and higher (900°C) temperature. The sintered samples at temperature 900°C have micro cracks, void and debonding layers. It is expected such bilayers hydroxyapatite with sintering at 800°C can initiate mineralization and then make a quick osseointegration.
Fabrication of Micro Dimples Pattern Using Ball End Mill
Authors: Bin Zaki Muhamad Izdhar , Saptaji Kushendarsyah , Ramdan Raden Dadan , Kurniawan Tedi
Published: September 2019

In this paper, the effect of workpiece tilt angle and feed direction in producing micro dimple pattern using ball end mill tools were studied. Experiments were conducted using carbide ball end mill tools, aluminium Al 6061-T6 workpiece and using CNC machine. Three workpiece tilt angles are selected 0°30° and 45°; and two feed directions z-axis and x-axis. Visual observations using Scanning Electron Microscope (SEM) and geometry measurements using laser scanning confocal microscope were conducted on the fabricated micro dimple patterns. The results show that the workpiece tilt angle produces less burr at the edge of the dimples compared to without tilt (0°). In addition, the workpiece tilt angle can avoid the formation of undercut at the center of the dimple. The workpiece tilt angle of 30° and z-axis feed direction produced better result compared to 0° and 45° tilt angles with the value of ratio diameter/depth closer to the theoretical value.
Effect of Composition and Pouring Temperature of Cu-Sn Alloys on The Fluidity and Microstructure by Investment Casting
Authors: Slamet Sugeng , Suyitno  , Kusumaningtyas Indraswari
Published: September 2019

The alloy composition and the pouring temperature are main parameters to avoid cast defects in the metal casting process. The aim of this study was to investigate the effect of tin composition and pouring temperature on the fluidity and microstructure of Cu-Sn alloys to minimize product failure. The material used in this study was Cu with the addition of tin composition (20-25)% Sn by melting Cu = 99.9% and Sn = 99.9%. The pouring temperatures were varied T1=1000°C and T2=1100°C. Mold for fluidity test was used the wax pattern with investment casting method. The wax pattern for mold of fluidity test shaped bars with a length of 400 mm, the width of 10 mm and cavity thickness varies from 1.5-5 mm. The mold material was used natural ceramic such as clay (SiO2). Increased of the tin composition decreases the length of fluidity, while the increased pouring temperature and the cavity thickness of the mold increase the length of fluidity. Increasing tin composition and pouring temperature increases the phase microstructure α and triggers the formation of columnar dendrites. The high rate of cast metal fluidity and the thickness of the mold cavity greatly affect the microstructure of the alloy.
Characterization of The Wear Resistance of 3D Printed Polylactic-Acid (PLA) in Water and Bovine Serum
Authors: Arifvianto B. , Putra A.T. , Prayoga B.T. , Mahardika M. , Suyitno
Published: September 2019

Three-dimensional (3D) printing has become an emerging technology for the fabrication of geometrically complex, patient-specific biomedical implants. However, several properties of the 3D printed material have not so far been fully understood. Among these properties, wear resistance is considered as the critical one for the 3D printed material that should be applied as a sliding component in an artificial joint prosthesis. In this research, the wear resistance of a 3D printed polylactic-acid (PLA) pin that slid over the surface of titanium plate was characterized in water and bovine serum by using a pin-on-plate tribometer. The result showed that the use of bovine serum could reduce the wear of the 3D printed PLA better than the use of the water as the lubricant. Based on the analysis of weight losses and worn surface morphology, polymer film transfer was proposed as the possible wear mechanism that occurred during the sliding of the 3D printed PLA pin over the surface of the Ti plate.
Corrosion Behavior Of New Type Titanium Alloy As Candidate For Dental Wires In Artificial Saliva On Fluctuating Temperatures
Authors: Affi Jon , Ihsan Fadhli , Fajri Hidayatul , Gunawarman
Published: September 2019

