392 research outputs found
Preparation and characterization of magnetite (Fe3O4) nanoparticles By Sol-Gel method
The magnetite (Fe3O4) nanoparticles were successfully synthesized and annealed under vacuum at different temperature. The Fe3O4 nanoparticles prepared via sol-gel assisted method and annealed at 200-400ºC were characterized by Fourier Transformation Infrared Spectroscopy (FTIR), X-ray Diffraction spectra (XRD), Field Emission Scanning Electron Microscope (FESEM) and Atomic Force Microscopy (AFM). The XRD result indicate the presence of Fe3O4 nanoparticles, and the Scherer`s Formula calculated the mean particles size in range of 2-25 nm. The FESEM result shows that the morphologies of the particles annealed at 400ºC are more spherical and partially agglomerated, while the EDS result indicates the presence of Fe3O4 by showing Fe-O group of elements. AFM analyzed the 3D and roughness of the sample; the Fe3O4 nanoparticles have a minimum diameter of 79.04 nm, which is in agreement with FESEM result. In many cases, the synthesis of Fe3O4 nanoparticles using FeCl3 and FeCl2 has not been achieved, according to some literatures, but this research was able to obtained Fe3O4 nanoparticles base on the characterization results
Preparation of high performance conductive Polyaniline Magnetite (PANI/Fe3O4) nanocomposites by sol-gel method
The conductivities of polyaniline magnetite (PANI/Fe3O4) nanocomposites prepared by sol-gel method were measured by standard van der Pauw DC 4-point probe method. PANI/Fe3O4 conductivity was measured as a function of wt % (5, 10, 15, 20 and 25 wt %) of Fe3O4 nanoparticles. It was observed that the conductivity of polyaniline containing certain percentage of Fe3O4 nanoparticles is slightly lower than the bulk PANI nanotubes and drastically decreases with increase of wt % Fe3O4 nanoparticles. The high conductivities of PANI/ Fe3O4 nanocomposites was observed due to high concentration of dopant (oxidants) used in the polymerization process and the optimization of these composites allows this being use as a parameter for the production of nanofibers. Fourier transform infrared spectra, field emission scanning electron microscope, X-ray diffraction and ultraviolet-visible absorption spectra are used to characterize the phase structure, morphologies and functional group of the PANI/Fe3O4 composites samples. Fourier transform infrared analysis indicates the presence of PANI containing Fe3O4 nanoparticles and the field emission scanning electron microscope (FESEM) results has proven that the formation of nanofibers in the PANI/Fe3O4 nanocomposites. The crystalline phase of PANI/Fe3O4 nanocomposites studied by X-ray diffraction indicated that the Fe3O4 nanoparticles was present in the PANI matrices
Design of Microcontroller-Based Portable Instrument for Measuring P-Wave Speed in Impact-Echo Method
Impact-echo method is widely used for non-destructive testing on concrete evaluation. One of the procedures of this method is determining P-wave speed by measuring travel time of P-wave ( between two transducers. For this purpose, a microcontroller-based portable instrument is developed. This research proposes a PIC microcontroller routine using interrupt-on-change and timer0 features. On concrete, impact waves reach the first accelerometer and will interrupt the main routine and start the timer0. When the waves reach the second accelerometer, the timer0 will be stopped. The value of the timer represents the travel time of P-wave. Therefore, the P-wave speed can be calculated. The routine is verified using controlled signal generated by internal PIC. The accurate result of the travel time measurements is presented. )t
Physicochemical properties of virgin coconut oil extracted from different processing methods
Virgin Coconut Oils (VCO) were prepared from fresh-dry (grated coconut route), chilling and thawing, enzymatic and fermentation method in this study. All of the VCO produced conformed physicochemically to the standards established by the Asian and Pacific Coconut Community (APCC) and Codex Alimentarius Commission. The highest FA (fatty acid) is lauric acid in all of the VCO and ranged from 46.36-48.42 %, while the principal TAG (triacylglycerol) is LaLaLa (La: Lauric) with 17.94-19.83 % of the total TAG. Tocopherol analysis showed the presence of beta, gamma and delta tocopherols at low levels. In all, the physicochemical, FA and TAG analyses of the VCO extracted from different methods showed some significant differences, while the tocopherol content does not differ significantly among the different types of extraction methods used
Quality of life satisfaction among converted Kelantan Chinese Muslims
This article investigates the quality of life of the Kelantan Chinese Muslim community before and after conversion to Islam, focusing on their level of satisfaction in term of economic aspect. This research was carried out using the sequential explanatory mixed method design involving 75 respondents selected for quantitative and five respondents for qualitative. The sampling method adopted was convenience and snowball samplings. The research data was collected using questionnaires and semi-structured interviews. The results revealed that respondents were moderately satisfied before conversion and satisfied after conversion. Besides that, there is no significant difference of quality of life before and after conversion to Islam (F = 0.868, p = 0.355) and it was not influenced by the period of conversion to Islam (F = 0.832, p = 0.589). This analysis indicates numerous respondents are still moderately satisfied in their quality of life even though the average data shows they are satisfied after conversion
Synthesis of bulk FeTe1−xSex (x = 0.1−0.5) at ambient pressure
In this study, polycrystalline samples with nominal composition FeTe1−xSe x (x=0.1−0.5) were synthesized by solid-state reaction method at ambient pressure. In order to minimize oxidation, argon gas flow was maintained throughout the heat treatment. The phase formation of FeTe1−xSe x samples was checked by X-ray diffraction (XRD). The polycrystalline FeTe1−xSe x samples were indexed to a tetragonal structure with space group of P4/nmm. The lattice parameters a- and c-axes shrink significantly with the substitution of Se. As shown by the scanning electron microscope (SEM) images, the samples developed a plate-like grain structure gradually with the increase of Se concentration. Measurements of temperature dependence of magnetic moment showed that the onset of superconducting transition temperature, T c, increased with Se concentration. The T c is about 10.6 and 13.5 K for x= 0.1 and 0.5, respectively. All the samples exhibit ferromagnetic behavior as shown by the field-dependent magnetization measured at room temperature
Gastrointestinal tract morphological alteration by unpleasant physical treatment and modulating role of Lactobacillus in broilers
1. An experiment was conducted to determine the effects of supposedly unpleasant physical treatment on broiler performance, small intestinal development and ameliorating role of probiotics.
