bluuebunny/crossref_metadata_2025 huggingface dataset:
The Transport Direction and Variation Process of Water Temperature Heat at Surface
Authors: Yang Dongfang , Li Ye , Fan Bailing , Su Chunhua , Zhu Sixi
Published: November 2019

According to the water temperature of Jiaozhou Bay in May, August and October of 1979, based on its horizontal and vertical variation, and the difference between water temperature at surface and bottom, the impact of the transport amount and time of water temperature heat on its variation at surface and bottom and regional variation was studied. The results showed that in May, from northeastern to northern nearshore waters, water temperature reached high as 15.30-16.50 °C, which began to rise from inside waters to bay mouth, and to outside waters. In August, from eastern to northern nearshore waters, it reached high as 28.09-28.70 °C, which began to rise in same order. In October, in eastern nearshore waters, it was as high as 18.39°C, which began to increase from outside waters to bay mouth, and to inside waters. Regionally, from inside waters to bay mouth and outside waters, the minus of water temperature at surface and bottom showed that when it was transported to Jiaozhou Bay, it first reached the surface, then rapidly and constantly to sea floor, showing the variation of water temperature at surface and bottom. Spatially, water temperature at surface caused low heat and slow increase along with the horizontal and vertical gradients in May, high heat and rapid increase in August and heat and increase in October. Besides, the homogeneous layer was formed in outside waters vertically from surface and bottom. In bay mouth, water temperature at bottom was slightly higher than that at surface, whereas, in inside waters, it was opposite. Therefore, the temporal and spatial variation displayed the variation of water temperature at surface along with horizontal and vertical gradients. In addition, the modelling diagram was proposed and the transport direction and variation process of water temperature heat at surface were clarified.
Application of Hilbert-Huang Transform in Ultrasonic Echo Signal Processing of Composites
Authors: Gao Chengqiang , Chen Guiming , Shi Xiaomei
Published: November 2019

The ultrasonic nondestructive testing signals of carbon fiber reinforced composites have the characteristics of non-stationary and low signal-to-noise ratio, and Hilbert-Huang transform has unique advantages in feature extraction of such signals. This paper introduces the basic idea and method of Hilbert-Huang transform, which decomposes ultrasonic echo signals into several intrinsic mode functions, highlights the local characteristics of signals, and then obtains Hilbert spectrogram, marginal spectrum and instantaneous energy spectrum, so as to reveal the process of simultaneous changes of signal energy in time domain and frequency domain.
Research on Stability Analysis of Bonded Flexible Submarine Pipeline
Authors: Ni Lingying , Sun Chuan , Zhen Qiang
Published: November 2019

As an important part of underwater oil and gas transportation system, the in-situ stability of submarine pipelines is particularly important. Comparing with steel pipe, flexible pipe has the advantages of high strength, corrosion resistance, light weight, coil supply and laying. In this paper, the finite element software ABAQUS is used to calculate the initial in-situ stress balance of soil, pipe weight, internal pressure load analysis and horizontal buckling simulation. The transverse horizontal displacement and stress distribution under high temperature and high pressure in flexible pipeline operation are calculated. The results show that the temperature difference and pressure difference in pipeline operation are the main causes of pipeline failure. The results show that the relevant parameters of seabed soil have different effects on pipeline failure, and the friction coefficient of soil and pipeline is more obvious.
Research on Dynamic Characteristics of Rigid-Flexible Coupling System
Authors: Li Li , Lixin Wei , Mingmin Liu , Jiazhao Li
Published: November 2019

In order to study the influence of a flexible component on the vibration of a rigid-flexible coupling system under a shooting condition, the finite element theory is used to calculate the modal of the flexible component and establish its rigid region. The dynamic theory is used to establish the system. The virtual prototype is coupled to the virtual prototype, and the virtual prototype is calculated. The vibration displacement of the system under different working conditions is analyzed and discussed. The simulation results show that the flexible component has an influence on the lateral and longitudinal vibration displacement at the muzzle under shooting conditions. The research on the muzzle vibration provides a theoretical basis of the aircraft gun firing accuracy and the overall design of the aircraft.
Performance analysis of a brake magnet
Authors: Ren Facai , Wu Xinghua , Tang Xiaoying
Published: November 2019

The performance of elevator brake is very important for the safe operation of elevator. In this study, the performance of a brake magnet used in a elevator was analyzed. The outer wall of engine base and the plunger were analyzed by the optical microscope, scanning electron microscope, energy dispersive spectrometer and microhardness analysis.
Preliminary study: Padina australis Hauck’s antibacterial activity and phytochemical test against pathogenic shrimp bacteria
Authors: Latifah L A , Soekamto N H , Tahir A
Published: November 2019

The potential of aquaculture organism, Shrimp, need extra watchfulness to prevent it against the pathogenic bacteria attack. The use of synthetic antibiotics in shrimp can make pathogenic bacteria resistant and pollute the environment. Lately, Marine Natural Products (MNP) are other ways to overcome this problem. In this study, the MNP were extracted from macroalga Padina australis Hauck. The study aimed to examine the antibacterial activity of n-hexane, ethyl acetate, acetone, and ethanol crude extract against three pathogenic shrimp bacteria (Vibrio harveyi, Vibrio parahaemolyticus, and Aeromonas hydrophilla) and phytochemical screening, respectively. Ethyl acetate crude extracts of Padina australis Hauck showed that it could act as an antibacterial agent against Vibrio harveyi (1,76 mm), Vibrio parahaemolyticus (2,3 mm) and Aeromonas hydrophilla (4,43 mm). The phytochemical tests revealed that P. australis Hauck contains a steroid, terpenoid, phenolic, tannin, and alkaloid compounds.
Bioactivity of methanolic extract of marine tunicate Pyura sp against methicillin resistant Staphylococcus aureus (MRSA)
Authors: Litaay M , Johannes E , Dwyana Z , Husain K , Sardiani N
Published: November 2019