Titanium alloys are widely used for implant material due to high biocompatibility properties. It is well known that the corrosion resistance of titanium alloys is better than other metallic materials. However, if the alloys are applied for unknown condition such as wire in orthodontic application, the fluctuating temperature is important to be considered as parameter which influences on corrosion rate. In this study, the effect of fluctuating temperature on corrosion behavior of TNTZ was investigated. Two conditions of TNTZ were used in this study, i.e., Ti-29Nb-13Ta-4.6Zr aging treatment (AT) and TNTZ solution treatment (ST). For comparison, the commercial Ti6Al4V ELI was also used in this study. The corrosion rates of the samples were characterized in artificial saliva on fluctuating temperatures range between 10°C and 50°C by immersion testing. The results showed that the lowest corrosion rate for each variation of temperature was TNTZ ST. The corrosion process seems to decrease the hardness of TNTZ up to 26 VHN. The result also showed that the corrosion rate of TNTZ is much lower than that of Ti6Al4V in all cycles. Moreover, the hardness of Ti6Al4V decreases more significantly i.e., up to 77.2 VHN. The artificial saliva with fluctuating temperature induces corrosion process and decreases the hardness of the alloys.
Development Of Short Carbon Fiber Reinforced Aluminium Matrix Composites By Low Pressure Infiltration Process
Authors: Meng Xuan , Choi Yongbum , Matsugi Kazuhiro , Wentao Hu , Wenchang Liu
Published: September 2019

Short carbon fiber reinforced aluminium based matrix composites were fabricated by a low-pressure infiltration process. This study is amid for development of short carbon fiber reinforced aluminium matrix composites. Short carbon fibers of 10 vol.% was used to preparing preforms for the low-pressure infiltration process. Afterwards, pure Al and Aluminium alloy under temperature of 1073K were infiltrated into the preforms under an applied pressure of 0.4MPa. Microstructure and Vickers hardness as well as microstructure–property relationships of these materials were studied. Microstructure observations indicated that: the SiO2 binder was coating on the surface of short carbon fiber and distributed at the corner of carbon fibers in preforms. Short carbon fibers were homogeneously distributed in the matrix. Furthermore, properties of short carbon fiber reinforced pure Al and A336 alloy composites showed that: the relative density was 95.8% and 97.2%, respectively. Hardness of short carbon fiber reinforced pure Al composite increased by 76% comparing to the base pure Al, and short carbon fiber reinforced A336 alloy composite increased by 10% comparing to the A336 alloy.
Effect of Aging Time on Characteristics of ADC12/SiC Composite with Addition of Sr Modifier and Al-5TiB Grain Refiner
Authors: Syahrial Anne Zulfia , Salman Muhammad , Utomo Budi Wahyu
Published: September 2019

An aluminium composite is developed as a light material with high strength for transportation application. Aluminium ADC 12 matrix was reinforced with SiC and added with Al-5TiB grain refiner and Sr modifier which is fabricated by stir-casting. The composites then were T6 treated for the various aging time from 2, 6, 10, 15 and 24 hours. The composites were characterized including tensile strength, impact resistance, hardness testing, wear resistance, density and porosity as well. The microstructural analysis to obtain the microstructure and phases changed after T6 using SEM-EDS and confirmed by XRD. Results show that T6 treatment has affected the morphology of primary and eutectic Mg2Si, as well as precipitation of metastable β’-Mg2Si from the aging process. T6 heat treatment has improved mechanical properties for all composites compared to as-cast composites. The highest ultimate tensile strength value and hardness are shown to be 144.5 MPa and 64.467 HRB after T6 for 6 hours at 170°C.
Nanotube Formation And Surface Evolution On Hydrothermally Treated Ti In Alkali Solution
Authors: Rukini Asywendi , Sukyoung Kim
Published: September 2019

The present study intends to check which nanotube formation mechanism match the surface evolution on bulk Ti surface after soaked in hydrothermal treatment. Polished cp-Ti disks were hydrothermally immersed in various concentration NaOH for 1h, 2h, and 4h at 220°C. The SEM observations and XRD studies showed a sequence transformation from polished Ti surface into titanium oxide with plate shape and leave-like structure in the beginning. Bigger plates or leaves oxide then evolved into sodium titanate nanorods that finally became nanotubes as the immersing time lengthened. Apparently self-assembly and partial dissolution were the most applied mechanism to explained the sodium titanate formation. Plate and leaves-like oxide mainly formed by dissolution of Ti metal followed by precipitation of TiO6 in self-assemble manner as the resultant of reaction between Ti(OH)3
+ and OH−. While, nanorod and nanotube structure were produced by partial dissolution of leaves structure followed precipitation of sodium titanate by reaction of Na+ with HTiO3
− generated from OH-reaction with Ti metal and TiO6.
Air Jet Erosion Study on Stir Casted Metal Matrix Composite Aluminum-SiC
Authors: Longalayuk M. , Ruskandi C. , Setiamarga B. H.
Published: September 2019

For equipment that operates in high-speed abrasive media, erosion will be the major factor for its failure. Metal Matrix Composite (MMC) Aluminum-Silicon Carbide has been developed for improving the lifetime for such application.

