Indonesia Conference Directory

Corresponding Author
Aritsya Imswatama

Institutions
(a) Mathematics Education Program, Muhammadiyah Sukabumi University. iaritsya[at]gmail.com
(b) Early Childhood Teacher Education Program, Muhammadiyah Sukabumi University

Abstract
The purpose of this research is to describe mathematical element in traditional house in Geopark Ciletuh Sukabumi. The type of this research is qualitative research. This research is triggered by a such condition of the low knowledge of local cultures and wisdoms owned by the students. They need to increase their knowledge of cultures and local wishdoms to integrate into their school education. In this way, there will be an integration between culture and education in school. Data collection techniques used in this research are interview, observation and documentation, then the data obtained are analyzed by using data reduction, data presentation, verification and conclusion. The results of this study show that in the architecture of traditional house there are mathematical elements such as geometry and tessellation. The results of this study can be used as an innovation and learning materials in elementary school mathematics, so it will increase students knowledge related to the application of mathematics in everyday life. It is expected that etnomatematics may become an innovation of learning mathematics in school and motivate the students to learn math related to the cultures and local wishdoms.

Keywords
ethnomathematics; traditional house architecture

Topic
Mathematics Education

Link: https://ifory.id/abstract/kXjeZ8vmVN3M

Corresponding Author
Susinggih Wijana

Institutions
Universitas Brawijaya

Abstract
The commercial seasoning that sold in the market containing artificial Monosodium Glutamate (MSG) as a flavor enhancer. However, the excessive use of MSG can endanger the health of the body. Therefore, it requires an alternative non-MSG seasoning. The use of MSG can be replaced with natural ingredients from protein enzymatic such as blondo protein hydrolysate. This study was conducted to understand the nutritional content and glutamic acid of blondo protein hydrolysate, to find out the appropriate formulation in making seasoning of blondo protein hydrolysate, and to understand the acceptance level of seasoning that made of blondo protein hydrolysate. The main study was the production of seasoning formulations with a raw material of blondo protein hydrolysate and additional spices that consisted of sugar, salt, white pepper powder, onion powder, and garlic powder. The formulation was made in 6 treatment levels based on the difference in the proportion of blondo protein hydrolysate, which were; 0%, 2%, 4%, 6%, 8%, 10%. Then tested using scoring test with 30 untrained panelists. The result of the proximate test on the raw material of coconut blondo raw which contained nutrients in the form of 9.09% water, 19.95% protein, 34.51% fat, 5.00% ash, 31.45% carbohydrate. The result of the proximate test on blondo protein hydrolysate were containing 8.21% water, 35.62% protein, 22.18% fat, 3.25% ash, 20.40% carbohydrate, and 10,41% glutamic acid. Based on the scoring test, could be known that the highest score for the parameter of taste, color, and aroma was a formulation with addition blondo protein hydrolysate around 8-10%. Thus, it could be stated that the use of vegetable seasoning products as an MSG alternative was possible and acceptable for consumers.

Keywords
coconut blondo, enzymatic hydrolysis, seasoning.

Topic
AGRICULTURAL PRODUCT TECHNOLOGY

Link: https://ifory.id/abstract/9Xt3aGELnFMR

Corresponding Author
Eko Yulianto

Institutions
(a) Department of Mathematics Education, Universitas Siliwangi, Siliwangi Street No. 24, Tasikmalaya, West Java, Indonesia
*ekoyulianto[at]unsil.ac.id
(b) Department of Guidance and Counseling, Universitas Muhammadiyah Tasikmalaya, Tamansari Street Km. 2,5, Tasikmalaya, West Java, Indonesia
(c) Department of Mathematics, Doctoral Program, Universitas Pendidikan Indonesia, Dr. Setiabudhi Street No. 229, Bandung, West Java, Indonesia

Abstract
This paper is a little practical reflection of the idea proposed by Freudenthal in his book titled ‘Revisiting Mathematics Education-. Theoretically, a fundamental study of more philosophical mathematical meanings was discussed by Freudenthal through the terms ‘wiskunde- and ‘wiskunst-. In essence, wiskunde means mathematics as an exact science, while wiskunst means an art in mathematics and science. Although there has been a lot of research that shows the success of RME in learning, the results of research that can contrast explicitly how the wiskunde and wiskunst phenomena work in the process of solving mathematical problems are still rarely found. This study aims to see the tendency of students towards the phenomenon of wiskunde or wiskunst in working on elementary math problems then describe the psychological factors and impacts that might be influential. This study used literature review and qualitative methods through the interview process for students who were given two elementary school math problems. Four out of forty students from fourth semester were chosen to be interview respondents to represent variations of the unique answers. Data analysis was carried out through a hermeneutic approach to student answers and interview transcripts. Research shows that the wiskunde phenomenon looks more dominant than wiskunst. This is thought to be related to the symptoms of psychological blockages of student-s college who are predominantly working on elementary math problems still using the very formal formulas, they should still be able to show a way of thinking like an elementary school kid. The impact of this wiskunde tendency indicates the ‘matherate- of students who have become blunt. The contrast of wiskunde and wiskunsts character and its reflection to the philosophy of education are discussed boldly in this paper.

