bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing the efficiency of a periodically poled LNOI waveguide using in situ monitoring of the ferroelectric domains
Authors: Niu Yunfei , Lin Chen , Liu Xiaoyue , Chen Yan , Hu Xiaopeng , Zhang Yong , Cai Xinlun , Gong Yan-Xiao , Xie Zhenda , Zhu Shining
Published: March 2020

Lithium niobate on insulator (LNOI) is a unique platform for integrated photonic applications and especially for high-efficiency nonlinear frequency converters because of the strong optical field confinement. In this work, we fabricated a 6-mm-long periodically poled LNOI ridge waveguide with an optimized duty cycle (50:50) using an active domain structure monitoring method. The performance of the single-pass second-harmonic generation and difference-frequency generation in the nanophotonic waveguide was characterized, and the normalized conversion efficiencies were ∼80% of the theoretical values. These high-quality frequency conversion devices can pave the way for the application of LNOI in nonlinear integrated photonics.
DBC1, p300, HDAC3, and Siah1 coordinately regulate ELL stability and function for expression of its target genes
Authors: Basu Subham , Barad Mahesh , Yadav Dipika , Nandy Arijit , Mukherjee Bidisha , Sarkar Jit , Chakrabarti Partha , Mukhopadhyay Satinath , Biswas Debabrata
Published: March 2020

Among all of the Super Elongation Complex (SEC) components, ELL1 (also known as ELL) is the only bona fide elongation factor that directly stimulates transcription elongation by RNA polymerase II. However, the mechanism(s) of functional regulation of ELL1 (referred to as ELL hereafter), through its stabilization, is completely unknown. Here, we report a function of human DBC1 in regulating ELL stability involving HDAC3, p300, and Siah1. Mechanistically, we show that p300-mediated site-specific acetylation increases, whereas HDAC3-mediated deacetylation decreases, ELL stability through polyubiquitylation by the E3 ubiquitin ligase Siah1. DBC1 competes with HDAC3 for the same binding sites on ELL and thus increases its acetylation and stability. Knockdown of DBC1 reduces ELL levels and expression of a significant number of genes, including those involved in glucose metabolism. Consistently, Type 2 diabetes patient-derived peripheral blood mononuclear cells show reduced expression of DBC1 and ELL and associated key target genes required for glucose homeostasis. Thus, we describe a pathway of regulating stability and functions of key elongation factor ELL for expression of diverse sets of genes, including ones that are linked to Type 2 diabetes pathogenesis.
Global perspectives on linguacultural variation in academic publishing
Authors: Belcher Diane , Yang Hae Sung
Published: March 2020

This primarily interview-based study explores the perspectives of published applied linguists around the world on what has facilitated their success in reaching multiple readerships. The focus, more specifically, is on scholars in non-English-dominant settings, a number of whom have made a commitment to both inter- and intranational academic publication, and their perceptions of intercultural rhetoric issues salient in various linguacultural contexts. The findings indicated that such scholars were divided in their views on whether or not there are considerable differences in the rhetorical expectations of international Anglophone and more region-specific, or intranational, journal audiences. What this study’s participants shared was an appreciation of the complexities of authorial cross-contextual negotiation of multiple research worlds, only some of which are Anglophone.
Drinking stories of emerging adults
Authors: Lojdová Kateřina
Published: March 2020

The period of emerging adulthood is seen as a period of transition from adolescence to adulthood and is associated with increased alcohol consumption. The aim of the study is to understand the meaning of alcohol for emerging adults through stories about alcohol intoxication. Eighty-two drinking stories written by emerging adults were analysed using the narrative oriented inquiry (NOI) method. The results are divided into three layers: (1) contents of the drinking stories, (2) discourses of drinking stories, (3) (re)construction of the identity of emerging adults in drinking stories. I sought to extend the current knowledge on drinking stories in two ways: (a) localization within emerging adulthood, (b) by using NOI methodology. Results show the importance of drinking stories for identity construction of emerging adults and as markers of the beginning and the end of emerging adulthood, albeit not a linear one.
Exploring autobiographical memory specificity and narrative emotional processing in alexithymia
Authors: Camia Christin , Desmedt Olivier , Luminet Olivier
Published: March 2020