The research on potential methanol extract from marine tunicate Pyura sp as antibacterial Methicillin-Resistant Staphylococcus aureus (MRSA) has been done from February to April 2017. This research was intended to know the potential of methanol tunicates extract of proposed tunicates as an antibacterial MRSA. Tunicates were collected from Barrang Lompo waters of Sangkarang Archipelago of South Sulawesi Indonesia. Samples were dried, then the active compound was extracted used methanol solvent according to a standard procedure elsewhere. Tunicate’s extract was prepared into three different concentrations: 10%, 15%, and 20%, were tested against MRSA bacteria. A test of inhibition zone was applied at 24 h and 48 h incubation time in order to determine the bioactivity of tunicate’s extract towards MRSA. The result indicates that crude extracts of tunicates P. Pyura sp at all concentration performs anti bacteria activity against MRSA. This study concluded that tunicate Pyura sp has bactericidal activity against MRSA and this can lead to developing a new antibiotic in the future.
Compatibility of MO PLUS biofertilizer and Paenybacillus polymyxa to stimulate rice germination
Authors: Baharuddin  , Jahuddin R , Yani A , Tuwo M
Published: November 2019

The level of productivity of rice plantations can be increased through technical improvements in culture, namely spur plant growth. Increasing the germination rate is done by using growth regulators. Plants have limited synthesizing growth hormones in support of optimal growth. Therefore, it is necessary to add additional growth hormone from outside which can be given through fertilizers and symbiosis of microorganisms, including through the help of growth-regulating bacteria. MO Plus which is a combination of biological fertilizers and microorganisms Bradyrhizobium japonicum which is forming soybean root nodules to take nitrogen directly from the air and Streptomycetes as biological control of plant diseases. Efforts to merge MO Plus with P. polymyxa isolates in a consortium of biological product formulations need to be initiated to stimulate rice germination. The research stage consisted of synergistic tests by growing P. polymyxa bacteria and microbial consortium and calculating the number of bacterial colonies 48 hours in liquid media Nutrient Broth. The ability test produced IAA using L-Triptofan as a precursor, and the ability to produce GA3. The results showed that the levels of IAA and GA3 in Mo plus were 0.095 and 2.225 µg.l−1 respectively, while P. polymyxa: 0.087 and 2.251 µg.l−1. Synergism test results show that P. polymyxa and MO Plus bacteria can be grown on the same media simultaneously with the number of colonies of 2.3.108 CFU/ml. The treatment of MO Plus + Paenybacillus has the best influence on germination, wet weight, and dry weight of rice seeds.
Gastropods and edible macroalgae
Authors: Soekendarsi E.
Published: November 2019

The study on gastropods on edible macroalgae was conducted at Kodingareng island on the west-side of South Sulawesi. Macroalagae of the genera Hypnea, Gelidium and Acanthophora were sampled together with their molluscan fauna. A total of 36 genera of gastropods were found on the three genera of algae. The genera Heliacus, Clypeomorus, Cerithium, Pyrene, Columbella, Mitra, and Morula were present on all three genera of algae. Cerithium and Rhinoclavis were the most common hervivores on Gelidium and Hypnea, while Littorina was the most common herbivores on Acanthophora.
The study of bacteria populations in phytoremediation of cadmium using Eichhornia crassipes
Authors: Fahruddin F , Tanjung R E
Published: November 2019

The method of phytoremediation using Eichhornia crassipes plants was able to overcome the problem of cadmium (Cd) heavy metal pollution. This study aims to analyze the population of bacteria in Cd phytoremediation in groundwater using E. crassipes. The treatment in the study included T1 of 3 mg/L, T2 of 7 mg/L and T3 of 9 mg/L. The parameters observed were Cd concentration, a total of bacteria numbers, change in pH and total suspended solids (TSS). Based on the results of the study, the T1 treatment was the best absorbs of Cd in groundwater when using E. crassipes was 82%. It was the highest compared to other treatments which presented T2 of 65% and T3 of 73%. The highest bacteria population in T1 treatment. For pH and TSS, all treatments on the 12th day relatively of similar. In addition, this study also produced five types of isolates based on the results of characterization, including M1, M2, M3, M4, and M5. This shows that the E. crassipes will be inhibited from absorbing Cd at high concentrations, also affecting bacteria growth.
Cocoa Clone Resistance to Phytophthora Pod Rot (PPR) and Cocoa Pod Borer (CPB) in South Sulawesi
Authors: Dewi V S , Asman  , Josua K , Tuwo M
Published: November 2019

This research aimed find out the resistant of some superior cocoa clones to Phytophthora palmivora in South Sulawesi. This research covers several stages ranging from selection and sampling of cocoa clones, pathogen exploration to cocoa clone’s resistant test with various methods that is attaching the cocoa pod part to the healthy cocoa pod, applying P. palmivora suspension to the cocoa surface and sticking P. Palmivora isolates to the healthy cocoa pod section. The results showed that the resistance of cocoa clones to the three inoculation methods showed different areas of spotting on each observation day. The three application methods show that different applications can affect the difference in infection rates in each cocoa pod clone so that the spots that arise from infection can occur in various ways.
Medaka fish Oryzias javanicus Bleeker as bio-indicator of lead content in waters
Authors: Andriani I , Litaay M , Sartika  , Tahir D
Published: November 2019