Keywords
Realistics Mathematics Education, Wiskunde, and Winskunt

Topic
Mathematics Education

Link: https://ifory.id/abstract/G4LFhxXzVNqd

Corresponding Author
Wendra G Rohmah

Institutions
Department of Agro-industrial Technology, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, Indonesia

Abstract
The aims of this study were to analyze the financial feasibility and value-added increasing of corn milk product development. The financial feasibility study carried out using the criteria of Net Present Value (NPV), Internal Rate of Return (IRR), Payback Period (PP), Break Event Point (BEP), B/C ratio and R/C ratio, while analysis of increasing value-added using the Hayami Method approach. The results showed that the product development of corn milk was financially feasible to be continued with increasing value-added of 52%. Based on the calculation of financial feasibility known that the Net Present Value (NPV) product development of corn milk is IDR 27,784,596.28. The value of Internal Rate of Return (IRR) is 81.49% and the Payback Period (PP) is 3 months. The value of business efficiency (R/C ratio) is 1.50; while the B/C ratio is 1.35. To obtain maximum profit, product sales must exceed the Break Event Point (BEP) value, which is sales of over 240 bottles or IDR 1,444,910,- with a selling price of IDR 6,000/bottle.

Keywords
corn milk, product development, financial feasibility, value added

Topic
AGROINDUSTRIAL PRODUCTION SYSTEM MANAGEMENT AND REGULATION

Link: https://ifory.id/abstract/p8FtLjTXzBfU

Corresponding Author
Martin Bernard

Institutions
a)Fakultas Pendidikan Matematika dan Sains, Institut Keguruan dan Ilmu Pendidikan Siliwangi, Jalan Terusan Jenderal Sudirman, Cimahi 40526, Indonesia
*pamartin23rnard[at]gmail.com

Abstract
Special needs children are children with characteristics that are different from disability in general without showing mental, emotional, or physical abilities. Special needs children find it difficult to define categories in understanding lessons and most of the views of the community state that children with special needs are considered as disabled children who cannot do anything. Especially in terms of academic achievement from language, mathematics and science. This can show that children with special needs cannot distinguish numbers properly so that errors occur in the calculation process. Even though mathematics is very necessary to apply it to daily life personally that develops society. Developing the ability to understand numbers, each student is given the opportunity to answer a different one to explain and the approach used is Open Ended. The teaching aids used are in the form of mathematics learning media created on Microsoft Excel based on VBA. VBA language functions so that images are more interesting and interactive so student learning independence and Self Efficacy learning outcomes are achieved.

Keywords
Developing Visual Basic Applications for Excel improve Learning Independence and Self Efficacy Children with Special Needs Through Open-Ended

Topic
Mathematics Education

Link: https://ifory.id/abstract/8p9H3dfNcvEX

Corresponding Author
Ningsi Lick Sangadji

Institutions
a) Chemical Engineering Department, Faculity of Engineering, University of Indonesia
Jalan Kampus UI, Kukusan, Beji, Depok, Jawa Barat 16424
*ningsilick[at]gmail.com

Abstract
The fermentation of succinic acid from oil palm empty fruit bunches (EFB) using immobilized bacteria from cow rumen were investigated. EFB is one of raw material that can be used for succinic acid production due to its cellulose content, low prices, and availability. Succinic acid can be produced effectively by several methods, one of them is fermentation which considered more environmentally friendly due to CO2 consumed during the process, thereby potentially contributing to reduction of CO2 emission. Bacteria used in this experiment were isolated from cow rumen which must be immobilized before getting into succinic acid production process. Fermentation is done by Semi Simultaneous Saccharification and Fermentation (SSSF) technique. Saccharification was carried out using cellulase enzyme for 2 – 6 hours before fermentation occurs. Yeast extract as nitrogen sources and MgCO3 as pH regulating agent were varied and compared in terms of product concentration, yield, and productivity. Fermentation was carried out for 48 hours in shaker water bath and the temperature maintained at 37oC. Fermentation product was then examined using HPLC to find out the succinic acid content. The optimum fermentation conditions for succinic acid production were found to be: saccharification time – 6 hours, initial nitrogen sources concentration – 20 g/L, initial pH regulating agent concentration – 20 g/L. At these optimized condition, the maximum production of succinic acid was found to be 1.43 g/L with 12.03 g/g yield of succinic acid to initial glucose concentration and 0.0297 g/L.h productivity.

Keywords
Succinic acid; Oil Palm Empty Fruit Bunches; Immobilized Bacteria; Semi Simultaneous Saccharification and Fermentaion

Topic
RENEWABLE ENERGY AND BIOREFINERY

Link: https://ifory.id/abstract/Vvdt9EUpBgKz

Corresponding Author
Martin Bernard

Institutions
a) Fakultas Pendidikan Matematika dan Sains, Institut Keguruan dan Ilmu Pendidikan Siliwangi, Jalan Terusan Jenderal Sudirman, Cimahi 40526, Indonesia
*pamartin23rnard[at]gmail.com

Abstract
The research was aimed to show that developing a learning media impacted to improve students ability in mathematical learning. The process implementated the application of VBA for microsoft word in mathematical learning. The formulation of the problem in this research are whether 1) can developing media assisted VBA for microsoft word improve mathematical ability? 2) Did Students show positive response in learning process? ADDIE was used as approach in this research. There are five stages in ADDIE approach. Population of this research was in group with 34 samples of vocational students. The instruments are cognitive test, interview and observation. Based on the results of the process, there was an increasing in mathematical ability of vocational students in trigonometry lesson through media VBA for microsoft word. The implementation of learning process through media VBA for microsoft word was success. Students enjoyed the process, active, responsive, and enthusiastic. The conclusions are the developing of media VBA for microsoft word can improve mathematical ability of vocational students before and after using media, and students showed positive response to learn by media in trigonometry.