Alexithymia encompasses difficulties in identifying and expressing feelings along with an externally oriented cognitive
style. While previous studies found that higher alexithymia scores were related to an impaired memory for emotional content, no study so far
investigated how alexithymia affects autobiographical narratives. Narrating personal events, however, is impaired in emotionally disturbed
patients in that they tend to recall overgeneral descriptions instead of specific episodes, which impairs their narrative emotional
processing. Adopting a qualitative approach, this pilot study explored autobiographical memory specificity, cognitive, perceptual and
emotional word use, and narrative closure in eight alcohol-dependent participants scoring very high or low in alexithymia. High alexithymia
participants showed no reduced memory specificity but impaired emotional processing and narrative elaboration, especially when talking about
negative events. Presumably because of this we found no group differences regarding narrative closure. Results are discussed in terms of
cognitive and emotional processing, avoidance strategies, and narrative psychology.
An analysis of microstructure and impression creep response of squeeze-cast AZ91–xBi–ySr alloys
Authors: Majhi Jichil , Das Tanmoy , Basu A. , Mondal A. K.
Published: March 2020

The present investigation deals with the microstructural modification following the Bi + Sr additions to the squeeze-cast AZ91 alloy and its effect on impression creep response. The Bi + Sr additions form the Al4Sr and Sr2Bi phases besides the α-Mg and β-Mg17Al12 phases, and improves creep resistance of the AZ91 alloy. The AZ91 + 1.0Bi + 0.5Sr alloy reveals the best creep resistance among the alloys. The stress exponent and the activation energy values of all the alloys are in the range of 4–7 and 100.2–112.7 kJ mol−1, respectively, depicting the pipe diffusion-controlled dislocation creep is the governing creep mechanism. The post-creep microstructural study confirms several dislocations pile-ups around the Al4Sr and Sr2Bi phases resulting in improved creep resistance of the modified AZ91 alloys.
ARHGEF10L expression regulates cell proliferation and migration in gastric tumorigenesis
Authors: Wang Da-wei , Tang Jun-yi , Zhang Guo-qing , Chang Xiao-tian
Published: March 2020

We recently reported that Rho guanine nucleotide exchange factor 10-like protein (ARHGEF10L) activated Rho GTPases as guanine nucleotide exchange factor to stimulate liver tumorigenesis. The present study continued to explore the effect of ARHGEF10L on the tumorigenic process of gastric cancer. This study detected increased expression of ARHGEF10L in GC tissues compared to peritumoral tissue samples. SGC7901 cells with ARHGEF10L overexpression showed increased cell proliferation, cell migration, and tube-like structure formation abilities, as well as increased expression of GTP-RhoA, ROCK1, and phospho-Ezrin/Radixin/Moesin. ARHGEF10L overexpression downregulated the expression of E-cadherin and upregulated the expression of N-cadherin and Slug, indicating an activation of EMT in the transfected cells. RNA-sequencing assay detected an increased expression of Heat shock 70 kDa protein 6 in the SGC7901 cells overexpressing ARHGEF10L. The above results suggest that ARHGEF10L expression can stimulate gastric tumorigenesis by prompting RhoA-ROCK1-phospho-ERM signaling, inducing EMT and increasing HSPA6 expression.
Peeping over Galileo’s shoulders: laying the foundations of
heliocentrism in elementary school
Authors: Pincelli M M , Brustle M , Formichella M del C , Perez-Millán C , Palmieri N , Otranto S
Published: March 2020

In this work, an adaptation is developed of the first observation attempted by
Galileo to demonstrate the heliocentric hypothesis to be correct. The objective
is to enable students in their final year of elementary school to confront by
themselves the same contradictory evidence that Galileo confronted during the
second decade of the 17th century. The results of its implementation in two
classes of 32 students aged 11–12 years are reported, and the first
impressions of this pedagogical approach are analyzed.
The role of predictive model data in designing mangrove forest carbon programs
Authors: Bukoski Jacob J , Elwin Angie , MacKenzie Richard A , Sharma Sahadev , Purbopuspito Joko , Kopania Benjamin , Apwong Maybeleen , Poolsiri Roongreang , Potts Matthew D
Published: March 2020

Estimating baseline carbon stocks is a key step in designing forest carbon programs. While field inventories are resource-demanding, advances in predictive modeling are now providing globally coterminous datasets of carbon stocks at high spatial resolutions that may meet this data need. However, it remains unknown how well baseline carbon stock estimates derived from model data compare against conventional estimation approaches such as field inventories. Furthermore, it is unclear whether site-level management actions can be designed using predictive model data in place of field measurements. We examined these issues for the case of mangroves, which are among the most carbon dense ecosystems globally and are popular candidates for forest carbon programs. We compared baseline carbon stock estimates derived from predictive model outputs against estimates produced using the Intergovernmental Panel on Climate Change’s (IPCC) three-tier methodological guidelines. We found that the predictive model estimates out-performed the IPCC’s Tier 1 estimation approaches but were significantly different from estimates based on field inventories. Our findings help inform the use of predictive model data for designing mangrove forest policy and management actions.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Concentration measurement on preparation of blending SiO2 nano biodiesel
Authors: Norhafana M , Noor M M , Hairuddin A A
Published: March 2020

