bluuebunny/crossref_metadata_2025 huggingface dataset:
Flood hazard on the Upper Angara river
Authors: Borisova T A , Beshentsev A N
Published: November 2021

The article provides the results of studies on flooding in the rivers of the northern Baikal on the example of the Upper Angara river basin. Some information about the situation with floods and mudflows in the dynamics since 1933 is highlighted. Spatial and temporal patterns of maximum levels, water discharge, duration of high levels, intensity of the water rise have been studied using standard methods of processing hydrological information to assess risks and hazard. On the basis of long-term observation series, expedition surveys we considered classification geohydrological characteristics of floods by genesis of their formation, recurrence of extreme levels, intensity and depth of floodplain inundation. The areas of possible flooding and waterlogging have been determined on the basis of large-scale maps using GIS technologies using ArcGIS. Settlements and infrastructure facilities located in hazardous areas have been identified. Engineering measures to mitigate flood risks in the Upper Angara river have been proposed.
Potential landscape stability of recreational zones on the southern shore of Lake Baikal
Authors: Tsygankova M V , Evstropieva O V
Published: November 2021

The article deals with the landscape stability of five recreational zones on the southern coast of Lake Baikal: Portbaikal’skaya, Kultuk-Slyudyanskaya, Utulik-Baikal’skaya, Murinskaya and Snezhinskaya, the boundaries of which were previously defined during the tourist and recreational zoning of the central ecological zone of the Baikal natural territory between 2017 and 2019. We studied the natural stability of recreational areas on a landscape basis using the results of component-wise assessments of vulnerability and stability. The landscape-typological structure of recreational zones and component-wise stability within the boundaries of specific landscape sections were analysed, the integral stability of landscapes was obtained, and a comparative analysis of the landscape stability of the selected recreational zones has been carried out.
Cluster analysis of border areas in the southern part of Siberia
Authors: Oydup T M , Chupikova S A
Published: November 2021

The purpose of the work is to carry out a comparative analysis of the location of the regions, to determine the location and status of each border region, to identify the constituent entities of the Russian Federation with the similar position and problem situations. The present work solved the problem of multidimensional data classification using the grouping method and cluster analysis. We conducted a comparative analysis of the regions using three criteria: social, economic and territorial. The following indicators were used: for the social criterion – the ratio of average per capita income to the subsistence level; for economic – the level of real fiscal security; for territorial – population density (people/km2). The method of cluster analysis was applied, and a dendrogram was constructed for the border regions of Southern Siberia in order to present the data in a visual form. Determining the status of a region according to three criteria gives an advantage over the traditional types of ranking and groupings from viewpoint of the objectivity of determining the rating position of a region, analysis of current social-economic problems.
Waste management system in Buryatia (Russia) and ways to reorganise it based on the Asian countries’ experience
Authors: Petrov S A , Urbanova Ch B , Beshentsev A N
Published: November 2021

Waste accumulation leads to pollution of atmospheric air, soil, surface water and groundwater. Russian waste management practice is storage in landfills and dumps, and incineration in specialised plants. Today the percentage of recycling is low. In this article we analyse foreign experience of Asian countries on separate waste collection (China). Introduction of information technologies and encouragement of citizens for separate waste collection - a basis of system of the waste management in the People’s Republic of China. The current situation and identified problems in the Republic of Buryatia show the necessity of separate waste collection. We proposed the ways of reorganization of the waste management system, its development directions and also highlighted its socio-economic and environmental effects.
Fatty acid composition and lipid quality indices of bream Abramis brama (Linnaeus, 1758) of Lake Kotokel (Western Transbaikalia)
Authors: Bazarsadueva S V , Radnaeva L D , Nikitina E P , Popov D V
Published: November 2021

This paper describes the study of fatty acid (FA) composition and lipid quality indices of bream Abramis brama (Linnaeus, 1758) from Lake Kotokel (Western Transbaikalia). In the muscle tissues of bream sampled in 2009 and 2019, high levels of polyunsaturated fatty acids (PUFA), including essential docosahexaenoic (DHA), eicosapentaenoic (EPA), and arachidonic acids were measured. Indicators of nutritional quality based on the fatty acid composition showed that the values of the hypocholesterolemic/hypercholesterolemic (HH) ratio indices were sufficiently high. The atherogenicity (AI) and thrombogenicity (TI) indices, which are indicators for the nutritional value, were less than 1 in the studied fish. In terms of flesh-lipid quality (FLQ), bream had the highest proportion of total EPA + DHA. According to the obtained data for the composition of fatty acids in the muscle tissue of the studied fish from Lake Kotokel, the anthropogenic load on Lake Kotokel has not yet had a statistically significant effect on the fish muscle quality.
Biological activity and humus state of soils in the near-adjacent part of the Selenga River
Authors: Korsunova Ts D-Ts , Baldanov N D , Chimitdorzhieva G D , Valova E E
Published: November 2021

Peculiarities of humus formation and manifestation of biological activity of soils are revealed. The objects of research are grey forest nonpodzolized, alluvial meadow soils as arable land, meadow-marsh soils as hayfield. Humus condition of the studied soils is in satisfactory condition within each soil type. The current state of the humus fund of old-arable grey forest soils is characterized by low humus content and unsatisfactory composition, which is caused by the absence of fertility change. The productivity of meadow-marsh soils is high and considerably exceeds grey forest and alluvial meadow soils. The information obtained on biological activity, can be used in agricultural practice to assess soil productivity, as well as in environmental monitoring.
Forest pathology studies of transboundary territories in Asian Russia
Authors: Morozova T I , Egorova I N , Voronin V I
Published: November 2021

