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Composite laminate design is an important procedure in defining the mechanical properties of laminated composite structure to be used in multi-directional service loading application. Composite technologies or manufacturers who is lack of knowledge regarding the importance of laminate design, tend to develop a composite structure that will collapse or fail below the service requirement. The purpose of this study is to determine the effect of fiber orientation on flexural properties of the designed glass fiber reinforced epoxy laminated composite. Six sets of laminates with different fiber orientation and sequence were simulated using CompositeStar© software to determine its flexural properties. Samples were fabricated to verify the simulated data and were tested in accordance to ASTM D2344. Moreover, crack pattern within the samples after the flexural test is studied. From the simulated results, it shows that laminates which have fiber in tri-direction and quasi-direction display a higher flexural modulus and strength compared to laminates with fiber in uni-directional and bi-directional. In addition, data from tested fabricated laminates samples displayed the same modulus patterns against the simulated data, with variants from 8% to 35%. Additionally, it is found that samples with fiber in ±45 direction shows a transverse and shear cracking which prolonged the cracking propagation before the samples show a complete failure.

Absorption spectra of different composition of tellurite glasses were analyzed in order to estimate their lasing properties. Composition of the investigated tellurite glasses are: 55TeO2-(43-x)ZnO-2Bi2O3-xEr2O3(x = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mol%). Glasses absorption spectra and density were measured at room temperature using UV-VIS-NIR Spectrophotometer and pycnometer, respectively; while their refractive index were measured by implying Brewster’s angle method. Lasing performance of glasses were then analyzed using Judd-Ofelt theory in order to obtain line strength (S), Judd-Ofelt parameters (Ωt, t = 1, 2, 3), and radiative life-times (τ). It is seen that incorporating Er3+ions of up to 2.5 mol% resulted in decreasing the radiative lifetime of electrons sitting at4I11/2. From Judd-Ofelt parameters analysis it can be concluded that these tellurite glasses tend to have the covalence nature of Er-O bond and thus represents the asymmetry around the Er3+ions site.

Borate glasses with composition 50B2O3 – (25-x) Bi2O3 – 25ZnO – xTiO2 where x = 0, 1, 2, 3, 4 (mol%) were succesfully fabricated using a convensional melt-quenching technique aimed at tailoring glass suitable for a low loss optical fiber fundament. For this purpose, glasses were characterized for their density, refractive index, reflectance, UV-Vis absorption and FTIR spectra. Density measurement was carried out by applying Archimedes principle. Refractive index was measured using Brewster’s angle method. UV-Vis spectrum was recorded within the range of 200-1100 nm and FTIR measurement was measured at IR range. Combining the spectra data recorded both from UV-Vis–NIR and FTIR, the theoretical minimum loss of the glass was obtained. In addition, the band gap energy of the present glasses was also calculated. From these data, it can be derived many other glass properties such as Oxygen Packing Density (OPD), ionic radius, and polaron radius.

Er3+-doped tellurite glasses with chemical compositions (in mol%): 55TeO2-35ZnO-(5+x)PbO-2Bi2O3-(2-x)Na2O-Er2O3 with x = 0; 0.5; 1.0; 1.5 and 2.0) were synthesized and explored their physical and optical properties. Density and refractive index were measured at room temperature and other physical properties such as ionic packing ratio, field strength, polaron radius, internuclear distance and molar refraction were derived. It was found that Na2O substitution by PbO causes both refractive index and glass density increase.

Due to the colloidal silica has many applications such as coating, a catalyst precursor, a nano-size filler, investment casting, semiconductor wafer polishing, and an inorganic binder, it still attracting to be studied. The colloidal silica layer has been coated on a glass substrate using the spray-coating process. Two kinds of colloidal silica were prepared, i.e., the colloidal silica formed by mixing of nano-silica from Balai Besar Keramik (BKK) and the silane hexamethyldisilazane (HMDS), and the colloidal silica polishing Mastermet (0.06 mm) commercial as a comparison. The HMDS percent was varied at 10, 20, and 30 vol.%. The contact angle measurement obtained the hydrophobic properties of the samples, and a UV-Vis spectrophotometer measured the transmittance samples. A water contact angle of 94.9° is achieved at 10% HMDS. For all samples, the transmittance of the before and after coated glass substrate can reach an average of 89% to 90%. From this study, it is concluded that the BBK nano-silica has met the commercial requirements that are the hydrophobic property in the contact angle and the transmittance.

