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When children only see their friends in little squares via Google Meet or Zoom, can teachers really address concepts like the importance of teamwork or how to manage conflict? This is a learning phenomenon during the COVID-19 pandemic and the era after it. This study aims to see the role of parents as children's learning companions in terms of mentors and motivators when online education takes place. This research using photovoice within phenomenological methodology and have been doing with thematic analysis and collecting data through interviews and observations. The participants were eight parents and one female teacher as a homeroom teacher. The research findings show that although there are many obstacles in online learning for children, learning during the COVID-19 pandemic can still run by involving the role of parents and teachers as pillars of education for preschool-age children. For further research, it is hoped that the findings will be a way in solving learning problems for children. Keywords: early childhood education, parents’ role, online learning References: Adedoyin, O. B., & Soykan, E. (2020). Covid-19 pandemic and online learning: The challenges and opportunities. In Interactive Learning Environments. https://doi.org/10.1080/10494820.2020.1813180 Aras, S. (2016). Free play in early childhood education: A phenomenological study. Early Child Development and Care, 186(7). https://doi.org/10.1080/03004430.2015.1083558 Arkorful, V. (2021). The role of e-learning, advantages and disadvantages of its adoption in higher The role of e-learning, the advantages and disadvantages of its adoption in Higher Education . International Journal of Education and Research, 2(December 2014). Atiles, J. T., Almodóvar, M., Chavarría Vargas, A., Dias, M. J. A., & Zúñiga León, I. M. (2021). 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Early Education and Development, 32(6). https://doi.org/10.1080/10409289.2020.1843925 Lau, E. Y. H., Li, J. Bin, & Lee, K. (2021). Online Learning and Parent Satisfaction during COVID-19: Child Competence in Independent Learning as a Moderator. Early Education and Development, 32(6). https://doi.org/10.1080/10409289.2021.1950451 Lilawati, A. (2020). Peran Orang Tua dalam Mendukung Kegiatan Pembelajaran di Rumah pada Masa Pandemi. Jurnal Obsesi: Jurnal Pendidikan Anak Usia Dini. https://doi.org/10.31004/obsesi.v5i1.630 Lim, K. F. (2020). Emergency remote teaching and learning in the time of COVID-19. Chemistry in Australia, August. Lin, X., & Li, H. (2018). Parents’ play beliefs and engagement in young children’s play at home. European Early Childhood Education Research Journal, 26(2). https://doi.org/10.1080/1350293X.2018.1441979 Michele L. Stites, Susan Sonneschein & Samantha H. Galczyk (2021) Preschool Parents’ Views of Distance Learning during COVID-19, Early Education and Development, 32:7, 923-939, DOI: 10.1080/10409289.2021.1930936 Muhdi, Nurkolis, & Yuliejantiningsih, Y. (2020). The Implementation of Online Learning in Early Childhood Education During the Covid-19 Pandemic. JPUD - Jurnal Pendidikan Usia Dini, 14(2). https://doi.org/10.21009/jpud.142.04 Ortlipp, M. (2015). Keeping and Using Reflective Journals in the Qualitative Research Process. The Qualitative Report. https://doi.org/10.46743/2160-3715/2008.1579 Paat, Y. F. (2013). Working with Immigrant Children and Their Families: An Application of Bronfenbrenner’s Ecological Systems Theory. Journal of Human Behavior in the Social Environment, 23(8). https://doi.org/10.1080/10911359.2013.800007 Plowman, L., Stephen, C., & McPake, J. (2010). Supporting young children’s learning with technology at home and in preschool. Research Papers in Education, 25(1). https://doi.org/10.1080/02671520802584061 Rona Novick, Suzanne Brooks & Jenny Isaacs (2021) Parental Report of Preschoolers’ Jewish Day School Engagement and Adjustment During the Covid-19 Shutdown, Journal of Jewish Education, 87:4, 301-315, DOI: 10.1080/15244113.2021.1977098 Sandi Ferdiansyah, S. S., & Angin, R. (2020). Pengalaman Mahasiswa Thailand dalam Pembelajaran Daring di Universitas di Indonesia pada Masa Pandemi COVID-19. Journal of International Students, 10(S3). Sonnenschein, S., Stites, M., & Dowling, R. (2021). Learning at home: What preschool children’s parents do and what they want to learn from their children’s teachers. 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Fintech adalah gabungan antara jasa keuangan dengan teknologi, yang memungkinkan terjadinya transaksi keuangan tanpa harus memiliki rekening bank, disatu sisi hal ini menimbulkan masalah terhadap masyarakat Indonesia yang belum siap menerima perubahan dalam aktivitas ekonomi, namun di sisi lain, FinTech yang telah terdaftar di Bank Indonesia, dapat membantu pembiayaan usaha kecil menengah untuk mengembangkan usahanya, dengan menjadi tempat transaksi peminjaman yang mudah dan aman. Tujuan penelitian ini adalah mengetahui dampak fintech terhadap delapan belas UMKM yang ada di kota Magelang. Metode penelitian yang digunakan dalam penyusunan jurnal ini adalah penelitian kualitatif deskriptif. Dengan menggunakan data sekunder dari Bank Indonesia, Badan Pusat Statistik (BPS), Data Kementerian Koperasi dan UKM, dan Dinas UMKM Kota Magelang. Hasil penelitian menunjukan bahwa Fintech berperan penting dalam meningkatkan kinerja UMKM yaitu berupa peningkatan efisiensi operasional, dan efisiensi yang dinikmati oleh anggotanya, namun demikian penerapan Fintech dalam UMKM juga memiliki tantangan tersendiri