In this research, MMC Al-SiC has been made using Al-7075 scrap with 5%, 10%, and 15% SiC powder addition. This MMC was manufactured using stir casting technique with 1% Magnesium addition. Optical metallography has been done to know the SiC distribution homogeneity. Erosion resistance of the MMC was studied using Air Jet Erosion Test with Alumina powder as abrasives.

The microstructural study showed that MMC Al-SiC has been successfully manufactured although the SiC particle distribution has not been fully homogeneous yet. Air Jet Erosion Testing revealed that the addition of 5% SiC powder was optimal in increasing its erosion resistance. The SiC addition from 10 to 15% did not improve its erosion resistance significantly.
Study of Si Surface Adsorption Towards Hydrogen Molecule
Authors: Dhaneswara D , Fajar Fatriansyah J , Bachtiar Yusuf M , Hanif Abdurrahman M , Riski Kuskendrianto F
Published: September 2019

Recent approaches to address more efficient method on storing hydrogen by using adsorbent materials has been done. The hydrogen adsorption on silicon has been studied through molecular dynamics simulations and experiment by researchers. We conducted molecular dynamics simulation using a Lennard-Jones potential to demonstrate the hydrogen adsorption capability of silicon surface (001) and (111) with various temperature applied. The amount of hydrogen adsorbed by silicon surfaces are higher as entropy of the system decreases. Without considering entropy, Si (111) has higher adsorption capability due to its lower energy surface than Si (001).
Synthesis and Characterization of Ca-doped Li4Ti5O12Using CaCO3from Chicken Eggshell as a Dopant for Lithium-Ion Battery Anode Material
Authors: Priyono B , Ibrahimi D K , Syahrial A Z , Jodi H , Subhan A , Nugraha M R
Published: September 2019

In order to improve the performance of Li4Ti5O12(LTO) anode, this research was focused on Ca2+ion doping as a substitute to Li+ion to form Li4-xCaxTi5O12with values of x=0, 0.05, 0.075, and 0.125 using solid-state reaction. The Ca2+ion source was CaCO3which synthesized from the chicken eggshell. The LTO was prepared by a solid-state method using TiO2Degussa. The pristine LTO and Ca-doped LTO sample powder was characterized by XRD, SEM, and were also tested its electrochemical performance by EIS, CV and CD. The CaCO3dopant characterization results showed CaCO3in calcite polymorph as the main phase, with agglomerated fine particulate morphology and high purity. Characterization of LTO sample powder with XRD revealed that dopant Ca successfully enter the structure of LTO spinel, with maximum addition level x=0.05, which excessive addition led to CaTiO3impurity forming. SEM result showed all Ca-doped LTO have almost similar morphology, which was agglomerated particulate. Ca-doped LTO samples have smaller particle size compared to pristine LTO. Electronic conductivity improvement was spotted at all of Ca-doped LTO sample, with Li3.75Ca0.125Ti5O12(LCaTO-3) showed the lowest charge transfer resistance of 29.5 Ω. Li3.75Ca0.125Ti5O12(LCaTO-3) also had the highest initial discharge capacity of 168.2 mAh/g. Nevertheless, in high rate application, the best performance was showed by Li3.85Ca0.075Ti5O12(LCaTO-2) with the discharge capacity of 30.2 mAh/g at 12 C, which capacity retention percentage of 21.43% compared to its discharge capacity at 0.2 C.
The Effect of Minimum Distance Between Bamboo Strengtheners on Flexural Strength of Bamboo Reinforced Cement
Authors: Ramelan Aditianto , Rachmantyo Riska , Hanif Ahmad Yasier , Sasmita Firmansyah
Published: September 2019

