Eksperimentasi Model Pembelajaran Problem Based Learning (Pbl) Dan Kooperatif Tipe Group Investigation (Gi) Pada Materi Peluang Ditinjau Dari Kemandirian Belajar Siswa

Models on learning achievement viewed from learning style types of the students. The learning models compared were PBL, GI, and classical with scientific approach model. The type of the research was quasi-experimental research with 3x3 factorial design. The population of this research was the students in grade X1 higher Secondary School in Lombok East on academic year of 2014/2015. The size of the sample was 282 students, which was taken by using stratified cluster random sampling technique. The instruments used for data collection were learning style questionnaire and mathematics achievement test. The hypothesis test used unbalance two ways analysis of variance. The results of the research were as follows. (1) the problem based learning model (PBL) and the cooperative learning model of the group investgation (GI) type with scientific approach result in equal learning achievement in mathematics, buth both problem based learning model (PBL) and the cooperative learning model of the group investgation (GI) type give better result in learning achievement in mathematics than the classical with scientific approach. (2) the student with the high, medium, and ow independent learning levels have equal learning achievement. (3) in each of the learning models, the high, medium, and, low independent learning levels, result in the equal learning achievement. (4) in each of the independent learning levels, the problem based learning model (PBL) and the cooperative learning model of the group investgation (GI) type with scientific approach result in equal learning achievement in mathematics, buth both problem based learning model (PBL) and the cooperative learning model of the group investgation (GI) type give better result in learning achievement in mathematics than the classical with scientific approach

Radiation-induced bystander effect in non-irradiated glioblastoma spheroid cells

Radiation-induced bystander effects (RIBEs) are detected in cells that are not irradiated but receive signals from treated cells. The present study explored these bystander effects in a U87MG multicellular tumour spheroid model. A medium transfer technique was employed to induce the bystander effect, and colony formation assay was used to evaluate the effect. Relative changes in expression of BAX, BCL2, JNK and ERK genes were analysed using RT-PCR to investigate the RIBE mechanism. A significant decrease in plating efficiency was observed for both bystander and irradiated cells. The survival fraction was calculated for bystander cells to be 69.48 and for irradiated cells to be 34.68. There was no change in pro-apoptotic BAX relative expression, but anti-apoptotic BCL2 showed downregulation in both irradiated and bystander cells. Pro-apoptotic JNK in bystander samples and ERK in irradiated samples were upregulated. The clonogenic survival data suggests that there was a classic RIBE in U87MG spheroids exposed to 4 Gy of X-rays, using a medium transfer technique. Changes in the expression of pro- and anti-apoptotic genes indicate involvement of both intrinsic apoptotic and MAPK pathways in inducing these effects. © 2015 The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology

New Optic Nerve Sonography Quality Criteria in the Diagnostic Evaluation of Traumatic Brain Injury.

BACKGROUND: New sonographic quality criteria to optimize optic nerve sheath diameter (ONSD) measurements were suggested. The latter were correlated to elevated intracranial pressure (ICP) in traumatic brain injury (TBI). AIM: We investigated whether ONSD measurements were correlated to simultaneous ICP measurements in severe TBI. METHODS: Forty patients with severe TBI (Marshall Scale ≥II and GCS ≤8) participated in the study. All patients had an intraparenchymal ICP catheter inserted, while ONSD was measured bilaterally, upon admission and over the next 48 hours, based on the new sonographic criteria. A total of 400 ONSD measurements were performed, while mean ONSD values of both eyes were used in the analysis. RESULTS: ONSD measurements were strongly correlated to ICP values (r=0.74, p < 0.0001). Receiver operator curve (ROC) analysis revealed that the ONSD cutoff value for predicting elevated ICP was 6.4 mm when using the mean of both eyes (AUC = 0.88, 95% CI = 0.80 to 0.95; sensitivity = 85.3%, specificity = 82.6%). Linear regression analysis nested models revealed that sex (p=0.006) and height (p=0.04) were significant predictors of ONSD values. CONCLUSION: When applying the new sonographic quality criteria, ONSD is strongly correlated to ICP in severe TBI. Whether to use such criteria to monitor ONSD as a proxy for ICP trend in TBI remains to be further explored.Peer Reviewe

Computational Analysis of Heat Recovery From Simple Cycle Gas Turbine Exhaust Stacks Through the Silencer Semi-Circular Sections

The challenge with exhaust heat recovery is that placing additional heat transfer surfaces in the exhaust flow path leads to pressure drop; which lowers the gas turbine (GT) performance. One way to overcome the increase in the pressure drop is to enlarge the exhaust flow path. However, that is associated with similar capital and space constraints as combined cycle (CC) conversion. This paper investigates the potential of integrating heat transfer channels within the existing semi-circular section of the exhaust silencer baffles of simple cycle (SC) gas turbines, in order to avoid such an exhaust flow path enlargement. A heat transfer fluid in the channels absorbs GT exhaust waste heat flow across the silencer. The heated fluid was utilized in the fuel gas pre-heater, leading to reduced fuel gas usage at the same GT output.In this paper, a computational model of the integrated heat exchanger was developed, and compared to an existing mathematical model; showcasing the computational fluid dynamics (CFD) results of the model.After describing the system, the paper describes the computer aided design (CAD) setup of the heat transfer model and flow channel details. The mesh setup and mesh independence study for optimal CFD analysis were conducted. The CFD setup, methodology and results using Ansys Fluent are described.The computational model was successful in estimating the convective heat transfer coefficient, heat exchanger outlet temperatures and flow rates. The proposed system resulted in 2.3 MW heat recovery rate. It was found that while the existing mathematical model over-predicted the heat recovery, the system still provides significant net power gain and reduction in CO2 emissions.The CFD flow visualization allowed for a greater understanding of the exhaust flow parameters enabling the localization of areas with maximized heat transfer coefficient potential. Utilizing this knowledge, areas of improvement for the heat transfer passages were identified; and future work proposed