Fruits and other horticultural products are commonly harvested at high atmospheric temperatures. Since high temperatures significantly make the respiration rate increase and may reduce the quality of the products, the products are necessarily cooled as soon as possible. Accordingly, the objectives of the studies were to develop models for estimating temperature distribution on spherical particles stacked in pipe and cooled by water surface evaporation. The temperature distributions on particles were based on the transient cooling on spheres. The temperature gradient along the pipe was related to the pipe size, particle size, particle position, and air flow rate. Dimensional analysis was used to relate the particle average temperature to the pertinent parameters. The average temperature was calculated using the Heisler chart based on particle center temperature. The results indicate that the average temperatures of the particles can be estimated based on the pertinent parameters. The formulae of the exact solution of the transient heat transfer on spheres can be used to estimate the temperature of the particle during evaporative cooling

The use of Instron instrument to predict bone texture of fish have been conducted by studying the relationship of data from Instron with organoleptic scoring by the panelists. Samples were fishbone and bone from pressure cooked fish respectively. Temperature distribution during cooking was measured using Data Logger, the results showed that the time for heating up to cooking temperature were generally very short, 10-15 minutes, for any temperature range of cooking, while time for cooling down to room temperature were long, 40-60 minutes. There were significant relationship between data obtained from measurement of the bone fragility expressed in force using Instron instrument and organoleptic scoring given by panelists. Nonlinear relationships were found for all samples between organoleptic scores and objective analysis using Instron except for the range temperature of cooking between 110°C and 125°C below the force of 100 N for the sample of bone, showed by the regression of Y -20,29X + 136,90 with Y is forces and X is organoleptic scores.

The salacca (Salacca zalacca cv. Pondoh) fruits were stored in various modified atmosphere conditions in the impermeable cuverles with the variation of oxygen concentration of 2, 4, 6 and 8%. carbon dioxide concentration of 1, 2. 3 and 4% and nitrogen concentration as the rest. The variation of temperature was 12, 20 and 24 C. Gases within each cuvette were replaced daily. The respiration rate of the fruit was mudded based on the enzyme kinetic theory. The result showed that the respiration model Mows the Michaelis-Menten enzyme kinetic, with CO2 as the uncompetitive inhibitor. The model was fit to predict the respiration rate of the fruit.

The banana (Musa sp.) cv. Raja fruits were stored at varied modified atmosphere, in the impermeable cuvettes, containing carbon dioxide concentration of 1, 2, 3, and 4%, oxygen concentration of 2, 4, 6, and 8% and nitrogen. The temperature treatments were 12, 20, and 24 C. The gas within the cuvette was replaced daily. The texture of the fruit was measured every two day. The model of textural behavior was developed The results showed that the model of textural behavior was fit to predict the banana texture stored in the modified atmosphere condition.

Damage to food particles during pumping was studied using potatoes shaped into cubes, cylinders and spheres. The variables studied included particle size ratio, density ratio, particle volumetric fraction, Reynolds number, Froude number, and Euler number. The results indicated that the particle size ratio, the Reynolds number, the Froude number, and the Euler number significantly affected the broken particle fraction. The effect of the volumetric fraction of particle was found to be significant when it was less than 0.01. The density ratio and the flow direction of liquid did not have significant effects on the particle fraction

The parameter tracking method was used to estimate the parameters of non linear viscoelastic spherical model during impact. A set of impact data of free Falling indoor lacrose ball used to estimate the parameters of the model. The results indicated that the three parameters of the Impact can be determined by the method appropriately. The impact parameters of non linear viscoelastic spherical object can be estimated with a single set of impact data.