An increase of heavy metal used in various products has lead to an increase of its pollution in water column elsewhere. Previous studies have shown that member of medaka fish is widely used as bio-indicator of pollution. Various medaka fish have been used in environmental as medical studies. The present study aims to observe capability of medaka fish Oryzias javanicus Bleeker as bio-indicator of lead [Pb] content in waters. Fish was collected from the mouth river of Jeneberang South Sulawesi and acclimatized at the Medaka Study Centre of Hasanuddin University. In order to study capability as bio-indicator, the fishes as test animals was treated with different concentration that of 0; 0.01; 0.03 and 0.05 mg/L Pb. Test animals were kept in media containing Pb for ten days before assessing their metal content. Pb content in animals was calculated after treatments. Composite method was applied for Pb content in medaka fish, in which fish was crushed and proceed to metal content analysis using EDXRF spectrofotometer. The result indicates that medaka fish Oryzias javanicus Bleeker survives at threshold concentration 0.05 mg/L Pb, respectively. We conclude that Oryzias javanicus can be used as bio-indicator of lead content in waters.
Cloning and expression of recombinant protein CFP21 from Mycobacterium tuberculosis as a tuberculosis vaccine candidate
Authors: Ahmad A , Agus R , Massi M N , Handayani I , Karim H
Published: November 2019

Increased resistance to TB drugs, may render vaccine development a more effective approach to stop or reduce TB epidemics. The antigen Culture Filtrat Protein Filtrat 21 (CPF21) is an immudominant protein encoded in RD 2 region of the Mycobacterium tuberculosis genome, capable of obtaining a strong hypersensitivity reaction and to induce very high interferon-gamma (IFN-γ) responses in patients with tuberculosis. In order to construct the recombinant plasmid pGEM-T Easy-CFP21 and express it in E. coli BL21, the CFP21 gene was amplified from M. tuberculosis H37Rv genomic DNA using PCR in vitro, and inserted into the pGEM-T Easy cloning vector. The recombinant plasmid was then transformed into E. coli JM109, followed by plasmid extraction, PCR amplification, and DNA sequencing. The correct recombinant CFP21 gene was subcloned into expression vector pGEX-2TK and transformed into E. coli BL21 strain. The white recombinant colony was selected, cultured, induced with 50 µM IPTG, and identified using SDS-PAGE electrophoresis method. These results demonstrated that CFP21 gene has been constructed and expressed successfully. The molecular weight was about 47 kDa as the fusion protein GST-CFP21 and expressed as insoluble protein. In conclusion, the target gene CFP21 has been cloned into host E. coli BL-21 strain and expressed successfully. In the future, the purified recombinant fusion protein GST-CFP21 paves the way for TB diagnosis and vaccine development.
Anti-dengue potential of bioactive protein from exophytic bacteria that are symbiotic with brown algae Sargassum sp.
Authors: Ahmad A , Wahid I , Massi M N , Arfah R , Karim H
Published: November 2019

Symbiont bacteria of algae are bioactive metabolite sources with potential as medicinal raw materials. This study aims to find out the anti-dengue potential of a protein fraction isolated from Enterobacter agglomerans SB 5(1) as the symbiont of brown algae Sargassum binderi collected from Lae-Lae island, South Sulawesi. These extracellular and intracellular fractions were isolated by ammonium sulphate fractionation at saturation levels of 0-20 %, 20-40 %, 40-60 %, and 60-80 %. The protein was purified by dialysis method using cellophane bag. Toxicity was tested by BSLT method using shrimp larvae of Artemia salina, Leach. Cytotoxicity test against vero cells infected with dengue virus DEVN-2 was performed by MTT method. Study findings indicate that intracellular protein fraction from E. agglomerans SB 5(1), a symbiont of brown algae Sargassum binderi, showed the presence of bioactive protein having strong toxicity with LC50 of 48.67 µg/mL. Anti-dengue activity toward vero cells indicates inhibition percentage and CC50 value of 70% and 260.37 µg./mL, respectively, therefore it had no potential as anti-virus dengue agent. In future studies, it is recommended to perform hydrolysis of protein compound from symbiont bacteria of Sargassum sp. to explore other peptide compounds with more potential as anti-dengue agents.
Synthesis and modification of mesoporous silica with sulfated titanium dioxide as a heterogeneous catalyst for biodiesel production from palm fatty acid distillate
Authors: Manga J , Ahmad A , Taba P , Firdaus
Published: November 2019

This study synthesizes fatty acid ethyl ester (FAEE) through esterification reaction of palm fatty acid distillate (PFAD) using SO4
2−/TiO2 supported by mesoporous silica as a catalyst. The steps of this study were a synthesis of mesoporous silica, catalyst preparation by impregnation and catalyst activity test through esterification reaction of PFAD by using ethanol. The variables of study on the esterification reaction were the weight ratio of catalyst and PFAD as 3%, 5%, 7%. Based on BET characterization, it shows that synthesized silica material is mesoporous silica. The characterization result of silica and catalyst using X-Ray of wide-angle powder (WAXRD) and SEM gives information that the existence of silica as support of SO4
2−/TiO2 active site. At the catalyst activity test through esterification reaction, it was obtained the best weight ratio of catalyst and PFAD was 5% with the conversion of ethyl ether formation as 98.9 %. Analysis data and physical properties were viscosity at a temperature of 40 °C and density at the temperature of 15 °C, it shows that the value fit a biodiesel standard of ASTM, meanwhile analysis data of GC-MS toward product of ethyl ester and PFAD has shown that most of the fatty acid in PFAD had been converted into ethyl ester.
Effect of filler and plastisizer on the mechanical properties of bioplastic cellulose from rice husk
Authors: Jannah M , Ahmad A , Hayatun A , Taba P , Chadijah S
Published: November 2019