Keywords
Student Worksheets, VBA for Microsoft Word, Trigonometry

Topic
Mathematics Education

Link: https://ifory.id/abstract/qHK8pUNkCvxu

Corresponding Author
Vitta Rizky Permatasari

Institutions
(a) Dept of Agroindustrial Technology
Faculty of Agricultural Technology
Brawijaya University
Jl. Veteran, Malang 65145

(b) Surfactant and Bioenergy Research Center
Bogor Agricultural University
Jl. Pajajaran No.1 Bogor 16144

Abstract
Eucheuma cottoni is one of the most utilized marine commodities for carrageenan production. Carrageenan can be utilize for probiotics production. This study aimed to obtain bacterial growth media with the highest probiotic activity before and after drying. The study consisted of several stages, namely: pre-hydrolysis, hydrolysis with inactive enzymes, chemical and microbiological characterization, drying with spray drying, and BAL viability test. From the results of the study concluded that the untreated sample had the best results compared to filtering and precipitation samples. The untreated sample had reduced sugar content of 0.35%, total sugar 2.81%, pH 5.37, total acid 0.147%, and total LAB of 8.2x108 CFU/ml. After drying with spray drying, the BAL viability reduced to 9.7x106 CFU/ml.

Keywords
Probiotic, Eucheumma cottoni, hydrolysis

Topic
FOOD MICROBIOLOGY

Link: https://ifory.id/abstract/KaqtL23xrzNm

Corresponding Author
Damianus Dao Samo

Institutions
Nusa Cendana University

Abstract
The purpose of this study was to produce a theoretical formula for developing the mathematics students higher-order thinking skills. This is a qualitative research that applies grounded theory which is a qualitative approach to produce and develop a theory based on the empirical data collected by the researcher. The subjects of this study are mathematics education students at FKIP Undana by considering proportional gender, demographics and mathematics skills. The written data were analyzed qualitatively by using the indicators of higher-order thinking skills then an in-depth interview about the subjects writing ability and thinking habit, influenced factors as well as other issues that relevant with the development of the subjects higher-order thinking skills was conducted. The process of theory formation through the stages of open coding, axial coding and selective coding. The stages of data analysis resulted an empirical theory of developing higher-order thinking skills namely 1) building motivation and confidence; 2) contextual learning (cultural context); 3) habit of asking scientific question, 4) group discussion; 5) higher-order thinking exercises; 6) family and community discussion routine; and 7) learn to modify questions. The seven points describe the whole process and support of personal self, lecturers and parents

Keywords
higher-order thinking skill, grounded theory

Topic
Mathematics Education

Link: https://ifory.id/abstract/WfCjmX9ALGv3

Corresponding Author
Novi Haryati

Institutions
Department of Agricultural Socio-economics, Faculty of Agriculture,
Universitas Brawijaya, Jl. Veteran Kota Malang Kode Pos 65145
Email: noviharyati[at]ub.ac.id

Abstract
Food security has become a central issue within the framework of Indonesias agricultural development. The problems mostly faced by this country are the uncertainty and instability of national food production happens. Agricultural innovation and training by agricultural extension agents is an effort to increase the skills of knowledge and capabilities of farmers to jointly improve food security. The objectives of this study are: 1) to determine the characteristics of rice farmers, and 2) to understand the relationship of training and innovation to the performance of farmers. This is a descriptive quantitative research that conducted with case studies in Singosari District, Malang Regency Indonesia. The sampling technique was purposive, derived from 30 rice farmers who had received training and counseling from the Singosari Sub-District Extension Education Unit. Primary data was derived through questionnaires. Data analysis was done by formulating structural equation models by using WarpPls 5.0 software. Rice farmers in Singosari Subdistrict are in middle to advanced age with low eductaion. Most of them are elementary school graduates with experience of farming around 30 years. Result showed that the Extent of Training, Preparedness to adopt paddy planting innovation has significant effect to human capital of farmers. Those three has a positive and significant influence on rice farming performance.

Keywords
Key words: farming, innovation, training, farm performance

Topic
FOOD SAFETY AND SECURITY

Link: https://ifory.id/abstract/aGAZ9TkB4Qfc

Corresponding Author
Taufik Nurrohman

Institutions
IKIP SILIWANGI

Abstract
The problem in this study is: "Is there a difference in mathematical understanding abilities of students who get the Problem Based Learning model with Project Based Learning models. The purpose of this study was to determine the differences in mathematical comprehension abilities between students who learned using the Problem Based Learning model and those using the Project Based Learning model. The benefits of this research for students are expected to be able to provide additional mathematics learning and serve as one of the inputs to select and develop appropriate learning models, pig researchers themselves are expected to provide an original description in the field regarding the implementation of the model applied in research. In this study, the type of research used is class research with group design The Grouppretest-Postest Desing Statics. The population in this study were students of SMPN 1 Bayongbong and the samples in this study were students of class VII-A and VII-D SMP 1 Bayongbong .. the instruments used consisted of: tests of mathematical comprehension skills and attitude scale based on Likert scale. The instrument was declared to have fulfilled the criteria for a good instrument to meet validity, reliability, differentiation, and difficulty. Data analysis was performed using the normality test, the homogeneous test of two variances, t-test and t-test. The results of this study indicate that there is no difference in the ability of mathematical understanding between the Problem Based Learning model and Project Based Learning models. The attitude of students towards mathematics learning with Problem Based Learning shows a good attitude. The attitude of students towards learning mathematics with Project Based Learning shows a very good attitude

Keywords
Mathematical Understanding, Problem Based Learning (PBL), Model Project Based Learning (PjBL)

Topic
Mathematics Education

Link: https://ifory.id/abstract/gLaU2qMYCR96

Corresponding Author
Aji Sutrisno

Institutions
Department of Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Brawijaya, Jl. Veteran, Malang 65145