Various species of Bamboo is widely available in Indonesia. Usually it is used as pillars, roof frame, and for walls in a woven form and it can be used for steel substitute in reinforced concrete. In making bamboo as a strengtheners or reinforcement a proper volume fraction should be chosen. Besides that, the minimum distance between bamboo bars or inter-strengtheners distance must be determined so that the reinforcement effect on cement matrix takes place. Ten variations of mixtures were used in this research. The number and distance between reinforce bars and its arrangement perpendicular or parallel with loading direction. From the observation it is found that both of the vertically and horizontally arranged bamboo bars at minimum inter-strengtheners distance of 10 mm gave maximum reinforcement and the flexural strength are 16.1 ± 0.3 MPa and 15.8 ± 0.6 MPa. Whereas cement only sample gave 7.2 ± 0.6 MPa hence 2 folds increase. For distance less than 10 mm, the flexural strength is lower, even volume fraction is relatively high and it supposed to give higher strength, in fact this is due to composite reinforcement effect did not occur and this is belief due to a hindered hydration process.
Young’s Modulus Determination of Polyester and Epoxy by Means of Ultrasonic Pulse Echo Testing
Authors: Sasmita Firmansyah , Candra Thea Athalia , Judawisastra Hermawan , Priambodo Toni Agung
Published: September 2019

The Young’s modulus or elasticity modulus is material ability to resist elastic deformation when loaded. Thermosetting polymers have a wide range of modulus elasticity values. To determine the elasticity modulus value, materials need to be destructive tested, such as tensile test or bending test. But in industrial field, they avoided destructive test. Theoretically, the modulus of elasticity can also be determined by ultrasonic testing pulse echo method. This method has already applied successfully for metals material. The goal of this research was to evaluate probe used in longitudinal velocity measurement of polyester and epoxy and to determine Young’s Modulus of polyester and epoxy by means ultrasonic pulse echo testing. This method was performed using three longitudinal probes that have different diameters, frequencies, and additional delay line. The specimens were varied with different thicknesses. The ultrasonic pulse echo method uses probe 3 with a diameter of 12.7mm, a frequency of 1.5MHz, and additional delay line is most suitable to measure the longitudinal velocity of polyester and epoxy with thickness of 2.82-36.72 mm. Probe 3 has a smaller diameter and additional delay lines thus eliminating the effect of dead zones. The elastic modulus error of thermoset polymer material through ultrasonic testing of pulse echo method compared to the mechanical modulus of elasticity is still very large, i.e. 102% for epoxy, and 159% for polyester. A large error is caused by attenuation and the use of the elasticity modulus equation from ultrasonic testing that still requires modification.
The Effect of Dibutyl phthalate plasticizer to Impregnation and Mechanical Properties of Biocomposite Sansevieria trifasciata/High Impact Polypropylene
Authors: Shieddieque Apang Djafar , Mardiyati  , Suratman Rochim , Widyanto Bambang
Published: September 2019

The aim of this research was to investigate the effect of dibutyl phthalate plasticizer to impregnation and mechanical properties of biocomposite sansevieria trifasciata/high impact polypropylene and to analyze the morphology of interfacial bond between matrix and fiber. In this research, biocomposite sansevieria trifasciata/high impact polypropylene was manufactured by using a hot press method with temperature 180°C and pressure 140 bar for 10 minutes. Fibers were extracted from sansevieria trifasciata by using mechanical retting. In this experiment, the fibers weree treated by NaOH 3% (wt%) solution at temperature 100°C for an hour. The volume fractions of fiber used in this experiment were 0%, 15%, 25%, and 35% with unidirectional orientation. To improve impregnation of high impact polypropylene matrix, 2% dibutyl phthalate was added as plasticizer. Actual density and mechanical properties of biocompositesare conducted based on ASTM standard testing methods D792 and D3039. The results showed that tensile strength, modulus of elasticity and elongations of bio composite sansevieria trifasciata/high impact polypropylene with plasticizer were higher than without added plasticizer. The fracture analysis was investigated by scanning electron microscope (SEM). The highest tensile strength, modulus of elasticity and elongation of biocomposites were 65 Mpa, 2.31 GPa and 0.42% respectively. Their highest properties were obtained from bio composites with 35 % volume fraction of unidirectional alkaline treated fiberand 2% dibutyl phthalate. Morphological feature based on scanning electron microscope (SEM) observation showed that biocomposites with added plasticizer had better interface bond between matrix and fibers.