85 research outputs found

    Quality assessment of ozone-treated citrus fruit juices

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    The aim of the present work was to analyse the impact of ozone treatment on the physicochemical parameters and antioxidant capacity of citrus fruit juices (orange, lemon and lime) with different juice components (total soluble solids). Each sample was ozonated at different ozone treatment time, between 0 to 30 min with fixed ozone concentration of 600 mg/h. The synergistic effects of ozone treatment and the different types of juice were found to significantly affect the pH, total colour difference (TCD), pectin methylesterase (PME) activity, ascorbic acid (AA) and total phenolic content (TPC) of treated juices, while total soluble solids, turbidity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay were found to be unchanged. It was observed that PME activity decreased with treatment time and this is related to the decrease of juice turbidity (R2 = 0.86) and TCD (R2 = 0.78). Ascorbic acid showed an abrupt decrease in all the juices especially in orange juice with percentage loss of 85%. TPC also showed decreasing trend for all juices with maximum loss of 84.4% in lemon juice after 30 min of ozonation time. The present work also found that lemon juice could retain most of its antioxidant activities (DPPH 98.9%, TPC 96%, AA 86.7%) after 10 min of ozone treatment time in comparison to orange and lime juices

    Production of high strength bioliquid from municipal solid waste (MSW) using mixed culture

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    Landfilling is one of the most commonly used methods of municipal solid waste (MSW) disposal. It is necessary because there are residues in all waste management processes that cannot be reused or recovered further and are essentially landfilled. For the degradation of MSW, thermal, mechanical and biological pretreatment techniques are used. MSW could be treated and converted into liquid biomass (bioliquid) by using enzymes. This research focused on the production of high strength bioliquid in MSW. The experiments were conducted in three stages namely: acclimatization process, preliminary study and factorial analysis to determine the production of high strength bioliquid in MSW. The selected factors were ratio of AMC and substrates (1:2 and 1:5), temperature (room temperature and 37 °C), pH (adjusted pH and no pH adjustment), PET plastics size (1cm2 and 4cm2) and Hydraulic Retention Time (3 hours and 9 hours). Design Expert software (Version 7) was used to construct an experimental table where all the factors were randomized. Two-level factorial analysis (TLFA) was used to analyze the most contributing factor and interaction between the factors. The results showed that the most significant factor was temperature, while the interaction factors were between temperature and HRT. The best conditions of COD increment were determined at AMC/S ratio 1:5, adjusted pH, PET plastics size of 1cm x 1cm, at room temperature and HRT of 3 hours. The experimental and targeted final increments of COD were 2.19 and 1.99 respectively. Since the error was less than 10%, it is acceptable, and the objectives of this research were successfully achieved

    Hollow-core photonic crystal fiber refractive index sensor based on modal interference

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    A refractive index sensor based modal interference in hollow core photonic crystal fiber (HCPCF) is proposed and demonstrated. The sensor is realized by splicing both ends of a HCPCF section to single mode fiber (SMF). At both splicing points, the HCPCF air holes are fully collapsed by the arc discharge. The collapsed regions excite and recombine core and cladding modes which formed modal interference for sensing purpose. The HCPCF sensor is tested in sugar solution and the response is measured from the wavelength shift in the interference spectra. The achieved sensitivity and resolution are 36.184 nm/RIU and 5.53-10-4 RIU, respectively, in refractive index range between 1.3330 and 1.3775. Result also shows that the sensor has a small temperature sensitivity of 19 pm/°C in the range of 35.5°C to 60.5 °C. The propos sensor potentially can be applied in biomedical, biological and chemical applications

    Wind characteristics and outdoor thermal comfort assessment in east Malaysia

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    Rapid urbanisation and industrialisation have had an adverse and deep impact on the environment contributing to global warming and climate change. These thermal environmental problems can be even more challenging to people living in regions with warm and humid climatic conditions throughout the year, such as Malaysia. This paper analyses wind characteristics and outdoor thermal comfort index at the hottest temperatures based on data recorded hourly between 2012 and 2014 for two cities in East Malaysia, namely Kuching (Sarawak) and Kota Kinabalu (Sabah). Wind characteristics were analysed using only wind velocity and direction, while the level of outdoor thermal comfort was measured using Universal Thermal Climate Index (UTCI). The results showed that hourly average wind velocities for Kuching and Kota Kinabalu were 1.84 m/s and 2.15 m/s respectively while the highest average wind velocities was 10.1 m/s and 12.4 m/s respectively. No wind movement (i.e. 0 m/s) was recorded for both locations. The prevailing annual wind flow is generally from South-Southeast (150°) in Sarawak and from East-Southeast (110°) in Sabah. It was also found that both Kuching and Kota Kinabalu experienced strong and extreme heat stress conditions with UTCI levels of 44.8°C and 49.8°C respectively. Thus, it can be concluded that, East Malaysia faces strong and extreme heat stress conditions. This study is an original contribution on the subject of outdoor thermal environment in Malaysia, Further research to better understand outdoor thermal environmental problems is recommended

    Molecular Analysis Of Cyp21 Gene In Patients Presenting With Ambiguous Genitalia.

