Quality assessment of ozone-treated citrus fruit juices

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

Potential of sea level rise impact on South China Sea: a preliminary study in Terengganu, Malaysia

The effect of the sea level rise was involved the existence of sea water intrusion and coastal erosion phenomenon in the coastal of Terengganu. This study aim to determine fluctuation of high and low tides of the South China Sea in their relation to water quality value of Marang and Paka Rivers as well as from wells monitoring along the Terengganu Coast. Sampling was carried out twice during high and low tides, first in November 2012 and was repeated in November 2015. For the river quality study, it involves six parameters and involves nine parameters for well survey. Two-way t-test was used under statistical analysis to differentiate between two samplings. The result of the study can be assured that sea level rise resulting in decreased concentration of salinity, EC and TDS from upstream to downstream as a result of qualitatively rise of sea level at Terengganu beach as an impact of global warming events.Keywords: Marang and Paka Rivers; water quality parameter; well water quality; sea level rise; South China Se

Ultrasensitive electrochemical detection of metal ions using dicarboethoxycalixarene-based sensor

In this paper, we have reported an electrochemical detection of metal ions based on Calixarene-based sensor. In the sensing strategy, 3-aminopropylsilane (APTMS) was initially self-assembled on indium tin oxide (ITO) followed by functionalization of dicarboethoxy-calix [4]arene (EtC4). The morphology and properties of electrodes were characterized by contact angle, atomic force microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. The electrochemical response characteristics of the modified electrodes (EtC4/APTMS/ITO) towards analyte ions; Zn(II), Cu(II), and Fe(II) ions were investigated by differential pulse voltammetry (DPV) under optimized conditions. It was found that the response of modified electrode towards the analytes was improved significantly as compared to the ITO electrode and resulted in limit of detections (LOD) of 9.88 pg/L, 8.33 μg/L and 1.15 μg/L, respectively. In addition, the detection limit of simultaneous detection quantification of Cu2 +, Zn2 + and Fe2 + ions could be achieved with the concentration 6.19 ng/L, 3.02 mg/L and 2.79 mg/L, respectively. It is worth to show that dicarboethoxy-calix [4]arene modified electrode is a promising candidate as electrochemical sensors for simultaneous and ultrasensitive heavy metal ions determination

An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

KH. Abdul Karim Djamak: Pendiri dan Peletak Dasar Ajaran Jam'iyyatul Islamiyah 1926-1996

In this journal discusses the journey of Islamic religious figures from Kerinci named KH. Abdul Karim Djamak in spreading the teachings of Islam according to his understanding is based on the Quran and Hadith. But with a background religious knowledge that is considered inadequate makes its teachings viewed deviate from the general or even be said to be misguided by some people. From Abdul Karim Djamak and his followers considered the allegations is a reason used to stop that study they do it because it has disturbed the scholars who are fighting for its influence there. From the results of the research obtained, the teachings taught by Abdul Karim Djamak in his studies is how to combine between the Shari'ah, ma'rifa, tarikat, and enlightenment to his students but not all of them fully understand the level so that his teachings are vulnerable to deviations among his followers. The perverted stigma that has been attached from the beginning. The study led by Abdul Karim Djamak continued until the figure founded a religious organization called Jam'iyyatul Islamiyah which is affiliated with Golkar. Various efforts are made to obtain recognition from the public, including by officially registering the organization, asks guidance to the Indonesian Ulema Council to rectify deviations, to join national figures to join the organization. All efforts are in do not successfully completely eliminate all accusations, even up to the main figure, Abdul Karim Djamak died

A review: methodologies review of magnetic water treatment as green approach of water pipeline system

This review is aimed to present an in-depth review of several methodologies on magnetic water treatment (MWT) that are employed as scale treatment in water pipeline and to critically discuss each method in order to determine the best outcome of MWT. The magnetically assisted water in pipeline in various applications are presented, argued and best variables are listed according to the performance of each MWT. The advantages and limitations of MWT are discussed and the main outcome from the review summarize the best method in MWT, especially in effectiveness of treating scale in terms of sustained environment benefits. Magnetic field application in water treatment has the potential to improve the water pipeline performance and lifetime. The application is also significant in controlling the growth of scale in upcoming system. Both of these benefits lead to healthier water treatment, increasing and maintaining the lifetime and performance of water system

