bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract

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

Abstract
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

Abstract
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.