Borotellurite glasses with composition (in mol%): 57B2O3–20TeO2–15Bi2O3–3TiO2–(4-x)Na2O–1Tm2O3-xHo2O3 (where x = 0, 0.5, 1.0, 1.5, 2.0, and 2.5) have been fabricated and characterized aims at studying their density, molar volume and refractive index. Glasses were fabricated by melt quenching method. Density measurements were carried at room temperature using picnometer while their refractive indices were determined by applying Brewster angle method. It is observed that both density and molar volume tend to increase with increasing Ho3+ ions concentration. The density, molar volume as well as refractive index of the reported glass increases from 4.72 to 4.91 g/cm3, 31.80 – 32.18 cm3/mol, 1.4906 to 1.7253, respectively, with increasing holmium oxide (Ho2O3) concentration. Other properties characterized the glasses were also derived, including oxygen packing density, field strength and polaron radius.

This paper presents the optical properties of erbium doped tellurite glasses with the composition of 55TeO2-2Bi2O3-35ZnO-5PbO-(3-x)Na2O-xEr2O3 where x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mol% . Refractive index of the glasses was measured using Brewster’s angle method and their optical absorption spectra were measured in spectral range 200 – 1100 nm recorded at room temperature. The results show that the glass refractive index increases with the increase of Er3+ ion content in the glass and the optical band gap energy decreases with the increase of erbium content in the glass.

This work was carried out as a preliminary study of electrospun LiFePO4/CA fibers. Cellulose acetate (CA) and LiFePO4 solutions were prepared separately using mixed solvent of acetone and water, prior to the electrospinning process. Then, electrospinning parameters including solution concentration, distance tip to collector, pump rate, and needle diameter size were optimized. Brunauer Emmett Teller (BET) was used to determine the surface area of CA fibers. Viscosity of CA solution was obtained by viscometer. LiFePO4/CA fibers were stabilized and carbonized at different temperature. The surface morphology and microstructure of the obtained LiFePO4/ CA fibers were then characterized using scanning electron microscope (SEM). In this work, it is shown that different electrospinning parameter, solution concentration and solution viscosity gives different fibers diameter and distribution. Moreover, the stabilization and carbonization temperature of LiFePO4/CA fibers may also affect the fibers microstructure.

The limited shelf life of carbon prepreg waste (CPW) from component manufacturing restricts its use as a composite reinforcement fibre on its own. However, CPW can be recycled with glass fibre (GF) reinforcement to develop a unique remediate material. Therefore, this study fabricated (1) a glass fibre-carbon prepreg waste reinforced polymer hybrid composite (GF-CPW-PP), (2) a polypropylene composite (PP), (3) a carbon prepreg waste reinforced composite (CPW-PP), and (4) a glass fibre reinforced composite (GF-PP) and reported their degradation and residual tension properties after immersion in water. The polymer hybrid composites were fabricated via extrusion technique with minimum reinforce glass-carbon prepreg waste content of 10 wt%. The immersion test was conducted at room temperature using distilled water. Moisture content and diffusion coefficient (DC) were determined based on water adsorption values recorded at 24-h intervals over a one-week period. The results indicated that GF-PP reinforced composites retained the most moisture post-168 h of immersion. However, hardness and tensile strength were found to decrease with increased water adsorption. Tensile strength was found to be compromised since pores produced during hydrolysis reduced interfacial bonding between glass fibre and prepreg carbon reinforcements and the PP matrix.