Abstract
Mannanase is the main enzyme that catalyzes depolymerization of -1,4 mannosidic linkages within the main chain of mannan releasing manno-oligosacharides.Since mannan is most soluble at alkaline solution and industrial enzymes application prefer high thermostability, therefore mannanase with alkaline and high thermostability is more desired. This aim of this study is to isolate mannase-producing microorganisms and to characterize mannanase that obtained from partial purification. Nine mannolytic isolates were found and the chosen isolate was R11 with mannolytic index of 3,287. The purity enzyme from partial purification was 6,06 fold with the specific activity 61,54 U/mg. Molecular mass of the mannanase analyzed by electhrophoresis and zymogram was 32,39 kDa. The optimal temperatures and pH were 65oC and pH 8, repectively. The enzyme was stable at pH 5 – 8 and temperatures up to 75oC. This properties makes mannanase R311 is attractive for biotechnological application for industries.

Keywords
Alkaline, isolation, characterization, mannanase, thermostable

Topic
INDUSTRIAL BIOTECHNOLOGY AND BIOPROCESSING

Link: https://ifory.id/abstract/YxUaDWV49TFp

Corresponding Author
Fitria Sulistyowati

Institutions
Pendidikan Matematika, Universitas Sarjanawiyata Tamansiswa Yogyakarta

Pendidikan Matematika, Universitas Muhammadiyah Purworejo

*fitria.sulistyowati[at]ustjogja.ac.id

Abstract
Abstract. This research is a descriptive-analytical study that aims to describe how student solve high order thinking (HOT) problem. The research subject was a student who was chosen based on HOT problem-solving in a non-routine way and took a mathematics course at Science Education of Universitas Sarjanawiyata Tamansiswa Yogyakarta DS Setiana1. Data were collected using observation, documentation and interviews methods, then will be analyzed descriptively. Based on the analysis that has been done, it was found that: (1) the strategy used by the student to solve the HOT problem was obtained from the internet; (2) there are errors when student applied the strategy that has been obtained in solving the HOT problem; (3) the student have difficulties when solving HOT problem in the same way. The results of this analysis are expected to provide a little description for educational activists related to the solving of HOT problem by students.

Keywords
HOT problem, trigonometry

Topic
Mathematics Education

Link: https://ifory.id/abstract/mNDbQrFB74T9

Corresponding Author
leo paul vaurs

Institutions
a) Faculty of Engineering, Prince of Songkla University, Hat Yai campus, Thailand
b) Faculty of Sciences and Industrial Technology, Prince of Songkla University, Surat Thani campus, Thailand

Abstract
Newspaper recycling is one of the most successful recycling story. As a result, newspapers have been collected worldwide for decades and thus represent a large quantity of a relatively cheap and available source of lignocellulose. If newspaper recycling has multiple advantages, it nevertheless involves some severe wastewater and odor emissions, and produces harmful sludge. Moreover, due to the loss of some fiber properties during the recycling process, paper can only be recycled 5-7 times. Therefore, investigating new valorization routes for unrecyclable newspapers are of interest. Newspapers used in this work contained between 51 to 64 % carbohydrates on a dry basis (74% being glucan), which could enzymatically be hydrolysed into fermentable sugars for further bioethanol or biochemical production. Low glucan conversions (20-49%) were found, however, which led to the investigation of multiple pre-treatments to improve sugars release. Surfactants such as sodium dodecyl sulfate (SDS), polysorbate 80 and polyethylene glycol (PEG) have the advantage of requiring mild conditions which significantly reduce the energy demand of the pre-treatment step. They can reduce the negative impact of lignin on enzymes, increase enzyme activity and protect cellulolytic enzymes. Several surfactant use strategies such as washing, soaking, addition during hydrolysis, surfactant combinations were tested using the 3 products mentioned earlier. A simple mass and energy model was developed to select the most economically feasible surfactant pre-treatment. Addition of 0.5% SDS in the reaction medium was found to lead to the maximum amount of the cheapest sugars with 20% extra been released.

Keywords
lignocellulose, enzymatic hydrolysis, newspaper, surfactant

Topic
WASTE AND ENVIRONMENTAL MANAGEMENT

Link: https://ifory.id/abstract/tNJQcBmY2jFw

Corresponding Author
Tri Susilawati

Institutions
a) Department of Civil Engineering, Sumbawa University of Technology
jalan Raya Olat Maras Kecamatan Moyo Hulu Kabupaten Sumbawa 84314, Indonesia
*tri.susilawati[at]uts.ac.id
b) Department of Agro Industrial Technology, Sumbawa University of Technologi
*mikhratunnisa[at]uts.ac.id

Abstract
The utilization of land in Sumbawa District to produce corn will effect cutting trees new land fields It-s not paddi field . It has effect on environment. Those such as lack of water in ground, flood, and soon. Henceforth this research aim at making optimation model cutting tree for new land could enhance the productivity of corn and making appropriate model to optimalize of farmets benefit by using simplex methode. Based on simplex counting, it-s needed 21.618 and 77.873 Ha paddy field and non paddy field to plant corn in order to increase corn harvest. To boost farner-s benefit, they harvest 672609 tonas follows, 434.001 ton of corn by 15% of water content, 46.182 ton of corn by 20% of water content and 192.426 ton of corn by 25% of water content.

