Karakteristik Minuman Laktat Sari Buah Durian Lay (Durio Kutejensis) yang Disuplementasi dengan Kultur Lactobacillus Selama Penyimpanan pada Suhu Rendah

Tujuan penelitian ini adalah mengkaji karakteristik minuman laktat sari durian lay yang disuplementasi dengan kultur bakteri asam laktat (BAL) selama penyimpanan pada suhu rendah. Kultur BAL terdiri dari Lactobacillus plantarum FNCC-0265, Lactobacillus acidophillus FNCC-0051, dan campuran keduanya. Sari buah durian lay diinokulasi dengan kultur berumur 24 jam lalu diinkubasi pada suhu 37 °C selama 2 jam dan kemudian disimpan selama 0, 1, 2, 3, dan 4 minggu. Perubahan pH, total asam, gula, total sel BAL. Total padatan terlarut, viabilitas BAL, dan sensori selama penyimpanan dingin diukur. Hasil penelitian menunjukkan bahwa terjadi Perubahan pH dari 4,79 ke 4,20; kandungan gula dari 4,52 ke 0,75%; total padatan terlarut dari 8,93 ke 7.97 °Bx, viabilitas BAL dari 100 % menjadi 95,90 %, dan skor sensori dari 3,71 suka ke 3,40 (agak suka); sementara pada total asam terjadi peningkatan dari 0,33 ke 0,69 %; dan sel hidup BAL meningkat dari 8,86 menjadi 9,14 log CFU/mL. Berdasarkan parameter sensori, perlakuan kultur campuran Lactobacillus plantarum FNCC-0265 dan Lactobacillus acidophillus FNCC-0051 yang disimpan selama 2 minggu merupakan perlakuan terbaik. Sari buah durian lay ini mempunyai karakteristik sebagai berikut: pH 4,45, total asam laktat 0,83 %, gula 2,20%, sel hidup BAL 9,33 log CFU/mL, total padatan terlarut 9,16 °Bx, dan karbohidrat 35,04 %. Asam organik yang terkandung pada jus durian lay ini adalah asam oksalat (108 mg/L), malat (528 mg/L), laktat (4382 mg/L) dan sitrat (351 mg/L)

Modelling of a 3-phase induction motor under open-phase fault using matlab/simulink

The d-q model of Induction Motors (IMs) has been effectively used as an efficient method to analyze the performance of the induction machines. This study presents a step by step Matlab/Simulink implementation of a star-connected 3-phase IM under open-phase fault (faulty 3-phase IM) using d-q model. The presented technique in this paper can be simply implemented in one block and can be made available for control purposes. The simulated results provide to show the behavior of the star-connected 3-phase IM under open-phase fault condition

Tingkat Pencapain Tugas Guru SMKN Di Kota Malang, Kaitannya Dengan Komunikasi, Motivasi Intrinsik, Dan Ekstrinsik

The purpose of this research is to determine the degree of achievement of teachers duties, with respect to communication, intrinsic and extrinsic motivation in Malang SMK. Research methods used descriptive and correlational design, while SMK teachers who worked as civil servants in Malang Raya (years of service > 3 years) were taken as study population, totaling 444 people from 12 schools. A number of 161 teachers were taken as sample by proportional random sampling technique. Instruments arranged on Likert scale and the validity and reliability were tested. The data obtained were analyzed using descriptive and correlational method, using SEM-PLS PLS 2-Smart program. Analytical results obtained: (1) the degree of achievement of teacher duties placed in the mediumcategory, (2) organizational communication, intrinsic and extrinsic motivation of teachers placed in high category, (3) the teacher duties level of achievement is affected by the organizational communication,extrinsic motivation, and intrinsic motivation, and (4) (extrinsic) motivation were affected by organizational communication. Tujuan penelitian ini adalah untuk mengetahui tingkat pencapaian tugas guru, kaitannya dengan komunikasi, motivasi intrinsik dan ekstrinsik pada SMKN di Kota Malang. Metode penelitian menggunakan rancangan deskriptif dan korelasional, dengan populasi penelitian adalah guru-guru SMKN di Kota Malang yang berstatus PNS (masa kerjanya > 3 tahun) berjumlah 444 orang dari 12sekolah. Dengan teknik proposional random sampling, sampel ditetapkan 161 guru. Instrumen disusunberdasar skala Likert dan diuji validitas dan reliabilitasnya. Data yang diperoleh, dianalisis secara deskriptif dan korelasional dengan menggunakan SEM-PLS program Smart-PLS 2. Hasil analisis diperoleh: (1) tingkat pencapaian tugas guru dalam kategori sedang; (2) komunikasi organisasi, motivasi intrinsik dan ekstrinsik guru dalam kategori tinggi, (3) tingkat pencapaian tugas guru dipengaruhi oleh komunikasi organisasi, motivasi ekstrinsik, dan motivasi intrinsik, dan (4) motivasi kerja (ekstrinsik) dipengaruhi olek komunikasi organisasi

