bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of high relative humidity and dry purging on VOCs obtained during breath sampling on common sorbent tubes
Authors: Wilkinson Maxim , White Iain R , Goodacre Royston , Nijsen Tamara , Fowler Stephen J 
Published: March 2020

Abstract
Offline breath analysis by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) requires the use of sorbent traps to concentrate and store volatile compounds. The selection of which sorbent to use and best practices for managing high relative humidity are important considerations to allow for reproducible, untargeted, biomarker discovery in water saturated breath samples. This work aims to assess three commonly used sorbent materials for their use in breath volatile sampling and determine how the high relative humidity inherent in such samples effects the capture of volatile compounds of interest. TenaxGR, TenaxTA/Carbograph1TD and TenaxTA/Carbograph5TD tubes were selected as they are the most commonly used sorbents in the breath sampling literature. The recovery of 29 compounds in a standard mix loaded using high humidity gas was tested for each sorbent and compared to loading in dry gas. Water retention and dry purge rates were determined for each sorbent for 500 ml and 1000 ml breath collections. Finally, breath samples were collected simultaneously on to each sorbent type using the ReCIVA and analysed by TD-GC-MS. All three sorbents exhibited acceptable reproducibility when loaded with the standard mix in dry gas (RSD < 10%). Loading the standard mix in humid gas led to reduced recovery of compounds based on their chemical properties. Dry purging performance for each sorbent material was assessed and was shown to be 1.14, 1.13 and 0.89 mg H2O min−1 for TenaxGR, TenaxTA/Carbograph1TD and TenaxTA/Carbograph5TD respectively when flushed with 50 ml min−1 of N2. A comparison of breath profiles on different sorbents showed differences in background artefacts (sulfur dioxide, cyclopenten-1-one and 3-nonene) and endogenous breath compounds (2-methyl-furan and furfural). This work demonstrates that high relative humidity during sampling reduces the ability of sorbent tubes to capture volatile compounds and could impact method detection limits during breath sampling. Sufficient water to impair accurate analysis was retained on all tubes. Minimal differences were observed between sorbent materials when used to sample breath, however, suggestions are provided for sorbent selection for future studies.
Major Accident Hazard in Bioprocess Facilities: A Challenge To Sustainable Industrial Development
Authors: Johari K A , Ramli A 
Published: March 2020

Abstract
Sustainable components of renewable biological resources in Malaysia provide the prospect for the growth of the bioeconomy via research, innovation and commercialisation. Malaysia is one of the few Asian countries that has most of its bio safety regulations and guidelines in place. In spite of the government is driving the sector in full force, there are still missing links and challenges. Some recent accidents involving the bioprocess raised concern on the safety of such technologies inclusive one incident happened in a bioprocess facility that has been selected as a case study. The facility selected is one of the Bioeconomy Transformation Programme (BTP) Trigger Projects in Malaysia. Holistic risk assessment is needed in order to identify and potential hazard related to bioprocess. With the usage of hazardous substances in the process, the approach towards risk assessment and accident prevention is crucial. Mechanical integrity and process safety related aspect is among the area need to be explored.
Application of two level factorial design to study the microbe growth inhibition by pineapple leaves juice
Authors: Mohd Ridza P N Y , Ya’acob A , Zainol N , Mortan S H 
Published: March 2020

Abstract
The yield of Ananas comosus (pineapple) is susceptible to microbial infection and the usage of chemical pesticides to control it has been often associated with negative impacts to the environment and human health. As pineapple leaves is one of the lavish organic materials with antimicrobial properties due to its total phenolic content (TPC), its potential as a microbial inhibitor is explored in this study. The objective of this research is to study the factors that affect microbe growth inhibition using pineapple leaves juice (PLJ). The factors evaluated were; reaction time between mixtures of PLJ and microbe (0.5 – 5 hours), concentration of TPC in PLJ (0.2563 – 0.5127 mg GAE/ml), reaction temperature (26 – 37°C), and ratio of microbe to PLJ (M/PLJ) (1:1 and 1:3). A two level factorial design was adopted to assess the effect of the above mentioned factors on the microbial inhibition by PLJ. The results show that the most contributing factor of 1.55 % was reaction temperature, meanwhile the highest contribution factor for interaction effect was between concentration of TPC in PLJ and ratio of microbe to PLJ at 5.17%. The best condition for microbe growth inhibition of 20.90% was found to be at reaction time of 0.5 hour, TPC in PLJ of 0.5127 mg GAE/ml, reaction temperature of 37°C, and M/PLJ at 1:1. This study demonstrates that pineapple leaves could be exploited as valuable sources of natural products that could be used as microbial growth inhibitor and thus become one of the cheap and green alternatives for more expensive chemical pesticides.
Determination of phenolics and saponins in fenugreek seed extracted via microwave-assisted extraction method at the optimal condition
Authors: Akbari S , Nour A H , Yunus R M 
Published: March 2020