A number of cross-border national parks have been established in the border areas of Russia. On the basis of the studies carried out, it is possible to outline a number of current forest pathology challenges facing the national parks. A full picture of sanitary state of the forest can only be obtained by detailed special surveys. It is necessary to organise monitoring of insects and phytopathogenic fungi on permanent touristic routs and model sites. When determining the situation with forest pathology in a vast region, a systematic approach is required. It includes a consistent study of the composition of pathogens, the selection among them of species causing epiphytotics, identification of their biological and ecological characteristics, assessment of the ecological and economic significance, a study of factors that increase the harmfulness. This makes it possible to determine the range of pathogens to be monitored, to identify forest areas with the highest probability of disease outbreak.
Characteristic Analysis and Prevention of Ice Galloping of Transmission Lines Based on Finite Element Method
Authors: Jian Zhou , Li Li , Feng Tao , Guo Jun
Published: November 2021

Ice galloping is one of the disasters that have the greatest impact on the safe operation of transmission lines in winter. This article analyze the characteristics and prevention method of ice galloping of electric grid transmission lines based on finite element method. The amplitude and time response of transmission line during ice galloping can be obtained. A new type of efficient anti-galloping interface spacer is proposed, which can reduce the galloping amplitude. The effectiveness of the proposed method and model is verified by application examples.
Identification of Rotor Crack Faults by Vibration Analysis
Authors: Zhang Xueyan , He Guoan
Published: November 2021

According to the vibration equation of the cracked rotor, the main vibration characteristics of the cracked rotor are summarized. On this basis, combined with the field diagnosis experience, a practical method of identifying the cracked rotor through vibration analysis is proposed. Furthermore, the proposed method is illustrated by three cases of rotor crack fault identification in the operation of steam turbine and boiler primary air fan. Successful diagnosis avoids the occurrence of potential major accidents.
Evaluation on Efficient Crushing Test in Deep Poor Drillability Formation
Authors: Ma Yongqian , Shao Ru , Liu Xiaolan
Published: November 2021

The ancient formation is very thick, strong abrasion and poor drillability. Formation pressure of some area is abnormal high-pressure, induced high mud density, and borehole instability problems in some formation restrict the positive displacement motor (PDM) application, and impact drilling tools are instable. All above factors restraint the rate of penetration. Based on the result of litho-mechanical experiments, the impacting experiments are performed on samples of the Jurassic formation, impact fractured efficiency are evaluated, the results show high impact resistance in the formation, the best impact speed is over 12m/s, and the result was important design basis for impact tools improvement to increase the rate of penetrate (ROP) in the deep poor drillability formation.
Preparation of Graphite Phase Bismuth Carbon Nitride Vanadate Composites and Experimental Analysis of Free Radical Capture
Authors: Wang Wei’e , Wu Bohong , Gao Zhiyang , Lv Yuguang
Published: November 2021

Photocatalysts are mainly divided into two categories: one is that they have good response to sunlight and visible light, such as BiVO4 and Fe2O3; One is that it has its own defects and can not make full use of the energy converted by visible light. In recent years, a class of oxides have attracted much attention because of their good performance of visible light photocatalytic degradation of pollutants. People also have a strong interest in the research of compound oxides in pollutant degradation. In order to further clarify the photocatalytic mechanism of GCB composite samples, different capture agents were added to determine the main active species in the photocatalytic process. Only through the method of modification, the synergistic effect can enhance its photocatalytic activity. 1% g-C3N4/BiVO4(GCB) sample, drhb = 90.4%, the photocatalytic activity did not change significantly after adding IPA. After adding EDTA and VC, the photocatalytic activity decreased, drhb = 32.6% and drhb = 51%. Therefore, the experiments show that h+ and ·O2- are active species of GCB catalytic system, O2 is more important for RHB degradation.
Lipid yields of algae dried in an enhanced solar chimney
Authors: Morris L O , Chu C M , Suali E
Published: November 2021

This work focuses on the lipid yield of algae dried using an enhanced solar chimney dryer with the aim towards high quality biodiesel production and low energy consumption. Jaworski’s medium was chosen for the cultivation in this research project as it can provide enough nutrients to green algae of type Chlorella. Sp. Centrifugation is an effective method to harvest the algae from its medium prior to a drying process. In this project, the methods used for drying were oven drying, open-sun drying and an enhanced solar chimney drying. The moisture content was determined where the average moisture content were 82.5% for oven drying method, 81.6% for open sun drying and 82.2% for solar chimney drying. Methods were found to affect differently the algae properties in terms of the lipid yield and mineral content. The lipid yields were 23.7%, for oven drying, 20.6% for open sun drying and 24.4% for enhanced solar chimney drying. While the oven drying was found to be the fastest way to dry the algae, the solar chimney drying proved best in energy saving while producing the same amount or more algae lipid within reasonable drying times.
Combustion temperature analysis in a fluidized-bed reactor by utilizing palm oil biomass for a renewable energy
Authors: Erdiwansyah  , Mahidin  , Husin Husni , Nasaruddin  , Muhibbuddin  , Faisal M , Muhtadin
Published: November 2021