Kinetics and isotherm of cadmium adsorption onto polyethylene microbeads in artificial seawater

This study investigates the interactions between cadmium (Cd) and microplastic under controlled laboratory conditions using low density polyethylene microbeads as model of plastic particles. Cadmium was added to suspensions of artificial seawater to investigate heavy metal adsorption on microbeads surface in five different concentration. Polyethylene microbeads proved to have affinity in providing surface area for cadmium. Microbeads served as an effective sorption surface and concentrated cadmium amount in seawater through adsorption process. The maximum adsorption was monitored for 96 hours. Maximum adsorption capacity determined to be 0.0101 mg/g occurring within 12-48 hours in test concentration. While, kinetic study was performed according to pseudo-first-order kinetic with kd at 0.011 L/g. Using data from pseudo first order, isotherm study was performed in nonlinear regression and dataset was in good agreement with Langmuir, Freundlich and Redlich Petterson with coefficient of determination at 0.865, 0.964 and 0.962 respectively. Adsorption of cadmium to polyethylene microbeads has important implications for the potential role of microplastics, in this case microbeads-cadmium contaminated act as a quantified link in aquatic food webs

Properties of microcrystalline cellulose prepared from oil palm empty fruit bunch at different sulfuric acid concentration and hydrolysis temperature

In this study, a green process was studied for the preparation of microcrystalline cellulose (MCC) from empty fruit bunch (EFB) by two steps of processes: steam explosion treatment and hydrolysis of sulphuric acid (H2SO4). Prior to hydrolysis, the EFB was treated with steam at 17 bar for 10 min. The effects of hydrolysis condition for example H2SO4 concentration were analyzed according to morphology, purities and also percentage of crystal and compared with the commercially available MCC. The higher crystallinity index was observed as the cellulose hydrolyzed with 3.5 M of H2SO4. The yield of MCC prepared was high as by using this condition. However, morphological images by SEM showed insignificant improvement as the synthesized MCC is still in fibres strand and looks like rod-shaped. This result might due to poor treatment process during the steam explosion treatment. The result was confirmed by the FTIR analysis which provided clear evidence that the characteristic peaks of lignin and hemicellulose were present in the spectrum. It can be concluded that the MCC can be produced with the hydrolysis process of 3.5 M and 80 °C

Effect of different bleaching reagents and process sequences on the properties of steam exploded empty fruit bunch (EFB) fiber

Bleaching reagent process is essential for the production of cellulose, pulp and paper to increase the appearance and quality of the final products. Empty fruit bunch (EFB) is an agricultural waste with lignocellulosic constituent. Recently, the conversion of EFB towards pulp for food packaging and paper manufacturing or cellulose based materials has been actively developed in lab and pilot scales. However, obtaining efficient extraction and bleaching processes is still the main challenge. In this paper, effect of different bleaching reagent at different sequences towards the brightness properties of the EFB fiber is observed. The EFB fiber was pre-treated using steam explosion process, hot water treatment, alkaline treatment before undergo the bleaching process. Four systems of bleaching process were set using NaOCl and NaO2Cl as the bleaching reagents. Two sets of the system are using single reagent and the other two sets are using mixed reagent. In the single reagent bleaching system, four stages of bleaching process were used for each NaO2Cl (C) and NaOCl (H) solution respectively. While, the mixed bleaching reagent was conducted with two stages of processes with different sequence of reagents (CH and HC). The bleached cellulose obtained via these two systems were characterized in terms of brightness, chemical composition, thermal characteristic and degree of crystallinity. The mixed bleaching reagent system the HC has produced the best quality of cellulose with brightness at 77.68%. The chemical and thermal characteristic of the bleached pulp fiber does not change when the bleaching method were applied to the fibers. Even though, single bleaching reagent system with sodium chlorite shows almost similar brightness at 78.66%, the quantity of solvent used is higher compared to the mixed bleaching reagent system. As a conclusion, mixed bleaching reagent system is an efficient system to produce better quality of cellulose and paper from EFB