Evaluation of electric and magnetic fields distribution and SAR induced in 3D models of water containers by radiofrequency radiation using FDTD and FEM simulation techniques

In this study, two software packages using different numerical techniques FEKO 6.3 with Finite-Element Method (FEM) and XFDTD 7 with Finite Difference Time Domain Method (FDTD) were used to assess exposure of 3D models of square, rectangular, and pyramidal shaped water containers to electromagnetic waves at 300, 900, and 2400 MHz frequencies. Using the FEM simulation technique, the peak electric field of 25, 4.5, and 2 V/m at 300 MHz and 15.75, 1.5, and 1.75 V/m at 900 MHz were observed in pyramidal, rectangular, and square shaped 3D container models, respectively. The FDTD simulation method confirmed a peak electric field of 12.782, 10.907, and 10.625 V/m at 2400 MHz in the pyramidal, square, and rectangular shaped 3D models, respectively. The study demonstrated an exceptionally high level of electric field in the water in the two identical pyramid shaped 3D models analyzed using the two different simulation techniques. Both FEM and FDTD simulation techniques indicated variations in the distribution of electric, magnetic fields, and specific absorption rate of water stored inside the 3D container models. The study successfully demonstrated that shape and dimensions of 3D models significantly influence the electric and magnetic fields inside packaged materials; thus, specific absorption rates in the stored water vary according to the shape and dimensions of the packaging materials.Comment: 22 pages, 30 figures and 2 table

Business strategy, leadership styles and performance of Takaful firms

Insurance represents an important business segment in the Malaysian economy.In particular, the takaful firms are viewed to play a key role in Malaysian insurance industry.Despite the importance of takaful firms, the literature reveals research on takaful firms remained limited as well as neglected.More specifically, a review of the business literature in Malaysia reveals that very few studies have attempted to determine the relationships between business strategy, leadership styles and performance of takaful firms.This study attempts to address this research issue.The data for the study was collected from 196 Takaful Agency Leaders by using mail questionnaires.Results of the study indicate significant positive relationships between business strategy, leadership styles and performance of the takaful firms

An adaptive threshold feedback compression scheme based on channel quality indicator (CQI) in long term evolution (LTE) system

Channel quality indicator (CQI) feedback in long-term evolution (LTE) system is an essential technique in describing the instantaneous channel state information. The CQI calculations highly depend on the accuracy of the channel estimation process in order to assign appropriate modulation and coding scheme. However, one of the critical issues affecting the LTE system performance is obtaining the CQI for each transmission period which will inevitably cost many resources. Therefore, an appropriate method for reducing CQI feedback overhead along with accurate channel estimation technique is required to manage the allocated resources and obtains significant improvements in system performance. In this paper, an adaptive threshold feedback compression scheme based on CQI scheme is proposed to obtain better system performance in terms of system throughput and error rate in LTE system. This proposed adaptive scheme dynamically adapts its threshold level to the signal to noise ratio variations, thus increasing the throughput and reducing the CQI feedback overhead. Results show that the proposed CQI based adaptive threshold feedback compression scheme enhances the tradeoff between system throughput and block error rate

Assessment on pollutant removal of interconnected wet detention pond

Best Management Practices (BMPs) have been used worldwide to control urban stormwater runoff. The objective of this paper is to assess the urban wet detention ponds on quality control for commercial and residential development in Denai Alam, Selangor, Malaysia. Field monitoring was conducted in this study area. Eight water samples were collected at 8 different locations from upstream to downstream of catchment area. All parameters were tested on-site except for TSS which was conducted at laboratory. The value of turbidity increased due to the occurrence of erosion and the side slope of detention pond. Total suspended solid (TSS) removal efficiency of Pond B is between 13 - 24%. However, this pond did not perform well in removing total phosphorus (TP) and ammonia nitrogen (NH -N) due to low concentration of dissolved oxygen. It is indicated3that the water samples is classified under Class III of Department of Environment (DOE) Water Quality Classification which further treatment is required. Maintaining the detention pond could reduce pollutant loadings to meet targeted requirements of water quality improvement