Keywords
Simplex Method, Optimization, Corn

Topic
Applied Mathematics

Link: https://ifory.id/abstract/8BJmEew9WTkA

Corresponding Author
Vita Purnamasari

Institutions
1 Doctoral Program of Agroindustrial Technology, Faculty of Agricultural Technology, Brawijaya University, Malang, Indonesia
2 Department of Agricultural Product Technology, Faculty of Agricultural Technology, Brawijaya University, Malang, Indonesia
3 Department of Biochemistry, Faculty of Medicine, Brawijaya University, Malang, Indonesia
4 Department of Biology, Faculty of Mathematics and Natural Science, Cenderawasih University, Jayapura, Indonesia

Abstract
Berries are known to contain bioactive compounds that can function physiologically to optimize health status. One type of bioactive compound found in berries is phenolic acid. Fruits are known to have activities to inhibit aldose reductase (AR). Inhibition of AR can control of microvascular complications of diabetes mellitus, such as blindness, nephropathy and neuropathy. But some AR inhibitors show side effects due to cross-reactions with analogous enzymes. Therefore, the purpose of this study is to predict the ability of phenolic acids berries binding to AR and predict selectivity of berries phenolic acids as AR inhibitor through in silico studies. The inhibition activity of twelve berry phenolic acids on AR was analyzed using in silico and compared with epalrestat as a commercial AR inhibitor. The phenolic acids were docked to AR using Autodock Vina in PyRx 0.8. 3D molecular interactions visualized using PyMOL were then analyzed with LigPlot+. Chlorogenic acid and neochlorogenic acid show binding are higher affinity (8.0 and 8.3 kcal/mol) than binding affinity epalrestat as a commercial AR inhibitor. The aromatic ring structure of chlorogenic acid and neochlorogenic acid plays an important role in binding to the active side of AR. Analysis of the interaction of the two phenolic acids with AR indicates binding occurs in the pocket specificity of the active side of AR, so chlorogenic acid and neochlorogenic acid of berries are predicted to inhibit the binding of free glucose on the active side of AR, preventing sorbitol production in hyperglycemic conditions.

Keywords
Berries, Phenolic acids, Docking, Binding affinity, Aldose reductase,

Topic
HEALTH, NUTRITION AND MEDICAL MICROBIOLOGY

Link: https://ifory.id/abstract/ne9KrwUgVTFb

Corresponding Author
desi alyawati

Institutions
Math education sriwijaya university

Abstract
Abstract. This study is design research aimed to describe the design result of problem-solving question that can be used to measure mathematical thinking for symbolization aspect in topic linear equation with two ariables. The subjects are three students grade 8 of junior high school. This study used a qualitative technique. There are three questions used in this study. The process of this study consists of two indicators, namely: manipulation symbol and algebra. As the results of this study, for question number 1, student 1 and 2 not correct becuase them can not to manipulation symbol, but student 3 showed of manipulation symbol and algebra. For question number 2, student 1-s answer was correct which also showed manipulation symbol and algebra, student 2 showed algebra but it-s not correct, student 3 showed manipulation symbol and algebra the answer is correct. For question number 3, all of student-s answer was correct, student 1 showed manipulation symbol and algebra, student 2 showed manipulation symbol and algebra, student 3 showed manipulation symbol and algebra

Keywords
Mathemaical Thingking aspeckt symbolization,manipulation symbol,algebra

Topic
Mathematics Education

Link: https://ifory.id/abstract/m4BKCdJwzN27

Corresponding Author
Mieke Alvionita

Institutions
Department of Chemistry, Faculty of Mathematics and Science, Universitas Negeri Malang
Jalan Semarang 5, Malang 65145, Indonesia
*subandi.fmipa[at]um.ac.id

Abstract
Gout is a common inflammatory arthritis caused by the formation of uric acid crystals in a joint. Due to their high prevalence in most countries, the discovery of gout treatment agent have gained many interests, mainly from natural resources. Some studies showed that bioactive product can replace the common gout medicine, allopurinol, which known have many negative effects. Thus, the aims of this study were to obtained ethanol extract of peanut shell, to determine their inhibitory activity toward xanthine oxidase (XO) and to determine the inhibitory activity of predicted compounds using in silico study. There are 4 steps in this work, namely: (1) ethanol extraction of bioactive compounds from peanut shell, (2) phytochemical analysis, (3) in vitro analysis as XO inhibitor and (4) in silico study of predicted bioactive compounds from peanut shell as XO inhibitor. The results had shown that Arachis hypogaea L. epidermis extract contained tannins, polyphenols, flavonoids, alkaloids, and terpenoids, whereas their outer peel extract have the same contents, except tannin. At the same concentration (100 ppm), the inhibition activity of epidermis and peanut shells extract towards XO were equivalent to 12 and 14 ppm of allopurinol, respectively. According to the previous study, the bioactive compounds in the peanut shell were luteolin, 5,7-dihydroxychromone, and eriodictyol. Our in silico analysis has revealed that each of those compunds has binding affinity higher than allopurinol has.

Keywords
Arachis hypogaea L. shell; xanthine oxidase inhibitor; in vitro and in silico analysis

Topic
HEALTH, NUTRITION AND MEDICAL MICROBIOLOGY

Link: https://ifory.id/abstract/cDyEVALYhkZT

Corresponding Author
Eva Dwi Minarti

Institutions
IKIP Siliwangi

Abstract
This study aims to examine the effect of mathematical disposition of junior high school students on mathematical critical thinking skills. A quantitative approach with a correlational method used by researchers to examine both variables. The subjects in this study were 32 students of class VIII in one of the Bandung junior high schools. The instrument used consists of a test instrument which is a test of mathematical critical thinking skills with indicators that are interpretation, analysis, evaluation and conclusion. The results of the study show that the mathematical disposition of junior high school students has a positive influence on mathematical critical thinking skills. Students with a positive disposition toward mathematical learning can interpret and not hesitate to express ideas.

