State University of Semarang

About: State University of Semarang is a education organization based out in Semarang, Indonesia. It is known for research contribution in the topics: Population & Curriculum. The organization has 7737 authors who have published 7790 publications receiving 38055 citations. The organization is also known as: Universitas Negeri Semarang.

Quality improvement by batch vacuum distillation and physicochemical characterization of clove leaf oil in Central Java, Indonesia

Abstract: Clove leaf oil is one of the essential oils which have high economic value and produced in considerable amount in Indonesia. As many as 60% of clove oil produced by Indonesia has exported to many countries in the world. Musuk and Ringinlarik Village, Boyolali District, Central Java Province is one of the areas in Indonesia which became the primary supplier of Indonesian clove leaf oil. Although, the quality of the resulting yield is still low because it uses a simple distillation kettle in the form of the iron plate or used the drum. The clove leaf oil produced by steam distillation from the dry whole leaves of the clove tree. The color of the oil is brownish black and dirty with the odor are fresh distilled, spicy, warm, and terpenic. The specific gravity at 25 °C of 1.529, the refractive index at 20 °C of 1.030, and based on GC-MS analysis, eugenol levels only 68% and caryophyllene is too high, i.e., 20%. The quality of clove leaf oil produced does not meet the specifications of international market standards. This work aimed to improve the quality of Indonesian clove leaf oil. The purifications done in this research was used by batch vacuum distillation with mode operation at vacuum -76 cmHg and reflux ratios 5:1. Clove leaf oil produced by using this method has a better physicochemical characterization, i.e., the appearance that is yellow to pale color with the odor is spicy, woody, warm, and terpenic. The specific gravity at 25 °C of 1.533, the refractive index at 20 °C of 1.038, and eugenol and caryophyllene contents has yielded 80.58% and 10%, respectively. By The enhancement quality of clove leaf oil by batch vacuum distillation, these oil is already meet international standards and income of clove leaf oil grower in Musuk and Ringinlarik Village, Boyolali District, Central Java Province, Indonesia could be increased.

Analisis efisiensi penggunaan faktor-faktor produksi usaha tani jagung di kabupaten grobogan tahun 2008

Abstract: Corn represent s one of the agricultu ral comodities in Grobogan regency . However, the average corn production in Grobogan is only 4,92 ton/Ha. It is below the standard production determined by the government which ranges from 5,5 to 6 ton/ Ha . The aim of this study is to know the efficiency of production factors in farm bussiness, especially corn farm in Grobogan regency. The samples are 90 divisible responde nts in Purwodadi, Toroh a nd Kradenan . Then, the purposive cluster of area random sampling was applied for having the samples and qu antitative descriptive approach was used for having the fi ndings. After analyzing the data, it is shown that the variables influence the efficiency of production factors in farm bussiness are land area, seed production, and fertilizer production. Furthermore, those variables are inefficient in the busssiness farm. It is based on the calculation that shows the following findings: technical efficiency is 0,9996633, the price efficiency is 1,53563 , and the economic efficiency is 1,5346. Knowing that the variables involve in the farm bussiness, especially corn have not been efficient yet, the government roles are needed, and agriculture policy should be issued for protecting the peasants.

Pengaruh profesionalisme guru, disiplin kerja dan lingkungan kerja terhadap kinerja guru mata pelajaran ekonomi di sma negeri se-kabupaten sragen

Abstract: Tujuan dari penelitian ini adalah untuk mengetahui pengaruh profesionalisme guru, disiplin kerja dan lingkungan kerja terhadap kinerja guru SMA Negeri Se-Kabupaten Sragen Populasi dan sampel dalam penelitian ini adalah guru mata pelajaran ekonomi di SMA Negeri Se-Kabupaten Sragen yang berjumlah 36 orang Teknik pengambilan sampel yang digunakan dalam penelitian ini yaitu metode sensus Metode yang digunakan dalam dalam pengambilan data adalah angket Data variabel dianalisis dengan statistik deskriptif persentase dan analisis regresi berganda Dari hasil analisis deskriptif diperoleh bahwa kinerja guru mata pelajaran ekonomi Di SMA Negeri Se-Kabupaten Sragen dalam kategori sangat tinggi, profesionalisme guru dalam kategori sangat tinggi, disiplin kerja dalam kategori tinggi dan lingkungan kerja dalam kategori baik Hasil penelitian ini secara statistik menunjukkan bahwa terdapat pengaruh profesionalisme guru, disiplin kerja, dan lingkungan kerja terhadap kinerja guru mata pelajaran ekonomi di SMA Negeri Se-Kabupaten Sragen (37,8%) Profesionalisme guru berpengaruh terhadap kinerja guru mata pelajaran ekonomi di SMA Negeri Se-Kabupaten Sragen (19,6%) Disiplin kerja berpengaruh kinerja guru mata pelajaran ekonomi di SMA Negeri Se-Kabupaten Sragen (15,92%) dan sedangkan lingkungan kerja berpengaruh terhadap kinerja guru mata pelajaran ekonomi di SMA Negeri Se-Kabupaten Sragen (11,90%) Saran yang dapat diberikan adalah guru harus berupaya meningkatkan kinerjanya dan guru di harapkan dapat membuat metode mengajar yang bervariasi agar dapat menarik minat peserta didik The objective of this research is to find out the influence of teacher performance, work discipline, and work environment on teacher performance at SMAN Sragen The population and sample in this research was 36 economic teachers at SMAN Sragen The subjects were selected by using census method technique The methode that was used to data retrieval was questionnaire Variable data was analyzed by descriptive statistic percentage and multiple regression analysis Based on the result of descriptive analysis showed that economic teacher performance at SMAN Sragen was very high, teacher professionalism was very high, work discipline was high and work environment was good The result of this research statistically showed that the influence of teacher professionalism, work discipine, and work environment on economic teacher performance at SMAN Sragen (37,8%) Teacher professionalism affected the economic teacher performance at SMAN Sragen (19,6%) Work discipline affected the economic teacher performance at SMAN Sragen (15,92%) and work environment affected the economic teacher performance at SMAN Sragen (11,90%) The suggestions were offered that teachers should make efforts to improve their performance and are expected to create varied teaching methods in order to attract learners

Heading Control on Differential Drive Wheeled Mobile Robot with Odometry for Tracking Problem

Abstract: This paper describes the process of designing odometry and heading controls from a differential steering wheeled mobile robot (DSWMR). The odometry system aims to estimate the position relative to the initial position of the robot to estimate changes in position from time to time in the trajectory tracking process. The problem that often arises in the tracking problem is the heading error that can be caused by a slip on the robot wheel or an irregularity between the speed of the DC motor on the robot wheel. Heading errors in DSWR can be obtained with the help of a rotary encoder located on a DC motor. This work applied PID control to obtain the heading error close to 0 degrees on the odometry system for trajectory tracking. It works by controlling the rotating speed of each DC motor on the robot wheel. The results of the PID control parameters implemented on the DSWMR were obtained from the results of tuning experiments.