Abstract
Fenugreek an ancient plant also known as Trigonella-foenum-graecum L. This plant has achieved a great interest due to its valuable medicinal properties. The current research is targeted to extract phenolic and saponin bioactive compounds from seeds of fenugreek via microwave-assisted extraction (MAE) technique. The seed extraction was carried out at irradiation time of (2-4 min), microwave oven power (500-700 W), ethanol concentration (4080 %), ratio of seed-to-extraction solvent (1:8-1:12 g/mL) and a constant extraction temperature (70°C). The statistical process of response surface methodology (RSM) under software of Design-Expert was used to optimize the recovery of total saponin content (TSC) and total phenolic content (TPC) in extract of fenugreek seed. One-factor-at-one-time (OFAT) was used to evaluate the levels of independent factors, and the suitable levels (-1, 0, and +1) were selected for the optimization process. Results indicated that the optimal conditions of extraction process to achieve the highest recoveries were 2.84 min, 572.50 W, 63.68% and 1:9 g/mL, respectively. Analysis of variance (ANOVA) indicated that TSC and TPC were significantly influenced by the time of irradiation, microwave oven power, solvent concentration, and ratio of seed-to-extraction solvent. FTIR results confirmed the presence of specific peaks belonging to saponins and phenolic compounds.
Effect of Microstructures in Microchannel for Single Phase Flow Mixing Intensification
Authors: Ling Fiona W M , Khleif Ali A. , Abdulbari Hayder A 
Published: March 2020

Abstract
Enhancing flow in microchannel is a serious fundamental challenge due to the laminar flow nature of the liquids in the microscale systems that prevents the traditional viscoelastic additives from interacting with the turbulence structures (eddies) for an effective drag reduction performance. Passive drag reduction technique is believed to be a promising solution and never been investigated in the microflow systems before. In this work, micro- riblets (V-shaped) with the size ranging from 20 to 100 μm were designed, fabricated, and placed at the narrow side-walls of the rectangular microchannel in an attempt to test its flow enhancement performances. The microchannels were fabricated through a direct writing method where polymethyldisiloxane was used as the substrate. The flow behavior was investigated through monitoring the flow rate of the fluids flowing through the system. The flow profile in the system was evaluated using micro-particle velocimetry (μ-PIV). The results indicated a flow enhancement up to ∼29% for a 60 μm of base-to-height riblet at an operating pressure of ∼200 mbar for a single phase flow system. Larger micro-riblets were found to produce a thicker laminar sublayer within the devices that narrowed the active core of the solution.
Performance of tight ultrafiltration membrane in textile wastewater treatment via MPR system: effect of pressure on membrane fouling
Authors: Desa A L , Hairom N H H , Sidik D A B , Zainuri N Z , Ng L Y , Mohammad A W , Jusoh N W C , Jalil A A 
Published: March 2020

Abstract
Industrial textile wastewater can be considered as main water polluting source in which constitutes a threat to human health and ecosystems; due to high water consumption and generated a large volume of color liquid waste. In the present study, the effect of various applied pressure in membrane photocatalytic reactor (MPR) system using ZnO-PEG nanoparticles and polypiperazine amide tight ultrafiltration (UF-PPA) for textile wastewater treatment was systematically investigated mainly through membrane fouling phenomenon. Results showed that the final permeate flux after 180 min was found to increase with the increase of applied pressure which obtained 0.4133 at 6 bar. Under 6 bar of pressure, the dye rejection of permeate was successfully reduced by approximately 100%. The Field Scanning Electron Microscopy (FESEM) analysis was also revealed that 6 bar of applied pressure did not affect or changed the structure of membrane cross-sectional pattern of UF-PPA membrane. In summary, the integrated usage of ZnO-PEG nanoparticles in photocatalysis combined with UF-PPA process improved the membrane fouling phenomenon and able to completely remove the colour from the feed of industrial dye wastewater.
Effect of Treating the Titanium Electrode of the Desalination Performance in Microfluidics System
Authors: Heng J T , Abdulbari Hayder A 
Published: March 2020