The relationship between environmental abundant electromagnetic fields and packaging shape to their effects on the 17O NMR and Raman spectra of H2O-NaCl

In this study, two identical groups of four containers with different packaging shapes made of polymethyl methacrylate (PMMA) were used to store H 2 O–NaCl solution for seven days at ambient room temperature (25°C). Faraday shield was used to shield one group. The surrounding electromagnetic fields were measured during the storage period by using R&S®TS-EMF EMF measurement system. Samples of H 2 O–NaCl were collected at the end of the storage period and examined by 17 Oxygene nuclear magnetic resonance spectroscopy ( 17 O NMR) and Raman spectroscopy. Electromagnetic simulation was used to explore the relationship between the packaging shape of H 2 O–NaCl containers and the environmentally abundant electromagnetic fields to their effects on the cluster size of water. The study showed variations in the cluster size of water stored inside the two groups of containers. It was observed that the cluster size of water stored in the unshielded containers was lower than that of the shielded containers. The cluster size of water stored in the unshielded pyramidal container was lower than the cluster size of water stored in the unshielded rectangular, square, and cylindrical containers. The EM simulation results showed significant variations in the total specific absorption rate SAR and maximum point SAR values induced in the H 2 O–NaCl solution in the unshielded container models at 2400MHz for both vertical and horizontal polarization. It can be concluded that the variations in the values of SAR induced in H 2 O–NaCl solution are directly related to the variations in the cluster size of the stored water

Packaging shape and its relationship to the quality of drinking water

The necessity of an effective packaging technique is rapidly growing alongside the development of food preservation technologies. Current packaging techniques, such as active packaging and intelligent packaging, in addition to the preservation techniques such as drying, freezing, smoking and chemical preservatives provide great solutions to extend food shelf life. Nevertheless, they have disadvantages related to cost, undesired effects on food and short or long term negative effects on human health, therefore a top priority in food sciences has been the elucidation of alternative, less stringent techniques. Applying the shape effect technique in food packaging combines preservation, packaging and water treatment in one process and is poised to be a safe, low cost, sustainable and innovative packaging solutions in the food industry. Halal production process should be an integrated processes from farm to fork, to produce not only food that is ritually blessed but must be wholesome, healthy, safe, clean, nutritious, quality and not harmful which means Tayyib. Shape effect is the enhanced energy fields generated inside some models of geometrical shapes, such as pyramid shape. This energy come from the interaction between packaging shape, the stored biological material and the surrounded electromagnetic radiation. There are many sources of electromagnetic radiation for example radio and television broadcasting stations, Wi-Fi antennas and mobile phone base stations. Tow electromagnetic simulation techniques FDTD and FEM were used to explain this interaction. What was found is that the peak level of electric and magnetic fields induced in water stored in pyramid-shaped container was higher than the peak level of the fields induced in water stored in the other containers. The effect of these energy fields on the physicochemical and microbiological parameters of water was determined by using the standard methods and on the molecular structure of water by using O-17 NMR. The results showed improvement in the quality of water stored in pyramid shaped container compared to the water stored in the other containers