Parameter tracking method was used to estimate mathematically the physical parameters of food. Five mathematicalmodels of the food properties were studied: linear model with one parameter, linear model with two parameters, non linear model with two parameters, exponential model with two parameters and non linear model with three parameters. The parameters of the first four mathematical models can be estimated using the parameter tracking method. Analytical solution of the fifth model that indicates whether the parameters will converge to their real values can not be found.

This paper presents a performance test and mathematical modeling of greenhouse effect (GHE)-Hybrid solar dryer with vertical rotating rack. The dryer consists of a greenhouse dryer (1100 × 860 × 1300) mm with eight rack and additional heating system consists of a flat plate collector (1,04 m2), a hot water storage tank (197 liters) and a heat exchanger. To investigate the performance of solar greenhouse dryer, five experimental variation speed of rack were conducted (1, 4, 7, 10 rpm) and without rotation. Materials used in the experiment are local cardamom (Amomum cardamomum Wild). Weight of each experiment about 9 to 10 kg. The average temperature of the hot water storage tank varies from 50.0 to 55.0 °C, drying air temperature between 38.9 to 45.9 °C, while the relative humidity (RH) of drying chamber ranged from 32.1 to 47.4 %. Variation of rotational speed affects on the uniformity of product temperature and water content in each rack drying. At rotation 1 rpm (experiment II), obtained as the best conditions (temperature and moisture content are most uniform). Increasing rotational speed of rack causes increasing in standard deviation of product temperature and moisture content. To simulate the performance of the dryer, mathematical modeling based on heat and mass transfer and a thin layer drying approaches were conducted. Equations solved numerically using the finite difference Euler with Visual Basic Application (VBA) program on Excel. Validation was conducted by comparing the calculation results of mathematical modeling (data prediction) with measurement data (data observation). Criterion validity was determined by the value of the coefficient of determination (R2), the value of RMSD and MAPD. Mathematical models that have been developed can be described precisely the temperature of the hot water storage tank, temperature of the drying chamber, temperature of the product as well as a moisture content decrease. ABSTRAKMakalah ini menyajikan uji unjuk kerja dan pemodelan matematik pengering energi surya (ERK)-Hibrid menggunakan rak berputar secara vertikal. Pengering terdiri dari bangunan rumah kaca berukuran (1100 × 860 × 1300) mm dengan delapan buah rak dan sistim pemanas tambahan yang terdiri dari kolektor plat datar (1,04 m2), tangki penyimpan air panas (197 liter) dan penukar panas. Untuk mengetahuikinerja pengering energi surya, dilakukan lima kali percobaan variasi kecepatan putar rak (1, 4, 7, 10 ) rpm dan tanpa pemutaran rak. Bahan yang dipergunakan pada pengujian adalah kapulaga lokal (Amomum cardamomum Wild). Masing-masing percobaan seberat 9 sampai dengan 10 kg. Rata-rata suhu air tangki penyimpan panas bervariasi dari 50,0 sampai dengan 55,0 °C suhu ruang pengering antara 38,9 sampai dengan 45,9 °C, sedangkan kelembaban relatif (RH) ruang pengering berkisar antara 32,1 sampai dengan 47,4 %. Perlakuan pemutaran rak berpengaruh terhadap keseragaman suhu bahan maupun kadar air pada masing rak pengering. Pada perlakuan pemutaran 1 rpm (percobaan II), didapatkan kondisi terbaik (suhu bahan maupun kadar air yang paling seragam). Dengan kecepatan putar rak yang semakin meningkat menyebabkan nilai ragam suhu bahan maupun kadar air semakin meningkat. Untuk melakukan simulasi unjuk kerja dilakukan pemodelan matematik berdasarkan pindah panas dan massa serta pendekatan pengeringan lapisan tipis. Persamaan diselesaikan secara numerik menggunakan finite difference Euler dengan bantuan bahasa pemrograman Visual Basic Aplication (VBA) Excell. Validasi dilakukan dengan membandingkan antara perhitungan hasil pemodelan (data prediksi) dengan data hasil pengukuran (data observasi). Kriteria kevalidan ditentukan dengan melihat nilai koefisien determinasi (R2), nilai RMSD maupun nilai MAPD. Pemodelan matematik yang telah dibangun dapat menggambarkan dengan tepat perubahan suhu air tangki penyimpan panas, suhu ruang pengering, suhu bahan maupun penurunan kadar air.

