In this paper, a compact planar ultrawideband (UWB) antenna and an antenna array setup for microwave breast imaging are presented. The proposed antenna is constructed with a slotted semicircular-shaped patch and partial trapezoidal ground. It is compact in dimension: 0.30λ × 0.31λ × 0.011λ, where λ is the wavelength of the lowest operating frequency. For design purposes, several parameters are assumed and optimized to achieve better performance. The prototype is applied in the breast imaging scheme over the UWB frequency range 3.10-10.60 GHz. However, the antenna achieves an operating bandwidth of 8.70 GHz (2.30-11.00 GHz) for the reflection coefficient under-10 dB with decent impedance matching, 5.80 dBi of maximum gain with steady radiation pattern. The antenna provides a fidelity factor (FF) of 82% and 81% for face-to-face and side-by-side setups, respectively, which specifies the directionality and minor variation of the received pulses. The antenna is fabricated and measured to evaluate the antenna characteristics. A 16-antenna array-based configuration is considered to measure the backscattering signal of the breast phantom where one antenna acts as transmitter, and 15 of them receive the scattered signals. The data is taken in both the configuration of the phantom with and without the tumor inside. Later, the Iteratively Corrected Delay and Sum (IC-DAS) image reconstructed algorithm was used to identify the tumor in the breast phantom. Finally, the reconstructed images from the analysis and processing of the backscattering signal by the algorithm are illustrated to verify the imaging performance.
Objective: To evaluate feasibility of hand gloves as a rubber dam isolation alternative, in respect of physical properties. Materials and Methods: A randomized controlled trial study design was used. Three types of gloves were tested with two types of a rubber dam used as the control group. Cut-out pattern of dumb-bell shapes were made from 35 samples for each type of groups and tensile strength were tested using Universal Testing Machine and the Trapezium X software. All tests for physical requirements were performed in accord-ance with American Society for Testing and Materials D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic Rubbers and Thermoplastic Elastomers-Tension. Findings were analyzed by analysis of vari-ance (ANOVA) and differences were compared using a Tukey-Kramer interval calculated at the 0.05 signifi-cance level. Results: Heavy gauge rubber dam has the highest Mean (calculated at the 0.05 significance level) except for maximum stress calculated at entire area. Medium-gauge rubber dam has significantly higher tensile strength (44.5075 N/mm2) when compared to heavy-gauge rubber dam (35.7787 N/mm2) although it was 0.09mm thinner. Discovery 2020 Powder Free Latex Examination Gloves with tensile strength value of 28.5922 N/mm2 (±3.27366) is more than the minimum requirement specified by American Federal Specification ZZ-R90B Rubber Dam (Dental, 1985) (4000 pounds per square inch or 27.6 N/mm2). For all variable tested, all groups are significantly different from each other. The mean square between the groups was quite large. Conclusion: This study shows that there are significant differences between the physical strength of latex gloves when com-pared to rubber dam. However, the comparison between thickness and tensile strength among various rubber dam, did not correspond proportionately. Only one type of rubber gloves met the minimum requirement but that is just one aspect. In view of these mixed results, more research is needed before we can conclude that it is feasable that we use hand gloves to replace rubber dam.
Objectives: To assess the prevalence of handedness and its impact on the perceived difficulty in clinical training amongst undergraduate dental students in Malaysia. Materials and Methods: A cross-sectional survey using a self-administered questionnaire was conducted in 5 dental schools around the Klang Valley. Samples consisted of year 4 and year 5 clinical undergraduate dental students. Information on the socio-demographic data, the determination of handedness and assesment of perceived difficulty in carrying out certain clinical procedures were collected. Results: A total sample of 347 participants of which 76.9% were females was obtained. The distribution of year 4 and year 5 students in the sample were equal. Eighty five percent of the samples were right-handed, 9.5% were ambidextrous and 5.5% were left-handed. Statistically significant difference was found between handedness groups for the combined clinical procedures variable: F (2.100), P
Objectives: To assess and compare the oral health-related quality of life (OHRQoL) of orthodontic patients who had and had not undergone micro-osteoperforations (MOPs) during orthodontic space closure. Methods: 27 orthodontic patients with fixed appliance who are undergoing orthodontic space closure with Niti coil springs were given the validated short version of the Oral Health Impact Profile (Malaysia) Questionnaire (S-OHIP) which was available in both Bahasa Melayu and English, containing 14 items. 17 patients underwent MOPs (MOP group) while 10 patients did not (control). Additive scores (ADD) were calculated by summing the response codes for the 14 items and simple count scores (SC) were calculated by a count of the number of items reported as occurring ‘quite often’ and ‘very often’. Results: A total of 24 patients responded to the questionnaire, with a response rate of 88.9%, and they comprised of 79.2% females and 20.8% males. There is no significant difference in the mean ADD (p = 0.347) and mean SC (p = 0.446) across both groups. Conclusions: The reported oral health-related quality of life is similar for orthodontic patients who did and did not undergo MOPs.
