bluuebunny/crossref_metadata_2025 huggingface dataset:
Different arrhythmia-associated calmodulin mutations have distinct effects on cardiac SK channel regulation
Authors: Ledford Hannah A. , Park Seojin , Muir Duncan , Woltz Ryan L. , Ren Lu , Nguyen Phuong T. , Sirish Padmini , Wang Wenying , Sihn Choong-Ryoul , George Alfred L. , Knollmann Björn C. , Yamoah Ebenezer N. , Yarov-Yarovoy Vladimir , Zhang Xiao-Dong , Chiamvimonvat Nipavan
Published: November 2020

Calmodulin (CaM) plays a critical role in intracellular signaling and regulation of Ca2+-dependent proteins and ion channels. Mutations in CaM cause life-threatening cardiac arrhythmias. Among the known CaM targets, small-conductance Ca2+-activated K+ (SK) channels are unique, since they are gated solely by beat-to-beat changes in intracellular Ca2+. However, the molecular mechanisms of how CaM mutations may affect the function of SK channels remain incompletely understood. To address the structural and functional effects of these mutations, we introduced prototypical human CaM mutations in human induced pluripotent stem cell–derived cardiomyocyte-like cells (hiPSC-CMs). Using structural modeling and molecular dynamics simulation, we demonstrate that human calmodulinopathy-associated CaM mutations disrupt cardiac SK channel function via distinct mechanisms. CaMD96V and CaMD130G mutants reduce SK currents through a dominant-negative fashion. By contrast, specific mutations replacing phenylalanine with leucine result in conformational changes that affect helix packing in the C-lobe, which disengage the interactions between apo-CaM and the CaM-binding domain of SK channels. Distinct mutant CaMs may result in a significant reduction in the activation of the SK channels, leading to a decrease in the key Ca2+-dependent repolarization currents these channels mediate. The findings in this study may be generalizable to other interactions of mutant CaMs with Ca2+-dependent proteins within cardiac myocytes.
Assessment of High-temperature Component Containing Multiple Flaws
Authors: Si Jun , Ren Facai , Ren Bin , Tang Xiaoying
Published: November 2020

Multiple flaws are often found in many high-temperature components. The interaction of multiple flaws may significantly affects service life of high-temperature components. Flaws re-characterization rules for multiple flaws have been proposed in ASME and BS7910. However, most rules are formulated according to the elastic fracture parameter. Due to the different failure mechanism among linear-elastic stress conditions, elastic-plastic conditions and high-temperature creep conditions, the interacting behavior of components containing multiple flaws is also different. Therefore, it is the important to investigate the interacting behavior of multiple flaws under the high-temperature creep conditions. In the current work, the high-temperature creep fracture parameter is calculated for plate containing multiple flaws by using the finite element analysis (FEA) under the tensile load. Based on these analyses, the new re-characterization rules are proposed to exclude the non-conservativeness caused by the current re-characterization rules in high-temperature creep conditions for heat-resistant steel. The coalescence rule for collinear cracks is S≤2.5a, and the parallel cracks can be treated as collinear cracks for all distance S when the equation h≥a is satisfied.
Microstructure Change in Welded TiNi Alloys
Authors: Wang Wei
Published: November 2020

Due to the obvious change of the weld structure and the original base metal structure after laser processing, under the action of instantaneous high energy density laser beam, the weld structure is coarse and the strength, plasticity and toughness are reduced. Compared with the base metal, the microstructure of the alloy after laser welding was studied by experiment.
Microstructure and brazing mechanism of TiAl/Ni-based superalloy joints using Ti-Zr-Cu-Ni-Co-Mo-B filler metal with different cooling rates
Authors: Wan Bao , Li Xiaoqiang
Published: November 2020

For the purpose of elevated temperature service and weight reduction in aerospace vehicle applications, a novel Ti-Zr-Cu-Ni-Co-Mo-B filler metal was employed to join TiAl to Ni-based superalloy (GH536). The effect of cooling rate on interfacial microstructure of the joints were analysed by scanning electron microscope and energy dispersive X-ray spectrometer. The representative joint microstructure was primarily composed of six characteristic layers, including TiAl substrate / B2 / τ3 (Al3NiTi2) / τ4 (AlNi2Ti) / Cr-rich (Cr, Ni, Fe)ss, τ4 (AlNi2Ti), Ni-rich (Cr, Ni, Fe)ss and TiNi3) / GH536 substrate. With the decrease of cooling rate in the range of furnace cooling-5 °C/min, the joint shear strength firstly increased and then decreased. The joint brazed at 1170 °C for 10 min and cooling to 870 °C with 10 °C/min obtained the maximum shear strength of 252 MPa and the shear fracture mainly occurred in τ3 phase area.
Recrystallization–precipitation interaction of a Ti microalloyed steel with controlled rolling process
Authors: Chen Songjun , Li Liejun , Xia Jinian , Peng Zhengwu , Gao Jixiang , Sun Haibo
Published: November 2020

