Guava is a climacteric fruit which has high nutritional content. It is a highly perishable fruit, undergoes rapid postharvest ripening in a few days under ambient condition. This paper aims to determine the effect of palm stearin and palm kernel olein blends on maintaining the quality of guava during storage. Two different coating formulations of palm stearin (PS) and palm kernel olein (PKOo) blends (1:1 and 3:2) were analysed for their slip melting point (SMP), cohesiveness, viscosity and density. Beeswax was used as a commercial coating for comparison whiles the uncoated guava was used as control. These coatings were applied onto guavas by hand-wipe technique using a sponge. Guavas were dried in corrugated fibre board boxes and stored in an air-conditioned room maintained at 20°C while a chiller maintained at 10°C was used for chilled temperature. Coating pick up, thickness and surface area were measured while guava properties were analysed for coating effect on weight loss, O2 and CO2 gases, firmness and glossiness during storage at ambient temperature (20°C) for 21 days and chilled temperature (10ºC) for 30 days. Microstructure analysis was conducted within 2 days of coating at ambient temperature (20ºC). The results obtained indicated that 1:1 PSPKOo blends had higher cohesiveness compared to beeswax. Both PSPKOo blends significantly (p
The effects of flow rate, different pressures and temperatures on cocoa butter extracted from cocoa nib using supercritical carbon dioxide (scCO2) were investigated. The yield was analyzed for total fat content, triacylglycerol (TG) profile, and fatty acid (FA) profile. Extractions were carried out at pressures of 20 and 35 MPa, temperatures of 50 and 60 °C, and CO2 flow rates of 0.5, 1, 2, 4 mL min(-1). The result shows that the yield of cocoa butter extract increased with increasing pressure, temperature, and flow rate and the optimum conditions for the maximum cocoa butter extraction were 35 MPa, 60 °C and 2 mL min(-1), repectively. TGs and FAs were found to be similar in composition to those of cocoa butter obtained by conventional methods. The lower molecular weight TGs and FAs showed higher selectivity compared to higher molecular weight TGs and FAs.
The impact strength of a newly developed experimental polyurethane-based polymer which is derived from palm oil (Experimental PU) was compared with denture polymers; heat-cured and self cured polymethyl methacrylate (PMMA) and ® Eclipse , light-activated urethane dimethacrylate prosthetic resin system. Ten specimens were ® prepared using heat-cured PMMA (Meliodent Heat Cure, Heraeus Kulzer, Germany), self cured PMMA ® (Meliodent Rapid Repair, Heraeus Kulzer, ® Germany), Eclipse baseplate resin (Dentsply, USA) and Experimental PU material. Specimens were prepared following manu- facturer’s instructions except for the Experimental PU material where it was prepared in bulk and sectioned to the desired dimension, 64 x 6 x 4 mm. A ‘V’ notch of approximately 0.8mm in depth was machine cut across the 6mm width. Prior to the Charpy type impact test, specimens were soaked in a water bath for 50 hours at 37ºC. ® Eclipse baseplate resin showed the highest 2 impact strength (2.73 kJ/m ±0.54) followed by ® 2 Meliodent Rapid Repair (2.50kJ/m ±0.65), ® 2 Meliodent Heat Cure (1.96kJ/m ±0.42) and 2 Experimental PU (1.04kJ/m ±0.29). One-way ANOVA showed significant interaction between materials (p
The prevalence of periodontal abscesses in emergency dental clinics was found to be between 8%-14%. The purpose of this study was to study the clinical features of periodontal abscesses seen in a specialist periodontal unit. There were 14 patients with equal distribution of gender. The mean age was 39.6 years. Twelve upper teeth (86%) were found to be involved as compared to two lower teeth (14%). There were more posterior teeth involved, a total of nine teeth (64%) as compared to five anterior teeth (36%). The mean pocket depth associated with the abscesses was found to be 7.4mm. There were ten buccal sites (71%) as compared to four palatal sites (29%). Average temperature of patients was 36.9° C. Only one patient was found to have cervical lympadenopathy (7%). The teeth involved were found to be mostly mobile with mobility of grade I to III (71%).