A simple checking algorithm with perturb and observe maximum power point tracking for partially shaded photovoltaic system

This paper presents a simple checking algorithm for maximum power point tracking (MPPT) technique for Photovoltaic (PV) system using Perturb and Observe (P&O) algorithm. The main benefit of this checking algorithm is the simplicity and efficiency of the system whose duty cycle produced by the MPPT is smoother and changes faster according to maximum power point (MPP). This checking algorithm can determine the maximum power first before the P & O algorithm takes place to identify the voltage at MPP (VMPP), which is needed to calculate the duty cycle for the boost converter. To test the effectiveness of the algorithm, a simulation model of PV system has been carried out using MATLAB/Simulink under different level of irradiation; or in other words partially shaded condition of PV array. The results from the system using the proposed approach prove to have faster response and low ripple. Besides, the results are close to the desired outputs and exhibit an approximately 98.25% of the system efficiency. On the other hand, the system with conventional P&O MPPT seems to be unstable and has higher percentage of error. In summary, the proposed method is useful under varying level of irradiation with higher efficiency of the system

Kajian Konfigurasi Escape Building untuk Evakuasi terhadap Bencana Tsunami di Kota Banda Aceh

Banda Aceh is one of the cities in Sumatra that is affected by the earthquake and tsunami Andaman on 26 December 2004. Banda Aceh has a sloping and relatively flat topography, with an average height of 0.8 meters above sea level, making this city became one of the cities with The worst effects of tsunami 2004, and still have the risk of earthquakes and tsunamis in the future. It is necessary for the system in the form of vertical evacuation like escape building, so that residents can take refuge from the tsunami. However, the number and location of the escape building existing only found in the Meuraxa village, so it can not reach all areas of tsunami inundation. This research use network analyst tool to the configuration of the escape building existing to analize the service area of each escape building. From this analysis it can be known that there are still many people who are not able to reach the nearest escape building or toward a secure area before the tsunami waves arrive. The scenarios analysist simulate varying evacuation time conditions, and there are two overload escape building. The simulation result shows that the percentage of residents who are not able to reach an escape building is very small, ranging between 23.73% -10.35%, so it is considered not effective, while the analysis of the escape building existing capacity shows two escape building had excess capacity, ranging between 55.48% - 55,78%

Improved output voltage quality using space vector modulation for multilevel inverters

Space vector modulation (SVM) has received wide acceptance due to many benefits over other techniques such as higher output voltages, lower total harmonic distortion (THD), high-efficiency and flexible to be implemented in vector control systems. In digital implementation, the SVM equations can be optimally computed by eliminate the use of complex forms. In this paper, the simple SVM based on twolevel inverter is employed for higher levels of inverters. This is to retain the simplicity of SVM computation for three-level and five-level cascaded H-bridge multilevel inverter (CHMI). Moreover, the proposed method utilizes two controller boards to perform high computational workloads and to eliminate glitch and error problems. Experiment results show that the THD of output voltage in five-level CHMI gives the smallest value among the results obtained from other levels

A New Fixed Switching Frequency Direct Torque Controlled PMSM Drives with Low Ripple in Flux and Torque