2. The following treatments were applied from day one: (1) chicks exposed to normal human contact fed basal diet (control); (2) chicks were exposed to unpleasant physical treatment and fed basal diet (UPT-BD); and (3) chicks were exposed to unpleasant physical treatment and fed basal diet supplemented with Lactobacillus (UPT-BDL). Chicks were exposed to UPT from days 1 to 21. Different segments of gastrointestinal tract were sampled at 14, 28, 35 and 42 d of age.
3. Broilers of UPT-BD had lower feed consumption compared with control group at 7 d of age. Overall, UPT-BDL birds showed higher body weight gain (BWG) and better feed conversion ratio (FCR) over the course of the experiment.
4. Birds of UPT-BD had lower concentrations of lactic, propionic and butyric acids in the caecum as compared with other groups at 14 d of age. Acetic acid concentration was profoundly decreased in both UPT groups compared to the control.
5. Duodenal villus height of UPT-BD broilers showed a slight reduction compared to the control and UPT-BDL birds at 14 d of age. Afterwards until day 42, UPT-BDL birds showed the highest villus height among treatments in different parts of the small intestine.
6. The results suggested that, even though UPT did not have significant inhibitory effects on the development of the small intestine and broiler performance, it negatively affected bacterial metabolic end products in the caecum, which could be ameliorated by the addition of Lactobacillus
Health-related quality of life and survival in liver transplant candidates.
Health-related quality of life (HRQOL) is an important measure of the effects of chronic liver disease in affected patients that helps guide interventions to improve well-being. However, the relationship between HRQOL and survival in liver transplant candidates remains unclear. We examined whether the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the Short Form 36 (SF-36) Health Survey were associated with survival in liver transplant candidates. We administered the SF-36 questionnaire (version 2.0) to patients in the Pulmonary Vascular Complications of Liver Disease study, a multicenter prospective cohort of patients evaluated for liver transplantation in 7 academic centers in the United States between 2003 and 2006. Cox proportional hazards models were used with death as the primary outcome and adjustment for liver transplantation as a time-varying covariate. The mean age of the 252 participants was 54 +/- 10 years, 64% were male, and 94% were white. During the 422 person years of follow-up, 147 patients (58%) were listed, 75 patients (30%) underwent transplantation, 49 patients (19%) died, and 3 patients were lost to follow-up. Lower baseline PCS scores were associated with an increased mortality rate despite adjustments for age, gender, Model for End-Stage Liver Disease score, and liver transplantation (P for the trend = 0.0001). The MCS score was not associated with mortality (P for the trend = 0.53). In conclusion, PCS significantly predicts survival in liver transplant candidates, and interventions directed toward improving the physical status may be helpful in improving outcomes in liver transplant candidates
A two-element planar multiple input multiple output array for ultra-wideband applications
In this article, a planar monopole two-element multiple input multiple output (MIMO) array has been designed and characterized with the intention of ultra-wideband (UWB) applications. The array has a voltage standing wave ratio (VSWR) working bandwidth (BW) of 13.258 GHz between 3.394-16.652 GHz, with a fractional BW (FBW) of 132.28% with respect to a center frequency of 10.023 GHz. The two elements of the MIMO array are 900 polarizations mismatched for better isolation. Consequently, less than 20 dB of isolation has been achieved throughout the entire BW. Also observed was a good combined realized peak gain of up to 5.85 dBi and total efficiency of greater than 85%. For MIMO performance key parameters, the array exhibits the envelope correlation coefficient (ECC) 9.983, total active reflection coefficient (TARC) <0.445, mean effective gain difference (MEG12) ≈0 dB, and the channel capacity loss (CCL) <0.4 bps/Hz. This design would encourage designers to create high-performance MIMO antennas for UWB frequency-related applications
Optimization of drilling process parameters on delamination factor of Jute reinforced unsaturated polyester composite using Box-Behnken design of experiment
This paper presents an investigation on the influence of the drilling parameters such as feed rate, spindle speed and drill tool diameter onto the delamination factor of the jute reinforced unsaturated polyester composite. Natural fibre based composite are mostly used for commodity application and often subjected to drilling during applications and may generate delamination of drilled holes on the workpiece. The composite was fabricated using woven jute fibre via vacuum bagging method followed a high temperature curing using hot press. The fibre was kept at 40 vol. %. The main effect and the interaction between the specified factors of feed rate (20-100mm/min), spindle speed (500-1500 rpm) and drill tool diameter (4-8 mm) with delamination factor as corresponding respond was structured via the Response Surface Methodology (RSM) based on three-level Box-Behnken design of experiment and the ANOVA. The levels of importance of the process parameters on flexural properties are determined by using Analysis of Variance (ANOVA). The optimised drilling process parameters obtained as 24.38 mm/min of feed rate, 1146.14 rpm of spindle speed and 5.51 mm drill tool diameter achieved the most minimal delamination factor. The feed rate and spindle speed were perceived as the most influential drilling parameters on the delamination factor of the jute reinforced unsaturated polyester composite
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