Rice husk is a product of the rice milling process. The high cellulose contents in rice husk that supports the use of it as raw material for bioplastic. This study aims to determine the effect of supporting polymer such as chitosan to the mechanical properties of bioplastic. The stages of this research were cellulose extraction from rice husk by maceration method, optimization of NaOCl concentration as a bleaching agent and printing of bioplastics with various treatments, namely cellulose-sorbitol (CS), cellulose-chitosan (CC) and cellulose-sorbitol-chitosan (CSC). Characterization was conducted by Fourier Transform Infrared (FTIR) and Universal Testing Machine (UTM). The study showed that the optimum NaOCl concentration was 2.0% with a cellulose content of 59.2% in the form of white powder. The best bioplastic was bioplastic cellulose-sorbitol-chitosan (CSC) with the tensile strength of 0.060 Kgf/cm2 and the elongation of 4.75%. The peaks appeared in the FTIR spectrum were O-H, N-H and C-O at 3450.64, 1638.41, and 1087.76 cm−1, respectively. The interaction between cellulose from rice husk, filler addition, and plasticizer effected the quality of bioplastic.
Steam Flush Pressure: A New Modification Method to Extraction chitin from Lingula sp
Authors: Arif AR , Himawan A , Erviani AE , Natsir H , Akbar A , Dirpan A
Published: November 2019

Lingula sp is one of the bivalves, where it is very popular for people as food consumption. However, the high consumption of society is not accompanied by the utilization of residual waste from Lingula sp. In the composition of the structure of the compound, the shell of Lingula sp contains chitin compounds which are very potential to be applied in the field of biotechnology and have an economical value. The aims of this study to isolated chitin from Lingula sp shell used steam flush pressure method. Chitin isolation was carried out with three stages of the process, namely deproteination, decolorization and demineralization at 121 °C, a pressure of 15-20 psi with variations of time 5, 15, 30, 45 and 60 minutes. Chitin characterization showed that 60 minutes was the optimum treatment time with characteristics of 9.5% water content, 1.01% ash content, total N-content of 6.87% and deacetylation degree 33.19% with a yield of 5.06%. These results showed that the exploration of chitin potential contained in Lingula sp is very potential to be used as a new source. In addition, the steam flush pressure method is a breakthrough to isolation chitin.
Accumulation of iron by perumpung (phragmites karka) and its adaptation in various pH of hydroponic solution
Authors: Rusmanta Y , Ahmad A , Raya I , Ibrahim B
Published: November 2019

Iron is included as micronutrient which is needed in limited quantities by plants. Extraction from the soil is carried out through ion exchange between roots and solution in the soil. While the transport mechanism from the root to the leaves is carried out through xylem by a capillary mechanism. Iron concentration in acid sulfate soils is excessive, so it becomes toxic to plants. This research has been carried out to determine iron accumulation by Perumpung in various pHs in hydroponic solutions. The research was also carried out to determine the level of adaptation in the acidic pH and stress of iron ions at a concentration of 50 mg Fe/L. Perumpung used in this study has been seeded on hydroponic media for 3 weeks. The experiment was carried out for 3 and 5 weeks. The nutrient solution used according to the standard Hoagland Solution then added iron ions to a concentration of 50 mg Fe/L. Then 4 variations of pH were made 3, 4, 5, 6 plus two variations as a comparison, according to Hoagland’s solution without the addition of iron (blank) and Hoagland’s solution with the addition of iron but the pH was not regulated (control). The results of this study showed the highest level of adaptation which grew on the blank, then followed by pH 5.6 (control), pH 6, pH 5, and pH 4. Perumpung at pH 3 dead. The highest level of iron accumulation in roots was occurred at pH 5, followed by pH 6, then pH 4, and the control. The accumulation of iron in roots was higher than in shoots. Perumpung was suitable to be used as an iron accumulator at pH 5, while for cultivation it was suitable to be planted at pH 6.
Adsorption of chromium ions by candlenut shell based carbon activated with H3PO4
Authors: Zakir M , Fauziah St , Sumpala A G T
Published: November 2019

Candlenut shell based carbon which was chemically activated using a solution of phosphoric acid and modified with nitric acid has been used to adsorb chromium ions (Cr(VI)). This study aims to examine the effect of phosphoric acid activation on the surface area of the candlenut shell carbon and the effect of nitric acid on the adsorption capacity of metal ions Cr (VI). The study was carried out by activating the candlenut carbon with 10% phosphoric acid for 24 hours then modified with 6 N nitric acid for 24 hours. The activated carbon that has been modified is then optimized with several parameters, namely time, pH and the number of adsorbents to maximize the performance of activated carbon. The surface area of candlenut based activated carbon was determined by methylene blue method and the adsorption capacity was measured using Atomic Absorption Spectrophotometer (AAS). The results showed that the carbon surface area before and after activation increased from 1557.3 m2/g to 1669.5 m2/g, respectively, and the surface area increased dramatically after HNO3 modification to 2090,8 m2/g. The adsorption capacity to the metal ions (Cr(VI)) tends to follow the Langmuir isotherm model which is equal to 20.4 mg/g.
Comparison of micronutrients content (Fe, Cu, Mn) in cacao beans from plantation area and transmigration area in East Luwu
Authors: Rombe Y P , Simanjuntak I O , Noor A , Nafie N L
Published: November 2019