The paper examines the propagation direction and speed of large scale travelling ionospheric disturbances (LSTIDs) obtained from GPS observations of extreme geomagnetic storms during the 23rd solar cycle; these are the October 2003 and November 2003 geomagnetic storms. In the analysis, the time delay between total electron content (TEC) structures at Scott Base station (SBA) (Lat. –77.85º, Long. 166.76º), McMurdo (McM4), (Lat. –77.84º, Long. 166.95º), Davis (DAV1), (Lat. –68.58º, Long. 77.97º) and Casey station (CAS1) (Lat. –66.28º, Long. 110.52º) GPS stations as well as the distance between these stations were employed in the analysis. The measurements during the October 2003 storm showed obvious time delay between the TEC enhancement occurrences at SBA/MCM4, DAV1 and CAS1 stations. The time delay indicated a movement of the ionospheric structures from higher to lower latitudes in a velocity ranging between 0.8 km/s – 1.2 km/s. The first sudden TEC enhancement was observed at SBA/McM4 (Lat. –75.84º) followed by CAS1 station (Lat. –66.28º) and the final TEC enhancement was seen at DAV1 station (Lat. –68.58º) with TEC magnitude decreasing while moving from higher to lower latitudes. One important observation was that although the latitude of the CAS1 station was lower than the DAV1 station, the TEC enhancement was firstly seen at the CAS1 station due to the shorter distance between SBA and CAS1 compared with the distance between SBA and CAS1 of about 500 km. The TEC measurements during the November 2003 storm showed an opposite propagation direction (i.e. poleward direction from lower to higher latitudes) which was seen with a velocity ranging between 0.3 km/s – 0.4 km/s. As similar response was observed using vertical TEC measurements obtained from individual PRN satellites but with higher velocity ranges (1.2 km/s – 2.4 km/s during October
and 0.5 km/s – 0.7 km/s during November). The equatorward or poleward expansion of LSTIDs during the October and November 2003 storms was probably caused by the disturbances in the neutral temperature which occurred close to the dayside convection throat or due to the neutral wind oscillation induced by atmospheric gravity waves launched from the aurora region.
Objective: A case of caffeine-induced sleep disorder is reported to illustrate the clinical benefits of assessing culturally determined health beliefs in such presentations. Method: A middle-aged Malaysian Chinese male presented with caffeine-induced sleep disturbance arising from dietary modifications. Result: Assessing the contribution of cultural beliefs regarding hot and cold drinks led to successful management of the patient’s sleep disturbance. Conclusion: It is important for clinicians to explore health beliefs and associated dietary and lifestyle behaviours in caffeine-related sleep disorders.
Monodispersed and size-tunable nanocrystalline cobalt (Co) particles in the range of 100 to 400 nm are prepared by the reduction of Co(II) species in propylene glycol. Control of the particle size is achieved by varying the initial Co(II) species concentration and by the addition of nucleating agents. Smaller Co particles are produced with increasing amounts of Co(II) species and in the presence of nucleating agents. X-ray diffraction analysis (XRD) shows that the Co particles are predominantly face-centered cubic crystals of about 8-14 nm. The Co particles are also ferromagnetic at room temperature.
Magnesium-based polymer gel electrolytes consist of magnesium triflate (MgTf) salt, a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) solvents as well as cellulose acetate as a polymeric agent were prepared via direct dissolution method. The highest ionic conductivity obtained for MgTf-EC:DEC(1:1) liquid electrolytes was 2.66 x 10-3 S cm-1 and enhanced to 2.73 x 10-3 S cm-1 with the addition of cellulose acetate. These results were in agreement with the activation energy obtained with the lowest value of 0.11. The best explanation on the enhancement in ionic conductivity of PGE is due to the “breathing polymeric chain model”. The plots of conductivity-temperature shown to obey an Arrhenius rule. The electrical properties of the sample with the highest conductivity were analyzed using electrical permittivity-based frequency and temperature dependence in the range of 100 Hz - 1 MHz and 303-373K, respectively. The variation in dielectric permittivity (εr and εi) as a function of frequency at different temperatures exhibited decays at higher frequencies and a dispersive behavior at low frequencies. Based on the observed electrical properties, it can be inferred that this polymer gel electrolyte could be a promising candidate as an electrolyte in electrochemical devices.
This paper reports an alternative method for making glass-ceramic from disposal waste water
sludge and soda lime silica (SLS) glass. The glass ceramic samples were prepared from a mixture
of wastewater sludge and SLS glasses, melted at 1375°C for 3 hours and quenched by pouring into
water to obtain a coarse frit. The frit glass was then crushed and sieved to 106μm before it was
pressed to a pellet. The sintering process was performed at various temperatures between 700-
1000°C for 2 hours and morphologically characterized with XRD, SEM, and EDX. Overall results
showed the crystalline phase of diopside sodian-critobalite glass-ceramic is depending on thermal
treatment process and making them attractive to industrial uses such as in construction, tiling, and
glass-ceramic applications.