The interaction between austenite static recrystallization and strain induced precipitation of a Ti microalloyed steel deformed in the non-recrystallization region was investigated by two-stage interrupted compression method and transmission electron microscopy (TEM). The softening rate curves of austenite were obtained by the true stress-strain curves of the two-pass of deformation. Results showed that the softening rates increased with increasing deformation temperatures. The softening rate curve exhibited a “S” shaped, and the static recrystallization was completed in 300 s when deformed at 1000°C, while deformed temperatures were lower than 950°C, the softening rates dropped sharply and increased very slowly as pass inter time increased. At 975°C or below, platforms appeared in softening curves, which implied strain-induced precipitates occurred during the isothermal process after the first deformation. The shortest incubation time of strain-induced precipitates was about 78 s when deformed at 925°C. Based on TEM results, strain-induced precipitates were found to be mainly distributed at dislocations and the diameters of the particles precipitated at dislocations were obviously larger than those of precipitated in other nucleation sites due to the effective route for the diffusion of Ti element. Evolution of austenite grains morphologies showed that the static recrystallization of deformed austenite was strongly inhibited by strain-induced precipitation and occurred again after the strain-induced precipitation finished.
Effect of sputtering gas pressure on the performance of WO3 thin films electrochromic device
Authors: Zhao Lin , Song Shipai , Li Le
Published: November 2020

WO3 films were deposited on transparent conductive indium tin oxide (ITO) glass under different working pressure conditions via radio frequency magnetron sputtering technology, and their electrochromic properties were studied. The morphology, electrochromic cyclic voltammetry characteristics, and light modulation properties of the films were studied using a scanning electron microscope, an electrochemical test station, and an ultraviolet-visible spectrophotometer. The transmittance modulation amplitude increases first and then decreases with the change of sputtering gas pressure, reaching the maximum transmittance modulation amplitude at 1.0 Pa. For the response time, the increase in sputtering gas pressure also shows a change of shortening and then increasing. By comprehensively considering the stability of the transmittance modulation amplitude and the stability of the response time, it can be found that as the sputtering gas pressure increases, the stability of the device’s electrochromic performance increases first and then decreases. Therefore, the sputtering gas pressure needs to be maintained in a relatively reasonable range. When it is too high or too low, it is not conducive to achieving good stability.
Microstructure and Performance Control of High strength and High Toughness Ti-Nb Microalloyed Marine Steel Plate
Authors: Gao Jixiang , Liao Daobiao , Li Liejun , Zhou Feng
Published: November 2020

Adopting Ti-Nb microalloying design technology, this paper studied the austenitic recrystallization law of Marine steel plate, control rolling process, control cooling process and steel normalizing process control systematically. The thickest 60 mm special Marine steel plate developed which has reached the yield strength of 420MPa and charpy impact energy of more than 200J (-20°C), has high strength, impact toughness, lamellar tear resistance and good welding performance, meeting the technical requirements of thick specification high strength and high toughness special Marine steel plate and realizing the application in large ships.
Microstructure and mechanical properties of B4C matrix composites sintered with (TiB2+Al)
Authors: Song Qi , Zhang Zhao-Hui , Yin Shi-Pan , Hu Zheng-Yang , Wang Hao
Published: November 2020

The B4C matrix composites were obtained with the addition of (24.5 % TiB2+2 % Al) using spark plasma sintering method at 1600 °C with the pressure of 80 MPa for 5 min. Compared with the monolithic B4C ceramics, due to the (24.5 % TiB2+2 % Al) additive in B4C matrix composite, the densification temperature of B4C matrix composite was obviously decreased and the flexural strength was significantly improved. The B4C matrix composites exhibited the high flexural strength of 528 MPa, and a moderate Vickers hardness of 24.2 Gpa. The excellent flexural strength attributed to the second phases in the composites can prevent the cracks from extending and the energy disspation effect resulted from the intergranular fracture.
Study on concrete beams under the action of steel corrosion and freeze-thaw cycles
Authors: hongming Wang
Published: November 2020

In order to study the effect of rust - freeze coupling on the flexural bearing capacity of concrete beams, a rapid corrosion test, rapid freeze-thaw test and a rust - freezing coupling test were carried out for 18 model beams. Under the joint action of the corrosion of steel bars and the freeze-thaw cycle, the yield strength ratio of the test beam decreases with the increase of rust rate and freeze-thaw cycle, resulting in the decrease of its resistance to deformation. Based on the present proposed calculation formula under the action of corrosion and freeze-thaw cycles, through comparing and analyzing experimental data to establish the a new calculation model under the action of the reinforcement corrosion and the freeze-thaw cycle of flexural bearing capacity.
Application of red clay improved with sand at the foot of mountain in subgrade filling
Authors: Fu Jianbao , Zhang Li
Published: November 2020

There is a large amount of red clay along a highway under construction in Southwest China. The red clay has high plasticity and small CBR which don’t meet the specification. Therefore, red clay often needs to be improved before being used as filler. This paper proposed a new subgrade filling technology of improved red clay with sand at the foot of mountain. The filling technology has three stages, four sections and eight processes. The improved red clay with sand at foot of mountain was used in a highway. The ratio of sand at foot of mountain to red clay was 4:6. After compaction, the degree of compaction could meet the designed compactness requirements. The improved red clay with sand at foot of mountain has achieved good application effect in the project.
Multi-row perforated concrete wall board with built-in sound insulation material
Authors: Chen Zhen-fu , Xiang Liu , Tao Qiu-wang , Xie Li-ping , Zhang Zhi-heng
Published: November 2020