In the cassava flour pneumatic drying process, mostly heat transfer occurred in convective mode. One of variables which could be used to evaluate the effectiveness of drying processperformance is heat transfer coefficient (h) during drying. The objectives of the research was to formulate a mathematical relationship between h and various pneumatic drying process variables of cassava flour by applying dimensional analysis. In the following research it had been constructed a pneumatic drying machine which was able to be according to the needed data that will be collected. Several parameters related to physical and thermal properties as well as operation of the drying machine were measured and used as the analysis variables was solved using dimensional analysis. Based on the result of the data, it was obtained that the relationship between h and the drying process variables could be expressed as follows This equation had quite high coefficient of determination, so that it could be used to predict the heat transfer coefficient in pneumatic drying process. Sensitivity analysis indicated that the dimensionless product which had the largest effect on h was .ABSTRAKPada proses pengeringan tepung kasava secara pneumatik, perpindahan panas terjadi terutama secara konveksi. Salah satu parameter yang digunakan untuk mengevaluasi efektivitas kinerja proses pengeringan tersebut adalah koefisien perpindahan panas (h) yang terjadi selama pengeringan. Tujuan dari penelitian ini adalah untuk menghubungkan secara matematis antara nilai h dengan beberapa variabel proses pengeringan pneumatik tepung kasava dengan menggunakan metode analisis dimensi. Pada penelitian ini telah dikonstruksi suatu mesin pengering pneumatik yang dirancang untuk dapat dilakukan pengaturan-pengaturan sesuai dengan kebutuhan data penelitian yang akan dikumpulkan. Beberapa parameter yang terkait dengan sifat fisik dan sifat thermis bahan serta operasional mesin pengering diukur dan digunakan sebagai variabel-variabel analisis yang diselesaikan dengan metode analisis dimensi. Berdasarkan hasil analisis data diperoleh hubungan antara nilai h dengan variabel-variabel proses pengeringan sebagai berikut Persamaan tersebut mempunyai nilai koefisien determinasi yang cukup besar, sehingga dapat digunakan untuk memprediksi koefisien perpindahan panas pada pengeringan pneumatic. Hasil uji sensitivitas menunjukkan bahwa dimensionless product yang paling berpengaruh terhadap nilai h adalah .

The soil of coastal plain is characterized by sandy soil texture, salinity problem, low water capacity, high oercolation rate and high soil temperature during day time. Due to those constraints, therefore much water is needed to be favorable to plant growth. Objective of the research is dealing with the application of numberical method to simulate heat and mass flow of water which is affected by soil moisture availability. A core of soil sample with size 50 cm x 50 cm x50 cm is used as a physical model. The research has been schedule from 1997 to 1998. Under high initial moisture content the simulation shows that there is similarity between predicted and observed value of soil moisture content with the correlation value more that 90% (t-test value 95%). However, the simulation is under estimate for low initial moisture content and high temperature. For the model applications, the factor's which influence on moisture movement in the soil was collected and rearranged in exponential equation: θv = 103,469. Qirr 0.015. T 0.061. t 0.235. x -0.161. z -2.842. From the model found that to keep soil moisture content in favorable condition (θv = 0,1 cm3/cm3), the discharge design of drip irrigation needed was 3.2 cm3/sec with 2 hours duration of irrigation. The discharge designed based on water needed for evaporation and heat flushing so that moisture in the root zone was maintained.

Research about effect of compression force on material temperature change in the markisa fruit effervescent tablet has not been properly. So that the objectives of the research are (1) to the develop a mathematical models to predict change of material temperature and (2) to study variables influences to material temperatures during compression. The investigation was done by varying six variables are the high of material in punch, punch diameter, particles diameter, moisture contents, compress force, and test speed. The result of the research showed that change of material temperature during compression can be predict with mathematical equation of dimension analysis. To prove whether the sixth independent variables influence to dependent variable together, with used analysis of variants and the research showed that the F value (35.33) is greater than the F table (2.51). This indicated that the sixth independent variables more influences to change of material temperature during compression.