This study aims to comparison micronutrient (Fe, Cu and Mn) concentrations in cacao beans and its potential as food product for fulfilling body nutritional adequacy, cacao beans comes from plantation area and transmigration area. The content of micronutrient was analyzed by Inductively Coupled Plasma (ICP)-OES Perkin Elmer Optima 8300. The results obtained that the average content of Fe, Cu, and Mn in cacao beans from plantation and transmigration area were 2.022 mg/100 g; 3.009 mg/100 g; 1.571 mg/100 g and 2.684 mg/100 g; 2.202 mg/100 g; 1.801 mg/100 g respectively. Analysis results indicated that Fe, Cu and Mn content in cacao content from plantation and transmigration area can be used as raw material for food products to fulfill the body nutritional adequacy.
Analysis activity 14C of coral in Barrang Caddi Island, Spermonde Archipelago
Authors: Firman N F A , Noor A , Maming  , Zakir M
Published: November 2019

This study aims to determine carbon-14 activity on coral from Barrang Caddi. Several stages of research were physical and chemical cleaning to eliminate contamination on coral. CO2 absorption pre-treatment method, titration to determine total carbon absorbed in the process of absorption CO2 and enumeration with LSC Hidex 300 SL to determine the optimum time of enumeration, the average value of activity 14C and specific activities 14C. In this study, marble from marble karst, Maros, was used as a background. The results show that the absorption capacity was 0.2188 mol CO2/mol OH, the absorption efficiency of 21.87%, total carbon mass was 0,168 gram, optimum counting time was 15 minutes, average activity 14C was 433,597 DPM, enumeration efficiency was 0,567 and specific activity was 15.262 DPM/gC. It was concluded that coral in Barrang Caddi relatively new.
Broken painting in the prehistoric cave and chemical content of paint used in Maros Regency, South Sulawesi
Authors: Thosibo A , Soekamto N H , Duli A , Mulyadi Y
Published: November 2019

An examination have been done of the cause of damage to the prehistoric paintings in Maros South Sulawesi. The cause of the damage is besides human factors, natural factors are the main cause. A total of 4 prehistoric caves as samples where four painting colors (red, black, brown and white) were taken. After being observed, it can be seen that the form of damage consists of peeling painting paint, weathering the rock where the painting is, and erosion. The method used is by gouging out damaged paintings as samples and analyzing these samples using X-Ray Fluoroscence (XRF) and X-Ray Difraction (XRD) instruments. Based on XRF and XRD data analysis, these colors contain compounds CaO, SO3, Cl, P2O5, V2O5, Nb2O5, MoO3, SiO3, Fe2O3, TiO2, Nb2O5, dan Sb2O3.

The results of the analysis show that in general the main content of all paint paintings from different locations is CaO and SO3 . This indicates that the measured paint contains a lot of lime. Other chemical components contained are reddish brown Fe2O3. This compound contributes to the color of red, brown and one black painting.

Based on the results of elution absorption and color reactions, paints of red and black are not derived from human or animal blood. The results of this study provide useful information about the composition of the compounds used to produce prehistoric painting paints, which can later be reproduced and utilized in the context of conservation and restoration of damaged paintings.
On identifying the irregularities of electricity customer behaviors using soft computing approach
Authors: Lawi A , Wungo S L , Manjang S
Published: November 2019

This study aims to implement a soft computing approach in identifying the irregularities of customer behaviour on the use of prepaid electricity pulses. The used methods are Support Vector Machine (SVM), Naïve Bayes (NB), Classification and Regression Tree (CART), and k-Nearest Neighbours (KNN). To evaluate the performance of the classification system, a 10-fold Cross Validation technique is used for the historical data of pre-paid pulse purchase transactions. Validation results are measured using accuracy, precision and recall values. This research shows that all soft computing methods gave good performances in classifying electrical consumption behaviours. CART method has the highest accuracy value of 100% compared with others algorithm. At precision values, KNN and CART methods have the highest precision value among other algorithms that are 99% to 100%. Whereas, the recall values of each method has a high recall value of 100%. Moreover, each method can predict morbidity accurately because the addition of the amount of data testing does not affect the performance of each method.
Double measurement on cognitive learning apps for children with mentally retardation
Authors: Persada A G , Ati O R L
Published: November 2019

There are four cognitive aspects revealed aim to develop learning application (apps) for children with mentally retardation (MR), namely perception, association, memory, and motoric. However, motoric aspects is less noticed in apps which had being developed. In this study, we aim to design the interaction of the apps which accommodate motoric aspect. Apps may be used as companion tool aside with formal learning. Apps is focused on motoric aspect, while another four aspects are adopted from existing apps. In order to reach high level of usability, interaction design (IxD) is measured iteratively using double measurements, cognitive walkthrough (CW) and heuristic evaluation (HE). Both method is covering each other. This way is suitable to verify previous measurement and strengthen usability. Result of the study stated that apps can properly used by students and teacher and relevant with user research. There is no major usability problems found either in CW or HE measurement. Moreover, HE method ensures end-user’s satisfaction is good design principles also.
An optimization of the machining parameters on delamination in drilling ramie woven reinforced composites using Taguchi method
Authors: Chandrabakty S , Renreng I , Djafar Z , Arsyad H
Published: November 2019