Due to the world's dwindling energy supplies, greater thrust has been placed on the utilization of renewable resources for global succinate production. Exploration of such biotechnological route could be seen as an act of counterbalance to the continued fossil fuel dominance. Malaysia being a tropical country stands out among many other nations for its plenty of resources in the form of lignocellulosic biomass. To date, oil palm frond (OPF) contributes to the largest fraction of agricultural residues in Malaysia, while kenaf, a newly introduced fiber crop with relatively high growth rate, holds great potential for developing sustainable succinate production, apart from OPF. Utilization of non-food, inexhaustible, and low-cost derived biomass in the form of OPF and kenaf for bio-based succinate production remains largely untapped. Owing to the richness of carbohydrates in OPF and kenaf, bio-succinate commercialization using these sources appears as an attractive proposition for future sustainable developments. The aim of this paper was to review some research efforts in developing a biorefinery system based on OPF and kenaf as processing inputs. It presents the importance of the current progress in bio-succinate commercialization, in addition to describing the potential use of different succinate production hosts and various pretreatments-saccharifications under development for OPF and kenaf. Evaluations on the feasibility of OPF and kenaf as fermentation substrates are also discussed.
This study employs dynamic panel data for 34 Sub Saharan Africa (SSA) countries for the period 1984-2016 to estimate the effects of renewable energy on environmental quality measured by three indicators, namely, per capita CO2 emissions, energy intensity (EI) and Aggregate National Savings (ANS). The study leveraged a battery of second-generation econometric tests and estimation and causality methods to obtain the coefficients between the regressed and the regressors. Results reveal that use of renewable energy reduces CO2 emissions and energy intensity while it enhances ANS. Economic growth still seems to be expensive for the region as it stimulates CO2 emissions. However, it has a positive effect on ANS. As expected, fossil fuels exacerbate CO2 emissions and energy intensity. FDI is found to be detrimental for the environment of SSA region with its positive significant coefficient on CO2 emissions. Financial development is reported to reduce CO2 emissions. Some causal links between variables are also noted.
Currently, the development of the sodium-ion (Na-ion) batteries as an alternative to lithium-ion batteries has been accelerated to meet the energy demands of large-scale power applications. The difficulty of obtaining suitable electrode materials capable of storing large amount of Na-ion arises from the large radius of Na-ion that restricts its reversible capacity. Herein, Mn2O3 powders are synthesised through the thermal conversion of MnCO3 and reported for the first time as an anode for Na-ion batteries. The phase, morphology and charge/discharge characteristics of Mn2O3 obtained are evaluated systematically. The cubic-like Mn2O3 with particle sizes approximately 1.0-1.5 µm coupled with the formation of Mn2O3 sub-units on its surface create a positive effect on the insertion/deinsertion of Na-ion. Mn2O3 delivers a first discharge capacity of 544 mAh g-1 and retains its capacity by 85% after 200 cycles at 100 mA g-1, demonstrating the excellent cyclability of the Mn2O3 electrode. Therefore, this study provides a significant contribution towards exploring the potential of Mn2O3 as a promising anode in the development of Na-ion batteries.
This study focuses on the potential of electric arc furnace (EAF) steel slag and copper mine tailings as asphalt paving materials with respect to issues of volumetric properties and leaching. In this study, four different asphalt mixes were investigated; each contained EAF steel slag and copper mine tailings of various proportions. Apart from the microstructure analysis of the materials, a toxicity characteristics leaching procedure (TCLP) test was conducted on both the mixes and the aggregates. All the mixes were evaluated by the following parameters: Voids in the mineral aggregates (VMA), voids in total mix (VTM), voids filled with asphalt (VFA), Marshall stability and flow and specific gravity. F-test ANNOVA was used to evaluate the degree of significance of the mixes with each of the evaluated standards. It was observed that the mixes containing either EAF steel slag or copper mine tailings or both gave better results than the control mix. In terms of the TCLP test, none of the detected hazardous elements exceeded the standard limits, which indicates the possibility of using them as construction materials.