Abstract
The commercially applied macro desalination methods such as reverse osmosis, multi-stage flash distillation and multi-effect distillation suffer from several drawbacks such as high power consumption and low separation performance. It is believed that the micro-scaled structures will optimize the mixing efficiency of the micro-flow liquid and lead to higher desalination performance. Large surface-area-to-volume ratio in micro-scale promotes the fluids interaction since the laminar flow properties in the microfluidic device allowing the high-velocity gradients and dominant interfacial effects which is the manipulation of fluid streams [1]. The present work introduces a microfluidics chip for water desalination which fabricated using polydimethylsiloxane soft lithography method. Three layers of polydimethylsiloxane (PDMS) were fabricated using soft lithography method where PDMS liquid mixture was mixed and poured onto the designed wafer and heated to become solid. The solid PDMS was then peeled off from the wafer and hence assembled together with another PDMS by using surface plasma treatment process. The flow rate was set at 90 mL/h and the system was supplied with 9 V of potential difference. Aluminium and titanium were being used as the electrodes which achieved 65% and 15% of salt removal efficiency, respectively. Titanium was further treated by using the etching method and the performance was studied. The desalination efficiency was analyzed and evaluated with the flow rate of 90mL/h using capacitive deionization method. The result revealed that the performance of untreated titanium was better than the treated titanium which achieves 10% improvement in salt removal efficiency. The finding in this work show that the desalination efficiency was relied on the electrode surface property where the oxide layer inhibits the deionization from occurs.
Effects of drying conditions on total phenolic content and other parameters of soursop jelly (Annona muricata L.)
Authors: Tran N Y T , Nhan N P T , Thanh V T , Nguyen D V , Thinh P V , Vy T A , Lam T D , Truc T T 
Published: March 2020

Abstract

Annona muricata Linn. (soursop) belongs to the family Annonaceae. This plant had been traditionally used for treatment of various infectious and inflammatory diseases. This study aimed to determine the effects of convection drying on the nutrient composition of the plant. Measured indicators included protein content, ash content, fat, total ascorbic acid content (TAA), total phenolic content (TPC), color and sensory level of soursop. At different temperatures of 40°C, 50° and 60°C, the evaluation criteria change significantly when supplemented with °Brix at 10%, 15% and 20%. Highest protein content achieved at 20% soluble solids concentration was 2.71 ± 0.09 and 2.68 ± 0.01 at 40 and 60°C, respectively. Most of the percentage of ash of the sample was unaffected and the change of the fat content is negligible. Moreover, TAA and TPC were found to decline after the process. About 68.62% TAA was retained when drying at 40°C (20% Brix) and the figure for TPC was 38.46% (60°C, 10% Brix). Typically, in the L* color space, all samples exhibited the value of higher than than 55 and there is a tendency to give a white color. In addition, the a* and b* values increased after drying. Optimal parameters are selected based on the commercial nature of the product and the retention of nutritional value. Final results consisted of the addition of 10% syrup sugar (60 ° Brix) in the sample under the temperature of 40 ° C for 390 minutes.
Effect of pH on the adsorption behaviour of Congo Red Dye on the Mg-Al layered double hydroxide
Authors: Nguyen T H T , Dao T T U , Pham G V , Do T S , Nguyen T T L , Nguyen T H L , Chu M N , Nguyen Quoc D Q , Tien N A 
Published: March 2020

Abstract
In the present study, the synthesis of Mg-Al layered double hydroxide at the molar ratio of 3:1 for Mg/Al are determined. One-step hydrothermal technique with slow hydrolysis of urea at a low temperature was employed without further annealing. The study was aimed at determining the effectiveness of Congo Red dye removal in the adsorption process onto Mg-Al layered double hydroxide (LDH) with respect to the change in pH of the solution. The experiment was conducted at concentrations of a sorbent 0.04g with 100 ml of Congo Red and at six values of the reaction, i.e. pH 2.0, pH 4.0, pH 6.0, pH 8.0, pH 10, and pH 12.0. It was found that pH affects the adsorbent surface charge and the degree of anionic dye dissociation. This can be explained to the chemical form of dye in the solution and functional groups present on the adsorbent surface at a specific pH.
Chemical constituents from n-hexane and ethyl acetate extracts of Euphorbia hirta L. grown in Vietnam
Authors: Bach Le Thi , Hue Bui Thi Buu , Tram Nguyen Thi Thu , Thu Do Nguyen Anh , Dung Le Tien 
Published: March 2020