In this study, the drilling parameters will be evaluated to obtain optimal parameters in minimizing the impact of drilling damage on composite materials reinforced by ramie woven. The impact of damage observed in the study is delamination that occurs in the drill hole, where the smaller value is desired. The drilling parameters are optimized using the Taguchi method with two control factors, namely the feed rate and spindle speed, each parameter is designed in three levels. This experiment then carried out on four different diameter drill bits, i.e., 4, 6, 8 and 10 mm. While experimental planning uses L9 orthogonal arrays and the “smaller is better” approach is given as a standard analysis. By performing an analysis of variance (ANOVA) statistics can be determined for the significance of each drilling parameter. A series of experiments were carried out to get the appropriate optimization. It was found that the critical factor causing delamination in drilling is the feed rate followed by spindle speed, where this phenomenon occurs in each diameter of the drill bit.
A dimensional reduction of an (n+1) compartmental model
Authors: Cahyono E , Elastic P , Soeharyadi Y , Mukhsar
Published: November 2019

An (n+1) dimensional compartmental model is studied. It is an n dimensional model sits in (n+1) dimensional space, consists of (n+1) variables and (n+1) equations. The model is a generalization of well-known SIR model. Reduced dimensional model is introduced. The reduced model consists of n variables and n equations. The equilibrium points of the original model and reduced model are discussed. The stability of the equilibrium points are analyzed and compared. Numerical simulation is applied for n = 5. The numerical result which is the evolution of the variables is presented.
Analysis of stenosis effect on blood pressure using moving particle semi-implicit method
Authors: Purnama H , Suprijadi  , Kurniasih N
Published: November 2019

Computational fluid dynamics are developed by scientists in the last few decades. Computing is used to explain the physical problem which is using a numerical method. In this paper, the phenomenon of stenosis inhibited blood flow is simulated and observed using the Moving Particle Semi-Implicit Method. The simulation was built using the Navier-Stokes equation. This simulation does not use data with quantitative units because it only aims to observe the phenomenon of blockage of stenosis in the bloodstream, so the value was obtained without units. The velocity profile of the blood particles which are located between the rigid stenosis will be fastest if the percentage of stenosis is higher. The velocity profile shows a fluctuation in the direction of the radial position = 0 when the horizontal position is 1.5 ⩽ x ⩽ 2.5 with the maximum velocity when the stenosis is 60% i.e 9.2 units. This shows that there are obstacles that cause the velocity profile to be higher than the blood flow without stenosis, and the greater the percentage of stenosis, the greater the fluctuations occurring in the area so that it has a higher velocity.
Harmonious labeling on prisms graph
Authors: Hinding N , Husain W , Massalesse J
Published: November 2019

In this paper, we show that C
2a+1 × Pn
and

(

C

2
n
+
1

×

P
n

)

+

K
¯

p

is harmonious for a ⩽ 1, and n is even.
Isomorphism From Quaternion To Matrix Ring Over Field ℤp
Authors: Amir A K , Anggriani N , Erawaty N , Bahri M , Azis M I
Published: November 2019

The quaternion ring and matrixs ring 2 by 2 over ℤ
p
are non-commutative rings. It seams, the two rings are not identical. However, the result of the study show that the two rings area identical or isomorphic. This paper, presents several forms of isomorphism between the two rings.
Around Zero-Divisor Graph of Skew Polynomial Rings over Real Matrix 2 by 2
Authors: Amir A K
Published: November 2019

Let R be an associative ring with non-zero two-sided multiplicative identity. The zero-divisor of R, denoted by Z (R). The directed graph Γ(R) is a graph with vertices Z (R) − {0}, where x → y is an edge between distinct vertices x and y if and only if xy = 0. On the other hand, assume that σ is a ring endomorphism on R. The skew polynomial ring R[x; σ,] is the ring of polynomials (with indeterminate x) over R. In this paper, in the case that R = M
2(ℝ), we study the zero-divisor graph of the skew polynomial ring R[x;σ].
Effect of vaccination and treatment on the MSEICR model of the transmission of hepatitis B virus
Authors: Muin R M , Toaha S , Kasbawati
Published: November 2019

This article studies a development of SEIR standard model for the spread of hepatitis B virus. The model is developed by considering immunized and carrier compartments of population. The model includes immunized, suspected, exposed, infected, carrier, and recovered compartments and written as MSEICR. Some of new born and the suspected are given vaccines and the infected is given a treatment. These strategies aim to reduce transmissions of hepatitis B virus in the population. The existence and stability of endemic and non-endemic equilibrium points are analysed via basic reproduction number (ℛ0) which is derived from the next generation matrix method. The results showed that the endemic equilibrium point does not exist when ℛ0 < 1. The endemic will appear when the value of ℛ0 > 1. Sensitivity analyses showed that vaccination and treatment may reduce the spread of hepatitis B virus and also eliminate endemic condition. Some simulations were conducted to visualize the effects of vaccination and treatment on the existence and stability of endemic equilibrium point.
Comparison of two varieties of Plectranthus scutellarioides based on extraction method, phytochemical compound, and cytotoxicity
Authors: Astuti A D , Yasir B , Subehan  , Alam G
Published: November 2019