Food packaging has seen a growth in the use of materials derived from renewable resources such as poly(lactic acid) (PLA). However, the initial costs to produce bioplastics are typically high. Tropical fruit waste as naturally sourced fibres, such as jackfruit skin, can be used as a cost-reducing filler for PLA. The main objective in this study is to fabricate a low-cost natural fibre-reinforced polymer that potentially applies in packaging with the aid of bleaching treatment. The treatment shows a rougher surface fibre in Scanning electron microscopy (SEM) micrographs and it is expected to have better mechanical locking with the matrix, and this is found similar with a Fourier-transform infrared spectroscopy (FTIR) analysis. Unfortunately, fibre insertion does find low tensile performances, yet bleached-fibre composites improved its performance significantly. A similar situation was found in the thermal characterization where a low-thermal stability natural fibre composite has lower thermal behaviour and this increased with bleaching treatment. Besides, bleached-fibre composites have a longer service period. Besides, a 15 wt% thymol insertion inhibits the growth of Gram-positive bacteria in the composites and the non-treated fibre composite has better thymol effects. The 30 wt% of the bleached-fibre insertion composite has a high potential to reduce the cost of bioplastic products with minimum alterations of overall performances.

When rubber is subjected to a load, deformation will occur. Microscopically, the rubber bond structure is transformed from one equilibrium corresponds to the unloaded rubber that corresponds to the loaded rubber. As with any other transformation process, this process will take time. This paper experimentally demonstrates the relaxation time dependence on the mass of load observed at a constant temperature. The experiment was carried out by inserting the fiber sensor was into a silicon rubber bar. As the rubber bar was loaded, the intensity of light coming out of the fiber decreases exponentially with time. It is shown that the relaxation time increases with the increase of mass loaded on the fiber. By knowing this, the results of the fiber sensor can be adjusted according to the time-based review of rubber deformation.

Two series of tellurite glasses with molar compositions of (55TeO2–2Bi2O3–(41-x) ZnO–2Na2O–xNd2O3 (x = 0.5, 1.0, 1.5, 2.0 and 2.5) and 55TeO2–2Bi2O3–(41-x) ZnO-xNa2O-2Nd2O3 (x = 1.0, 2.0, 3.0, 4.0, 5.0) were fabricated using melt quenching technique. Based on the measured densities, refractive indices and absorption spectra, physical and spectroscopic properties of these two-glass series are evaluated and compared. Whereas substitution of ZnO by Nd2O3 causes the values of density and refractive index increase, the substitution of ZnO by Na2O has been shown to impact the glass density and refractive index in the opposite manner. Molar volume of both series increases with an increase of either Nd2O3 or Na2O concentrations. In this regard, a dynamical model explaining the density and molar volume was proposed. Additionally, Judd-Ofelt theory was applied in order to predict the physical and laser properties of the two glasses series as a function of glass compositions, i.e., Judd-Ofelt parameters Ω t (t = 2, 4, 6), branching ratios (β), calculated lifetimes (τ), the emission to exited state absorption intensity ratio (A em /A ESA ) and spectroscopic quality χ = Ω4/Ω6. Equations to relate χ with branching ratios for laser transitions 4F3/2 to 4IJ’ (with J′ = 9/2, 11/2, 13/2 and 15/2) were also derived.

Glasses with composition (in mol%): 60TeO2-(30-x)ZnO-10PbO-xTiO2 (TZPb:Ti) (where x = 0, 1, 2, 3 and 4) have been fabricated and characterised in order to study their physical and optical properties. Density and refractive index of glasses were measured at room temperature by applying Archimedes’s principle and Brewster’s angle method, respectively. Absorption spectra within range of UV-VIS-NIR were measured at room temperature using UV-VIS Spectrophotometer while those at IR range using FTIR. We have shown that density decreases with the increase of TiO2 while refractive index and optical energy band gap behave conversely.

Modal characterization carried out reported in this paper was aimed determining the refractive index and thickness profile of Ag+/Na+ Ion Exchanged planar waveguides formed in Soda Lime Glass. Modal characterization was carried out using prism coupling technique and applied to all waveguides fabricated at temperature of 240 °C, 260 °C and 280 °C and processed for different duration. It was shown that the number of modes tends to increase with the increase of both temperature and duration of ion exchange process.