This aim of this research is to investigate thermal stability of virgin coconut oil, (VCO) which was heated at 190°C upon 40 days storage as compared to extra virgin olive oil (EVOO). The changes in fatty acids composition through (GC), Fourier Transform Infrared (FTIR) spectra, iodine value (IV) and total phenolic content were determined throughout the period of study. Results from GC showed that there was significant changes (P
The objective of this research is recovery of squalene from palm fatty acid distillate (PFAD) using supercritical fluid extraction (SFE). The extraction process was performed by using the SFE and recovered squalene was analyzed from total lipid extracts using HPLC. A central composite design was used to study the effect of SFE variables namely pressure (X₁) from 200 to 400 bar and temperature (X₂) from 40 to 60⁰C on the total lipid extracts (Y₁) and squalene concentration (Y₂) and optimize the SFE conditions. The nonlinear regression equations were significantly (p < 0.05) fitted for both responses with high R₂ (> 0.965), which had no indication of lack of fit. The results indicated that a combined pressure (200 bar) and temperature (50⁰C) was predicted to provide the optimum region in terms of total lipid extracts (13.84 ± 0.52%) and squalene concentration (418.31 ± 18.40 ppm) studied.
Cockle (Anadara granosa) meat wash water precipitate was hydrolyzed using bromelain. Experiments were carried out to determine optimum conditions for temperature, enzyme concentration and hydrolysis time using response surface methodology (RSM) based on a central composite rotatable design (CCRD) to obtain the highest value of nitrogen content (NC) and degree of hydrolysis (DH). Results revealed that the optimum conditions for temperature, enzyme concentration and hydrolysis time were 33.7°C, 1.45% (E/S) and 28.42 hrs, respectively. At the optimum condition, hydrolysis of cockle meat wash water precipitate using bromelain resulted in a NC of 0.6% and DH of 48%. The NC and DH were significantly influenced by temperature, enzyme concentration and hydrolysis time. When the bromelain concentration, hydrolysis time and temperature were increased, the values of NC and DH also increased. The hydrolysate produced contained flavor compounds found in clam and oyster which were 3-methylbutanol and 1-pentanol. The compound 3-MCPD was not found in the hydrolysate.
Henna plant (Lawsonia inermis) is an Indian medicinal plant used in traditional medicine for the treatment of various diseases, besides its popularity as a natural dye to colour hand and hair. Research in the recent past has accumulated enormous evidence revealing henna plant to be an excellent source of antioxidants such as total phenolics. In this study, the extraction of total phenolics from henna stems was evaluated using the Folin-Ciocalteu assay. A set of single factor experiments was carried out for identifying the optimum condition of each independent variable affecting total phenolic content (TPC) extraction efficiency of henna stems, namely the solvent type, solvent concentration (v/v, %), extraction time (min) and extraction temperature (oC). Generally, high extraction yield was obtained using aqueous acetone (about 40%) as solvent and the extraction yield could further be increased using a prolonged time of 270 min and a higher incubation temperature of 55°C. Under these optimized conditions, the experimental maximum yield of TPC of 5554.15 ± 73.04 mg GAE/100 g DW was obtained.
Malaysian Borneo has a lower population density and is an area known for its lush rainforests. However, changes in pollutant profiles are expected due to increasing urbanisation and commercial-industrial activities. This study aims to determine the variation of surface O3concentration recorded at seven selected stations in Malaysian Borneo. Hourly surface O3data covering the period 2002 to 2013, obtained from the Malaysian Department of Environment (DOE), were analysed using statistical methods. The results show that the concentrations of O3recorded in Malaysian Borneo during the study period were below the maximum Malaysian Air Quality Standard of 100ppbv. The hourly average and maximum O3concentrations of 31 and 92ppbv reported at Bintulu (S3) respectively were the highest among the O3concentrations recorded at the sampling stations. Further investigation on O3precursors show that sampling sites located near to local petrochemical industrial activities, such as Bintulu (S3) and Miri (S4), have higher NO2/NO ratios (between 3.21 and 5.67) compared to other stations. The normalised O3values recorded at all stations were higher during the weekend compared to weekdays (unlike its precursors) which suggests the influence of O3titration by NO during weekdays. The results also show that there are distinct seasonal variations in O3across Borneo. High surface O3concentrations were usually observed between August and September at all stations with the exception of station S7 on the east coast. Majority of the stations (except S1 and S6) have recorded increasing averaged maximum concentrations of surface O3over the analysed years. Increasing trends of NO2and decreasing trends of NO influence the yearly averaged maximum of O3especially at S3. This study also shows that variations of meteorological factors such as wind speed and direction, humidity and temperature influence the concentration of surface O3.
A 'green tyre' concept has the advantage of low rolling resistance, improved wet grip and enhanced handling. It has been reported that 3% decrease in rolling resistance is equivalent to 1% fuel saving, thus giving the 'green tyre' economic benefits and customer satisfaction. In this study, epoxidised natural rubber (ENR) compounds containing various loading of silica filler were prepared. The processibility and viscoelastic properties were investigated using the rubber processing analyser and Mooney viscometer. Results showed that the properties were adversely affected by the poor dispersion of silica as supported by the bound rubber measurement. In addition, a reversion in the cure behaviour was also observed as the curing temperature was increased to 170ºC.