The multi-row perforated concrete wallboard with built-in sound insulation materials studied in this paper is a new type of lightweight sound insulation wall. With reference to the authorized utility model wall, this work performs sound isolation tests on walls with different internal structural parameters cast on multiple sections, using the experimental method of sound insulation room. Based on the experiment, COMSOL numerical simulation software is used to establish a sound-solid multiphysics model to achieve the numerical solution. Three kinds of changing parameters are studied with respect to the effect of the sound transmission on the wall panel. The optimal cross-section combination structure discovered is a foam concrete wall panel with a 15mm thick sound insulation layer, multiple rows of 30 mm diameter holes and a large flow resistance.
The Influence of γ-Rays Irradiation and Thermal Sequence Aging on the Mineral Composition of GMZ Sodium Bentonite
Authors: Dong LIANG , Tao WANG , Wei LIU , Zhongtian YANG
Published: November 2020

This paper aims to determine the impacts of γirradiation and thermal sequence aging on the mineral composition of Gaomiaozi natural sodium bentonite with Beishan groundwater and to broaden the assessment and scope of buffer materials for geological disposal of high-level radioactive waste (HLW). FTIR, XRD and Mössbauer spectra of the bentonite (contain groundwater from Beishan area) have been studied that under accumulative radiation with doses at 3.0 MGy, hereafter heated at 90 °C, 150 °C, 170 °C, 190 °C and 210 °C respectively continue 2 monthes, 4 monthes, 6 monthes, 8 monthes, 10 monthes and 12 monthes. In addition, the solubility of silicon in groundwater from Beishan area have been tested. The results indicate that, the content of montmorillonite decreased significantly with the increment of the thermal temperature and time. The concentration of SiO3
2- in groundwater increased obviously as the thermal temperature and time increased. There have the tendency that Fe (IItransformed to Fe(III) in the bentonite after aged, however, the content of Fe(II) increased and the content of Fe(III) decreased aged by γ irradiation. But the types of mineral and functional groups remain the same. All in all, the mineral composition of GMZ natural sodium bentonite have been varied after thermal aged, and further research is needed to comprehend specific sitiations.
Computational and experimental investigation of progressive damage accumulation in I-plate composite structure
Authors: Chengcheng Zhang
Published: November 2020

As the research object to the I-plate composite structure, a stiffness degradation method is developed by combined continuum damage mechanics with the solid finite element analysis method. The Tsai-Wu failure criterion is applied for structural damage initiation. Additionally, exponential equation associated with stress is used to simulate damage development. Based on the progressive damage model established, a 3D finite element technique is proposed to perform the progressive failure process in ANSYS. The structural damage development and simulated load–displacement curve are received, and compared with experimental results under transverse bending load. The compare results show the validity of progressive damage analysis method.
An Introduction to Ultraviolet Detectors Based on III Group-Nitride Semiconductor
Authors: Yang He
Published: November 2020

Ultraviolet (UV) detectors are drawing increasing attention in the past decades due to their reliable application in industrial, environmental, and even spatial fields. Among all of the candidate materials for UV detector, III group-nitride semiconductors—typically (In, Al) GaN—have stand out for their good thermal stability and conductivity, high response speed and breakdown electric-field, as well as robust radiation hardness. In this article, the author comes up with possible improvements on structural defects-induced degradation of device by providing a comprehensive introduction to the conventional device classification and principles of UV detectors as well as up-to-date processing arts of III group-nitride materials for UV detectors. Finally, we conclude with the promising nano-structured GaN-based UV detectors and expect their applications under super thermo-stable requirements.
Effect of Particle Size and Morphology on the Molar Enthalpy and Molar Entropy of Nanomaterials in Different Processes
Authors: Gao Rui
Published: November 2020

When the size of the material reaches the nanometer level, due to surface effects and small size effects, the substances would cause great changes in chemical reaction equilibrium, reaction kinetics, phase transition, adsorption, electrochemistry and catalysis, and these changes are attributed to changes in their thermodynamic properties. Particle size and morphology are the main factors affecting the thermodynamic properties of nanomaterials, while molar enthalpy and molar entropy are important thermodynamic properties of nanomaterials. The effects of particle size and morphology on molar entropy and molar enthalpy in phase transitions (including melting and sublimation), electrochemistry and adsorption are described in this paper.
Research on the Development and Application of Lightweight Automotive Materials
Authors: Han Chengzhi
Published: November 2020

With the continuous improvement of people’s living standards, mobility tools have also evolved from walking and cycling to today’s private cars. The rapid increase in the number of private cars has caused China’s energy consumption to increase. China does not have sufficient energy resources. In order to alleviate the pressure on energy, the energy conservation and emission reduction of automobiles must be paid attention to. There are many ways to save energy and reduce emissions of automobiles. One of them is to reduce the weight of the car. Once the weight of the car is reduced, the amount of energy consumed will be reduced, thereby achieving the goal of energy conservation. Based on this, this article focuses on the use of lightweight materials in current automotive materials, and introduces a variety of lightweight materials in detail to help cars reduce weight, reduce energy consumption, and achieve sustainable development in the automotive industry.
The X80 Pipeline Steel produced by a Novel Ultra Fast Cooling Process
Authors: Zhou Feng , Dai Jietao , Gao Jixiang , Zhou Qing , Li Liejun
Published: November 2020