This study investigated the effects of water ageing and low-velocity impact loadings on E-glass fibre/epoxy composite pipes subjected to monotonic internal pressure. The pipes, which consisted of six antisymmetric layers with (±55°)3 winding angles, were manufactured by the filament winding process. The specimens were cut from the pipes to the required test length. The specimens were then subjected to the ageing process by being immersed in 80 °C tap water for time intervals of 500, 1000, and 1500 h. Impact loadings of three different energy levels (5 J, 7.5 J, and 10 J) were applied, which were followed by monotonic burst tests. Scanning electron microscopy images were captured and the correlation between the ageing time and the level of impact energy on the pipes' burst strength was identified. The results indicated that the peak force and displacement increased as the impact energy increased. The monotonic burst test results revealed that the specimens that had been aged and were impacted by higher energy yielded lower burst strength. Weepage and eruption failures were observed depending on the applied impact energies. Keywords: Filament winding, GRE composite pipe, Ageing, Impact loading, Monotonic burst test

Transmission structures such as transmission towers or transmission poles were designed to endure multiple combinations of acting force. However, these current structures that were made from concrete and metal are heavyweight materials that cause difficulties in handling during assembly, maintenance and reinstallation purposes. The other problem is vandalism issues on the metallic bracing of the transmission towers. Glass fiber reinforced polymer, (GFRP) is a type of fiber reinforced composites that combine the continuous high strength reinforcing fiber material and lightweight properties of polymeric matrix, thus offers an alternative solution for those problems. In this paper, a laminate design of GFRP samples were simulated using CompositeStar© software to determine the mechanical strength and its reserve factor. The composite panels were varied in term of fiber direction and it was designed to withstand a distributed load of 5 kN service load in longitudinal (x-axis) and transverse (y-axis) direction on samples with thickness range between 4.00 to 4.20 mm. From the simulated results, it shows that the panels with fiber orientation in bi-direction and quasi-direction display a balance strength and acceptable reserve factor in both x-direction and y-direction. Therefore the properties and reserve factors of laminate design simulated from this software can be used as a benchmark in designing a laminated composite.

The effects of winding angle on the behaviour of glass/epoxy composite tubes under multiaxial cyclic loading were investigated. The performance of such composite tubes was studied using an indigenous automated test procedure that is compatible with the internal qualification requirements of the composite pipe manufacturers. Glass fibre reinforced epoxy (GRE) composite pipes with three winding angles, namely, [±45°]4, [±55°]4, and [±63°]4, were tested. A novel automated test rig was fabricated to accommodate five stress ratios, ranging from pure axial to pure hoop loadings. The cyclic pressure test was conducted until droplets of water were seen on the outer surface of the pipe. Failure envelopes were then constructed based on the first ply failure (FPF) points determined from the axial stress to hoop strain response at five stress ratios. Three functional failure modes, namely, tensile axial, weepage, and local leakage failures, were observed during the tests. The results indicate that each winding angle dominates a different optimum pressure loading condition, namely, [±55°]4 for pure hydrostatic loading, [±45°]4 for hoop to axial loading, and [±63°]4 for quad hoop to axial loading. The envelopes show a strong dependence on the stress ratio and winding angle. Keywords: Glass fibre reinforced epoxy (GRE), Ultimate Elastic Wall Stress (UEWS), First ply failure (FPF), Multiaxial stress ratio, Cyclic loading

This study investigates the effect of winding angle on the mechanical properties of kenaf fiber reinforced epoxy composite which is produced by filament winding technique. This study investigates the effect of 45° and 63° angle variations of fiber winding placement fixed by 2 layers using kenaf fiber and glass fiber as raw materials. Mechanical properties of the sample were determined by using tensile test (ASTM D3036), compressive test (ASTM D695) and 3-point flexural bending (ASTM D790). Both mechanical properties of kenaf fiber and glass fiber were compared to determine the possibility of kenaf fiber to replace glass fiber in composite industries in the future. From this study, all result showed that treated kenaf fiber has higher mechanical properties compared to untreated kenaf due to improvement of NaOH treatment on kenaf fiber. Result also has showed that higher winding angle, which is 63° has higher mechanical properties as compared to lower angle placement of 45° of the winding composites.