Biomass from palm oil is a renewable energy source that can be utilized and has very promising availability. Biomass energy is a renewable and sustainable energy that can replace conventional (fossil) fuels. The main objective of the experiment in this article is to analyze the combustion temperature, emissions, and efficiency of palm oil biomass fuel to use and applied in rural/remote areas. The palm oil biomass used in this study is palm kernel shells, empty fruit bunches, oil palm midrib, and oil palm fibers. The experiments in the research carried out in a fluidized-bed combustion chamber designed explicitly with capacities of up to 5 kg of biomass. The results of operations on fluidized-bed when the valve is open 100%, 75%, and 50% with overall palm oil biomass show a high combustion temperature. The highest combustion temperature was recorded in the TC test for 100% open valves with 3 kg biomass of 943°C. While the minimum combustion temperature obtained on TF2 at 50% open valve with 1 kg biomass of 619°C, overall combustion temperatures in this experiment showed high results. The maximum emission for O2 is 20.4% which is obtained at 50% open valve, while for CO2 the maximum emission is produced when 100% open valve is 19.9% with a biomass weight of 1 kg and 3 kg, respectively. The yield for maximum combustion efficiency when using 1 kg of biomass recorded at 50% open valve was 94.9%. While the minimum efficiency of 87.7% is obtained when the valve is 100% open with biomass of 2 kg. As the biomass fuel used in fluidized-bed increases, the combustion temperature also increases significantly.
Microwave-assisted synthesis of photoluminescent carbon dots from palm fronds biomass wastes
Authors: Ang W L , Alqasem Q A , Mohammad A W
Published: November 2021

Oil palm fronds (OPF) is one of the largest biomass sources in Malaysia that has been underutilized. In this work, OPF has been used as a precursor to synthesize carbon dots (CDs) via microwave irradiation method. The impacts of irradiation power and duration and the reacting solution have been investigated. It was discovered that CDs with the highest photoluminescence intensity was obtained at microwave irradiation power of 385 W for 30 s. Irradiation at lower or higher power resulted in incomplete or over carbonization that reduced the fluorescence property. In addition, CDs synthesized with diethylene glycol (DEG) as reacting solution possessed higher photoluminescence intensity as compared to ultrapure water solution. This could be attributed to more complete CDs formation that happened at higher temperature, which could only be achieved by DEG solution (higher boiling point). The CDs were then tested as a sensor for lead (II) ions. The UV-vis absorbance was found to be reduced with the presence of lead (II) ions. This indicated that the lead (II) ions might interact with CDs and disrupted with the absorbance of UV light. Overall, OPF could be a potential precursor for the synthesis of low-cost and easily available CDs for environmental applications.
Hydrogenation of CO2 to methanol using Cu-based catalyst supported on oxide pellets
Authors: Berahim N H , Abu Seman A , Yasin N H , Abd Halim N S , Mohd Zabidi N A
Published: November 2021

Hydrogenation of CO2 into methanol is one of the most economical process to reduce CO2 concentration in the atmosphere. Since methanol is an industrial commodity used in chemical products as well as transportation fuel, this process has gained considerable interest, which enables the effective utilization of CO2. Nevertheless, the efficiency of direct CO2 hydrogenation to produce methanol is strongly reliant on the activity of the catalyst. In this regard, the present work highlights the synthesis of methanol, catalytic evaluation and characterization of catalysts Cu/ZnO supported on Al2O3 and SBA-15 pellets with the addition of group IV, V and VII metal oxides mixture as promoters. The catalysts were systematically prepared via impregnation technique with fixed Cu:Zn and promoter ratio from group VII:V:IV. The synthesized catalysts were characterized by H2-temperature-programmed reduction (H2-TPR), field emission scanning electron microscopy (FESEM), X-ray fluorescence (XRF), N2 adsorption-desorption and N2O pulse chemisorption method. The crushing strength of the pellets were also tested. Catalytic performances were evaluated for methanol synthesis from CO2 hydrogenation in a tubular, stainless steel fixed-bed reactor at 250 °C, 2 MPa, gas hourly space velocity (GHSV) 4000 ml/g.h and H2/CO2 ratio of 3:1. The tri-promoted Cu/ZnO supported on Al2O3 pellet resulted in CO2 conversion of 13.3 % compared to 11.61 % from that of SBA-15-supported catalyst. However, the catalyst supported on SBA-15 pellet exhibited 54.59% methanol selectivity, whereas Al2O3-supported catalyst only resulted in 46.73 % methanol selectivity.
Simulation of ozonolysis of volatile organic compounds: Effect on flue gas composition
Authors: Lim M , Lea-Langton A R
Published: November 2021

This study shows that the reaction of ozone with various volatile organic compounds (VOC) yields different flue gas composition in terms of the carbon dioxide, oxygen and moisture contents. Steam production and thermal output requirements from a combustion system (i.e., a boiler) may dictate the range of operating conditions, such as the air to fuel mass flow rates. To improve the combustion efficiency in these operating conditions, low temperature plasmas have been used to ionize air and generate ozone as an oxidant for ozonolysis with the VOC. Therefore, this study simulates the reaction mechanism of the ozonolysis of VOC and the effect on the flue gas composition, which affects the combustion efficiency. Simulation results show that residual oxygen in the flue gas reduces, reducing the excess air. Thus, the corresponding efficiency loss through dry flue gas would be reduced. Literature data shows that emissions of alkanes, alkynes and alkenes per unit mass of solid fuel is evident for both coal and biomass, and thus ozonolysis of these VOC would reduce the excess air, improving the combustion efficiency.
Continuous desalting concept on ionic liquid-mediated de-acidification process of crude oil: A pilot study
Authors: Hussain A , Basar J
Published: November 2021