Keywords
Mathematical Disposition, Mathematical Critical Ability, Middle School Students

Topic
Mathematics Education

Link: https://ifory.id/abstract/tX8HPMQbGm9h

Corresponding Author
Suharti Suharti

Institutions
1Department of Chemistry, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Malang, East Java, Indonesia
2Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia.

Abstract
Keratin is an important biomaterial for industrial applications. About 90% of keratin is found in chicken feathers. Chicken feathers are accumulated from poultry processes and produced in millions of tons annually. Besides being abundant and cheap, keratin is insoluble in water and organic solvent which makes it difficult to recycle. Previous study showed that Solid state fermentation of keratinase using Bacillus sp. MD24 using chicken feathers a sole carbon and nitrogen source produced micro-keratin as a solid by-product. This paper reported our investigation in the soluble keratin in liquid by-product. Liquid by-product was produced through Solid-State fermentation of keratinase for 10 consecutive days by Bacillus sp. MD24 . Liquid by-product was separated from solid byproduct by centrifugation at 2000 rpm. The size of soluble keratin was examined by zeta particle analyzer. The soluble keratin was filmed and the film was characterized using fourier transform infrared spectroscopy (FTIR), and film surface was analyses using scanning electron microscopy. Dissolution of keratin using ionic liquids ([BMIM]Cl and [EMIM]Ac) was done to compare its properties. Dissolution was performed under nitrogen atmosphere at 130 °C for 7 hours. Insoluble fraction was recovered by addition of water. The results showed the liquid by-product contains soluble keratin with size between 100-600 nm, and FTIR spectrum indicated the presence of polypeptide with high concentration of –S-H bond. There is no difference on surface structure between keratin biofilm produced from soluble keratin by-product and soluble keratin produced by dissolution using ionic liquids.

Keywords
keratin, Solid-State Fermentation, luquid by-product, Ionic Liquids

Topic
WASTE AND ENVIRONMENTAL MANAGEMENT

Link: https://ifory.id/abstract/U8jd4beAnahB

Corresponding Author
Wita Ratna puspita

Institutions
a) Pendidikan Matematika, Universitas Pendidikan Indonesia, Jl. DR. Setiabudi No. 229, Isola, Sukasari, Bandung, 40154, Indonesia
*witaratna[at]upi.edu
b) Pendidikan Matematika, Universitas Pendidikan Indonesia, Jl. DR. Setiabudi No. 229, Isola, Sukasari, Bandung, 40154, Indonesia

Abstract
Tujuan penelitian ini untuk menguji keefektifan pembelajaran matematika dengan menggunakan model learning cycle 5E dan model learning cycle 7E; serta membedakan pembelajaran yang lebih efektif di antara model learning cycle 5E dan 7E ditinjau dari self-efficacy siswa kelas VIII dalam belajar bangun ruang sisi datar. Penelitian ini merupakan penelitian eksperimen semu dengan desain pretest-posttest non-equivalent comparison-group design. Populasi penelitian mencakup seluruh siswa kelas VIII SMP Negeri di Kota Yogyakarta yang terdiri dari sekolah level tinggi dan level sedang. Dengan teknik stratified random sampling, terpilih 2 sekolah sebagai sampel penelitian. Instrumen penelitian menggunakan angket self-efficacy siswa. Untuk menguji keefektifan model LC 5E dan model LC 7E, ada tidaknya interaksi antara model pembelajaran dengan level sekolah, serta ada tidaknya perbedaan self-efficacy siswa di sekolah level tinggi dan sekolah level sedang, digunakan uji two way anova. Selanjutnya, untuk membandingkan self-efficacy siswa yang menggunakan model LC 5E dan model LC 7E di sekolah level tinggi maupun sekolah level sedang digunakan independent sample t test, sedangkan untuk menguji ada tidaknya perbedaan efektivitas antara model LC 5E dan model LC 7E terhadap self-efficacy siswa digunakan rumus efektivitas N-Gain. Setiap analisis dilakukan pada taraf signifikansi 5%. Hasil penelitian menunjukkan bahwa: 1) tidak terdapat perbedaan self-efficacy antara siswa yang pembelajarannya menggunakan model LC 5E dan siswa yang pembelajarannya menggunakan model LC 7E; 2) self-efficacy siswa yang menggunakan model LC 5E tidak lebih tinggi dibandingkan dengan yang menggunakan model LC 7E di sekolah level tinggi maupun sekolah level sedang; 3) tidak terdapat interaksi antara model learning cycle dengan level sekolah pada pembelajaran bangun ruang sisi datar; 5) tidak terdapat perbedaan self-efficacy antara siswa di sekolah level tinggi dan siswa di sekolah level sedang; serta 6) tidak terdapat perbedaan efektivitas antara model LC 5E dan model LC 7E terhadap self-efficacy siswa.

Keywords
Learning Cycle, Self-efficacy

Topic
Mathematics Education

Link: https://ifory.id/abstract/AxcUtrWaTzLH

Corresponding Author
AMAN SANTOSO

Institutions
a* Chemistry Departement, Universitas Negeri Malang, Indonesia
Jalan Semarang 5 Malang
Email: aman.santoso.fmipa[at]um.ac.id

Abstract
The purpose of this study is to synthesize methyl esters from copper oil (Voor-Oogst) with KOH catalyst using ultrasonic waves and potential test as biodiesel. Tobacco seed samples were obtained from the Paiton Probolinggo . The stages in this study are: isolation of tobacco seed oil using soxhletation with n-hexane solvents; decreasing free fatty acids by esterification process; transesterification with variations in KOH catalyst concentration; characterization of synthesized biodiesel; and identification of components of methyl ester synthesis by GC-MS. The results showed: Synthesis of methyl esters with transesterification reaction at 0.8% KOH catalyst concentration; 1% and 2% w / w of oil with ultrasonic waves produce biodiesel with the result are 77.45% respectively; 84.55% and 80.72%, (2) Methyl esters from tobacco oil fit the SNI biodiesel criteria with a viscosity of 4.44 cSt, density 0.865 g / mL, refractive index 1.45, acid number 0.56 mg/g. The main constituent of methyl ester which is synthesized in the form of methyl palmitate, linoleic, oleic and stearic is 18.72% respectively; 30.76%; 27.26% and 9.35%.

