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.

Experimental observation of magnetic surface polaritons in FeF2 by attenuated total reflection.

Abstract: We present the first direct experimental evidence for the existence of magnetic surface polaritons in a uniaxial antiferromagnet. The modes are excited in Fe${\mathrm{F}}_{2}$ by attenuated total reflection with the uniaxis along an applied magnetic field ${H}_{0}$. The resonance is observed as an attenuation of the reflected intensity as the frequency of the far-infrared beam is scanned. We find nonreciprocity between the $+{H}_{0}$ and $\ensuremath{-}{H}_{0}$ spectra as a consequence of the nonreciprocity of the surface polariton modes when ${H}_{0}$ is introduced. We also observe broad dips due to the excitation of bulk modes.

The use of FTIR spectroscopy and chemometrics for rapid authentication of extra virgin olive oil

Abstract: The authenticity of high value edible fats and oils including extra virgin olive oil (EVOO) is an emerging issue, currently. The potential employment of Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics of multivariate calibration and discriminant analysis has been exploited for rapid authentication of EVOO from canola oil (Ca-O). The optimization of two calibration models of partial least square (PLS) and principle component regression was performed in order to quantify the level of Ca-O in EVOO. The chemometrics of discriminant analysis (DA) was used for making the classification between pure EVOO and EVOO adulterated with Ca-O. The individual oils and their blends were scanned on good contact with ZnSe crystals in horizontal attenuated total reflectance, as a sampling technique. The wavenumbers of 3,028–2,985 and 1,200–987 cm−1 were used for quantification and classification of EVOO adulterated with Ca-O. The results showed that PLS with normal FTIR spectra was well suited for quantitative analysis of Ca-O with a value of the coefficient of determination (R2) > 0.99. The error, expressed as root mean square error of calibration obtained was relatively low, i.e. 0.108 % (v/v). DA can make the classification between pure EVOO and that adulterated with Ca-O with one misclassified reported.

Biopsychosocial model of illnesses in primary care: A hermeneutic literature review.

Abstract: Biopsychosocial model is a useful worldview for primary care or family doctors. However, it is often considered as impractical or too complicated. The objective of this study is to review the implementation of the biopsychosocial model in clinical practice, and its contributions to clinical outcomes. Hermeneutic circle literature review was conducted to provide experiential learning in an attempt to understand biopscyhosocial model, first developed by George Engel. Literature search started with review articles in Medline and Scopus as search engines. Citations from previous articles, editorials, and research articles were identified and interpreted in the context of the knowledge derived from all identified relevant articles. The progress of biopsychosocial model has been slow, and primary care doctors do not implement biopsychosocial medicine in their practice, while biomedical thinking and approach are still the dominant model. Biopsychosocial research addressed chronic illnesses and functional disorders as conditions in need for biopsychosocial model implementation. As payment scheme, clinical guidelines and clinical performance indicators are biomedically oriented, there is no incentive for primary care doctors to adopt biopsychosocial model in their practice. Workload and lack of competence in primary care may hinder the implementation of biopsychosocial model. Biopsychosocial model helps primary care doctors to understand interactions among biological and psychosocial components of illnesses to improve the dyadic relationship between clinicians and their patients and multidisciplinary approaches in patient care. Biopsychosocial model potentially improves clinical outcomes for chronic diseases and functional illnesses seen in primary care.

Quality attributes of dark chocolates formulated with palm sap-based sugar as nutritious and natural alternative sweetener

Abstract: Consumer demand for healthier alternative sweeteners and attempts to replace the most common sweetener used in chocolate, namely sucrose, continue to increase in recent times. One sucrose alternative that has not been fully explored in chocolate is palm sap-based sugar. This work investigated the impact of sucrose replacement by coconut sugar (CCS1 and CCS2) and palm sugar (CPS1, CPS2 and CPS3) on the quality attributes of dark chocolate, more particularly colour, hardness, flow behaviour and aroma profile. The results showed that chocolates formulated with palm sap-based sugar were lighter in colour and harder than the reference chocolate made with sucrose, which could be attributed to a lower particle density and a higher moisture of palm sap-based sugar than that of sucrose. Analysis of the major volatile compounds recorded the presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) and high concentration of pyrazine-based compounds in the palm sap-based sugar-sweetened chocolates. The former compound (DDMP) was, however, absent in the sucrose-sweetened dark chocolate. The physicochemical properties of the sugars also had a significant effect on the rheological behaviour of the final chocolates with chocolates formulated with coconut sugar recording the highest Casson viscosity. With regard to fat melting, chocolates sweetened with palm sap-based sugar and sucrose exhibited similar melting range temperature. Palm sap-based sugar nevertheless seems to have great potential for dark chocolate applications with additional health benefits.