Direct Torque Control (DTC) has gained popularity for development of advanced motor control due to its simplicity and offers fast instantaneous torque and flux controls. However, the conventional DTC which is based on hysteresis controller has major drawbacks, namely high torque ripple and variable inverter switching frequency. This paper presents an improved switching strategy for reducing flux and torque ripples in DTC of PMSM drives; wherein the torque hysteresis controller and the look-up table used in the conventional DTC are replaced with a constant frequency torque controller (CFTC) and an optimized look-up table, respectively. It can be shown that a constant switching frequency is established due to the use of the CFTC while the reduction of torque and flux ripples is achieved mainly because of the selection of optimized voltage vector (i.e. with an optimized look-up table). This paper also will explain the construction of DTC schemes implemented using MATLAB-Simulink blocks. Simulation results were shown that a significant reduction of flux and torque ripples which is about 90% can be achieved through the proposed DTC scheme

A Comparative Modeling and Analysis of Voltage Variation by Using Spectrogram

In this paper, the power quality (PQ) disturbance which is the voltage variations consist of voltage swell, sag and interruption are model and analyze. Different types of voltage variations PQ disturbances models are developed and created by using MATLAB/Simulink as well as mathematical models. The mathematical and Simulink model are used to compare in terms of time-frequency representation (TFR). The Simulink models include shutting down enormouscapacities from system to resemble voltage swell, large loads energizing and three-phase fault to simulate voltage sag as well as implementing permanent three-phase fault to simulate voltage interruption. The signals generated are analyzed by using linear time-frequency distribution (TFD). The signal parameters such as root mean square voltage (Vrms), total harmonic distortion (THD) and power value are estimated from the TFR to identify the characteristics of the voltage variation. The results of analysis on the PQ disturbance waveforms generated are identical to the actual real-time PQ signals and the models can be modified to any desired situation respectively. The PQ waveforms obtained are suitable to be further analyzed

PUSAKA SAUJANA BOROBUDUR: PERUBAHAN DAN KONTINU ITASNYA {Borobudur Cultural Landscape: Change and Continuity}

Penelitian ini dilakukan di kawasan Borobudur, Kabupaten Magelang, Jawa Tengah, untuk mengkaji potensi dan nilai keunggulan pusaka saujana Borobudur, serta tnengetahui perubahan dan kontinuitasnya. Dengan interpretasi sejarah dan penjelasan secara naratif, wujud pusaka saujana Borobudur dapat diapresiasi dalam bentuk: a) pola pengolahan lahanb) tata kehidupanc) arsitektur tradisional kawasandan d) bentukan-bcntukan alami. Potensi yang dimiliki pusaka saujana Borobudur meliputi potensi budaya, sejarah, bentukan-bentukan alami, dan panorama kawasan. Potensi-potensi yang dirniliki kawasan Borobudur, serta kontinuitas kondisi bentanglahan dan budayanya menjadikan kawasan Bo~obudur sebuah pusaka saujana yang unggul, dan nilai keunggulan ini meliputi a) kandungan sejarah lingkungan kawasan, b) kawasan peninggalan benda-benda arkeologi, c) saujana-saujana desa yang menunjukkan kehidupan agraris masyarakatnya, dan d) panorama indah bentanglahan. Dalam lingkungan yang dinarnis, pusaka saujana Borobudur terus mengalami perubafian yang dapat mengancam kontinuitasnya. Perubahan terjadi terutama pada tata guna lahan, kualitas visual. dan scbagian budaya masyarakat, sedangkan kontinuitas masih dapat ditemui pada kegiatan pertanian secara tradisionalsebagian tradisi atau adat istiadat yang berkaitan dengan pertanian, keagamaan, dan kcpercayaanarsitcktur tradisional kawasan perdesaandan panorama indah bentanglahan. Sampai saat ini, pcrubahan-pcrubahan yang terjadi belum berdampak pada hilangnya atau menurunnya kontinuitas pusaka saujana Borobudur. Meskipun demikian, upaya-upaya pelestarian dan pengelolaannya diperlukan untuk menjaga kontinuitasnya