This paper presents the effect of TiO2 addition on the physical and optical properties of TeO2-ZnO-Na2O glasses. For this study, glasses with the compositions of 63.16TeO2 - (31.57-x) ZnO – 5.26 Na2O – xTiO2 (where x = 1.06, 2.11, 3.16, and 4.22 mol%) were prepared with melt quenching technique. Glasses were characterized in order to obtained glass density, refractive index, and absorption spectra ranging from UV to IR regions. From these basic data, we have evaluated the values of molar volume, oxygen packed density, polaron radius, inter-ionic distance, field strength, and optical band gap. It was observed that incorporating TiO2 into the glasses to substitute ZnO have resulted in decreasing the values of density, inter-ionic distance, and field strength; and yet increasing molar volume, oxygen packed density and polaron radius. The structural units building the glass networks have also been evaluated.

The development of smart-mat as a pressure mapping sensor has received great interest. These sensors have been used for variety of human needs, from medical to smart-house. The main objective of this research is to point out the feasibility and effectivity of mapping fiber sensor subjected to a load given to a certain area to the pressure distribution on the mat surface. The proposed pressure distribution fiber sensor was made by sandwiching partially scratched polymer optical fiber to form a web. Five strands of partially scratched fiber were inserted sandwiched horizontally in a rubber mat and the other six strands were sandwiched vertically. As the mat is loaded, optical fiber sandwiched underneath the load is bent resulting in light attenuation. Analyzing the attenuation light from both sides using matrix method, a contour area representing pressure distribution can be constructive.

− Brewster's angle method is one that commonly used for measuring high index material. This method enables one to measure unlimited range of refractive index. Due to complicated setup of measurement, measurement is commonly carried manually. This paper presents an automatic instrument for measuring Brewster's angle designed using microcontroller unit (MCU) Arduino. Calibration was made by comparing what was measured by this method with that measured using ABBE Refractometer. It was found that both method showed resembling results. The designed instrument is used to measure the value of the refractive index of the Soda-lime planar waveguide, PMMA glass, and Silica glass. From the measurement, it is known that the refractive index value of the three materials are 1.522, 1.463, and 2.055 respectively.

Characterization of soda-lime has been done with aluminum doping on soda-lime glass using an electric-field-assisted solid-state ion exchange method (EFASSiE) to produce an aluminum coating on the glass. EFASSIE is an ion-exchange method that enables the doping of glass surfaces with aluminum ions. The variations used in ion exchange are temperature and electric fields. Variations of temperature start from 400°C until 500°C, increased temperature will cause the ions inside the glass to vibrate and forming a gap, allowed aluminum ions to penetrate into the glass structure. Variations of electric field start from 300-500 V/mm. Electric field that been exposed to the soda lime glass will accelerate the penetration process of the aluminum ion and pushes the smallest ion out of the glass. The results of the soda-lime glass characterization test shows that the greater the value of temperature and electric field used, refractive index of the soda lime after the ion exchange will increase. Otherwise, glass transmittance after ion exchange process has a relatively small compared to the glass before the process. Soda-lime glass Microstructure after the ion exchange process are known from SEM-EDX test, the result proved that alumunium ion penetrate into the soda-lime glass.

Fiber Metal laminates, FML, is a combination of metal with fiber/resin laminates and it is a well-known application in composite laminates due to its dimension stability and properties consistency. Generally, the strength of these laminates systems is much depends on the mechanical interlocking mechanism between the metal surface and the composite laminates. Therefore, surface treatment is needed to enhance the laminates strength. In this research, aluminum plates with different surface roughness were laminated with carbon-fiber/epoxy laminates. The strength of these hybrid systems was then characterized to study the effect of surface roughness on the interfacial strength. It shows that the higher surface roughness will result in better interfacial interaction between the metal surface and the fiber laminates.