Desalting process concept was tested using methyltrimethylammonium methylcarbonate [N4441][MeCO3] treated Pyrenees crude oil (initial Total Acid Number (TAN) of 1.6 mg KOH/g oil) with the aim to gain empirical evidences on the effectiveness of in-line water washing and electrostatic aided phase separation as mean to recover the naphthenic acid derivatives for recycling. The treated crude oil (final TAN value of less than 0.3 mg KOH/g oil) was subjected to typical operating scheme such as single stage desalting and effects of water wash volumes. The novelty of the work comes from the utilisation of ionic liquids to neutralise acid components of the crude oil. Furthermore, the work is also able to test the hypothesis of whether naphthenate salts behave as is its inorganic counterpart and quantify the solubility behaviour in water as extraction medium. The effectiveness of such scheme will be measured against naphthenic acids derivative percent recovery in the wash water. The results indicate the electrostatic conditions can facilitate the recovery of the naphthenate salts post neutralization with high recovery rate of average of 70.6 % with 30 % water wash volume in a single-stage contact, observed over 12 hours steady-state operation. The water wash weight was observed to increase post separation which indicate hydrocarbon carry-over in the heavy phase due to formation of tight water – oil emulsion. The technique is viable should the amount of water required is available and the process water can be recycled safely into the desalter again without causing tripping to the desalter. Ionic liquid can be used in conjunction with desalter and the presence of electrostatic field did hasten the separation of the phases, however the amount of water used may hinder the viability of the solution.
Grease formulation and characterization from waste automotive engine oil with the use of complex thickener
Authors: Rahman N W A , Ying S S Y , Aziz M A A
Published: November 2021

Waste engine oil one of the most abundant wastes in Malaysia, and through the reutilization of waste automotive engine oil helps to create a sustainable environment. The objective of this research is to develop the best formulation of lithium complex grease derived from waste automotive engine oil as base oil. The main focused parameter in this study is the different formulation ratio of base oil, thickener and co-thickener. Lithium 12-hydroxystearate is mixed with azelaic acid to produce lithium complex 12-hydroxystearate. Two different type of base oils, i.e. fresh automotive engine oil (FAO) and waste automotive engine oil (WEO) are used to formulate Li-complex grease. The grease derived from FAO is used to compare the physical properties derived from WEO. The texture of the formulation of base oil higher than 82 weight percentage was very fluid. The formulation of grease is carried out by differencing the ratio of the waste automotive engine oil, lithium complex 12-hydroxystearate and azelaic acid, which are 82:18, 80:20 and 70:30. The properties of the grease formulated is conducted through several tests, such as ASTM approach, Fourier Transform Infrared Spectroscopy (FTIR) characterization, oil separation and thermogravimetric analysis (TGA). Such interesting properties included consistency, chemical compound of the grease, oil separation and thermal stability. Based on the finding, the best formulated Li-complex grease is WG3, classified NLGI 3. The significant peak derived from FAO and WEO to observe is 1710 cm−1 as this peak indicated the oxidation stability. From the result, the intensity of carboxylic acid is weak that ranged 1709 – 1711 cm−1. Hence, this indicated the grease formulated exhibited better oxidation stability. Furthermore, the formulated grease was thermally stable as the onset temperature was 250.09 °C. In conclusion, the formulation of Li-complex from WEO can be used as an alternative source of base oil in the grease industry, due to the good properties exhibition and preserving the environment as well as the increment of fossil fuel’s demand and cost.
The impact of the mulberry (Morus nigra L.) leaf extract on the physicochemical properties of poly(vinyl alcohol) blend films
Authors: Rafflisman N S , Mah S K , Lee S Y , Yee K S P , Chowdhury S
Published: November 2021

In this work, mulberry (Morus nigra L.) leaf extract was added in poly(vinyl alcohol) (PVA)-based films and its impact on the film’s properties was evaluated. In addition, HCl and glycerol were studied for their use as additives to prepare PVA-based films. The results showed that HCl and glycerol have minimal impacts on the films’ appearance, while mulberry leaf extract imparted green colour to the films produced, mainly due to the presence of green pigments. Moreover, the results suggested that a significant interaction has occurred between the polymer matrix and leaf extract, contributing to a more compact and uniform film morphology. The tensile strengths of the films increased from 21.38 to 28.28 MPa after the addition of mulberry leaf extract. Additionally, the films were tested for their application as food wrapping films. Overall, the results showed that PVA-based films incorporated with mulberry leaf extract have higher capability to preserve the freshness of food when compared to commercial cling wraps from brands such as Diamond and Glad. Appropriate proportions of additives (mulberry leaf extract, HCl and glycerol) used in the formulation of P-GH-M20 films showed improvement in its mechanical properties and food preservation capability.
Comparative laboratory cost analysis of various activated carbon activation process
Authors: Lai J Y , Ngu L H
Published: November 2021