The relation between microstructure characteristics and mechanical properties of X80 pipeline steels produced by ultra fast cooling process was investigated using energy dispersive spectrometer, scanning and transmission electron microscopy. Results showed that ultra fast cooling kept hot rolled austenitic work hardened, induced a large number of carbonitride precipitation, limited the growth of cementite. Therefore ultra fast cooling was beneficial to increase the steel strength and improve the steel ductility and toughness.
Analysis of Reaction Crystallization Process of Wollastonite Glass Ceramics Using Infrared Spectra
Authors: Si Wei , Chen Sitong
Published: November 2020

The wollastonite glass ceramics were successfully prepared using waste glass and gehlenite powder. The effects of preparation process parameters on synthesis of wollastonite glass ceramics were studied by fourier transform infrared spectoscopy (FT-IR). The crystalline phase, crystal morphology of wollastonite glass ceramics were characterized by XRD and SEM. The results show that the flake like wollastonite glass ceramics can be obtained by changing the sintering temperature, the content of gehlenite and the holding time when using the reaction crystallization method. With the increasing of each preparation condition parameter, the increase of [Si-O] unsaturated degree will aggravate the fracture of network structure and then lead to various network fractures. The optimum preparation conditions were confirmed as follows: sintering temperature of 900 °C, content of gehlenite of 30 %, holding time of 2 hours.
Densification behavior of high Co-Ni steel prepared by spark plasma sintering
Authors: Huo Guojing , Zhang Zhaohui
Published: November 2020

High Co–Ni steel with excellent mechanical properties has been extensively used in aerospace and military industries. In this study, spark plasma sintering (SPS) method was used to sinter high Co–Ni steel powders. The powder compacts were heated at 100 °C/min to the desired sintering temperature under 40MPa with 10 min holding. Microstructure of the samples sintered at different temperatures were observed and their mechanical properties were tested. The results show that the as-sintered sample obtained at 1050 °C is nearly full density. The sintered high Co–Ni steel mainly composed of lath martensite shows a high level of ultimate tensile strength and yield strength.
Research on acceleration performance of fuel vehicles and electric vehicles based on Advisor
Authors: Bai Youjun , Zheng Yan
Published: November 2020

In this paper, through the analysis of the theoretical knowledge of the vehicle, the differences between the fuel vehicle and the electric vehicle in terms of power performance, as well as the influencing factors are compared. Through the use of advisor simulation analysis, it is found that the acceleration performance of the electric vehicle in the early stage is better than that of the fuel vehicle, and it has better effect when it is used in the city.
Numerical study of the influence of high-transonic outlet blade angle of the Wedge diffuser with airfoil characteristics on the performance centrifugal compressor
Authors: Bai Huan , Li Qingkuo , Wang Yi
Published: November 2020

In this paper, a transonic centrifugal compressor is investigated, and a design method of a wedge diffuser with airfoil characteristics is proposed. The effect of different outlet blade angles of the wedge diffuser with airfoil characteristics on the performance of the compressor was studied using a validated numerical calculation method. The results show that the use of a wedge diffuser with airfoil characteristics can more suitable for the transonic flow, which greatly reduces the flow loss of the diffuser pressure surface due to the inconsistent incidence. In addition, without changing the shape of the prototype compressor, the compressor performance is best when the outlet blade angle is 20 ~ 22 °. Compared with the prototype compressor, its peak efficiency increased by 0.93%, the pressure ratio increased by 0.517%, and the stable working margin increased by 4.2%.
Analysis on vibration characteristics of tubing under pressure operation
Authors: Hong Yukui , Dong Liangliang , Tang Geng , Xie Youli , Chen Malin , Liu Xiaodong , Liu Rui , Yang Lei
Published: November 2020

Pressure operation is a kind of advanced down hole technology which can be used to lift and lower the string under the condition of maintaining a certain pressure in the wellbore, not killing the well or releasing the pressure. However, due to the pressure fluctuation at the front end of the string, the string vibration is caused, which is extremely unfavorable to the operation with pressure. According to industry data, in a series of oilfield safety incidents from 2008 to 2015, nearly 65 %o of the total was due to vibration in the downhole string. Therefore, it is necessary to further study the factors affecting the vibration of the pipe string, so as to reduce the influence of the pipe string vibration, which is also an important means to avoid accidents. In this paper, the dynamic grid method is applied to the numerical simulation analysis of the pipeline, and the pressure fluctuation at the front end of the pipe string is obtained. At the same time, the influence of different shapes at the front end of the pipe string on the vibration of the pipe string is studied, which provides a certain theoretical background for relevant scholars.
A Zero Point Offset Monitoring Method of Rotation Axis Based on Siemens 840D System
Authors: Li Qing , Gao Qiangrong , Zhao Guobo , Chen Xuezhen
Published: November 2020