Abstract
The medicinal plant Euphorbia hirta L. has been widely acknowledged for use in traditional medicine of Vietnam. The whole plants of E. hirta are commonly applied to cure a wide range of diseases, especially gastrointestinal disorders, skin problems, and respiratory system. This study focused on chemical composition of the E. hirta L. whole plant. The chemical investigation of n-hexane and ethyl acetate extracts of this species led to the isolation and structural determination of taraxerol (1), campesterol (2), astragalin (3), hymenoxin (4), luteolin-7-O-β-D-glucopyranoside (5) and quercetin 3-O-α-L arabinofuranoside (6) by spectroscopic methods including 1D-NMR, 2D-NMR, IR, HR-MS in combination with published literature.
Evaluation of Bio-red Pigment Extraction from Monascus purpureus FTC5357
Authors: Daud N F S , Said F M , Ramu M , Yasin N M H 
Published: March 2020

Abstract
A suitable extraction technique helps to increase the extraction yield and stimulate higher quality of pigments. Therefore, investigating the effect of different extraction solvents on red pigment produced via solid-state fermentation (SSF) by Monascus purpureus FTC 5357 are essential. In this study, oil palm frond (OPF) was used as a substrate for the fermentation process. The fermentation was conducted at 30 °C for eight days. Variation of solvents (95% ethanol, 60% ethanol and distilled water), pH and time of extractions were applied on the fermented product. The extracted pigment was then analysed using spectrophotometer at 500 nm, for red pigment. Combination of pH 6 and 60% ethanol at 16 h pronounced to be the best conditions to extract the pigment, with an absorbance value of 207 AU/g.d. The advantage of the ethanol as a solvent extraction is cheap and non-toxic. Later, the extracted pigment is safe to be used in food applications.
CO2 Absorption Capacity and its Enthalpy of Absorption in Aqueous Blend of MDEA/Piperazine/Arginine
Authors: Talkhan A.G. , Benamor A. , Nasser M. S. , El-Naas M. 
Published: March 2020

Abstract
In this work, the solubility data of CO2 in aqueous blends of N-Methyldiethanolamine, Piperazine and Arginine (MDEA/PZ/ARG) of a total concentration of two moles is presented. CO2partial pressure was varied from 9 to 99 kPa while temperature ranged from 293 to 323 K in increment of 10 degrees. The experimental results showed that the solubility of CO2 decreased with increasing ARG ration in the mixture. These results were modelled using a semi-empirical (SE) vapor liquid equilibrium (VLE) model. The model was found able to adequately represent the experimental data with an average absolute deviation (AAD) less than 3.13 %. Using a truncated form of the semi-empirical model, the heat of CO2 absorption, ΔHab, at low pressure was estimated and found to be in the range of 32-66 kJ/mole CO2 absorbed.
Enzymatic hydrolysis of lignocellulosic biomass from pineapple leaves by using endo-1,4-xylanase: Effect of pH, temperature, enzyme loading and reaction time
Authors: Rosdee N A S M , Masngut N , Shaarani S M , Jamek S , Sueb M S M 
Published: March 2020

Abstract
Pineapple leaves; is one of lignocellulosic materials that composed of about 80% of carbohydrate containing lignin, cellulose and hemicellulose This waste still retains a considerable amount of soluble sugars that can be transformed into valuable fermentable sugars. This research was conducted to study the effect of different pH, temperature, enzyme loading and reaction time in order to identify the best working conditions to produce the highest yield of sugar. Prior to enzymatic hydrolysis, the pineapple leaves were subjected to hydrothermal pretreatment in order to obtain the hydrolysate liquid. Enzymatic hydrolysis was then carried out by using endo-1,4-xylanase and the reducing sugar was analyzed by using dinitrosalicylic (DNS) method. The result has shown that the highest reducing sugar concentration of 70.9 mg/L was obtained both at pH 5.5 and 50 °C. In addition, the best enzyme loading and reaction time were recorded at 0.5% (w/v) and 45 min that resulted 60.1 mg/L and 72. 0 mg/L respectively.
Elucidation of flux decline phenomenon in ultrafiltration of polydisperse silica solution
Authors: Ramli N H , Zakaria C S , Mohd Sueb M S , Rahman Sunarti Abd , Badrul Hisham N E 
Published: March 2020