Activated carbon (AC) is an established adsorbent for organic pollutants reduction, metal removal, and liquid and gas adsorption. Cost analysis corresponds to determining the best approach for AC production depending on activation techniques with different degrees of activation is still minimal in literature. A cost estimation of AC production in laboratory scale using different conventional activation and post-activation surface modification process is performed in this study. This study attempts to develop a cost-friendly selection of activation process from laboratory scale prices. Chemicals and utility costs were acquired from vendor quotes (i.e., Sigma-Aldrich and Fisher Scientific) and Sarawak industrial electricity tariffs based on 100 g production. Oil palm-based ACs produced from five different activation or surface modification methods were compared to ascertain the least expensive production approach in terms of estimated production cost. Of the five methods investigated, method that quoted the least expensive production cost is chemical activation using potassium hydroxide (KOH) with minimum estimated cost of $7.30 whereas the most expensive production cost involves surface modification by polyethyleneimine (PEI) impregnation with cost of $873.00. Therefore, the estimated production cost for KOH activation is the minimum at $0.073 g−1while the maximum is $8.73 g−1for PEI impregnation.
Development of poly(ethylene glycol) diacrylate membrane for facilitated CO2/N2 separation
Authors: Kim T P , Jawad Z A , Chin B L F
Published: November 2021

Carbon dioxide (CO2) is responsible for approximately 80% of greenhouse gases emission that is the main source to global climate change causing notable environmental impacts. Poly (ethylene glycol) diacrylate (PEGDA) have polar PEG repeating units, which provide a strong affinity towards carbon dioxide (CO2) molecules has been blended with 3-aminopropyltrimethoxysilane (APTMS) to synthesize membrane for CO2/nitrogen (N2) separation. The new synthesized membrane is studied for potential applications in gas separation and to be implemented in control CO2 emission. APTMS is also used to delay the diffusion between polymer and solvent. In this study, concentration of polymer of PEGDA and casting solvent of APTMS in terms of mol ratio from a range of 0.9:1.1 to 1.3:0.7 is discussed. Based on the results, PEGDA membrane shows best gas separation performance at mol ratio of PEGDA to APTMS of 1:1 where the permeance for both CO2/N2, and CO2/N2 selectivity are 75.21±0.15 GPU, 22.95±0.05 GPU and 3.28±0.12, respectively. An optimal aminosilane/polymer reaction ratio benefits the gas separation performance of the membrane due to the affinity of the membrane towards CO2 and formation of different membrane surface morphology.
Optimization of lipids extraction from Moringa oleifera seeds for biodiesel feedstock
Authors: Fizal A N S , Zainordin N H , Jamil M I M , Hamid H A , Khalil N A , Hossain M D S , Zulkifli M , Yahaya A N A
Published: November 2021

This paper explore the mechanism of lipid extraction efficiency on Moringa oleifera seeds using Soxhlet extraction method. This present study essential to determine the effect of particle size of the sample, extraction time and type of solvent applied towards the efficiency in extracting the lipids from the material. Soxhlet extraction method utilizing Buchi B118 was use in this study and response surface method was applied to analysed the data and determine the optimum parameter condition to obtain the highest yield of Moringa oil extraction. Moringa oil derived from Moringa oleifera seeds was converted into biodiesel (FAME) via Transesterification process. Conversion of Moringa FAME was observed using three different alcohol oil to molar ratio by based-catalysed. This study shows significant strong correlations between particle size of the sample, extraction time and type of solvent use towards extraction yield. The Response surface analysis shows that 1.3611 mm particle size of sample, 3 hours of extraction time and hexane as extraction solvent was the optimum condition in order to get the highest yield of lipids extract from both Moringa oleifera samples. Authentication extraction based on RSM recommendation showed an average Moringa oil yield of 39.75 % by weight.
Microcrystalline cellulose (MCC) as an adsorbent in copper removal from aqueous solution
Authors: Khalil N A , Abdullah N S , Rahman A S A , Hamid H A , Fizal A N S , Zulkifli M , Hossain M S , Yahaya A N A
Published: November 2021

Many studies have been done on the natural adsorbent, natural/raw cellulose, modified cellulose and modified MCC as media for removing copper. However, the usage of unmodified microcrystalline cellulose (MCC) as an adsorbent to remove heavy metals contaminants such as copper from an aqueous solution is scarcely being explored. Thus, the current study was done to assess the performance of the MCC, without any modification, based on the adsorption capacity and the Cu removal efficiency under varied process parameters. The MCC was successfully used for Cu2+ or Cu (II) removal at pH < pH6. The adsorption parameters such as pH (1 to 6), contact time (0.5 to 24 hours), temperature (25 to 70 °C), initial Cu concentrations (1 to 5 mg/L) and MCC dosage (0.05 to 0.5 g) were significantly influenced the adsorption performance of the MCC. This study indicated the adsorption process occurred at pH ranging from pH 2.8 to 6 with 3 to 24 hours of duration were required to achieve the equilibrium condition. Lower temperature ranges (25 to 30 °C) were more favourable for adsorption than higher temperature ranges (40 to 70 °C). The increase in initial Cu concentration enhanced the adsorption capacity of MCC but decreased Cu removal. On the other hand, the increase in the MCC dosage resulted in the decreased adsorption capacity, however, increased Cu removal. MCC dosage of 0.225 g managed to remove Cu (II) with 95% efficiency at the initial Cu concentration of 1 mg/L, pH 5 and temperature 25 °C within 24 hours of contact time with 0.18 mg/g of adsorption capacity. Overall, high Cu removal efficiency (up to 95%) was achieved by the MCC which render its usage as adsorbent.
Comparison of chemically surface treated Luffa cylindrica using scanning electron microscopy (SEM)
Authors: Kamran M J , Jayamani E , Soon K H , Wong Y C
Published: November 2021