In order to monitor the abnormal condition that the zero point of the encoder does not coincide with the actual mechanical zero position in the full-closed control loop of a rotating axis, a Siemens 840D numerical control system based on abnormal condition inspection method is proposed. According to the gathered data by the measurement system of a rotating axis servo motor, the logical comparison program in PLC (Programmable Logic Controller) is developed to monitor the zero point of rotating axis by using Siemens 840D numerical control system and STEP7 software platform. The verification experiment results show that the proposed method can quickly identify the abnormal displacement of the zero point for a rotating axis and disable the servo motor in time, which can effectively avoid the poor quality problem caused by the abnormal condition in rotating axis.
Micro-catalytic gas sensor operating modes for extended life service, increasing sensitivity to target gases and power consumption reduction
Authors: Samotaev N , Oblov K , Dzhumaev P , Filipchuk D , Ducso C
Published: November 2020

Catalytic gas sensors are among of the most old and widespread gas sensors for combustible gas concentration measurements. However, power consumption these sensors provide is relativity high for modern electronic applications. In this paper research results of combination a silicon MEMS fabrication with operating modes for extended life service, increasing sensitivity to target gases and power consumption reduction are presented. The described solutions allow achieving long-term stability of the sensor in difficult operating conditions - the main requirement for industrial applications, where the continuity of the process is of high value expressed in tangible assets and human lives.
Oil-contaminated Surface Cleaning using Oxygen and Nitrogen Nanobubbles
Authors: Ulatowski Karol , Sidorski Michał , Sobieszuk Paweł
Published: November 2020

Surface cleaning is extremely important topic in various industrial and laboratorial applications. Cleaning agents should fulfil numerous requirements, including effectiveness, leaving minimal amount of residue as well as being able to clean different surfaces and contaminants. In this work, the nanobubble dispersions were tested for cleaning of two different contaminants: vegetable oil and UV color protective oil. Both contaminants were applied onto glass slides and stainless steel plates. Nanobubble dispersions were generated in distilled water. Outflow from nanobubble generator was set tangentially to the contaminated surface during nanobubble generation. The effectiveness of cleaning was assessed visually and by contact angle analysis. Results have shown that the effectiveness of cleaning is higher for oxygen nanodispersion compared to nitrogen nanodispersion. However this process requires further fine-tuning to increase its effectiveness.
Multiple Emulsions as a Biomaterial-based Delivery System for the Controlled Release of an Anti-cancer Drug
Authors: Dluska E , Markowska-Radomska A , Metera A , Ordak M
Published: November 2020

This paper focuses on developing multiple emulsions as a pH-responsive drug delivery system, for glioblastoma multiforme-GBM therapy, with reduced toxicity to healthy cells. The multiple emulsions with a stimuli-responsive biopolymer (CMC- sodium carboxymethylcellulose) were prepared in a Couette-Taylor flow contactor. As an external stimulus, the difference in pH of the cancer environment, and normal tissue, was investigated by adding salts as a triggering agent. The cancer cell lines of glioblastoma multiforme were investigated: U87MG, LN229, T98G, in order to verify emulsions’ components cytotoxicity to cells. Also normal (healthy) cells, K21-fribroblast, were analysed. Rhodamine B was used as a model drug instead of the clinically used chemotherapeutics (e.g. doxorubicin) in oncology. Results showed that multiple emulsions by themselves had no adverse effect on the viability of investigated cells, excluding one cell line: LN229. The control and modulated release rates of a model drug, by stimuli-responsive biopolymer, were established. Results confirmed the possibility of controlling the release rates of a drug in the acidic environment of the cancer cells. The proposed multiple emulsion could be explored for the potential delivery of chemotherapeutics in GBM therapy.
Study on Influence of Joint Orientation on Rock Engineering Properties for Mining and Infrastructure Design
Authors: Purwanto  , Djamaluddin  , Aswad Sabrianto , Wahyuwibowo Dedi Eka , Qaidahiyani Nirmana Fiqra , Yasuhara Hideaki
Published: November 2020

Rock strength is the most important parameter for mining and infrastructure design. Accurate determination of rock strength is needed as a basis for implementing safe and economical rock engineering projects such as tunnels, open pit mines, and slope cutting for roadways. Rock is heterogeneous, anisotropic, and discontinuous materials. The discontinuities can be found as joints, faults, fissures, bedding, etc. In rock mechanics, the term of joint is generally used to represent all types of discontinuities. Joints are the planes of weakness in rock masses and can be found in various geometrical shapes, depending on past geological processes. This research briefly focuses to study the influence of joint orientation on rock strength based on UCS test. Application of this research could be recommend applying for mining and infrastructure design.
Geology and 2D modelling of magnetic data to evaluate surface and subsurface setting in Bongongoayu geothermal area, Gorontalo
Authors: Manyoe I N , Suriamihardja D A , Irfan U R , Eraku S S , Napu S S S , Tolodo D D
Published: November 2020