Deep-fat frying was a process of cooking and drying through contact with hot oil and it involves simultaneous heat and mass transfer. The aims of this research was to study the misture loss and fat uptake phenomenon during sweet potatoes frying using deep-fat frying method. Sweet potatoes were shaped in bar-strip measuring 1x1x5 cm3 and fried with varying temperature of 160, 170 and 180ºC. The moisture loss and oil uptake phenomenon can be analogicially modeled referring to Newton's Law of Cooling, by equation (R2=0,997), (R2=0,997) and (R2=0,997) for moisture loss and (R2=0,95), (R2=0,94) and (R2=0,98) for fat uptake on 160,170, and 180ºC frying temperature, respectively. The activation energies were 2,72 kJ/mol for moisture loss and 4,19 kJ/mol for oil uptake. Moisture and fat content had linier relationship for 170 and 180ºC and non-linier relationship for 160ºC.ABSTRAKDeep-fat frying merupakan proses pemasakan dan pengeringan yang terjadi melalui kontak dengan minyak panas dan ini meliputi perpindahan panas dan massa secara simultan. Penelitian ini bertujuan untuk mengkaji phenomena penguapan air dan penyerapan minyak yang terjadi selama proses penggorengan ubi jalar dengan metode penggorengan deep-fat frying pada berbagai suhu penggorengan. Ubijalar dibentuk irisan balok dengan ukuran 1x1x5 cm3, kemudian digoreng pada suhu 160,170, and 180ºC. Model analogi Hukum Pendinginan Newton dapat menjelaskan dengan baik laju penguapan air dan penyerapan minyak pada penggorengan ubi jalar menggunakan metode deep-fat frying dengan persamaan MR= e-0,0052.t (R2=0,997), MR= e-0,0054.t (R2=0,997) dan MR= e-0,0064.t (R2=0,997) untuk penguapan air dan OR= e-0,0015.t (R2=0,95), OR= e-0,0018.t (R2=0,94) dan OR= e-0,0023.t (R2=0,98) untuk penyerapan minyak pada suhu 160,170 dan 180ºC. Energi aktivasi untuk penguapan air adalah 2,72 kJ.mol dan untuk penyerapan minyak adalah 4,19 kJ/mol. Kadar air dan minyak ubi jalar selama penggorengan berhubungan secara linier pada 170 dan 180ºC dan nonlinier pada 160ºC.

Heat penetrated slowly during conventional roasting of cocoa resulting in possibly less effective and gradation change. In this experiment microwave energy was applied to reast cocoa nib. The objective of this research was to study changes of temperature, moisture content, color, polyphenol content and antioxidative activity during microwave roasting of ground cocoa nibs. Ground cocoa nib passing through 20 mesh screen wa contained on glass bowl, and then heated in a microwave oven for 2-12 min. Conventional roasting using electric oven at 140ºC for 40 min was conducted for comparison. The result indicated that microwave roasting took a shorter time compared to that using conventional method as shown by the increasing temperature rate and the decreasing rate of moisture and polyphenol contents, i.e.10, 11 and 13 times faster than those given by the conventional roasting, respectively. Microwave roasting was more suitable for high roasting to get dark brown product. The trends of inhibition of linoleic acid oxidation by the product roasted using micorwave energy were similar to that of conventionally roasted, ground cocoa, i.e. 85-90%. A longer roasting of ground cocoa nibs was caused the polyphenol content in product more minimize, but this matter did not have an effect on reality to antioxidative activity of this product.ABSTRAKPada penyangraian biji kako cara konvensional proses pemanasan berlangsung lambat, sehingga tidak efisien dan senyawa dalam biji kako banyak mengalami perubahan terutama kandungan polifenol dan aktivitas antioksidatifnya. Penelitian ini bertujuan untuk menentukan pengaruh penyangraian keping biji kakao menggunakan enerji gelombang mikro (EGM) terhadap perubahan suhu, kadar air, warna, kandungan polifenol dan aktivitas antioksidatif produk yang dihasilkan, dibandingkan dengan penyangraian konvensional. Hancuran keping biji kako lolos ayakan 20 mesh sebanyak 50 g, ditempatkan dalam mangkok gelas, dipanaskan dalam oven EGM 900 watt, 2450 MHz selama 2 sampai dengan 12 menit pada power 20%. Penyangraian konvensional dilakukan menggunakan oven listrik pada suhu 140ºC selama 20 menit sampai dengan 140 menit. Hasil penelitian menunjukkan bahwa penyangraian dengan EGM menghasilkan kenaikan suhu 10 kali lebih besar, penurunan kadar air dan kansungan polifenol masing-masing 11 dan 13 kali lebih besar, dibandingkan dengan penyangraian konvensional. Penyangraian menggunakan EGM lebih cocok untuk penyangraian tingkat berat dengan produk yang berwarna coklat kehitaman. Pola perubahan aktivitas penghambatan oksidai asam linoleat selama penyangraian menggunakan EGM adalah serupa dengan pola perubahan pada penyangraian konvensional, dengan nilai antara 85-90%. Selama penyangraian kandungan polifenol menurun, dengan pola mendekati garis lurus. Perubahan kandungan polifenol selama penyangraian tidak berkorelasi secara nyata dengan perubahan aktivitas penghambatan oksidasi asam linoleat.

