The Effectiveness of Mathematics Worsheet Based on Creative Problem Solving (CPS) for Reasoning Ability of Elementary School Students

This study  aimed to know the effectiveness of creative problem solving (CPS) based mathematics worksheet reviewed by reasoning ability of students’ elementary school. This study used experimental method with Randomized Subject Posttest Only Control Group Design. The samples of this study consisted of two classes namely experimental class (Creative Problem Solving based Mathematics Worksheet) and control class ( conventional method). The taking of sample was conducted by cluster random sampling. Technique of data collecting consisted of cognitive aspect using objective test method and affective aspect using questionnaire. Technique of data analysis applied descriptive and inferential analysis. The hypothesis test used t-test by requirement of normality test and homogeny. The result of study indicated that (1) learning by using creative problem solving (CPS) based mathematics worksheet was implemented well. (2) The implementation of creative problem solving (CPS) based mathematics worksheet was reviewed by aspects: (a) mean score of students’ reasoning was 87,12 categorized as a very good. The gain was 0,78. The students’ reasoning ability classically was 91,25% ≥85%. (b) students’ learning activity was categorized as a good. (c) responds were categorized as a positive. The result of hypothesis test on 0,05 significant using t-test indicated that learning of creative problem solving (CPS) based mathematics worksheet was effective to students’ reasoning of elementary school.

Determining the water damage resistance of nano-clay modified bitumens using the indirect tensile strength and surface free energy methods

Water infiltration into asphalt mixtures is one the serious distresses which lowers the performance of the top layer of road pavements. This problem is even worse in tropical countries which experience high temperature and heavy rainfalls. Therefore, this study aims to evaluate the effects of water infiltration on a 60/70 penetration grade bitumen vis-a-vis bitumen modified with 2 and 4% nano-clay. The Fourier Transform InfraRed (FTIR) test was done to identify any chemical changes that might occur in the nano-clay and the bitumen. The loose and compacted mixtures of the nano-clay modified bitumen were tested to determine their resistance to water damage. The loose mixture was tested by conducting the boiling water, the Vialit adhesion, and surface free energy (SFE) tests, while the compacted mixture was tested using the indirect tensile strength (ITS) test. Aging simulation was done for samples tested using SFE and ITS. The results of the tests show that adding nano-clay alters the mixtures’ ability to resist water damage. The improvement in the samples varies depending on the type of binder as well as its aging stage. Unaged bitumen modified with 2% nano-clay show better ability to resist water damage compared to both the unmodified bitumen and the bitumen modified with 4% nano-clay. However, after being subjected to short-term aging (STA) and long-term aging (LTA), the results of both the ITS and SFE tests show that the addition of 4% nano-clay enhance the bitumen’s resistance to water damage in comparison with the unmodified bitumen and the bitumen modified with 2% nano-clay. The addition of nano-clay reduces water’s effect on the binder, hence indicating the benefit of using nano-clay as an additive to mitigate water effect

Synthesis and characterization of Gd2O2S:Pr3+ nanophosphors using gamma irradiation method

Praseodymium ion, Pr3+ doped Gd2O2S nanophosphors were successfully synthesized via gamma irradiation route along with the heat treatment. The effect of the gamma irradiation (0-150 kGy) on the structural, morphology and photoluminescence properties of Gd2O2S:Pr3+ were characterized via X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and photoluminescence spectroscopy (PL). The thermal properties of precursor sample were tested by the thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The chemical bonding of the precursor samples were analyzed by Fourier transform infrared spectroscopy (FT-IR). The XRD result confirmed the formation of hexagonal phase of Gd2O2S:Pr3+ without the presence of any impurities. The FESEM inspection showed the non-symmetrical shape of particles transformed into grain-like shape. The optimum photoluminescence (PL) emission intensities of Gd2-xO2S:xPr3+ occur at 50 kGy dose of gamma irradiation and 2 mol% concentration dopant of Pr3+ ions. The spectra under 325 nm UV excitation shows a strong green emission at 515 nm, which match the 3P0 → 3H4 transition of Pr3+ ions. The Gd2O2S:Pr3+ nanophosphors possessed many useful approaches in various applications mainly as radiation detection and biomedical diagnostic

Effect of silver nanoparticle addition on the structure and characteristics of radio-photoluminescence glass dosimeter

A series of silver-activated phosphate glass was prepared by melt quenching method. The effect of silver nanoparticle addition on the phosphate glass microstructure, composition and chemical characteristics was investigated using x-ray diffraction, fourier transform infrared and photoluminescence spectroscopy. Other physical property such as density was also evaluated. The density increased when the amount of silver ions were increased, due to the enhanced formation of non-bridging oxygen. In this study, we discuss the emission mechanism of two radio-photoluminescence peaks at 460 nm and 620 nm, where the electrons and holes produced by γ-irradiation a re-trapped by Ag+ ions to produce Ag0 and Ag2+ ions respectively, when the Ag+-doped phosphate glass is exposed to γ-ray. We proposed that an emission mechanism of 460 and 620 nm radio-photoluminescence peaks with these Ag2+ and Ag0 ions. Furthermore, a correlation between the investigated properties and glass composition is discussed