The world as we probably know is currently facing a big difficulty referred as environmental pollution. Researchers from around the globe have been working on biodegradable materials in order to reduce the overall consequences due to environmental pollution. Furthermore, biodegradable composites also known as green composites made using natural fibers are highly considered over non-green synthetic fiber composites. Additionally, natural fibers are low in cost, have good mechanical properties, biodegradability and require less production energy. Focus of this research paper was on one of the natural fibers, Luffa cylindrica (LC). There are plenty of surface treatments available including chemical and mechanical surface treatments. However, the focus of this paper was on chemical surface treatments. Sodium hydroxide, silane and acetylation chemical surface treatments were utilized. Chemically surface treated LC was compared with untreated LC with the help of scanning electron microscopy (SEM). With the help of SEM, it was observed that all of the chemical surface treatments were effective. Furthermore, it was also noticed that each of the chemical surface treatment affected LC differently. However, sodium hydroxide surface treated LC samples showed the best outcome by removing waxy impurities as well as voids from the surface of LC.
Evaluation and characterisation of candidate prebiotics extracted from coconut husk by ultrasound-assisted extraction technique
Authors: Tang S L , Koh C C , Hii S L
Published: November 2021

Oligosaccharides are carbohydrates containing between three to ten sugar moieties. Certain oligosaccharides such as inulin and fructo-oligosaccharides are known as prebiotics that promote the growth of beneficial bacteria in the human gastrointestinal tract. This study began by comparing the efficiency of two different solvents (distilled water and 10% w/v sodium hydroxide) in extracting oligosaccharides from the coconut husk by ultrasound-assisted extraction (UAE). Following that, the coconut husk extract (CHE) extract was subjected to a series of prebiotic evaluation tests. The findings indicated that a significantly high extraction yield (40.51 ± 6.00%) could be achieved with 10% w/v NaOH treatment. The in vitro enzymatic digestion study found that there was 43.70 ± 0.15% of hydrolysis at pH 8 after five hours of incubation. For the in vitro gastric juice digestion, 29.21 ± 0.71% of hydrolysis was recorded at pH 1 after four hours of incubation. The extract was able to stimulate the growth of selected beneficial bacterial strains. FTIR and NMR analysis of the CHE revealed that the extract has a similar structure to the well-known prebiotic inulin.
Simultaneous degumming and deacidification of crude palm oil using mixed matrix PVDF membrane
Authors: Othman N H , Latip R A , Noor A M , Lau W J , Goh P S , Ismail A F
Published: November 2021

The research work aimed to investigate the compatibility of polyvinylidene difluoride (PVDF) membrane embedded with various inorganic adsorbents for producing a mixed matrix membrane (MMM) and to examine the capability of mixed matrix PVDF membrane (PVDF-MMM) for simultaneous degumming and deacidification of crude palm oil (CPO). Four different adsorbent were tested which includes calcium silicate (CaS), magnesium silicate (MagS), ZSM-zeolite (ZSM) and activated carbon (AC). The in-house made PVDF-MMM was fabricated according to the dry-jet wet spinning method. The performances of these PVDF-MMMs were assessed with respect to the removals of phosphorus, FFA and colour. Based on finding showed that the combination of 18PVDF embedded with 3 wt% MagS showed the most compatible polymer-inorganic hybrid MMM to perform pre-treatment of CPO. Increasing the MagS concentration from 3 to 8 wt% in the polymer matrix recorded the highest removals of FFA at 16.51 %, phospholipid at 93.31 % and colour at 18.8 %, respectively. Nevertheless, high amount of MagS added to the polymer matrix affected the spinnability and reproducibility performance of MMM. Future work, surface modifications of inorganic adsorbent can be evaluated to facilitate good dispersion of filler in polymer matrix during membrane fabrication to maintain good membrane reproducibility.
Aloe vera as a natural flocculant for palm oil mill effluent (POME) treatment - characterisation and optimisation studies
Authors: Chu R L , Vasanthi S , Anurita S
Published: November 2021

In the present study, fenugreek and aloe vera were investigated for the removal of turbidity (TUR), total suspended solids (TSS) and chemical oxygen demand (COD) from POME by using a central composite design (CCD) in the Design Expert software. The effects of three factors such as pH, coagulant dosage and flocculant dosage were analysed using jar test experiment and optimised using response surface methodology (RSM). The optimum results obtained from process optimisation analysis were pH 4, 24.13 g of coagulant dosage and 20 ml of flocculant dosage that are sufficient to remove 82.78 % of TUR, 83.40 % of TSS and 32.95 % of COD. The maximum error between the optimised values and the experimental values (82.78 % for TUR, 83.08 % for TSS and 33.76 % for COD) were below 4 %, indicating that satisfactory agreement was achieved. This showed that modelling and optimisation of the coagulation-flocculation process can be achieved by RSM approach. From analytical studies, it was found that the interactions between coagulant-flocculant and colloidal particles involve the mechanisms of charge neutralisation, adsorption and bridging, due to the active components such as amine (N-H) and hydroxyl (O-H) groups contained in the fenugreek and aloe vera.
Modelling, optimization and control of continuous two-stage Cephalosporin C production
Authors: Chin J F Y , Nandong J
Published: November 2021