Bongongoayu is one of the regions in Indonesia that has geothermal potential. Bongongoayu requires surface and subsurface data to support the preliminary data. This research aims to determine surface and subsurface data conducted by geology and magnetic method. The surface data, including geomorphology, lithology, hydrology and manifestation. The subsurface data have taken by the magnetic method. The result showed that the geothermal manifestation of Bongongoayu is a hot pool. The surface temperature is 43 to 59 °C. The geomorphology units is composed of volcanic hills unit and lake plains unit. The lithology of the research area is composed of granite and alluvial deposits. Based on petrographic analysis, the level of alteration in granite rocks is 65% and is classified as moderate alteration. The recharge area is in the north and southwest of the research area. Discharge area is in the central area. Based on 2D magnetic modeling, there are two subsurface layers. The first layer is alluvial and the second layer is granite. Rocks that are under the alluvial layer and have been altered are interpreted as a cap rock. 2D magnetic models show normal faults in the research area as a controlling factor for geothermal fluid.
Geochemical Exploration of Geothermal Manifestations: Study Case of Bajawa Volcanic Complex, Flores Island, East Nusa Tenggara Province
Authors: Herzhegovina H H , Abdurrachman M , Hafidh M , Divi M
Published: November 2020

Currently Indonesia occupy third place in the World demand of geothermal energy with using of 1375 Mwe (Mega Watt electrical). Energy utilization is only used around 4 – 5 % of geothermal energy capacity owned by Indonesia. Surely, this fact encourages many researcher to develop geothermal field with multidisciplinary sciences. One of potential geothermal areas is Nage geothermal field located in Bajawa City, Ngada District, East Nusa Tenggara Province. Four hot springs and fumarole were founded in the area. The Exploration using geochemical analysis in the form of descriptive method and analysis of geothermal fluid data. Based on regional geology, Bajawa volcanic complex composed of three periods of volcanic, first is old volcanic that formed Nage Caldera and Old Inierie volcanoes, then formed Bajawa Cinder Cone unit with North – South and North East – Southwest alignment, this alignment surely controlled as a linear eruptions. And the last is Inierie unit, this unit is active stratovolcano. The results of data obtained from one fumarole and four hot springs sample were taken from Wolo puti fumarole, Bena hotspring, Keli hotspring, Nage I hotspring and Nage II hotspring. Based on the relationship of chemical element ratio and plotting of triangular Giggenbach diagram shows that Keli and Bena hot springs are sulphate type, this hotspring controlled by Wolo puti fumarole as upflow of the geothermal system then Keli and Bena hot springs are in the outflow zone, which has mixed by meteoric water. Nage I and Nage II hot springs are chloride type, which has different geothermal system from Keli and Bena hot springs. Based on the geothermometer calculation of the Na-K-Mg diagram, the temperature of reservoir is 220° - 340° C, which is included of high enthalpy geothermal system.
Facies Study of Lake Deposits Formation (Qpl) To Determine Deposition Environment of Ancient Limboto Lake: a Preliminary Result
Authors: Amin A K M A , Sakakibara M , Arifin Y I , Akase N
Published: November 2020

Limboto Lake located in the Gorontalo Province is a part of the places where the disclosure of various types of rocks as well as various tectonic deformations, the genesis of this lake is a low basin included in shallow lake type or type of flood plain. Development of Limboto Lake starts from the existence of the Neogene extension exactly on slab-rollback extension of the Banda embayment in Early Miocene, rapid uplift and subsidence near Gorontalo Basin in Late Miocene. Various problems that occur in the Limboto Lake both silting and susceptibility to lake water flows allegedly related to the tectonic activity that ever happened even today. This study reports new determination about the ancient environment of Limboto Lake. The purpose of the study is the facies study of the Lake Deposits Formation (Qpl) to determine the depositional environment of ancient Limboto Lake in Gorontalo Basin against its influence on the current Limboto Lake. The environment facies identified in the Gorontalo Basin are marine deltaic facies and shallow marine carbonate facies (carbonate rimmed shelf). The evidence found by stratigraphically features is: (a) Marine Deltaic Environment: (1) Lithologies: mainly sandstones (compositionally dominate immaturely) through muddy sandstones, sandy mudstone to mudstone; also the presence of lignite; compressed weakly and in the form unconsolidated, (2) Texture: not diagnostic, average sorting and rounding sand grains, (3) Structure: cross-lamination and wave-lamination of various types in the sandstones, flat-bedding, and channel common. Finer sediment show flasher, wavy bedding and are heterolithic. Some sediment containing rootlets; (b) Shallow-Marine Carbonate Facies: (1) Lithologies: Skeletal packstone-wackestone, and mudstone, (2) Texture: diverse, (3) Structure: cross-lamination, parallel-lamination, wave-lamination, desiccation crack; in the reef limestone is massive and unbedded, with intense bioturbation. Based on the ancient environment determine to encourage the high activity of silting Limboto Lake because the material around the lake easily detached.
Landslide disaster and its prevention works in Shikoku region of Japan
Authors: Kimura Kazunari , Nagata Tomohiro , Kan Shuya
Published: November 2020

This study introduces two examples of landslide countermeasures in Shikoku, Japan. The first case is a landslide that occurred in the Chichibu belt. This landslide was characterized by loose rock mass (past landslide mass) distributed at a maximum thickness of approximately 30m. As a result of comparing and examining the three types of construction methods as countermeasures against this landslide, it was judged that the countermeasure works combining the anchor works and the drainage boring works was the most appropriate. This landslide experienced the largest downpours since the completion of the countermeasures, but no landslide activity has been confirmed. The second case is a landslide that occurred in the Mikabu belt. This site was a place where fragile geology was distributed, but a cut at the lower end of the slope was implemented for road construction. After this cutting work, landslides occurred on the slope during heavy rain. Two landslides occurred step by step with the rainfall. As a result of a comparative study of the two countermeasures for this landslide, it was determined that the countermeasure that combined earth removal, anchoring and drainage boring was the most appropriate. The landslide activity was stopped after the countermeasure work was completed, and road construction was completed safely.
The Influence of Rock Resistance for Geomorphology of Krakatau Islands, South Lampung District, Lampung Province
Authors: Ismail Taufik , Abdurrachman Mirzam , Rizal Yan , Hardjawidjaksana Kumala , Arbie Rahmawati
Published: November 2020