Artificial neural networks (ANN) was used to predict the quality parameters of tomato, i.e. Brix, citric acid, total carotene, and vitamin C. ANN was developed from Red Green Blue (RGB) image data of tomatoes measured using a developed computer vision system (CVS). Qualitative analysis of tomato compositions were obtained from laboratory experiments. ANN model was based on a feedforward backpropagation network with different training functions, namely gradient descent (traingd), gradient descent with the resilient backpropagation (trainrp), Broyden, Fletcher, Goldfrab and Shanno (BFGS) quasi-Newton (trainbfg), as well as Levenberg Marquardt (trainlm). The network structure using logsig and linear (purelin) activation function at the hidden and output layer, respectively, and using the trainlm as a training function resulted in the best performance. Correlation coefficient (r) of training and validation process were 0.97 - 0.99 and 0.92 - 0.99, whereas the MAE values ranged from 0.01 to 0.23 and 0.03 to 0.59, respectively.ABSTRAKJaringan syaraf tiruan (JST) digunakan untuk memprediksi parameter kualitas tomat, yaitu Brix, asam sitrat, karoten total, dan vitamin C. JST dikembangkan dari data Red Green Blue (RGB) citra tomat yang diukur menggunakan computer vision system. Data kualitas tomat diperoleh dari analisis di laboratorium. Struktur model JST didasarkan pada jaringan feedforward backpropagation dengan berbagai fungsi pelatihan, yaitu gradient descent (traingd), gradient descent dengan resilient backpropagation (trainrp), Broyden, Fletcher, Goldfrab dan Shanno (BFGS) quasi-Newton (trainbfg), serta Levenberg Marquardt (trainlm). Fungsi pelatihan yang terbaik adalah menggunakan trainlm, serta pada struktur jaringan digunakan fungsi aktivasi logsig pada lapisan tersembunyi dan linier (purelin) pada lapisan keluaran. dengan 1000 epoch. Nilai koefisien korelasi (r) pada tahap pelatihan dan validasi secara berturut-turut adalah 0.97 - 0.99 dan 0.92 - 0.99; sedangkan nilai MAE berkisar antara 0.01-0.23 dan 0.03-0.59.

There are three approaches in the current social network analysis study: Graph Representation, Content Mining, and Semantic Analysis. Graph Representation has been used for analyzing social network topology, structural modeling, tie-strength, community detection, group cohesion visualization, and metrics computations. This paper provides a taxonomy of social network analysis based on its graph representation., Comment: 11 pages, 2 tables, 2 figures

Knowledge of moisture diffusivity was important for water loss modelling during deep fat vacuum frying. The appropri- ateness of model depended on the accuracy of moisture diffusivity value. The objective of this research was to calculate carrot moisture diffusivity during deep fat vacuum frying. Moisture diffusivity was obtained from rate of water loss multiplied by L2/π2. The rate of water loss was determined from unsteady-state diffusion equation. The slope of the time vs. dimensionless concentration ratio plot was the rate of water loss. Carrot was used as a sample in this research. The rate of water loss was determined during deep fat vacuum frying with variation of absolute pressure, temperature and initial moisture content. The result showed that moisture diffusivity depended on absolute pressure, temperature and initial moisture content. The result indicated that an increase in the temperature of frying and initial moisture content caused an increase in moisture diffusivity. While an increase in the absolute pressure induced decreasing of moisture diffusivity. The moisture diffusivities were accurately predicted at absolute pressure range from 20 – 40 kPa, initial moisture content range from 198 % (db) to 940 % (db) and temperature range from 80 to 110 oC.ABSTRAKPengetahuan mengenai difusivitas air sangat penting untuk pemodelan kehilangan air selama penggorengan hampa udara. Kesesuaian model tergantung atas akurasi nilai difusivitas air. Tujuan penelitian ini adalah untuk menghitung difusivitas air sebagai fungsi tekanan absolut, suhu dan kadar air awal bahan selama penggorengan hampa udara. Difusivitas air diperoleh dari laju kehilangan air dikalikan L2/π2. Laju kehilangan air ditentukan dari persamaan di- fusi tak mantap. Kemiringan dari kurva lama penggorengan terhadap rasio konsentrasi merupakan laju kehilangan air. Penilitian ini menggunakan wortel sebagai sampel. Laju kehilangan air ditentukan selama penggorengan hampa udara dengan variasi tekanan absolut, suhu dan kadar air awal bahan. Hasil penelitian menunjukkan bahwa difusivi- tas air tergantung atas tekanan absolut, suhu dan kadar air awal. Peningkatan suhu dan kadar air awal menyebabkan peningkatan difusivitas air. Sedangkan peningkatan tekanan absolut menyebabkan penurunan nilai difusivitas air. Difusivitas air diprediksikan secara tepat pada range tekanan absolut 20 - 40 kPa, suhu 80 - 110 oC dan kadar air awal 198 - 940 % (bk).