Fibre-metal-laminated composites that consist of aluminium and carbon fibre/epoxy was widely use in engineering fields such as in aerospace and civil application. An issue arise for this laminate systems is that aluminium surfaces must be treated to ensure the effectiveness of load transfer mechanism in the interfacial region. In this research, the effect of anodized layer on the aluminium surface towards strength of the carbon fibre-aluminium-laminated composites was studied. Aluminium 6061-T6 was anodized using phosphoric acid as electrolyte and different anodizing voltage to produce different surface morphology. The surface roughness and morphology were determined via Atomic Force Microscopy and its wettability was determined by Static Contact Angle. Then, anodized aluminium was laminated with carbon fibre/epoxy system via vacuum bagging techniques. It shows that the strength of laminated composite with anodized surface increases up to 26% compared to laminates without anodized surfaces. Furthermore, the failure mechanism of laminated composite with anodized surface resulted in partial adhered failure instead of adhesive failure. These show that anodized surfaces contributes to the effectiveness of load transfer mechanism in fibre-metal-laminates composites.

This paper presents the refractive index measurement of tellurite glasses using Brewster angle method. We propose a simple experimental method for finding the refractive index of tellurite glasses material using the polarization of light reflected by a dielectric surface near the Brewster angle. The refractive index of tellurite glasses with the composition of [55 TeO 2 -2Bi 2 O 3 -35ZnO-5PbO-(3-x)Na 2 O-xEr 2 O 3 ] with x = 0, 0.5, 1, 1.5, 2, 2.5, and 3 % mol are 1.85 for the first sample, 1.87 for the second sample, 1.91 for the third sample, 2.01 for the fourth sample, 2.05 for the fifth sample, 1.83 for sixth sample, and 1.67 for the last sample. The refractive index of tellurite glasses is also compared with the calculation of Lorentz-Lorenz equation.

An optical fiber sensor based on evanescent wave absorption designed for measuring glucose solution consentration was proposed. The sensor was made to detect absorbance of various wavelength in the glucose solution. The sensing element was fabricated by side polishing of multimode polymer optical fiber to form a D-shape. The sensing element was immersed in different concentration of glucoce solution. As light propagated through the optical fiber, the evanescent wave interacted with the glucose solution. Light was absorbed by the glucose solution. The larger concentration the glucose solution has, the more the evanescent wave was absorbed in particular wavelenght. Here in this paper, light absorbtion as function of glucose concentration was measured as function of wavelength (the color of LED). We have shown that the proposed sensor can demonstrated an increase of light absorption as function of glucose concentration.

A series of quaternary tellurite glasses of the form of 55TeO2 –2Bi2O3 –[43-x]ZnO–xPbO (TZBP) were prepared by conventional melt quenching method. The amorphous nature of the glasses has been confirmed using XRD, and their tendency against crystallization has been concluded using DSC. Optical properties of the glasses aimed to gain information on the glasses refractive index, range of transparence, and theoretical minimum loss wewe obtained from measurement using Brewster angle measurement, UV-VIS-NIR spectrophotometer and FTIR. It is shown that the index of refraction increases with increasing PbO content. The IR-edge tends to be red-shifted. No clear tendency of UV-edge was observed. The combined results show that the width of the transparency increase slightly with the increase of Pb2+ content in TZBN glasses.

This paper reports the optical properties of the optical planar waveguides in a soda lime glass fabricated by ion exchange. Planar waveguide fabrication was carried out by immersing the soda lime glass in molten 100 % AgNO3 bath for different duration (ranging from 15 minutes to 735 minutes) and at temperature of 280°C. The results show that the surface refractive index values of the ion exchanged glasses are independent of both the ion exchange duration and temperature. The number of modes and the effective diffusion depth, however, increase with increasing the duration of ion exchange process.

