Gadjah Mada University

About: Gadjah Mada University is a education organization based out in Yogyakarta, Indonesia. It is known for research contribution in the topics: Population & Adsorption. The organization has 17307 authors who have published 21389 publications receiving 116561 citations. The organization is also known as: University of Gajah Mada & Universitas Gadjah Mada.

SARIMA (Seasonal ARIMA) implementation on time series to forecast the number of Malaria incidence

Abstract: The usefulness of forecasting method in predicting the number of disease incidence is important. It motivates development of a system that can predict the future number of disease occurrences. Fluctuation analysis of forecasting result can be used to support the making of policy from the stake holder. This paper analyses and presents the use of Seasonal Autoregressive Integrated Moving Average (SARIMA) method for developing a forecasting model that able to support and provide prediction number of diasease incidence in human. The dataset for model development was collected from time series data of Malaria occurrences in United States obtained from a study published by Centers for Disease Control and Prevention (CDC). It resulted SARIMA (0,1,1)(1,1,1)12 as the selected model. The model achieved 21,6% for Mean Absolute Percentage Error (MAPE). It indicated the capability of final model to closely represent and made prediction based on the Malaria historical dataset.

Preparation and Properties of Clay-Reinforced Epoxy Nanocomposites

Abstract: n any medium, provided the original work is properly cited. The clay-reinforced epoxy nanocomposite was prepared by the polymerization method. The effect of clay addition on the mechanical properties of epoxy/clay nanocomposites was studied through tensile, flexural, impact strength, and fracture toughness tests. The morphology and tribology behavior of epoxy/clay nanocomposites were determined by X-ray diffraction (XRD) and wear test, respectively. The wear test was performed to determine the specific abrasion of the nanocomposites. In addition, the water absorption characteristic of the nanocomposites was also investigated in this study. XRD analysis indicated that the exfoliation structure was observed in the epoxy nanocomposites with 3 wt% of clay, while the intercalated structure was shown at 6 wt% of clay. It was found that the addition of clay up to 3 wt% increased the tensile strength, flexural strength, impact strength, and the fracture toughness. On the contrary, the presence of above 3 wt% of clay produced a reverse effect. It could be concluded that the best properties in mechanical, wear resistance, and water resistance were obtained for the epoxy nanocomposites containing 3 wt% of clay.

Physicochemical properties and antioxidant activities of chocolates enriched with engineered cinnamon nanoparticles

Abstract: The use of nanocapsules to overcome incompatibility between bioactive compounds and food matrices targeting fortification has been widely acknowledged. This study provides a novel method to enhance the nutritional properties of chocolate by employing lyophilised colloidal nanoparticles made of a combination of shellac, xanthan gum and cinnamon extract. Lyophilised colloidal nanoparticles containing cinnamon extract (LCNP-CE) were prepared by an anti-solvent precipitation method followed by freeze drying. Cinnamon extract was loaded into nanoparticle to entrap the aroma of the cinnamon extract; thereby, the cinnamon extract can be incorporated in the chocolate to expand its bioactive profile without altering its sensorial characteristic. LCNP-CE was formulated into white and milk chocolate in multilevel ratios (0–2% w/w). The results show that the fortification of milk and white chocolates by LCNP-CE significantly improved the total phenolic content and antioxidant activity of the chocolates without remarkable changes in the fineness and melting profile properties. Even though slight changes in the hardness, flow behaviour and colour have been observed, the enriched chocolates are likely in the range of acceptable values. Encapsulation has a positive impact on preventing flavour alteration on the cinnamon enriched chocolates; however, a drawback in the release behaviour of the cinnamon extract from the chocolate was observed.