An experiment was carried out to investigate the effects of oxalic acid administration on feed intake and nutrient digestibility in goats. Four female cross bred (Boer × local) goats (average body weight of 46.3 kg) were randomly assigned to four experimental diets including oxalic acid administration at levels of 0, 2.25, 4.50 and 6.75 g/animal/d in a 4×4 Latin Square design. Oxalic acid diluted with water was administered orally via syringe to experimental goats once daily for four experimental periods. Each experimental period was lasted 21 d in length, comprising 14 d of adaptation to the experimental diet followed by 7 d of data collection. All the animals were individually fed with Napier grass ad libitum supplemented with 300 g (fresh basis) pelleted compound feed per goat per day throughout the study. Feed composition, feed intake, nutrient intake and nutrient digestibility were determined. Intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and metabolisable energy tended to linearly decrease with the increasing rate of oxalic acid administration, with the value in the 6.75 g oxalic acid/animal/d treatment being significantly (p<0.05) lower than the control (0 g oxalic acid/animal/d) treatment. The oxalic acid administration had no effect on apparent digestibilities of DM, OM, CP and NDF. The experiment demonstrated that oxalic acid administration may influence in the DM and nutrient intakes, but not influence on DM and nutrient digestibilities in goats.
The effects of salinity on the gastric emptying time (GET) and absorption of nutrient along the alimentary tract of tiger
grouper (TG) × giant grouper (GG) (Epinephelus fuscoguttatus × E. lanceolatus) hybrid were studied. Juveniles TG×GG
hybrid grouper (10.0 ± 0.5 cm total length; 50.5 ± 2.0 g) were reared in different salinities (10, 15, 20, 25 and 30 parts per
thousand (ppt)) and fed with commercial pellet diet during the 60-day experimental period. The fish were then slaughtered
sequentially at different time intervals after initial feeding to obtain GET. Our results showed that low salinity (10-20 ppt)
lead to a shorter GET in the hybrid grouper. The shortest and longest GETs were observed in 15 ppt (12 h) and 30 ppt (18
h) treatments, respectively. Apparent digestibility coefficient (ADC) using ash contents was measured to determine the
absorption of nutrient in each treatment. The absorption of macronutrient in TG×GG hybrid grouper was increased as
the salinity decreased. The highest absorption occurred in 15 ppt (72% protein, 75% lipid, 68% carbohydrate and 74%
energy) while the lowest absorption occurred in 30 ppt (59% protein, 64% lipid, 34% carbohydrate and 55% energy).
The findings of this study suggested that 15 ppt salinity facilitates faster digestion and maximize the nutrient absorption
of TG×GG hybrid and may enhance the growth rate of this newly developed grouper species.
In this paper, a defected ground-structured antenna with a stub-slot configuration is proposed for future 5G wireless applications. A simple stub-slot configuration is used in the patch antenna to get the dual band frequency response in the 5G mid-band and the upper unlicensed frequency region. Further, a 2-D double period Electronic band gap (EBG) structure has been implemented as a defect in the metallic ground plane to get a wider impedance bandwidth. The size of the slots and their positions are optimized to get a considerably high impedance bandwidth of 12.49% and 4.49% at a passband frequency of 3.532 GHz and 6.835 GHz, respectively. The simulated and measured realized gain and reflection coefficients are in good agreement for both operating bandwidths. The overall antenna structure size is 33.5 mm × 33.5 mm. The antenna is fabricated and compared with experimental results. The proposed antenna shows a stable radiation pattern and high realized gain with wide impedance bandwidth using the EBG structure, which are necessary for the requirements of IoT applications offered by 5G technology.
An organic compound known as 5-hydroxymethylfurfural (HMF) is formed from reducing sugars in honey and various processed foods in acidic environments when they are heated through the Maillard reaction. In addition to processing, storage conditions affect the formation HMF, and HMF has become a suitable indicator of honey quality. HMF is easily absorbed from food through the gastrointestinal tract and, upon being metabolized into different derivatives, is excreted via urine. In addition to exerting detrimental effects (mutagenic, genotoxic, organotoxic and enzyme inhibitory), HMF, which is converted to a non-excretable, genotoxic compound called 5-sulfoxymethylfurfural, is beneficial to human health by providing antioxidative, anti-allergic, anti-inflammatory, anti-hypoxic, anti-sickling, and anti-hyperuricemic effects. Therefore, HMF is a neo-forming contaminant that draws great attention from scientists. This review compiles updated information regarding HMF formation, detection procedures, mitigation strategies and effects of HMF on honey bees and human health.