Bending in the optical fiber can result in a loss of optical fiber. Bending causes the output light intensity smaller than the intensity of the light source. Bending can be utilized to a sensor based on optical fiber. This paper presents to know the correlation between the optical fiber sensor utilizing bending effect with rubber coil to a circular and an elliptical shape.The principle of this sensor is a detecting change in the output voltage through an optical fiber. The output voltage then converted to transmittance with the program of a computer. The optical fiber is divided into two arms, that is one reference arm and one modulate arm. Fiber bending sensor was made by coiling optical fiber in modulating arm. The displacement loaded to the optical fiber coil in a rubber thread, so that occur of bending. Rubber threaded used to have a 1.0 cm diameter for the circular shape, and 1.1 cm mayor axis and 0.9 cm minor axis for the elliptical shape. Tests are taken from variations in a number of turns, that are 1, 2, 3, and 4 turns and displacement load from 0.0–10.0 mm.The results can be concluded that the loss is greater with the more number of turns. The larger of displacement load has also resulted in the greater loss. The ratio of loss generated to both of the rubber shapes is visible. The circular shape shows that the loss is a very small firstly. But, after the cross section coil turned into an elliptical shape with a minor axis, the loss increased significantly. While for the elliptical shape shows that the loss increased significantly from the first displacement loaded.

A fiber optic sensor is to detect the cholesterol content in blood serum-based biosensor using plastic optical fiber that has been designed. The fiber optic sensor designed with sensing area was a fiber optic grated by 5 scratches then given bending treatment by 5 cm. The first test was by UV-Vis spectrometer with linearity of 0.96. The second test was by light spectrometer with linearity in white LED of 0.94. Optical fiber sensors were made to work well on a range of blood serum concentration of 140 mg/dL to 250 mg/dL.

The cure process and the mechanical properties of liquid polymethylmethacrylate grafted natural rubber (LMG30) modified epoxy have been studied. Addition of LMG30 significantly increased the fracture toughness and the impact strength of the epoxy resin. The fracture toughness increased up to 22 fold (17.3 MNm-3/2) when modified with 5 phr LMG30. The glass transition temperature however, decreases as the rubber content increases. The SEM analysis shows uniform dispersion of rubber particles within the epoxy matrix with average particle size between 0.4 to 0.8 0m in diameter.

This study presents an overview influence of the refractive index parameter to the parameter and radiative properties of analyticaly results on Judd Ofelt tellurite based glass, in the hope of clarifying the importance of education with good refractive index measurement. The main stages carried out is the matching between the result of the parameters and the radiative properties of analytical results on Judd Ofelt tellurite glass with composition 55TeO2-2Bi2O3-(40-x) ZnO-3NA2O-xNd2O3 (x = 2.5) from a value the refractive index is estimated by the value of the refractive index obtained by measurement using Brewster angle method. The results showed that the difference in the Brewster angle ranging from 2o course, will change the value of laser parameters and radiative properties Judd-Ofelt analytical results, with the exception of the Branching Ratio value. Still very much needed insight for learners to use this method. This is an example of a case where educators need to create activities that will facilitate learning well to push the conceptual change. Experiment with new variation of activities will encourage a conceptual change and the ability to analogize concept.Keywords: Refractive Index, Judd-Ofelt, Tellurite, Glass

Fiber optic is a light waveguides media that are cylindrical. Optical fiber has certain properties when it transmits light so it can be developed to be a sensing device or sensor. Evanescent wave phenomena appear when there are total internal reflections from many modes in an optical fiber. In this research, the Biochemical Fiber Sensor (BFS) using polishing cladding and some of the core fiber will be fabricated. BFS is used to interact with a biochemical compound. The principle of BFS is based on evanescent absorption which absorbs the typical spectrum of a biochemical compound. By measuring the spectrum from the light output in the BFS, evanescent absorption spectra can be analyzed an optical fiber. In this study, the biochemical compounds that used are lindane that is one of the Persistent Organic Pollutants (POPs). The result showed that there is a change from BFS spectra when it was exposed by POPs compound with various concentration. That change showed that there is evanescent absorption in BFS. Concentration of POPs compound is proportional with evanescent absorption of the POPs compound.

Theoretical and experimental study of light propagation in acrylic triangle waveguides has been studied theoretically and experimentally aimed to obtain a light cone which can tunnel and bring the light to a certain place. Numerical aperture of light cones which have a length of 7 cm but different cross-section area have been measured using he-Ne laser (λ=632 nm) and the results were compared to those obtained theoretically and no significant different was observed.