Since its invention, polyimide (PI) has been widely used in micro-electro-mechanical system (MEMS) devices. For fabrication, the PI membrane, PI-2723 HD-Microsystems was used as the membrane material due to its Young's modulus of 2.7 GPa and its film thickness could easily be controlled by changing the speed of the spin coater system. The application PI as membrane structure on silicon wafers therefore gave a much better mechanical performance then conventional membranes made of silicon dioxide (SiO2) or silicon nitride (Si3N4) layers. The fabrication of PI membrane was the same as for SiO2 and Si3N4 membranes; the basic step was to etch a side of the silicon wafer using wet anisotropic etching. This paper proposes an effective process for fabrication of PI membrane with f ast and little supervision. In this process, a dual step process was wet anisotropic etching of single crystal silicon using pottasium hydroxyl (KOH) with different concentrations and temperature processes. For the first process, 45% KOH under boiling temperature was used to etch at least 90%–95% of the silicon. In the second process, the silicon was submerged in 45% KOH with temperature at 70ºC–80ºC to etch away the residual silicon until a clean and transparent PI membrane was achieved. Using this method, the fabrication of PI membrane could be generated fast.
Solvent flow reactor system was introduced into the extraction system to increase the system efficiency and enhance the extraction yield by adding fresh solvent during the extraction processes. The liquefaction experiment was carried out at various flow-rates (1, 3 and 5 ml/min), reaction times (30, 45 and 60 min) and reaction temperatures (300ºC, 350ºC, 400ºC, 420ºC and 450ºC) with tetralin as solvent. Despite the ability of adding fresh solvent into the extraction process, the conversion of oil+gas was still considered to be low as there was ~25% of coal extracts left to be converted into low molecular weight compounds. One possible option to increase the oil yield is by applying catalyst that will further break up the coal extracts into small molecular weight compounds. In this study, a second reactor was introduced consisting of catalyst (NiSiO2) assuming that the catalyst would interact more effectively with coal extracts rather than the coal itself. In the
absence of catalyst, the oil yield was 55%. By introducing the Ni catalyst, the oil yield increased by 15%. Further analysis of GCMS showed that the oil from catalytic liquefaction gave out more low molecular weight compounds in comparison to the un-catalytic liquefaction oil.
Indicators, whether referred to as ecological, biological or environmental, help us in assessing environmental conditions. Hypothetically, joint influences are predicted of the parameters associated with the number of water-borne, food-borne and vector-borne cases in study areas. Regression analysis of the dependent variables in water—borne diseases such as Cholera, Typhoid, Dysentery and Hepatitis indicated that the total coly°orm, fecal colform, residual chlorine, mean monthly rainfall and temperature influence almost hay of the cases in the 3 District of Serernban. Thus, coordinated monitoring of physical, chemical and biological parameters is needed to continue to build databases and to develop models integrating environnrental and social conditions, consequences and costs.
A study on the effect of the modify values of x in CaCu3-xMn4+xO12 system has been carried out with x = 0.1, 0.3, 0.5, 0.7 and 0.9. The materials were prepared via solid-state reaction. The preparation conditions have been optimized using thermogravimetry analysis (TGA) technique. Material formations under the reported conditions have been confirmed by X-ray diffraction (XRD) studies. The results show that the formation of CaCu3Mn4O12 started at calcinations temperature of 600 0 C with the presence of raw material and was formed completely at 850 0 C. Field emission scanning electron microscopy (FESEM) analysis indicated that the increase of x value in the composition had changed the microstructures to be more faceted. The impedance spectrum is characterized by the appearance of two semicircle arcs whose pattern of evolution changes with rise of values x in the CaCu3-xMn4+xMn4O12 system. Bulk resistance (Rb) and grain boundary resistance (Rgb) of CaCu3- xMn4+xO12 decreases form 824.24 : to 98.68 : and 418.18 : to 2.20 : respectively, with the increasing of x value.
The present investigation deals with the development of ethanol-vapour-sensing materials coated with the semiconducting oxide TiO2. Thick films of anatase TiO2 were deposited using the sol-gel dip-coating technique on alumina substrates by conventional alkoxide sol and modified sol added with Degussa P-25 as the sensing medium. It was shown that crystallised TiO2 anatase was obtained at the annealing temperature of 500oC. The fabricated TiO2 sensors exhibited highest sensitivity at the sensing temperature of 350 ºC. Sensitivity towards the ethanol vapour was further increased with UV light effect. The enhancement of the sensitivity of the modified catalytic pellet can be explained by the crystallite of anatase TiO2 and the effect of the photocatalytic of TiO2. The high sensitivity of the TiO2 film deposited with modified sol revealed that the modified sol could be a new alternative in the development of a TiO2 ethanol sensor.