Meningkatkan Hasil Belajar Siswa pada Mata Pelajaran IPA Menggunakan Media Pernafasan Paru-Paru

The purpose of this study was to improve students' learning outcomes in science subjects grade VI SD Negeri 02 Ujan Mas by using lung respiratory media. This research uses a type of Class Action (PTK) research conducted in 2 cycles, each cycle consists of 4 stages, namely the stage of planning, implementation of actions, observation and reflection. This research subsection numbered 19 people. Data collection techniques are carried out through tests, and observations. The results showed before learning using respiratory media (Pre-Test) learning results can be categorized as medium with a high category of 2 people, a moderate category of 15 people, and a low category of 2 people.  Learning results when using respiratory media (Pre-Test) can be categorized as moderate or sufficient, this is evidenced by the results of learning in a high category of 0 people, a moderate category of 19 people and a low category of 0 people. The results of the analysis showed no significant influence of lung respiratory media on the results of science study grade VI SD N 02 this is evidenced by the results of rxy value data known correlation between variable X and variable Y of 0.061279 located at intervals of 0.00-0.20. In conclusion, there is no significant influence of lung respiratory media on the learning outcomes of science grade VI SD N 02 Ujan Mas.   Keywords: Lung Respiratory Media, Learning Outcomes, Science Lesson

Hemicellulose Extraction and Characterization of Rice Straw and Leucaena Leucocephala

Local production of agricultural waste is increasing. It is not fully  utilized  and  can cause an environmental issue if it is not handle wisely. Thus, it is important to increase utilization of lignocellulosic biomass by improving their added value and subsequently decrease the agriculture waste. In this study, rice straw and Leucaena leucocephala were subjected to alkali treatment (4% sodium hydroxide) with different concentration ratio of samples to sodium hydroxide (1:10 to 1:50). The physical and chemical properties of extracted hemicelluloses were studied. The yield of hemicellulose was higher from rice straw compared to Leucaena leucocephala. The chemical functional groups present in hemicellulose were confirmed by Fourier tranform infrared spectroscopy (FTIR). The surface morphology and roughness of xylan were examined by scanning electron microscopy (SEM). Keywords: rice straw, hemicellulose, sodium hydroxide, alkal

Effect of heat and thermosonication on kinetics of peroxidase inactivation and vitamin C degradation in seedless guava (Psidium guajava L.)

This study aims to evaluate the effect of heat and the simultaneous application of heat (80-95°C) and ultrasonic waves (thermosonication) on the inactivation kinetic of peroxidase and vitamin C degradation in seedless guava. Ultrasonic wave’s amplitudes except 25 and 100% had significant (P<0.05) effect on peroxidase inactivation rate. The thermal and thermosonication inactivation of peroxidase was described well by first-order kinetics (R2>0.98). In the heat blanching process, the peroxidase inactivation rate constant increased from 1.1×10-2 to 4.6×10-2 s-1. However, the inactivation rate of peroxidase was increased by 1.5–3 times in the temperature range 80–95ºC, with the 50 and 75% ultrasonic wave amplitudes, respectively. Decreases in vitamin C contents due to blanching treatments were found. Blanching processes at high temperature and short time resulted in higher vitamin C retention. It was found that thermosonication treatment inactivates seedless guava peroxidase at less severe blanching conditions and consequently retains vitamin C content at higher levels. The present findings will help to design the blanching conditions in order to reduce the severity of conventional thermal treatments and, therefore, improving the quality of the thermally treated product

