Implementation of Group and Individual Supervision Techniques, and Its Effect on the Work Motivation and Performance of Teachers at School Organization.

Teachers have a very important role in determining the quality of the teaching-learning process and the students' learning outcomes. Learning outcomes will optimally be achieved if it is supported by qualified teachers. One way to enhance the teachers' performance is through instructional supervision which can be divided into two techniques, namely group and individual supervision techniques. Therefore, this study aims to find out the influence of instructional supervision techniques on the work motivation and performance of elementary school teachers. This study was conducted in East Java, Indonesia, and an explanatory research design was used. The sample was taken from 80 elementary school teachers in Malang and Blitar using a multi-stage random sampling technique. Data were collected through the use of questionnaires and documentation, and then they were analyzed by using the structural equation modeling technique. The result of this study showed that group supervision has a significant effect on teachers' performance, whereas individual supervision influenced teachers' work motivation and it affected their performance.

Maleo- and fumaro-pimaric acids synthesized from Indonesian Pinus merkusii rosin and their sizing properties.

This research is directed at characterizing purified maleopimaric acid (MPA), looking at the amount of MPA and fumaropimaric acid (FPA) made from a large amount of rosin and maleic anhydride (MA) or fumaric acid (FA) with various molar ratios and sources of rosin and evaluating the properties of fortified rosin sizes made from both MPA and FPA. Results showed that identification of the Diels-Alder adduct of abietic acid and maleic anhydride using Mass spectrometry produced a mixture of endo-maleopimaric acid methyl ester with endo-maleopimaric acid tri methyl ester, as indicated by a fragment ion at m/z = 146 with a molecular weight of 414 and fragment ions at m/z = 121, 187, 316 and 386, denoting an endo-maleopimaric acid methyl ester. A fragment ion at m/z = 146 with a molecular weight of 460 and other fragment ions at m/z = 187, 121, 400 and 428 indicated endo-maleopimaric tri methyl ester. Using a large amount of rosin as a raw material to produce MPA, the equation Y = -0.8475 X2 + 10.448X - 9.7125, at a reaction temperature of 200 degrees C is still relevant as it denoted that a molar ratio of 1:6.2 (rosin and MA) is the best. However, the equation Y = -0.46X2 + 5.268X - 4.47 did not apply to FPA. Using a large amount of rosin, an increase in the molar ratio led to an increase in FPA products. In terms of free rosin and pH, the maleo-and fumaro-pimaric rosin sizes have met the requirement of Indonesian national standards for paste rosin size. In terms of free alkali property, the maleo- and fumaro-pimaric rosin sizes were better than the free alkali of the commercial forms.

Reaction of abietic acid with maleic anhydride and fumaric acid and attempts to find the fundamental component of fortified rosin.

Identification of the Diels-Alder adduct of Abietic Acid (AA) and maleic anhydride (MA) or Fumaric Acid (FA) using a Shimadzu QP 5050A Gas chromatograph Mass spectrometer revealed that AA and MA produced endo-maleopimaric acid (MPA) and endo-maleopimaric acid tricarboxylic acid. A reaction product of abietic acid and fumaric acid generated three peaks identified based on their mass spectra as fumaropimaric acid (FPA), FPA adducts and endo-MPA. To maximize the reaction between AA and MA or FA, molar ratio (AA and MA or FA), reaction time and reaction temperature were investigated. The best Diels-Alder reaction between abietic and maleic anhydride was at 125 degrees C for 1 h with a molar ratio of AA to MA of 1: 2. The best Diels-Alder reaction between AA and FA was at 200 degrees C for 1 h with a molar ratio of AA and FA of 1: 2.

Characteristics and chemical composition of maleo-pimaric and fumaro-pimaric rosins made of Indonesian Pinus merkusii rosin.

This study was directed to look at the chemical composition of maleo-pimaric and fumaro-pimaric rosins made of unmodified rosin with maleic anhydride (MA) or fumaric acid (FA). The results showed that one peak of a maleopimaric acid (MPA) adduct on the chromatogram was obtained when a sample of this reaction product was injected into a Gas liquid chromatography (GLC) or Gas chromatograph-Mass spectrometer (GC-MS) system. Identification of this adduct using a GC-MS showed that a reaction product of rosin and MA produced endo-maleopimaric acid methyl ester. This peak of the adduct had a similar profile as in a previous study with a base peak at m/z =146 and prominent ions at m/z = 386, m/z = 187 and at m/z = 121. In the making of MPA and fumaropimaric acid (FPA) adducts, the increase in molar ratio for both reaction temperatures of 125 and 2000C and all rosin samples used in the reaction process gave a higher yield of endo maleopimaric acid. The largest amount of this product was obtained at a molar ratio of 1:10 with the reaction at 200 degrees C. Among the origin of the rosin used in this experiment, rosin from Central Java produced the highest MPA, while the highest FPA was achieved by using rosin from North Sumatra. The relationship between the molar ratio and the concentration of MPA or FPA could be expressed as a quadratic equation. From the equation, one could predict the best molar ratio to produce the highest MPA or FPA adducts at a suitable molar ratio. Using the equation Y = -0.8475 X2 + 10.448X - 9.7125, at the reaction temperature 200 degrees C, the highest MPA (around 22.50%) could be achieved by using a molar ratio of rosin and MA of 1:6.2.