Abstract
Ultrafiltration (UF) is widely used in water filtration process due to its ability to operate at low pressure with higher permeate flux. However, fouling is one of the constrains usually occurred in UF, especially when involving colloidal material. Colloidal silica widely used as a synthetic form of colloidal foulant to investigate membrane performance. It has a special characteristic which can change the charge around the molecules easily depending on the surrounding condition. This study was aimed to identify the most significant factor contribute to permeate reduction of UF membrane of polydisperse silica solution that could lead to the fouling issue of this membrane. The factors that have been studied were ionic strength, pH, transmembrane pressure, ratio of feed solution and types of membrane used (modified or unmodified). Fractional factorial design was used to investigate the effect of individual factors and also the interaction factors on the reduction of permeate flux by using Design Expert software. The finding from this study revealed that the factors of fouling was related to each other. In determining the rate of permeate flux, the ionic strength, pH and pressure should not be considered separately. The only independent factor affecting the permeate flux was ionic strength. However, the effect was not prominent compared to interaction factors. Also, surface-modified membrane by using Pebax 1657 has shown opposite trend in terms of pH and pressure effect on permeate flux.
Bio-based sorbitol azelaic acid ester synthesis through germanium (IV) oxide catalysed esterification
Authors: Nurwadiah A , Chin SY , Kamaruzaman M R , Haniif P 
Published: March 2020

Abstract
Conventionally, polyurethane (PU) is derived from the non-renewable petroleum feedstocks, polyol polyester and di-isocyanate. Bio-based polyol polyester is an alternate to reduce the environmental impacts of the petroleum-based polyol polyester. Bio-based reactants, sorbitol (SL) and azelaic (AA) acid were used in the esterification to produce sorbitol azelaic acid ester (SAAE) using germanium (IV) oxide (GeO2) as a catalyst. The experimental studies set at various operating conditions were conducted to determine the best operating condition that gave product with highest AA conversion and acceptable colour. The best operating condition was achieved at a temperature of 200°C, SL/AA reactant ratio of 4:1 and catalyst loading of 0.5 wt%, with the corresponding AA conversion of 90.10%. The kinetic data was well fitted to the Langmuir Hinshelwood Hougen Watson (LHHW) model with the corresponding activation energy of 11.55 kJ/mol.
Inverted decoupling MIMO internal model control using Mp tuning
Authors: Azizah Z , Sutikno J P , Handogo R , Hikmadiyar R A 
Published: March 2020

Abstract
Chemical industry requires a very high-security level and thus requires better process control. Each operating unit needs different operating conditions depending on where one unit with another unit often interact with each other. A very strong interaction process requires multivariable controller. Illustrative examples such as wood & berry and deisobutanizer dual condenser columns are given to show the performance of the proposed control scheme where both processes have time delay and interaction between variables. In this study, not only select the pairing but also add the strategy of inverted decoupling to reduce interactions between process variables. The controller used is MIMO IMC with maximum peak (Mp) stability criteria tuning method. Inverted decoupling MIMO IMC is able to obtain better performance than decoupling MIMO IMC and MIMO IMC without decoupling.
Production of biofertilizer using Lactobacillus inoculants and glycerin pitch from oleochemical industry
Authors: Nasarudin A A , Ngadi N , Yusoff N A , Ali N , Aziz M A A , Rahman R A 
Published: March 2020

Abstract
Production of glycerol waste from oleochemical industry in the form of glycerin pitch poseses risk when disposed to the environment. Conventional methods to recover glycerol are infeasible due to the cost constraint, which has urged the exploration into alternative methods by converting glycerol waste into a valuable product at low cost. The glycerol has a potential to be utilized as a cheap carbon source in fermentation attributed to its high availability. This study focuses on the use of Lactobacillus inoculant and glycerin pitch as a medium for the production of biofertilizer and the effectiveness of the biofertilizer application in promoting the growth of cucumber plant. The results found that biofertilizer with the ratio of 2:1 in the volume of Lactobacillus to glycerin pitch had high effectiveness in promoting the height of cucumber plant by up to 40 cm in 18 days which is almost 2-fold compared to the commercial fertilizer. The produced biofertilizer contained a formulation of pH 5.11, 3.78 Megapascal second (MPas) viscosity and carbon to nitrogen ratio (C/N ratio) of 38.85 after 14 days of storage.