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    Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders of adrenal steroidogenesis

    The benefits and challenges of practicing work-life balance among women entrepreneurs

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    In Today’s Fast Paced Business World, The Ability To Achieve Work Life Balance (WLB) Is Becoming More And More Difficult As People Are Constantly Pushed To Work Faster To Cope With An Increasing Workload. This Paper Presents A Review Of The Challenges And Contribution (Benefit) Of Practice Work – Life Balance. Women Entrepreneurial Success In Their Life And Business Always Being Connected With The Excellent Management Of WLB. An Overview Of The Issues Surrounding Women Entrepreneur Development Draw To The Extension Of More Literature Reviews. Therefore, 34 Articles Have Been Selected And Analysed. There Was Found That Applying Of Work – Life Balance Was Increase Dual Earner For Family Economy And Improving Productivity In The Business. Meanwhile The Main Challenges Of WLB Implementation Among Woman Entrepreneurs Has Always Related To Time Management And Busy Schedule At Work Place. Based On The Issues Identified, Work – Life Balance Strategies Are Proposed To Increased Malaysian Woman Entrepreneurial Potential, Enhance Their Wellbeing In Life And Encourage Them To Part In Business

    Granite Exploration by using Electrical Resistivity Imaging (ERI): A Case Study in Johor

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    Electrical Resistivity Imaging (ERI) is a tool used in near surface geophysical surveys by flowing an electric current through electrodes that were injected into the ground. The usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in geotechnical engineering application owing to the efficiency and effectiveness of the method in term of time, cost and also data coverage. The survey performed with respect to the particular reference to ERI in determining the granite rock underneath the ground. There were seven (7) lines of ERI performed at the study area by using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Six (6) boreholes were also drilled to obtain engineering properties of rock at the study area. In order to develop the relationship between resistivity and engineering properties, a comparison between borehole field test result and the resistivity value were made. Results from the ERT indicated the presence of zones with high resistivity values identified as overburden soil, fractured granite and solid granite. The findings of this study also showed that the electrical resistivity imaging coupled with borehole drillings were applicable tools for the determination of the granite rock underneath the ground via subsurface profiles and such as depth of overburden soil and engineering properties of soil

    Green artificial aggregates as self-curing agent in concrete

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    Improper curing during concreting on site causing low quality of concrete. The concept of self-cured concrete capable to mitigate the process of water evaporation and increase the capacity of water retention in concrete. Thus, the process of hydration occurred continuously and developed dense concrete. This paper presents the potential of green artificial aggregates as self-curing agent for normal strength concrete. In this study, normal granite aggregates were replaced by 10%, 20% and 30% of green artificial aggregates. Two types of curing regime were applied to the concrete specimens which is wet curing and air curing. The effectiveness of the green artificial aggregates as self-curing agent was evaluated in terms of workability, ultrasonic pulse velocity, and compressive strength at 3 and 7 days. The results showed that concrete with green artificial aggregates produced comparable performance with control sample. This shows that the green artificial aggregates have potential to be used as self-curing agent in concrete

    Modelling erosion and landslides induced by farming activities at hilly areas, Cameron Highlands, Malaysia

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    This work was conducted at hilly farms of Cameron Highlands to model the incidences of soil erosion and landslides using historical data and field observations. IfSAR data with spatial resolution of 5 m was used which enable clear observation and delineation of the geographic features within the study area. Field visits were conducted to various places where landslides occurred on agricultural farms in order to validate the model. Also, the rate of soil erosions was evaluated using geospatial techniques. The potential landslide event and its probability of occurrence were combined using bivariate statistical analysis. The results revealed that most of the landslides incidents were occurred at areas with intensive agricultural activities with no proper erosion control measures. It was gathered that more than 75% of landslides occurred in agricultural activities areas are under sheltered farms. The annual soil erosion rates in both Telom and Bertom Catchments ware 38 ton /ha/year and 73.9 ton /ha/year respectively. It was revealed that, there is high risk of erosion-induced landslides in agricultural farms. However, the erosion induced landslide map shows that most the landslide occurred close to the rivers. This indicated that both agricultural operations and proximity to rivers are influencing factors for the incidences

    A systematical characterization of teo2–v2o5 glass system using boron (Iii) oxide and neodymium (iii) oxide substitution: Resistance behaviors against ionizing radiation

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    This study aimed to performan extensive characterization of a 74.75TeO2–0.25V2O5–(25 - x)B2O3-xNd2O3 glass system with (x = 0, 0.5, 1.0, and 1.5 mol%) for radiation shielding properties. Linear and mass attenuation coefficients were determined using Phy-X PSD software and compared with the simulation using Monte Carlo software MCNPX (version 2.7.0). Half value layer, mean free path, tenth value layer, effective atomic number, exposure buildup factor, and energy absorption buildup factors of VTBNd0.0, VTBNd0.5, VTBNd1.0, and VTBNd1.5 glasses were determined, respectively. The results showed that boron (III) oxide and neodymium (III) oxide substitution has an obvious impact on the gamma ray attenuation properties of the studied glasses. It can be concluded that the VTBNd1.5 sample with the highest content of neodymium (III) oxide (1.5 mol%) is the superior sample for shielding of gamma radiation in the investigated energy range. © 2021 by the authors
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