The purpose of this research was to develop a simple computer vision system (CVS) to non-destructively measure tomato quality based on its Red Gren Blue (RGB) color parameter. Tomato quality parameters measured were Brix, citric acid, vitamin C, and total sugar. This system consisted of a box to place object, a webcam to capture images, a computer to process images, illumination system, and an image analysis software which was equipped with artificial neural networks technique for determining tomato quality. Network architecture was formed with 3 layers consisting of1 input layer with 3 input neurons, 1 hidden layer with 14 neurons using logsig activation function, and 5 output layers using purelin activation function by using backpropagation training algorithm. CVS developed was able to predict the quality parameters of a Brix value, vitamin C, citric acid, and total sugar. To obtain the predicted values which were equal or close to the actual values, a calibration model was required. For Brix value, the actual value obtained from the equation y = 12,16x – 26,46, with x was Brix predicted. The actual values of vitamin C, citric acid, and total sugar were obtained from y = 1,09x - 3.13, y = 7,35x – 19,44, and y = 1.58x – 0,18,, with x was the value of vitamin C, citric acid, and total sugar, respectively.ABSTRAKTujuan penelitian adalah mengembangkan computer vision system (CVS) sederhana untuk menentukan kualitas tomat secara non­destruktif berdasarkan parameter warna Red Green Blue (RGB). Parameter kualitas tomat yang diukur ada­ lah Brix, asam sitrat, vitamin C, dan gula total. Sistem ini terdiri peralatan utama yaitu kotak untuk meletakkan obyek, webcam untuk menangkap citra, komputer untuk mengolah data, sistem penerangan, dan perangkat lunak analisis citra yang dilengkapi dengan jaringan syaraf tiruan untuk menentukan kualitas tomat. Arsitektur jaringan dibentuk dengan3 lapisan yang terdiri dari 1 lapisan masukan dengan 3 sel syaraf masukan, 1 lapisan tersembunyi dengan 14 sel syaraf berfungsi aktivasi logsig dan 5 lapisan keluaran dengan fungsi aktivasi purelin menggunakan algoritma pelatihan back­ propagation. CVS yang dikembangkan dapat digunakan untuk memprediksi nilai parameter kualitas tomat yaitu Brix, vitamin C, asam sitrat, dan gula total, meskipun dibutuhkan persamaan kalibrasi. Persamaan kalibrasi untuk Brix, nilai aktualnya diperoleh dari persamaan y = 12,16x – 26,46 dengan x adalah nilai Brix prediksi. Sedangkan kadar vitamin C, asam sitrat, dan gula total aktual secara berturut-turut diperoleh dari y = 1,09x - 3.13, y = 7,35x – 19,44, dan y =1.58x – 0,18, dengan x adalah nilai vitamin C prediksi, asam sitrat prediksi, dan gula total prediksi.