It is important to study optimism as it is negatively correlated with anxiety and depressive and positively correlated with quality of life in cancer patients. This study translated and investigated the psychometric properties of the Malay version of the Life Orientation Test-Revised (LOT-R) among Malaysian cancer patients. The validated Malay version of the LOT-R will be used for assessing level of optimism among Malaysian cancer patients in future studies and determine factors associated with it in order to design effective psychosocial intervention which will enhance level of optimism in cancer patients. Concurrent translation and back translation of original English version of the LOT-R to Malay was performed and the Malay version was administered to 195 cancer patients of different cancer diagnoses at baseline assessment and repeated 2 months later at follow up. Reliability was assessed with internal consistency (Cronbach’s α) and test-retest reliability (intraclass correlation coefficient), validity was assessed with face, content, convergent, and discriminant validities. Construct validity was examined with exploratory factor analysis. Two third of the participants (n = 129/195; 66%) were of middle age, three forth were females (n = 142/195; 72.8%) and eight tenth were Malays (n = 160/195; 82.1%). The LOT-R (Malay) total score (Cronbach’s α = 0.58; ICC = 0.62) and its domains (Cronbach’s α [Optimism) = 0.60; Cronbach’s α[Pessimism) = 0.42; ICC[Optimism] = 0.61; ICC[Pessimism] = 0.59) demonstrated questionable internal consistencies but acceptable test-retest reliability. Convergent and discriminant validities were achieved by the LOT-R (Malay). Construct validity was also demonstrated by the LOT-R (Malay) as exploratory factor analysis showed that all the items had factor loadings > 0.4.
The LOT-R (Malay) has acceptable psychometric properties and suitable to assess optimism in Malaysian cancer patients. It should be validated for use in other Malaysian populations.
Introduction The most effective and affordable public health strategy to prevent
hypertension, stroke and renal disease is by reducing daily salt consumption.
Therefore, this study aims to determine the association of knowledge, attitude
and practice on salt diet intake and to identify foods contributing to high
sodium intake.
Methods Secondary data analysis was performed on MySalt 2016 data. It was
conducted from November 2015 until January 2016 which involving Ministry
of Health Staff worked at 16 study sites in Malaysia. Salt intake was
measured using 24 hours urinary sodium excretion. Food frequency
questionnaire was used to determine the sodium sources. Knowledge, attitude
and practice of salt intake were assessed using a validated questionnaire
adapted from WHO. Demographic data and anthropometric measures also
were collected. Sodium levels of more than 2400mg/day was categorised as
high sodium intake. Data were analysed using SPSS software version 21.
Results The mean sodium intake estimated by 24 hours urinary sodium excretion was
2853.23 + 1275.8 mg/day. Food groups namely rice/noodles (33.8%),
sauces/seasoning (20.6%), meat and poultry (12.6%) and fish/seafoods
(9.3%) were the major contributors of dietary sodium. In multiple logistic
regression analysis, being a male (aOR=2.83, 95% CI 2.02 – 3.96) and obese
(aOR=6.78, 95% CI 1.98 – 23.18) were significantly associated with high
urinary sodium excretions. In addition, those who were unsure that high salt
intake can cause hypertension (aOR=1.24, 95% CI 0.65 – 2.36), those who
think that they consumed too much salt (aOR=2.10, 95% CI 1.13 – 3.87) and
those who only use salt rather than other spices for cooking (aOR=2.07, 95%
CI 1.29 – 3.30) were significantly associated with high urinary sodium
excretion.
Conclusions This study showed that the main sources of sodium among Malay healthcare
staff is cooked food. Poor knowledge and practice towards reducing salt
consumption among them contributes to the high sodium consumption. The
practice of healthy eating among them together with continuous awareness
campaign is essential in order to educate them to minimize sodium
consumption and to practice healthy eating.
This study investigates metal removal rate (MRR) of the biomaterial by using discharge machine Neuar CNC A50 Electrical Discharge Machine Die Sinking (EDM DS). The purpose of this study is to compare machining curvature cup for material SKD 11 and stainless steel with shape curvature cup acetabular. The result showed that electrode wear is higher when high current is applied. For each applied current 0.5A and 3.0A could result electrode wear of 0.236 mm, 0.246 mm and 0.269 mm respectively. Mean time of complete discharged for each pit with 0.3mm depth with supply 0. 5A is 6.51 minutes; 1. 5A is 3.54 minutes and 3A is 1.52 minutes. The biggest mean parameter of the pit is 0.356 mm, with 3A of current is applied. From this study, it can be concluded that low current set may give lower electrode copper wear. The experiment will help a researcher to discharge biomaterial types of metal with small size of copper electrode use of EDM DS Neuar for discharge multi hole or micro pit.