Effect of gamma irradiation on the physical stability of DPPC liposomes

Unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) were prepared by the reverse-phase evaporation method and extrusion through a polycarbonate membrane filter. Liposomes at 0.7 mg/mL lipid concentration in deionized water were exposed to gamma irradiation at a dose in the range 0.5 to 25 kGy. Gamma irradiation of liposomes resulted in the degradation of DPPC lipids into free fatty acids, lysophosphatidylcholine and 1,2-palmitoyl-phosphatidic acid (DPPA). The effect of gamma irradiation towards the physical stability of liposomes was investigated by means of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential analysis. From the DLS analysis, no significant changes were observed in the hydrodynamic size of liposomes. TEM images indicate that the liposomes surface became smoother and rounder as higher irradiation doses were applied. Zeta potential analysis showed that gamma irradiation of DPPC liposomes at radiation doses as low as 0.5 kGy resulted in a drastic rise in the magnitude of the zeta potential. The results also demonstrate that gamma irradiation of liposomes suspension enhanced the overall stability of liposomes. Hence, it can be concluded that gamma irradiation on DPPC liposomes may potentially produce liposomes with higher stability

Penilaian kualiti air bawah tanah di Kelantan dan Pahang, Malaysia

Air bawah tanah yang menjadi sumber kegunaan domestik kepada pengguna memerlukan penilaian air bawah tanah bagi mengelakkan berlakunya isu kesihatan. Kajian ini dijalankan untuk menilai kualiti air telaga tiub dalam aspek kandungan logam berat, bahan radioaktif semula jadi (NORM) dan bakteria patogen di Kelantan dan Pahang, Malaysia. Hasil kajian ini menunjukkan kandungan Fe (90-42100 µg/L) dan Mn (3-478 µg/L) yang diperoleh adalah tinggi dan boleh menjejaskan kualiti air secara keseluruhan. Kandungan NORM yang terkandung dalam air telaga adalah 0.02-0.08 Bq/L bagi jumlah pengaktifan Alpha dan 0.02-0.15 Bq/L bagi jumlah pengaktifan beta, yang berada di bawah paras selamat yang telah ditetapkan oleh WHO. Kandungan NORM dalam sampel tanah adalah dalam julat 401-1348 Bq/kg untuk 40K, 19-175 Bq/kg untuk 232Th dan 28-318 Bq/kg untuk 238U yang boleh diterima di Malaysia. Anggaran dos sinaran tahunan adalah antara 52 µSv/tahun hingga 379 µSv/tahun dan berada dalam julat selamat untuk orang ramai. Kesemua sampel air dari Kelantan dan dua sampel air dari Pahang mengandungi bakteria enteropatogen terutamanya Escherichia coli dan Salmonella sp. yang melebihi piawaian Kualiti Air Kebangsaan. Boleh disimpulkan bahawa kualiti air bawah tanah selamat untuk digunakan semasa kecemasan, tetapi ia perlu dirawat sebelum diminum

Mesoscopic structure and surface behaviour of the tear film lipid layer

The tear film lipid layer (TILL) forms a continuous sheet that extends across the ocular surface from lid to lid. It acts as an effective barrier to water evaporation, decreasing the loss of the aqueous component of tears and aiding in the prevention of tear film breakup. It also provides a smooth optical surface for the cornea and aids in anti-microbial activity. The hypothesised structure of the TILL is a 3D multilayered structure composing of two lipid phases: an amphiphilic (polar) phase one molecule thick adjacent to the aqueous-mucin phase and a thicker overlaying hydrophobic (non-polar) phase intercalated with the aliphatic clIains of the amphiphilic phase. Although the hypothesised structure of the TILL has been extensively studied, there is little evidence that attests ·to the presence of this multilayered structure and resolves the lipid-lipid interactions that are responsible for the finer details ofits organisation. We applied a set of carefully selected techniques borrowed from the arsenal of membrane biophysics to investigate both the surface behaviour and mesoscopic structure of the natural and synthetic TILL systems, and subsequently'comparing the results to another artificial' system mimicking the inner leaflet layer of the red blood cell plasma membrane, that while sharing a significant proportion of their lipid composition, have different properties and serve distinctive biological functions. We demonstrate that the natural TILL and its synthetic replica do form a 3D multilayered structure, although the natural system displayed a much superior efficiency compared to the synthetic replica in forming and deforming this 3D structure. We also demonstrate that cholesterol ester (CE), a hydrophobic component of the TILL, promotes and sustains this 3D formation, providing a synergistic relation between the amphip4ilic and hydrophobic layers. Through fluorescence microscopy imaging, we demonstrated that the natural TFLL and the synthetic replica are separated into two major components (amphiphilic and hydr~phobic). At higher surface pressures, the hydrophobic domains cover the amphiphilic domains, reinforcing the conclusion of a multilayer formation. The natural TILL displays a more organised domain structure than the model system, encouraging us to speculate that these organised domains are similar to lipid rafts in the plasma membrane. Measurements of the TILL viscoelasticity demonstrate that the dilational modulus response is dominant in all the systems probed and is independent of. the oscillation frequency. The dilational modulus is however, dependent on the phase state in which the monolayer is in during oscillation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Microscopic study of AOT and CTAB anionic-rich catanionic phase