Krakatoa Islands is one of the results of high activity volcanic islands located in the Sunda Strait, Indonesia. Volcanic activity of the research area is highly influential on the typical morphological conditions. Rocks produced from this volcano activity a role in the formation of geomorphology that is typical of areas with high volcanic activity. Rocks in the study area were the result of volcanic activity such as lava, pyroclastic alluvial. Geomorphology analysis was conducted by analyzing river flow pattern, slope criteria analysis and shoreline analysis since 1984. East Anak Krakatoa island which is dominated by lava, in contrast to the krakatoa west of which the rock formers are dominantly pyroclastic fall. Unconsolidated rocks form west Sertung island, east Panjang island and south Rakata island which the rock formers are dominantly pyroclastic flow. Evidence of 1883 catastrophic eruption is highly visible on the north Rakata island, east Sertung island and west Panjang island shown by vertical high cliff which is indicated as a caldera structure. The results of the geomorphological analysis are poured into geomorphological maps. Geomorphology unit in research area consist of 9 (nine) geomorphology units of Krakatoa Islands. Krakatoa Islands in this geomorphological case, is still controlled by climate change, erosional of sea water wave, 1883 catastrophic eruption which produces rock in the form of lava and pyroclastic and volcanic activity still continues to this day.
Mercury exposure from small scale gold mining activities and neurological symptoms on inhabitants and miners: a case study in Bolaang Mongondow, North Sulawesi Province, Indonesia
Authors: Arifin Yayu Indriati , Sakakibara Masayuki , Sera Koichiro , Fenty Usman Puluhulawa , Lihawa Fitryane
Published: November 2020

Mercury level in scalp hair of inhabitants and gold miners’ livings at two artisanal and small-scale gold mining (ASGM) sites in Bolaang Mongondow regency of North Sulawesi Province was studied. Totally 50 scalp hairs were collected from Tanoyan, Tobongon and Kotamobagu city, and kept for further analysis. The mercury hair contents were determined using Particle Induced X-ray Emission (PIXE) at Nishina memorial research facility of Iwate Medical University of Japan. Mean levels of mercury in scalp hairs of inhabitants and ASGM workers were around 5 ppm. The highest mercury levels were found at females’ miners in Tobongon and female teenagers in Tanoyan. Neurological assessment was conducted on several inhabitants and gold miners. 12 symptoms ((1) Signs of bluish discoloration of gums; (2) Rigidity and ataxia (walking or standing), (3) Alternating movements or dysdiadochokinesia, (4) Irregular eye movements or nystagmnus, (5) Field of vision, (6) Knee jerk reflex, (7) Biceps reflex, (8) Babinski reflex, (9) Labial reflex, (10) Salivation and dysarthia, (11) Sensory examination and (12) Tremor.) were used to describe the neurological disorder which may related to mercury expousure. It was found that nine neurological symptoms were dominantly observed among miners than inhabitants and three sypmtoms (8, 9 and 10) were less frequently observed.
Socioeconomic and Mercury Exposure to The Goldsmiths in Manggal Subdistrict of Urban Artisanal Gold Mining (UAGM) Area in Makassar, South Sulawesi, Indonesia
Authors: Abbas Hasriwiani Habo , Sakakibara Masayuki , Sera Koichiro , Arma Lukmanul Hakim , Sididi Mansur
Published: November 2020

People living in gold mining towns experience high inorganic mercury levels when mercury vapor is emitted during the burning of amalgam as well as gold dorè in gold shops. These activities occur in Makassar, Indonesia, where a group of urban people established an artisanal waste recycling industry, in which they use mercury to recover the fine gold particles contained in the waste from goldsmiths’ activities. The goldsmith in Manggala is one of UAGM activities to design and manufacture of the unique gold jewelry. Mercury exposure to the goldsmith was happened through gold refining process. The aims of this research are to characterize the socioeconomic and potential mercury exposure to the goldsmith workers. The socioeconomic characterization of goldsmith was obtained by questionnaire survey, in-depth interviews and mercury exposure in hair was analyzed by using Particle-induced X-ray emission (PIXE) from Iwate Medical University. The result showed that the goldsmith workers in Manggala sub district is better than the other gold workers in Makassar in term of income and education. The lower education was graduated from elementary school and the higher education was graduated from the university. The monthly income of goldsmiths are unskilled, skilled and owner, 751 (11%), respectively. The goldsmiths were exposure by mercury through the refining process in the gold. Therefore, it’s found that the average mercury concentration in hair is 6.6 μg/g (min-max:1.6-47.7 μg/g). The concentration of mercury in human hair of goldsmith is 5.03 μg/g, for indirect exposed and 8.18 μg/g for direct exposed. This result indicate that the level of mercury is seriously problem according to HBM threshold limit. Therefore, mercury exposure from UAGM activities must be prevented before the greater impact on society.
Regional Geochemical Map of West Java, Indonesia: Evaluation for Environmental and Mineral Resources
Authors: Sendjaja Purnama , Kusniadi Ari
Published: November 2020