Keywords
oil, tobacco seeds, methyl ester, ultrasonic waves

Topic
RENEWABLE ENERGY AND BIOREFINERY

Link: https://ifory.id/abstract/t4D8fwX2RB7x

Corresponding Author
Zetriuslita Zetriuslita

Institutions
Universitas Islam Riau

Abstract
The aim of this study was to identify and analyze the effectiveness of utilizing Geogebra in improving students- mathematical communication skill viewed from academic level. This study is a mixed method research which combines both quantitative and qualitative methods with sequential explanatory strategy. The population was the second semester students of Mathematics Education and used purposive sampling technique. The result of this study showed that there was effectiveness of using Geogebra in improving students- mathematical communication skill viewed from their academic level. The students felt that their skill improved and developed through Geogebra-assisted Directed Instruction learning.

Keywords
Direct learning, Geogebra, mathematical communication, academic level

Topic
Mathematics Education

Link: https://ifory.id/abstract/LQNP7JTqzD3y

Corresponding Author
Suharti Suharti

Institutions
Department of Chemistry, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Malang, East Java, Indonesia

Abstract
As we know keratin is a structural protein. Keratin can be obtained from chicken feathers. At present, chicken feathers are one of the great potentials of waste because of its abundance and very cheap. CMC has a similar structure to cellulose. Cellulose has a very abundant amount in nature and its existence as waste and CMC and CMC is a derivative of natural cellulose polymers that are easily degraded naturally. This paper reported our preliminary work on developing novel composite biofilm from both natural biopolymer to provide novel environmentally friendly biomaterials. Keratin solution was prepared from chicken feathers by the acid method. Variations in the number of CMCs were used to see differences in bio-membrane rigidity. The size of keratin in the bio-membrane can be measured using a PSA. SEM and FTIR are used to see the presence of keratin embedded in bio-membranes. The homogeneity of keratin in biofilm is analyzed using XRD while its resistance to temperature is measured by TGA. With the presence of keratin as a sturdy fiber and CMC as a supporting matrix can produce biofilm that are strong and environmentally friendly.

Keywords
biofilm; CMC; keratin

Topic
WASTE AND ENVIRONMENTAL MANAGEMENT

Link: https://ifory.id/abstract/PbzVGDqpR4Tv

Corresponding Author
Cita Dwi Rosita

Institutions
(1) Departement of Mathematics Education, Universitas Swadaya Gunung Djati
(2) Departement of Mathematics Education, Universitas Pendidikan Indonesia

Abstract
This experiment investigated the impact of reading and writing learning strategies on mathematics preservice teachers critical thinking dispositions. The sample in this study were 80 students in the mathematics education program who were purposively selected from 120 total populations reviewed based on: (1) students prior mathematical abilities; (2) learning model group. In this study also analyzed the interaction between the students prior mathematical abilities and learning strategies towards enhancing students mathematical critical thinking dispositions. The results showed that: (1) the average enhance in critical thinking dispositions of students who received a reading and writing learning strategy was better than those who received conventional learning as a whole; (2) there are differences in the average enhance in mathematical critical thinking dispositions between students who get reading and writing learning strategies and students who get conventional learning are reviewed based on their prior mathematical ability groups; (3) there is no interaction between learning and students prior mathematical abilities towards increasing students mathematical critical thinking dispositions.

Keywords
mathematical critical thinking disposition; reading and writing learning strategy

Topic
Mathematics Education

Link: https://ifory.id/abstract/cwxPVRrefjgb

Corresponding Author
AMAN SANTOSO

Institutions
(a) Department of Chemistry, Universitas Negeri Malang
Semarang Street 5 Malang 65145
Email: aman.santoso.fmipa[at]um.ac.id

Abstract
The characteristics of yogurt are influenced by the concentration of starter and incubation time in the manufacturing process. The purpose of the study was to determine the effect of variations in starter concentration and incubation time on the characteristics of yogurt. The study consisted of several stages, namely: Sample preparation (pasteurization of cows milk); Incubation of cows milk yogurt with variations in starter concentration and incubation time; Characterization of the physical and chemical properties of yogurt include organoleptic tests of color, aroma, taste and texture, pH and viscosity tests, and the chemical properties of yogurt including analysis of total acid levels and protein content. The results of analysis of variance for pH, viscosity, organoleptic tests (texture, aroma, taste and color), total acid levels and protein content showed that the variation in treatment carried out significantly affected the physical and chemical characteristics of the yogurt produced. The pH of yogurt produced ranged from 3,841-4,000, the total acid level and yogurt protein levels produced in this study ranged between 1.22-1.40% and 2.72-4.82%. The Mann-Whitney test results showed that the yogurt produced had a soft texture, a distinctive flavor, a rather acidic and colored white.