Pada penelitian ini dilakukan pengeringan bahan herbal dan obat-obatan tradisional yang peka terhadap panas yaitu daun sambiloto menggunakan pengering bertekanan rendah. Tekanan yang rendah akan membuat titik uap air akan turun sehingga air akan menguap pada suhu di bawah 100°C. Suhu rendah ini juga bertujuan untuk mengurangi tingkat kerusakan kandungan kimia bahan peka panas. Sedangkan tujuan penelitian adalah menganalisis konstanta laju pengeringan daun sambiloto selama proses pengeringan menggunakan pengering tekanan rendah. Pengeringan daun sambiloto dilakukan pada suhu dan tekanan yang bervariasi yaitu variasi suhu 30°C, 40°C, 50°C dan variasi tekanan 61 kPa, 48 kPa dan 35 kPa. Pengeringan daun sambiloto dilakukan dari kadar air ± 70% hingga ± 10%. Selama proses pengeringan perubahan kadar air diukur dengan interval waktu 10, 20, 30, 60, 90, 120, 150 dan 210 menit. Pengukuran kadar air dilakukan dengan cara termogravimetri. Analisis konstanta laju pengeringan menggunakan persamaan lapis tipis. Hasil penelitian menunjukkan nilai konstanta laju pengeringan pada tekanan rendah berkisar 0,01-0,0175 men1. Pengeringan menggunakan tekanan rendah dapat meningkatkan laju pengeringan. Persamaan empiris konstanta laju pengeringan sebagai fungsi suhu dan tekanan yang dinyatakan sebagai kprediksi = 0,00075T0,823P-0,021 dapat diaplikasikan untuk memprediksi perubahan kadar air daun sambiloto selama pengeringan pada tekanan rendah. Kata kunci: konstanta laju pengeringan, pengeringan bertekanan rendah, daun Sambiloto Herbs (traditional medicine) such as sambiloto leaves are senisitive to heat, therefore the drying process of herbs were performed at low-pressure. At low pressure, evaporation of water in the herbs can be carried out at a temperature below 100°C. The low temperature of drying may reduce the destruction of heat-sensitive chemicals inside the herbs. The present study aimed at analyzing the drying-rate constant of sambiloto leaves during low-pressure drying. Sambiloto leaves were dried at varied temperature of 30°C, 40°C, and 50°C, and varied pressure of 61 kPa, 48 kPa, and 35 kPa. The water content of sambiloto leaves was reduced from ± 70% to ± 10%. The change in water content was measured after 10, 20, 30, 60, 90, 120, 150 and 210 minutes, by using thermogravimetry technique. The drying-rate constant was calculated using the equation of thin films. The drying-rate constant was 0.01 – 0.0175 min-1. It was observed that the drying-rate increases as the pressure decreases. To predict the change of water content in sambiloto leaves during low-pressure drying process, an empirical equation for the drying-rate constant as a function of temperature and pressure was derived from the experimental data, kprediction= 0,00075T0,823P-0,021. Key words: drying-rate constant, low-pressure drying, sambiloto leaves

The natural colour of fruit flaky product is one of specific property prefered by consumer. To maintain the natural colourof the fruit flaky during frying, it is necessary to pay attention the characteristic changes of raw material and control the process in order not to have much changes to get the intended colour. The objective of this research is to develop empirically mathematical model of fruit flaky colour changes during vacuum frying process by considering the change of water and sucrose contents in the product. Sample of the research were jack fruits fried in the temperature of 70–100OC, frying duration of 15–60 minutes, and vacuum pressure of 13-23 kPa. The observed parameters are colour (L), colour (a), colour (b), water and sukrose contents before and after frying. The result showed that colour changes (L, a and b) were influenced by free water vaporization and sukrose decreasing in product, so empirically, the developed mathematical model of colour changes (L, a and b) can be used to predict fruit flaky colour changes during vacuum frying. ABSTRAK Warna alami pada produk keripik buah adalah merupakan salah satu sifat khas yang disukai oleh konsumen, untukmempertahankan warna alami keripik buah agar tidak banyak mengalami perubahan selama dalam penggorengan, perlu diperhatikan perubahan karakteristik bahan baku dan pengendalian proses, agar warna keripik buah yang dihasilkan sesuai dengan yang diinginkan. Penelitian ini bertujuan untuk mengembangkan secara empirik model matematik perubahan warna keripik buah selama dalam proses penggorengan vakum dengan mempertimbangkan ke dalam model perubahan kadar air dan kadar sukrosa di dalam padatan. Sampel penelitian adalah buah nangka digoreng pada suhu70-100 OC, lama penggorengan 15-60 menit dan tekanan vakum 13-23 kPa. Parameter yang diamati adalah warna (L), warna (a), warna (b), kadar air dan kadar sukrosa sebelum dan setelah sampel digoreng. Hasil penelitian menunjukkan perubahan warna L, a dan b dipengaruhi oleh penguapan air bebas dan penurunan kadar sukrosa di dalam padatan, sehingga secara empirik model matematik perubahan warna L, a dan b yang dikembangkan dapat digunakan dengan baik untuk memprediksi perubahan warna keripik buah selama dalam proses penggorengan secara vakum.