A The regional geochemical mapping project was conducted by the Centre for Geological Survey, Geological Agency, Ministry of Energy and Mineral Resources during 2011 to 2012 in Banten and West Java Provinces areas. Geological and topographic maps with scale of 1:100.000 as the base maps were used. Stream sediment samples were collected in this geochemical mapping project with the fraction size are 80# and the density of samples represent one sample for about 25 km2. The project already successfully collected 1215 stream sediment samples covering twenty one base maps. The samples collecting were the result of collaboration between Geological Agency and universities. Moreover, the geochemical analysis was conducted with the XRF (X-Ray Fluorescence) method at the Geological Laboratory of Centre for Geological Survey. This method could analyze for 30 elements and show significant anomalies with presuming result from natural product or derived from human or urban activities. The volcanic products from quaternary volcanoes are clearly identified on distribution of As, Ba, Cl, Cu and Zr elements. Epithermal mineralization zone has an anomaly of distribution of Cu, Fe, Pb, and Zn. Meanwhile the human activities are showing from geochemical map of Cl, Cr, Cu, Hg, Pb and Zn that show scattered anomalies localized close to the cities, industries and mining area.
“Gunung Api Purba Nglanggeran” welcomes UNESCO Global Geopark Reassessment in 2019
Authors: Soviana Nabila Novasari , Brahmantyo Budi , Abdurrachman Mirzam , Sabila Firman Sauqi Nur
Published: November 2020

Coincide in 2019, Gunung Sewu UNESCO Global Geopark (UGGp) will be reassessed by UNESCO based on UNESCO’s geopark criteria. This research is conducted to evaluate one of the components of Gunung Sewu UGGp, namely Gunung Api purba Nglanggeran Geosite that is located in Nglanggeran, Patuk Gunungkidul, Yogyakarta Daerah Istimewa Yogyakarta from the geotourism point of view and UNESCO’s geopark criteria. In addition, this research also conducted to present new geotourism objects for Gunung Sewu UGGp especially in Gunungkidul, Daerah Istimewa Yogyakarta. The research methods are divided into two focuses, the field observation method and the geotourism questionnaire method on Gunung Api Purba Nglanggeran Geosite area. Field observation method consists of geomorphological observation, geological structure observation, and lithological observation in the research area. Geosite recommendations are obtained from further analysis of the field observation methods. The Geotourism questionnaire method takes up the evaluation of geotourism at Gunung Api Purba Nglanggeran Geosite based on UNESCO’s geopark criteria with questionnaire respondents from geosite visitors and residents around the geosite area. The research area consists of landscape in the form of ridge, hills, and plains that some areas potentially become new geosites at the Gunung Sewu UGGp. Based on the results of field observation analysis that refer the assessment scheme for value and basic description of geological heritage resources, the new recommended geosites are Kali Ngalang Hulu, Air Terjun Kedung Kandang, Bukit Kembang, Gunung Gentong, dan Batu Miring Oyo. Gunung Api Purba Nglanggeran Geosite is still considered to maintain UNESCO’s geopark criteria. All the results of this research are expected to be used as a simulation for the assessment of UGGp Gunung Sewu pre-reassessment by UNESCO in 2019 and as the consideration of the authorized stakeholders to add geosites to UGGp Gunung Sewu to increase visitor attraction.
The Development of Earthquake Risk Reduction Curriculum for 4-6 Years Old Children in Gorontalo
Authors: Ardni P P , Arifin I N , Syahputra H , Pupala B
Published: November 2020

This research was conducted for the development of earthquake risk reduction curriculum for children aged between 4-6 years old in Gorontalo. This research used Research and Development method. The data analysis technique used in this research is qualitative data analysis technique Milles and Hubberman model and quantitative data analysis using the t-test. This research was conducted in Gorontalo. The researcher modified the Dick and Carey’s design of research and development. Step 1, the researcher did a preliminary study through literature studies related to the concepts of models to be developed. Then, the researcher did the field study for the initial knowledge on the disaster risk reduction curriculum for children aged between 4-6 years old. Next, the researcher performed required analysis as the basis for developing the model. Step 2, is the development stage and step 3, is the implementation of the earthquake risk reduction curriculum program model. The research is still in step 1. The duration of this research was one and a half years. The data were collected through interviews, forum group discussion, observations, and documentation. The first year research was to conduct preliminary research to collect information (literature review, preliminary observation). In addition, the researcher identified the problems encountered in the learning process. Then, the researcher evolved the planning (identification and definition of skills, purpose, determination of learning sequence), and then finally, conducted the expert test or expert judgment. The first Development product includes Program design of disaster risk reduction curriculum. There are three main processes in the curriculum: the concept stage, the training phase, and the rehabilitation phase. Activities in three stages of this process through a series of curriculum development frameworks comprise the determination of learning objectives, then the learning process, and the evaluation process (for early childhood phase, the learning process is more important than the outcome). Last but not least is the reflection stage to review the design and improve the learning objectives.