Collagen binding activity of bacteria isolated from pig and cow small intestine

Bacterial adherence to connective tissue, especially to collagen has been vastly known for their invasive and infectious activities. However, the ability to exploit the unique and specific interactions between bacteria and collagen as a novel approach in detection of placental collagen has never been explored. This study aimed to determine bacteria with binding specificity to placental collagen (Type IV) derived from human and sheep. In order to do this, total bacteria from small intestines of pig and cow were isolated and their ability to bind to Type IV placental collagen (human and sheep) was determined. Interestingly, three bacterial samples; P5, P9 (pig small intestine origin) and B7 (cow small intestine origin) were found to be able to bind strongly to the placental collagen. The bacterial binding to human placental collagen was however, diminished after the bacteria were treated with trypsin, proteinase K (for removal of surface protein) and guanidine hydrochloride (for S-layer removal), suggesting that the interaction of these bacteria to placental collagen was promoted by protein(s) present at the bacterial surface. In addition, significant reduction of placental collagen-binding ability of the bacteria pre-incubated with soluble human placental collagen showed that there is a specific interaction between the bacteria and collagen. P5, P9 and B7 bacteria were found to share 95-97% 16S rRNA sequence similarity to Enterococcus faecalis ZL, Enterococcus hirae ss33b and Enterococcus faecium M3-1, respectively. The results presented here may facilitate future studies in identifying bacterial surface protein(s) responsible for the specific binding of bacteria to collagen and opens new opportunity to utilize the protein(s) for the detection of placental collagen in nutraceutical and food supplements

Review of channel quality indicator estimation schemes for multi-user MIMO in 3GPP LTE/LTE-a systems

Multiple-in multiple-out (MIMO) in long-term evolution (LTE) is an essential factor in achieving high speed data rates and spectral efficiency. The unexpected growth in data rate demand has pushed researchers to extend the benefits of multi-user MIMO. The multi-user MIMO system can take full advantage of channel conditions by employing efficient adjustment techniques for scheduling, and by assigning different modulation and coding rates. However, one of the critical issues affecting this feature is the appropriate estimation of channel quality indicator (CQI) to manage the allocated resources to users. Therefore, an accurate CQI estimation scheme is required for the multi-user MIMO transmission to obtain significant improvements on spectral efficiency. This paper presents overviews of multi-user MIMO in LTE/LTE-advanced systems. The link adaptation, scheduling process, and different factors that affect the reliability of CQI measurements are discussed. State-of-the-art schemes for the post-processing CQI estimation, and the comparisons of various CQI estimation schemes to support multi-user MIMO are also addressed

Gold nanoparticle sensor for the visual detection of pork adulteration in meatball formulation.

We visually identify pork adulteration in beef and chicken meatball preparations using 20 nm gold nanoparticles (GNPs) as colorimetric sensors. Meatball is a popular food in certain Asian and European countries. Verification of pork adulteration in meatball is necessary to meet the Halal and Kosher food standards. Twenty nm GNPs change color from pinkish-red to gray-purple, and their absorption peak at 525 nm is red-shifted by 30–50 nm in 3 mM phosphate buffer saline (PBS). Adsorption of single-stranded DNA protects the particles against salt-induced aggregation. Mixing and annealing of a 25-nucleotide (nt) single-stranded (ss) DNA probe with denatured DNA of different meatballs differentiated well between perfectly matched and mismatch hybridization at a critical annealing temperature. The probes become available in nonpork DNA containing vials due to mismatches and interact with GNPs to protect them from salt-induced aggregation. Whereas, all the pork containing vials, either in pure and mixed forms, consumed the probes totally by perfect hybridization and turned into grey, indicating aggregation. This is clearly reflected by a well-defined red-shift of the absorption peak and significantly increased absorbance in 550–800 nm regimes. This label-free low-cost assay should find applications in food analysis, genetic screening, and homology studies

RF-DC power conversion of Schottky diode fabricated on AlGaAs/GaAs heterostructure for on-chip rectenna device application in nanosystems

The Schottky diodes enjoined with coplanar waveguides are investigated for applications in on-chip rectenna device applications without insertion of a matching circuit. The design, fabrication, DC characteristics and RF-to-DC conversion of the AlGaAs/GaAs HEMT Schottky diode is presented. The RF signals are well converted by the fabricated Schottky diodes with cut-off frequency up to 25 GHz estimated in direct injection experiments. The outcomes of these results provide conduit for breakthrough designs for ultra-low power on-chip rectenna device technology to be integrated in nanosystems