Research of optical fiber-based heart rate detection sensor has been conducted using the reflection configurationon the thorax motion modified. Optical fiber used in this research was Plastic Optical Fiber (POF) with a diameter of 0.5. Optical fiber system is made with two pieces of fiber, the first fiber is to serve as a transmitter transmitting light from the source to the reflector membrane, the second fiber serves as a receiver. One of the endsfrom the two fibersis pressed and positioned perpendicular of reflector membrane which is placed on the surface of the chest. The sensor works on the principle of intensity changes captured by the receiver fiber when the reflector membrane gets the vibe from the heart. The light source used is in the form of Light Emitting Diode (LED) and Light Dependent Resistor (LDR) as a light sensor. Variations are performed on the reflector membrane diameter. The light intensity received by the detector increases along with the increasing width of the reflector membrane diameter. The results show that this sensor can detect the harmonic peak at a frequency of 1.5 Hz; 7.5 Hz; 10.5 Hz; and 22.5 Hz in a healthy human heart with an average value of Beat Per Minute (BPM) by 78 times, a prototype sensor that is made can work and function properly.

Optical fiber sandwiched pad designed as a pressure mapping sensor has been configured and characterized. Optical fiber sensor was aligned to form a web-like configuration (x- y matrix). Several fibers were positioned to form lines parallel to y-axis while others are in parallel to x-axis. When a mass with a particular surface contour was loaded on the fiber pad, we have shown the dependence of the magnitude of light attenuation on the mass surface contour. Combining these light attenuation results we have successfully constructed a three dimensional contours showing the pressure distribution given by the mass to the fiber pad.

This paper presents an experimental result on developing an optical fiber sensor for measuring refractive index of sugar solution. Sensor was developed using polymer optical fiber with diameter of 3 mm. This sensor is working based on intensity modulation due to reflection. Light coming out from the transmitter optical fiber is reflected by a mirror to the receiver optical fiber. Due to the variation of sugar concentration in solution surrounding this sensor, the way of light entering the fiber receiver depends on the sugar concentration (numerical aperture). It is clear from the experiment that light intensity detected by photodetector (represented by electric voltage) is linearly dependent (R2 = 0.987) on the variation of sugar solution refractive index.

A reflective optical fiber sensor designed for measuring refractive index and sugar concentration of aqueous solutions is described. Two strains of parallel polymer optical fibers (POF) were wrapped in a bundle such that one of their fiber's end cross-sections had the same distance to the mirror surface. The light coming out from one strain of the fiber was reflected by the mirror to the second fiber. Sugar concentration of the aqueous solution filling the space between the fiber ends and the mirror was varied (1.0 M, 1.5 M, 2.0 M, 2.5 M, 3.0 M, 4.0 M, and 5.0 M). It was shown from the experiment that light intensity detected by photo-detector is linearly related to the percentage of the dissolved sugar in the solution as well as the variation of the sugar solution refractive index (R2 = 0.987).

Physical and optical properties of lead telluride (Pb:TZBN) glasses with composition 55TeO2-(41-x)ZnO-2Bi2O3-2Na2O-xPbO where x = 1.0, 1.5, 2.0, 2.5% mol are presented. UV-VIS-NIR spectra of the glasses in the range of 300 - 800 nm along with their densities and refractive indices at 746 nm were recorded at room temperature. The optical bandgap energy (Eg) has been calculated from the fitting of Tauc plot. On the basis of these results we found that with the increase of Pb2+ content, their refractive indices are increased while their optical bandgaps are decreased. From this experiment, no distinct relationship between the Pb2+ content variation and the electronic polarizability (αO2-) as well as their optical basicity values (A) were observed.

This paper reports the isothermal differential scanning calorimeter (DSC) method used to study the crystallization kinetics of aluminum fluoride glass. The effective activation energy of crystallization (ΔEa/n) was evaluated from the DSC curves using the Johnson‐Mehl‐Avrami equation. The value of the effective activation energy (Ea/n = 113.3 kJ/mol) found from the isothermal DSC curves was slightly higher than that obtained previously with the non‐isothermal DSC method (ΔEc/n = 108.1 kJ/mol). It turns out that both methods can be used in this case.