Catanionic system using anionic sodium bis-(2ethylhexyl)sulfosuccinate (AOT) and cationic cetyltrimethylammonium bromide (CTAB) is studied. The system is prepared by addition of CTAB solution to a prepared AOT solution until slight anionic-rich catanionic phase is produced. Catanionic system consists of the mixture of different types of surfactants and counterion due to electrostatic interaction between the oppositely charged surfactant. Both of these products affect the in surface activity of the surfactant. Hydrodynamic diameters decrease and clearer solution were seen with the increase of CTAB concentration in solution mixture. As a result, mixed surfactant with larger hydrophobic region and the presence of counterion will induce smaller vesicle to form in catanionic system

Keberkesanan pelaksanaan Sistem Latihan Amali / Industri dalam pengurusan penempatan latihan industri bagi pelajar Pusat Pengajian Fizik Gunaan

Latihan Amali/Industri telah dijalankan sejak sesi 1996/97 pada peringkat fakulti selaras dengan hasrat Universiti Kebangsaan Malaysia (UKM) yang ingin meningkatkan kepelbagaian dalam pengalaman pelajar. Untuk memudahkan pengurusan latihan amali / industri, UKM telah melaksanakan Sistem Latihan Amali / Industri (SLAI) sejak tahun 2011 yang merupakan satu komponen dalam portal Sistem Maklumat Universiti (SMU). Walau bagaimanapun, keberkesanan penggunaan SLAI di Pusat Pengajian Fizik Gunaan (PPFG) belum pernah dikaji sejak dilaksanakan oleh pihak universiti. Objektif kajian ini adalah untuk mengkaji keberkesanan dan penambahbaikan pelaksanaan SLAI dalam pengurusan penempatan latihan industri pelajar PPFG. Soal selidik diberikan kepada 105 responden yang diberikan kepada pelajar PPFG yang telah terlibat dengan latihan industri. Hasil kajian menunjukkan 87.95% bersetuju bahawa sistem SLAI adalah mesra pengguna dan senang diakses dan 65% bersetuju supaya sistem ini terus digunakan bagi proses permohonan penempatan pelajar-pelajar untuk mejalani latihan industri pada masa akan datang. Ini dapat memberi kesan positif terhadap keyakinan dan keberkesanan SLAI yang dibangunkan oleh Pusat Teknologi Maklumat UKM

Synteza polimerów szczepionych nanocząstkami złota z wykorzystaniem promieniowania gamma

The research focused on the synthesis of polytetrafluoroethylene (PTFE) grafted with gold nanoparticles (AuNP). The Turkevich method, one of the common techniques of AuNP synthesis, was used to obtain an AuNP solution with a nanoparticle size of 20 nm. The PTFE-AuNP samples were subsequently irradiated and the absorbed doses were 0.5, 2, 5, 10 and 20 kGy. It was noticed that samples irradiated with 0.5 and 2 kGy were less stable and less concentrated than samples irradiated with higher doses due to aggregation and formation of precipitation after 30 days.W artykule omówiono technikę syntezy poli(tetrafluoroetylenu) (PTFE) szczepionego nanocząstkami złota (AuNP). Metodą Turkevicha, jedną z powszechnie stosowanych technik syntezy AuNP, uzyskano roztwór AuNP o wielkości cząstek 20 nm. Próbki roztworu PTFE-AuNP były następnie naświetlane promieniowaniem gamma; zaabsorbowane dawki promieniowania wyniosły 0,5, 2, 5, 10 oraz 20 kGy. Stwierdzono, że w przypadku dawek 0,5 i 2 kGy roztwór był mniej stabilny, a stężenie nanocząstek było niższe niż w przypadku wyższych dawek. Wiązało się to z agregacją i precypitacją nanocząstek po upływie 30 dni od naświetlania