Cephalosporin is one of the most consumed antibiotics for its effectiveness against a wide variety of infections. Most cephalosporin products are the semi-derivatives of Cephalosporin C (CPC), a metabolite of the fungus Acremonium chrysogenum. Since naturally the desired metabolite is not produced in a large amount by the fungus, an innovative operational strategy is required to increase its yield for the production of the antibiotic to be economically feasible. One way to increase the cephalosporin productivity is by increasing the concentration of thin hyphae cell in the bioreactor, but this will lead to a higher blower power requirement for providing adequate availability of oxygen in the fermentation broth. Lack of oxygen will retard the growth rate and reduce the productivity. Conversely, excessive aeration of the fermentation broth will lead to high shear stress that can kill the cells. The present work investigates through dynamic simulation the effectiveness of a continuous two-stage aerobic fermentation for the CPC production. The operating conditions are optimized to determine an optimal trade-off between the cephalosporin productivity and blower power. An increase of the dissolved oxygen in the first bioreactor from 10 % to 20 % can increase CPC productivity by 75.5 % from 24.42 mg/L.hr to 42.86 mg/L.hr.
Towards zero carbon dioxide concentration in sweet natural gas product from amine sweetening plant
Authors: Sahl Abdulqader Bin , Siyambalapitiya Tharindu , Mahmoud Ahmed , Sunarso Jaka
Published: November 2021

This work presents a two-step method to reduce CO2 concentration of sweet natural gas product from amine sweetening plant via amine blending (Step 1) followed by minor process modification (Step 2). In Step 1, an industrial natural gas sweetening plant was simulated using Aspen HYSYS and the simulation results were validated against the plant data. Afterwards, different blends of methyl diethanolamine and monoethanolamine (MDEA-MEA) and methyl diethanolamine and diethanolamine (MDEA-DEA) were investigated. Then the optimum amine blend of 28 wt.% MDEA and 10 wt.% MEA was reported. The optimum amine blend achieved a significant reduction in CO2 concentration of sweet natural gas of 99.9% compared to the base case (plant data). In Step 2, two types of amine stream splits, i.e., lean amine stream split and semi-lean amine stream split were studied. The study covered split stream amount, absorber recycle stage, and regenerator stage withdrawal. Both types of stream splits attained a significant reduction in CO2 concentration of sweet natural gas product and amine circulation rate compared to Step 1. However, the semi-lean amine stream split was superior to lean amine split with 69.1% and 63.6% reduction in CO2 concentration of sweet natural gas and lean amine circulation rate, respectively.
Effect of open pore and pore interconnectivity in the Ni-SDC cermet anode microstructure on the performance of solid oxide fuel cells
Authors: Ali Muhammed S A , Muchtar A , Mah J C W , Raharjo J , Khaerudini D S
Published: November 2021

In nickel-samarium-doped ceria (Ni-SDC) cermet anode layers, the open pores and interconnected pores in the microstructure are the main factors that affect the mechanical and electrical properties. In this work, porous Ni-SDC cermet anode layers are fabricated using various quantities of potato starch (0 to 25 wt.%) as a pore forming in the anode powders. The properties of the Ni-SDC cermet anode layers were characterised by FESEM-BSE microscopy, Archimedes method for density measurement, Vickers hardness, flexural strength, and DC four-point electrical conductivity. The findings revealed that the different content of potato starch greatly affected the percentage of porosity and pore interconnectivity in the microstructure and consequently altered the mechanical and electrical properties of the Ni-SDC cermet anode. The degree of shrinkage, relative density, mechanical strength and electrical conductivity of the Ni-SDC cermet anodes decreased as their pore former content increased. Furthermore, the research shows that the large porosity (> 40%) in the Ni-SDC cermet anode microstructure affected the continuity of Ni-Ni, SDC and Ni-SDC phases and thereby affected the mechanical and electrical properties. The Ni-SDC cermet anode with 10 wt.% exhibited sufficient porosity, Vickers hardness, flexural strength and electrical conductivity of 34%, 48 MPa, 72 MPa and 2028 S/cm (at 800 °C), respectively. Therefore, optimisation of porosity in the Ni-SDC cermet anode microstructure strongly contributes to the well-connected pore channels for the rapid diffusion of hydrogen for oxidation and mechanical strength.
Eggshell waste as a catalyst for biodiesel production: A preliminary study
Authors: Ali N A , Khairuddin N , Siddique B M
Published: November 2021