Sugarcane juice deteriorates rapidly as enzymatic browning and microbial spoilage take place soon after juice extraction. Therefore, the effects of pasteurization treatment (70ºC for 10 minutes) and addition of calamansi juice at different concentrations (0, 1.0, 1.5, and 3.0%, v/v) on the physicochemical (color, pH, total soluble solid, titratable acidity, and peroxidase enzymatic activity), microbiological (total plate count, yeast and mold), and sensory characteristics of black stem sugarcane juice were investigated. Quantitative descriptive analysis (QDA®) was conducted by eight trained panelists to determine the intensity of the sensory attributes of sugarcane juice, such as brownish color, grassy aroma, citrus aroma, sweetness, sourness, sweet aftertaste, and overall acceptability using a 15 cm unstructured line scale. The results showed that the pasteurization treatment significantly (p ˂ 0.05) increased the L* value (lightness) of sugarcane juice at 0% (v/v) of calamansi juice. Increasing the concentration of calamansi juice decreased the pH value and increased the titratable acidity of the sugarcane juice at 5% significance level. The relative effectiveness in reducing the peroxidase (POD) enzymatic activity and microbial load of sugarcane juice was shown after the addition of calamansi juice and pasteurization treatment, respectively. Significant (p ˂ 0.05) changes in the intensity of brownish color, grassy aroma, and sweet aftertaste of sugarcane juice were observed after the pasteurization treatment at 0% (v/v) calamansi juice; whereas, the addition of calamansi juice at different concentrations increased the intensity of citrus aroma and sourness, but decreased the intensity of grassy aroma and sweet aftertaste of sugarcane juice at 5% significance level. Hence, pasteurization treatment coupled with the addition of 1.5% (v/v) calamansi juice was effective in achieving microbial stability and consumer’s acceptability on sugarcane juice.
This paper examines the temperature profile of a building material and also a
built space. The study directly examines the influence of solar radiation on
building material and the heat it generated and diffuses into the built space.
Two experiments are presented. The first look at a simple technique for
evaluating heat performance of a building material, and the second evaluates
the performance of a cross-ventilated built space with respect to solar radiation.
In this paper, the problem of free convection boundary layer flow on a horizontal circular cylinder in a nanofluid with viscous dissipation and constant wall temperature is investigated. The transformed boundary layer equations are solved numerically using finite difference scheme namely the Keller-box method. Numerical solutions were obtained for the reduced skin friction coefficient, Nusselt number and Sherwood number as well as the velocity and temperature profiles.The features of the flow and heat transfer characteristics for various values of the Brownian motion parameter, thermophoresis parameter, Lewis number and Eckert number were analyzed and discussed.
Liquid natural rubber (LNR) was functionalized into liquid epoxidized natural rubber (LENR) and hydroxylated LNR (LNROH)
via oxidation using a Na2
WO4
/CH3
COOH/H2
O2
catalytic system. Microstructures of LNR and functionalized LNRs
were characterized using Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies. The
effect of CH3
COOH, H2
O2
, Na2
WO4
, reaction time and temperature. reaction time and temperature on epoxy content were
investigated. LNR-OH was obtained when oxidation reaction was conducted at a longer reaction time, higher temperature
or excess amount of catalyst. Thermogravimetric analysis (TGA) reported the thermal behavior of functionalized LNRs.
Molecular weight and polydispersity index (PDI) were determined using gel permeation chromatography (GPC).
The effect of graphene content on the structure and conductivity of an eco-friendly cellulose/ graphene (CG) composite was investigated. Different compositions of graphene content from 0 to 70 wt. % were prepared using the sol-gel method. Ionic liquids 1-butyl-3-methyl-imidazolium chloride was used to disperse graphene between the cellulose. The investigation showed that CG composite with higher graphene composition exhibits higher conductivity. The highest conductivity (2.85×10-4 S cm-1) was observed at 60 wt. % graphene composition. Sample without graphene showed the lowest conductivity of 1.77×10-7 S cm-1, which acts as an insulator. The high conductivity of CG composite can be associated with the X-ray diffraction (XRD) patterns. The XRD patterns of α-cellulose exhibits a decrease in crystallinity at peak 15° and 22° due to the depolymerization in CG composite. At 60 wt. % composition, XRD pattern showed the decrease in intensity at peak 26° indicates that graphene is more dispersed in the cellulose mixture. This is supported by Fourier transform infrared spectrum of CG composite where the absorption peaks of C-O stretching are weakened at wavelength of 1163 and 1032 cm-1, suggested dehydration and rupture of cellulose. The dehydration and rupture of cellulose result in the high conductivity of CG composite. This research is believed to provide an eco-friendly method to produce cellulose/graphene composite which is useful in future applications of energy.