Plectranthus scutellarioides have more than 173 varieties that can be distinguished from leaves foliage. Each variety produces certain second metabolite. Among all varieties, color blaze dark star was the one commonly used in Indonesia as traditional medicine. Optimization extraction process, qualitative phytochemical analysis, and preliminary assessment of toxicity of color blaze dark star and trailing queen variety of Plectranthus scutellarioides were investigated. Extraction process in color blaze dark star variety using Microwave assisted extraction show the highest %yield of extract but in trailing queen variety the highest %yield of extract was obtained from soxhletation method. Qualitative phytochemical analysis using thin layer chromatography from methanol, ethanol, and water extract with all method of extraction showed that both of varieties of Plectranthus scutellarioides contain alkaloid, flavonoid, tannin, and phenol. The highest toxicity with LC50 39 µg/ml was showed from ethanol extract using microwave assisted extraction of color blaze dark star variety.
Development of lengkuas (Alpinia galanga) and cortex of banyuru (Pterospermum celebicum, miq) extract for topical preparation on validation methods analysis of total flavonoid levels
Authors: Marzuki A , Rahman L , Kasim S
Published: November 2019

The research has been to development cortex banyuru (Pterospermium celebicum, Miq) [1] and lengkuas (Alpinia galangal extract) topical preparations to validate the method of analyzing total flavanoid levels [2]. The aim of this study was to find a method suitable for developing preparations with total flavanoid priority be applied to soap Banyuru and Lengkuas extracts [3]. Valiadation parameters used in this study are specificity, linearity, range, precision, and accuracy [4].The results of the study will show that this method is specific and has a standardized linearity value, ie the range value. obtained the acquisition value, in the precision test obtained RSD (relative standard deviation) value. Based on the results of this study it can be concluded that the validation method of analysis of total flavanoid levels in soap [5]. Meuserements of spectrophotometry visible with AlCl3 reagents has specificity, linearity, range, accuracy, and precision showed the good results. The valid analysis method was then applied to the analysis of the total flavanoid content of 5 soap [6] formulas extracted from Banyuru and Lengkuas bark, and from these results total flavanoid levels were obtained.
Numerical solutions to Helmholtz equation of anisotropic functionally graded materials
Authors: Paharuddin  , Sakka  , Taba P , Toaha S , Azis M I
Published: November 2019

In this paper, interior 2D-BVPs for anisotropic FGMs governed by the Helmholtz equation with Dirichlet and Neumann boundary conditions are considered. The governing equation involves diffusivity and wave number coefficients which are spatially varying. The anisotropy of the material is presented in the diffusivity coefficient. And the inhomogeneity is described by both diffusivity and wave number. Three types of the gradation function considered are quadratic, exponential and trigonometric functions. A technique of transforming the variable coefficient governing equation to a constant coefficient equation is utilized for deriving a boundary integral equation. And a standard BEM is constructed from the boundary integral equation to find numerical solutions. Some particular examples of BVPs are solved to illustrate the application of the BEM. The results show the accuracy of the BEM solutions, especially for large wave numbers. They also show coherence between the flow vectors and scattering solutions, and the effect of the anisotropy and inhomogeneity of the material on the BEM solutions.
Synthesis Ag nanoparticle by laser fragmentation for high sensitive ammonia residue detection
Authors: Zahrah A N , Herbani Y , Tahir D
Published: November 2019

We have been synthesis silver nanoparticles by using chemical analysis and successfully reduce silver nanoparticles by femtosecond laser fragmentation method with various silver nanoparticles size ranges from 60 - 75 nm, 10 - 35 nm and 9-17 nm. Characterization is carried out by Modular UV-Vis Spectrometer (MayaPro200, Ocean Optics) and Transmission Electron Microscope (TEM FEI Tecnai G20 S-Twin 200kV). Based on the results, silver nanoparticles (particles size are 9-17 nm) is high potential for detection of ammonia residues by ammonia PPM enhancement (10 PPM, 100 PPM, 150 PPM, 200 PPM, 250 PPM, 300 PPM, 350 PPM, 400 PPM, 450 PPM, and 500 PPM) and a maximum shift of absorbance at a wavelength of 433.39 nm, while TEM characterization have the structure is round.
Fabrication and characterization starch/chitosan reinforced polypropylene as biodegradable
Authors: Jangong O S , Gareso P L , Mutmainna I , Tahir D
Published: November 2019

The production of bioplastic from starch/chitosan reinforced polypropylene with different ratio from 35/65, 50/50 and 65/35. In present study, bioplastic was investigated by using tensile strength test, X-Ray diffraction (XRD), and Fourier transform infra-red (FTIR) spectroscopy, and respectively. XRD analysis shows that the sample have amorphous phase structure with the main broad peaks 18° to 30°. FT-IR used to investigate functional group and the result analysis show that the main bonding is of O-H hydrogen bonds (carboxylic acid), C-H alkanes, C=C alkenes and C-O alcohols. The tensile strength obtained for bioplastic were 68.41Mpa at ratio 65/35, respectively. These bio plastics have exhibited mechanical properties with high biodegradability that makes them a suitable alternative for the existing conventional plastics.
Evaluation of Typical Dose Rate Values, Maximum Dose Rate in Air and Dose Rate in Surface Image Intensifier (Ii) in Dual Function Fluoroscopy (Fl)
Authors: Bariah K , Dewang S , Suryani S
Published: November 2019