Keywords
starter; incubation time; characteristics; yogurt, cows milk

Topic
FOOD MICROBIOLOGY

Link: https://ifory.id/abstract/kpZNEjWHKLa2

Corresponding Author
Eka Senjayawati

Institutions
1Pendidikan Matematika, Institut Keguruan dan Ilmu Pendidikan Siliwangi, Jl. Terusan Jenderal Sudirman, Cimahi 40526, Indonesia

*ekasenjayawati[at]ikipsiliwangi.ac.id

Abstract
This research aims to learn and analyze the capability of the students mathematical material connection withvector analysis. The Data collected are the result of test instruments and interview result with Several students. The method of this research uses descriptive qualitative method. The subject of this research is Siliwangi Teachers Training Students who have taken material vector analysis. Based on the Data from the analysis of the test results of the mathematical connection of the problem indicator, the first indicator percentage is Obtained items, namely finding the relationship between the various concepts of representation and procedures, then understanding the relationship betweenmathematical topics, the presentation is 41.25%. The second indicator of understanding the equivalent representations of the same concept, the presentation is 67.5%. The third presentation indicator, using mathematics in other fields of study or in daily life is 65%. As for the fourth indicator, use an evaluation of the relationship between mathematical topics and the mathematical topic outside is 47.5%. The results of the interviews show that students sometimes forget to use formula prerequisite concepts as material.

Keywords
Mathematical Connection, Vector Analysis

Topic
Mathematics Education

Link: https://ifory.id/abstract/H8rb7GRV3Awf

Corresponding Author
Thutug Rahardiant Primadi

Institutions
Department of Chemistry, FMIPA Universitas Negeri Malang

Abstract
Abstract. Until now, the concrete utilization of frying cooking oil (jelantah) has not been optimal. This study seeks to convert this waste into biodiesel. Given that used cooking oil still contains high concentration of free fatty acids which can be converted into methyl esters through trans-esterification by methanol. This effort is in line with the increasing demand for renewable energy sources. The waste contains high of free fatty acids concentration and rancidity number. Therefore it is necessary to think about the proper process conditions and the use of superior catalysts for trans-esterification. One of the allegedly superior catalysts is ferrit-based nanocomposite catalyst, namely SrO@CoFe2O4. This hypothesis is based on the properties of ferrite which is thermally and chemically stable, and its magnetism, high reactivity (because it is in the form of nano-sized particles), and its composite with strong base oxide SrO which is insoluble in methanol. The purpose of this study was to synthesize and characterize SrO@CoFe2O4, then apply it as a catalyst in biodiesel production from the waste. The main steps include: (1) synthesis of CoFe2O4 with co-precipitation; (2) Impregnation of SrO into CoFe2O4 and converted to SrO@CoFe2O4; (3) characterization of the synthesized material with XRD, EDX and Zetasizer; (4) application of SrO@CoFe2O4 to biodiesel production from used cooking oil; (5) characterization of biodiesel produced. Based on the results of XRD and EDX analysis, the SrO@CoFe2O4 catalyst has been successfully synthesized. The application of catalysts on waste-based trans-esterification provides a conversion of 80-90%.

Keywords
ferrit, impregnation, oxide, biodiesel, frying cooking oil (jelantah)

Topic
RENEWABLE ENERGY AND BIOREFINERY

Link: https://ifory.id/abstract/Mx6JEAyebN7P

Corresponding Author
Rika Amelia

Institutions
a) Master Program in Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, INDONESIA
*rika17003[at]mail.unpad.ac.id
b) Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, INDONESIA

Abstract
One of the main obstacles in crop cultivation is the occurrence of fungal infections. Fungal spores can spread due to direct contact between susceptible hosts and infected hosts, which can be controlled using botanical fungicides. We constructed a mathematical model of the growth of logistics on the spread of plant diseases. From this model, we show the value of the Basic Reproduction Number (R0) of plant diseases transmission. The value of R0 is obtained by finding the largest eigenvalue of the next generation matrix. The results obtained show that when R0 is greater than one (R0>1), the endemic equilibrium point will be stable. However, if R0 is less than one (R0<1), the endemic equilibrium point is unstable. In addition, the results of this discussion indicate that by using botanical fungicides can reduce the infected host population. We provide numerical simulations to describe the results of the analysis obtained.

Keywords
Basic Reproduction Number; Local Stability Analysis; Optimal Control

Topic
Applied Mathematics

Link: https://ifory.id/abstract/RJNaQbHnjVmv

Corresponding Author
Grace Maria Ulfa

Institutions
a) Food Science and Technology Departement, Universitas Brawijaya, Indonesia
*gracemariaulfa[at]gmail.com

Abstract
Sweet potato is a common tuber found in Indonesia, however its usage is still lower than cassava or corn. Whereas, it is rich for starch that can be used for many industrial application, although it has many drawbacks such as its low solubility and stability. Pregelatinization can be used to overcome those drawbacks and increase its industrial value. The swelling power (SP), solubility (S), and water binding capacity (WBC) of pregelatinized white sweet potato starch were analyzed. The starch was obtained by precipitating the suspension of sweet potato slurry, drained, milled, and sieved. The starch then pregelatinized with different temperature at 35, 40, 45, 50, 55, 60oC. The swelling power and solubility of sweet potato starch ranged from 16.26-30.30 g/g and 1.58-26.39 %, respectively. Moreover, the WBC obtained are 76.07-232.37 %. Pregelatinized sweet potato starch showed a higher SP, S, and WBC as the increasing of temperature until some point. The variation obtained in the starches- properties was important for some industrial requirements.

Keywords
pregelatinization, solubility, sweet potato starch, swelling power, water binding capacity

Topic
AGRICULTURAL PRODUCT TECHNOLOGY

Link: https://ifory.id/abstract/m4uJPKct3jHg