Application of FTIR spectroscopy in determining sesamol in sesame seed oil

A new analytical method was developed for determining sesamol in sesame seed oil by FTIR spectroscopy. Sesamol was also spiked at 0 to 1000 mg/kg in freshly refined, bleached, and deodorized palm olein (RBDPOo) and groundnut (peanut) oil. FTIR spectra were recorded using a transmission (NaCl) cell accessory at room temperature, and the partial least squares regression statistical method was used to derive calibration models for each oil. The standard errors of calibration were 6.07, 5.88, and 4.24 mg/100 g for sesame, RBDPOo, and groundnut oils, with coefficients of determination (R2) of 0.9947, 0.9940, and 0.9662, respectively. The calibration models were validated by the “leave-one-out” cross-validation method, and the R2 of validation, the standard errors of prediction, and SD of the differences for repeatability and accuracy were computed. Our results support the premise that FTIR spectroscopy is an efficient and accurate method for determining minor components such as sesamol in edible oils. Paper no. J10132 in JAOCS 80, 1–4 (January 2003)

A new method for determining aflatoxins in groundnut and groundnut cake using FTIR spectroscopy with attenuated total reflectance technique

A new analytical method was developed for the determination of aflatoxins in groundnut and groundnut cakes by Fourier transform infrared (FTIR) spectroscopy using horizontal attenuated total reflectance technique. Groundnut and groundnut cake samples were used in this study. The wavelengths were selected for the four types of aflatoxins—B1, B2, G1, and G2—and the standards prepared for each by spiking some clean sample with the aflatoxins in concentrations of 0–1200 parts per billion. A partial least square regression was used to derive the calibration models for each toxin. The coefficients of determination (R2) of the calibration model were computed for the FTIR spectroscopy predicted values vs. actual values of aflatoxins in parts per billion. The R2 was found to be 0.9911, 0.9859, 0.9986, and 0.9789 for aflatoxins B1, B2, G1, and G2, respectively. Standard errors of calibration for groundnut samples were found to be 1.80, 2.03, 1.42, and 2.05 for aflatoxins B1, B2, G1, and G2, respectively. Calibration models were validated with an independent set of samples. The R2 of validation models were computed. The SD of the difference for repeatability of the FTIR method was found to be better than that of the chemical method. Based on the results obtained, FTIR spectroscopy can be a useful instrumental method for determining aflatoxins in oilseeds and oilseed cakes. With its speed and ease of data manipulation by computer software, it is a possible alternative to the standard wet chemical methods for a rapid and accurate routine determination of aflatoxin levels in food and feed

PROMOTING GUIDED-DISCOVERY LEARNING THROUGH WHATSAPP TO STUDENTS IN OPEN UNIVERSITY

Long-distance learning uses an online platform to transfer the knowledge. It has become a breakthrough in this modern era. The online learning brings many benefits to students, but it is also challenging to be implemented by the tutors in distance education universities. This paper tends to investigate the use of the guided-discovery learning (GDL) method in the psycholinguistics online tutorial class. The participants are the students of the English Education program in Universitas Terbuka, who take Psycholinguistics subject with online tutorial service. The methodology of this research is qualitative by using a case study. The researchers use the WhatsApp application as the platform in conducting the course. The students are required to follow the lesson step by step through WhatsApp. Based on the finding, this research reveals that there are two perspectives of the use of GDL toward psycholinguistics online tutorial class. The first perspective is in students that has two major advantages. The second can be seen from the learning perspective which also has two benefits of the use of GDL

Multivarate calibration of fourier transform spectra in determining the malonaldehyde as a TBA reactive substance (TBARS) in palm olein

Fourier transform infrared (FTIR) spectra of palm oil samples between 2900 and 2800 cm–1 and 1800 and 1600 cm–1 were used to compare different multivariate calibration techniques for quantitative determination of their thiobarbituric acid-reactive substance (TBARS) content. Fifty spectra (in duplicate) of palm oil with TBARS values between 0 and 0.25 were used to calibrate models based on partial least squares (PLS) and principal components regression (PCR) analyses with different baselines. The methods were compared for the number of factors, coefficients of determination (R2), and accuracy of estimation. The standard errors of prediction (SEP) were calculated to compare their predictive ability. The calibrated models generated three to eight factors, R2 of 0.9414 to 0.9803, standard error of estimation (SEE) of 0.0063 to 0.0680, and SEP of 1.20 to 6.67