This study aims to determine the value of the typical dose rate, the maximum dose rate in the air and the dose rate on the surface of Image Intensifier (II) in 3 types of dual function Fluoroscopy (FL). This study used a dual function Fluoroscopy, X-Ray safe multimeter, Pb plate, Cu plate, and phantom perspek. Typical dose rate measurement were carried out by placing a multimeter X-Ray of phanrom perspek of a thickness of 18 cm, so that the examination table distance from the detector was 18 cm and source distance from image of 96 cm according to normal patient position. Measuring the maximum dose rate in teh air is done by placing the detector at distance of 300 mm above the examination table, placing the Pb 2 mm below the collimator, the exposure is carried out at the maximum automatic kVp. Measuring the dose rate of the surface Image Intensifier (II) is done by placing the detector above II, the Cu plate with a thickness of 2 mmCu is affixed to the surface of the collimator and the exposure is carried out on the automatic kVp. Typical dose rated to test results from FL (A) and FL (C) with the same size II are 35 cm while FL (B) sized II is 23 cm. The results of the tipical dose rate test for FL (A), FL (B), and FL (C) are 11.428 mGy/minute, 11.712 mGy/minute and 12.518 mGy/minute, respectively. All results of the testing of the typical ESD dose rate are still within the test passes which are ⩽17 mGy/minute as required by BAPETAN Regulation No. 2 in 2018. The value of the maximum dose rate in air of each planes is very varied from the maximum value on FL (B) is 11.402 mGy/minutes, while the minimum value occur to FL (C) is 4.311 mGy/minutes. As for FL (A), the maximum dose rate in air is 7.998 mGy/minutes. All results of testing the maximum dose rate in air are still below the test pass value required by BAPETAN which is 50 mGy/minutes. The value of the dose rate of surface II varies greatly from FL (B) having a maximum value is 68.2 µGy/m inutes while FL (A) and FL (C) are 33.3 µGy/minutes and 2.4 µGy/minutes, resvectively. All results of testing the dose rate of the surface of Image Intensifier (II) are still below the test pass value required by BAPETAN which is 60 µGy/minute for size II 23 cm and 90 µGy/minute for size II ⩾ 23 cm.
Sensitivity Enhancement of Strain Sensor Based on Polymer Optical Fiber for Concrete Testing
Authors: Arifin A , Samsu A , Yunus M , Abdullah B , Tahir D
Published: November 2019

Research has been carried out about sensitivity enhancement of strain sensor based on polymer optical fiber used for concrete testing. Strain sensor testing was done by applying of pressure to the concrete using the Ultimate Testing Machine (UTM). Strain sensor was made from polymer optical fiber without coat with straight, U and rectangular configurations. At both ends of the sensor connected with Light Emitting Diode (LED), phototransistor and amplifier circuit that produces output value in the form of analog voltage that is converted by the Arduino Uno microcontroller into the digital voltage value displayed on the computer. The results showed that the greater the load given on the concrete, the greater the strain on the sensor, so that the output voltage read on the computer gets smaller. The best sensitivity value obtained at rectangular configuration with 3 cm amplitude is 0.117 V/cm with 0.008 cm resolution. Strain sensor in the concrete structures testing based on polymer optical fiber has advantages including low cost, simple measurement system, easy fabrication with high sensitivity.?
Three Decades State of the Tombolo Related to Wind Climate (1985 to 2015): Case of Galesong Beach, Takalar Regency
Authors: Pada B T , Suriamihardja D A , Sakka  , Paharuddin  , Assegaf M A H
Published: November 2019

Tombolo-shaped beach in Galesong District orientated westward is a nice morphology behind the detached Sanrobengi Island in front of mainland of Takalar Regency. Our main interest is formulated as the problem of how the tombolo whether is experiencing continual growth or retreated. This study aims to explain changes of shape and its area of the tombolo morphology for each five-year period along the shoreline based on the influence of wind directions. This study uses Google Earth Pro Image from 1985 to 2015 to map key changes of the shoreline, where the obtained data are analysed using ArcGIS 10.3. Wind data is obtained from the European Centre Medium-Term Weather Forecast (ECMWF) from 1985 to 2015 where the wind data is analysed using Ocean Data View, and WRPlot 5.3 is used to form wind rose diagrams. Shoreline of the tombolo is divided into six segments and studied into five-year periods from 1985 to 2015. The obtained results showed that the wind direction is enough to influence the change of shorelines in the area of the Tombolo. From 1985 to 2015, the dominant wind direction is from the West and Northwest. Overall changes are as follow, the area of tombolo is developed during the period of 1985 to 1995; while the area of tombolo is retreated in the period of 1995 to 2015.
Modeling of Extreme Rainfall Recurrence Using Conditional Probability Approach
Authors: Sunusi N
Published: November 2019

Forecasts for the occurrence of extreme rainfall are related to time lapse estimates until the next extreme rain event. The accuracy of these estimates depends on the choice of interevent time distributions of extreme rain events. The aim of this research is to estimate the probability of time recurrence of extreme rainfall. In this research, we observed the time between extreme rain events distributed by Weibull and Pareto. Let T be the time interval for the next extreme rain and it is assumed that there has been no extreme rain at time interval (0, t
0]. To analyze the occurrence of the next extreme rain event, the concept of conditional probability P(Δt
0|t
0) is used. P(Δt
0|t
0) is the probability of extreme rain occurrence during the time interval Δt
0. The results show that by using three models, we found that the next extreme rain event is not depending on the time interval Δt
0 since the last extreme rain event. Other results show that for case studies of extremerain events in South Sulawesi it was found that the time of occurrence of extreme rainfall was influenced by parameter value for each model.