This research aims to observe the usability of waste eggshells as a heterogeneous CaO-based catalyst to produce biodiesel via the transesterification process. The waste eggshell contains CaO and serves as a heterogeneous catalyst that can be extracted using a simple heat treatment technique. The catalyst loading used in this study were 1, 2, 3, 4, and 5 wt.%. The biodiesel yield affects the variables of the reaction, including the amount of catalyst used. According to the findings in this work, the low-weight catalyst produced more biodiesel (64% of yield) than other catalysts in the studies. Using the same CaO catalyst with a 1 wt.% catalyst, previous studies showed a biodiesel yield of 56.64%. Outcomes revealed that waste eggshells could be used as an effective catalyst to transform waste cooking oil into biodiesel, thereby significantly lowering biodiesel costs and improving product yield and fuel properties.
Numerical simulation and experimental study on hematite production by oxidation of mill scale
Authors: Aldiramadan M T , Nabilah J , Ridwan M , Khaerudini D S
Published: November 2021

Mill scale is a waste product from steel hot rolling processes and containing a high amount of FeO and Fe3O4. It is crucial to recycle and reuse this waste for the recovery into a metallic iron or its single oxide derivative. One of the end products of mill scale oxidation is hematite which has multitude of uses in various application. In this present study, mill scale is converted to hematite by roasting a mixture of mill scale at a specific set of conditions at 900°C for a varied time under ambient air environment by addition of pelletized limestone as a heat storage media. In this work, the Dimensionless Degree of Oxidation Prediction Model (DDOPM) has been constructed to gain hematite purity approach in the resulting powder by using Matlab. The Buckingham Pi Theorem is used to find dimensionless parameters considering the effect of different parameters including the geometric factor of tubular horizontal furnace used, characteristic of mill scale, ambient air factor, and thermal characteristics of limestone. The degree of oxidation from experimental result was obtained from XRF analysis and compared to the result of DDOPM to show the correlation between the experimental and numerical.
Assessment of air pollution control technologies to reduce SOx emission from thermal oxidizer for oil and gas industry
Authors: Haji Nawawi N H B , Jaafar M N
Published: November 2021

Many countries have put in place, various legislations that govern air emission limits/pollutants from the industries. The common pollutants being monitored are Sulphur Oxides (SOx), Nitrogen Oxides (NOx), Carbon Monoxide (CO), Carbon Dioxide (CO2), Volatile Organic Compounds (VOCs), particulate matters and dioxins. In Malaysia, the regulatory requirement aims to regulate emissions of air pollutants from industrial activities including oil and gas, power plants, waste fuel plants and asphalt mixing plants. One of the emission limits under Clean Air Regulation (CAR2014) is emission level for SOx should be less than 600 mg/m3 (reference condition at 3 % of O2, 273 K, 101.3 kPa) whereby sum of SO2 and SO3 expressed as SOx. Excessive SOx emission can affect both health and the environment. Aligning with the regulation requirement, Group Technical Solution (GTS) under PETRONAS has embarked on assessment of technology solutions to meet the emission limit on SOx emission limit for thermal oxidizers which cover new and existing facilities. This paper describes on the work methodology and approach adopted during the assessment. The objective of the assessment is to determine the suitable process technology to reduce SOx emission in order to achieve the desired emission limit for flue gas at outlet stream of thermal oxidizer. Thorough evaluation was carried out based on proposal submission from various technology providers and Vendors. The selection criteria was developed and established. For existing thermal oxidizers, the assessment is more complex taking into consideration the nature of brownfield project and to ensure the proposed modification has minor impact to operability and maintainability of existing facilities. This study has successfully enabled identification of feasible process technologies such as Caustic Scrubber, Seawater Flue Gas Desulfurization and Ammonia based Desulfurization to meet the desired emission limit at thermal oxidizer outlet for Oil and Gas Industry and supporting environmental protection. The selected technology is varies based on plant/project specific requirement. Among main considerations are the by-product management, consumable and utility consumption as well as compatibility of the technology with existing plant on shutdown requirement.
Synthesis and characterization of (3-aminopropyl) triethoxysilane (APTES) functionalized zeolite AlPO-18
Authors: Anbealagan L D , Chew T L , Yeong Y F , Jawad Z A , Ho C D
Published: November 2021

Over the years, functionalization of zeolite is gaining popularity among researchers to further modify the properties of the zeolite for wide applications. The procedure of functionalization is crucial to ensure that the framework and structure of the zeolite would not be destroyed by the functionalization process. In this work, zeolite AlPO-18 was synthesized via hydrothermal synthesis method and functionalized by (3-Aminopropyl) triethoxysilane (APTES). The effect of the APTES functionalization on zeolite AlPO-18 was investigated in this work. Both unfunctionalized and silane-functionalized zeolite AlPO-18 were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA) for their properties. The morphology and the composition of the elements present in zeolite AlPO-18 and zeolite NH2-AlPO-18 were examined using Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive spectroscopy (EDX) respectively. The XRD pattern of NH2-AlPO-18 was similar to that of zeolite AlPO-18, however, the intensity of the peaks was lower compared to zeolite AlPO-18. Based on the FTIR spectra, the presence of N-H stretching and bending vibration band of aminosilane were observed in the NH2-AlPO-18 sample. According to FESEM images, the morphology of NH2-AlPO-18 was comparable to that of zeolite AlPO-18 even after functionalization, proving that functionalization of aminosilane on zeolite does not affect on the zeolite structure. Besides that, EDX proves the presence of 3.02 % of element N in the NH2-AlPO-18 sample which is absent in the zeolite AlPO-18 sample. All of the characterizations evinced the presence of aminosilane, APTES in the NH2-AlPO-18 sample.