Biodiesel is an important renewable energy candidate for the future energy. To improve the fuel properties, many experimental works and trial for the fuel blend. The fuel enrichment method by addition of nano-additives is widely accepted by numerous researchers. The nano-additives are used to achieve specific fuel properties and to improve the performance characteristics and to attain a good emission control of the Compression Ignition (CI) engine without any modification. It is important to blend in right concentration in order to avoid the effect on fuel properties. This paper reports the calculation on how to measure concentration of blending biodiesel fuel with nanoparticles with the appropriate method which is mass concentration method. This paper investigates the details of concentration measurements of blending biodiesel (B7) with SiO2 nanoparticle by using the mass fraction method for only 0.5 liter of fuel. This method also can use for other types of fuel and nanoparticles. Thus, by using the correct method of mass concentration would not be affect to its fuel properties, engine performance and also exhaust emissions.
Sequential ultrasound-microwave assisted extraction of water soluble proteins from Eurycoma longifolia roots
Authors: Abugabr Elhag H E , Sulaiman A Z , Ajit A
Published: March 2020

Even though Eurycoma longifolia was extensively studied, few researches investigated the protein content in its water extracts with the consideration of establishing the most suitable extraction method to increase their yields with high efficiency and less time consumption. The study applied a sequential extraction method to increase the yields of water soluble proteins (WSPs) in E. longifolia root extracts by the application of two nonconventional extraction methods, Microwave assisted extraction (MAE) and ultrasound assisted extraction (UAE). The study was established by circumscribed central composite designs (CCCDs) to indicate the optimum extraction conditions and the corresponding maximum WSPs yields for both the methods by investigating the MAE factors which were temperature (T); microwave power (W) and irradiation time (i) and UAE factors temperature (T); ultrasonic intensity (UI); and sonication time (s). The optimum conditions of MAE (T: 54°C, W: 301W and i: 15 min) led to the WSPs yield 23.101±1.647%.The optimum conditions of UAE (T: 46°C; UI: 1.84 W.cm”2 and s: 24 min) led to 24.181±0.321%. These predicted optimum conditions were then employed for the two proposed sequential extraction method, sequential ultrasound-microwave assisted extraction (SUMAE) and sequential microwave-ultrasound assisted extraction (SMUAE). Results revealed that the highest WSPs yield (27.172±1.086%) was obtained by initiating the sequential extraction with UAE for 10 minutes followed by MAE treatment for 5 minutes was the best extraction process. Therefore, SUMAE illustrated more efficiency than SMUAE. This concluded that the SUMAE is a more efficient extraction process than the one-step nonconventional extraction methods and was nominated for the upscaling of extracting proteins from E. longifolia roots in pilot and industrial scales.
Evaluation of offshore marine current energy performance in Malaysia
Authors: Zahari S H , Ng C Y , Kurian V J , Wong L W , Selamat I M
Published: March 2020

Venturi Marine Current Energy Device (VMCED) is a current energy converter, which is focused in this research that aimed to harness the continuous movement of ocean current. It focuses on the venture effect to increase the efficiency of the flow velocity in resulting higher output energy from the ocean current. This research aimed to identify the best potential location of Malaysian waters to deploy the device. A computational fluid dynamic analysis was conducted in this study considering two important parameters i.e. velocity and differential pressure in the VMCED. These parameters were adopted in the analysis to measure the highest velocity and pressure differential. Among of the locations in Malaysia analysed in this study, it is to conclude that VMCED is best to be deployed in Straits of Malacca. This location measured the highest velocity and differential pressure of ocean current compared to others.
Simulation analysis of fuel cell integration in a hybrid car
Authors: Asus Z , Madon M I S , Che Daud Z H , Muhamad Said M F , Aglzim E H , Ab. Talib M H , Ahmad Z A
Published: March 2020

Fuel cell is one of the green technologies that can help reduce toxic gas and decreasing effect of greenhouse gases in the world. This paper attempts to improve simulation model of fuel cell system that is easy to use and at the same time have an acceptable accuracy. The simulation model is developed through Matlab/Simulink software using Energetic Macroscopic Representation method which accuracy is compared with an established model. Simulation analysis of fuel cell integration is conducted by using experimental data from a real hybrid car. There are two potential types of system that were considered for the hybrid car in term of electricity generation and power produced to move the car, a full fuel cell car or a hybrid of fuel cell and battery. Analysis reveals that the hybrid car using combination of fuel cell and battery system is more effective compared to the car using fully fuel cell system due to factors that prevents fuel cell wide utilization for the vehicle.
Analysis of cylinder pressure cyclic variability operating with butanol blends in a diesel engine
Authors: Mat Yasin M H , Mamat R , Sapee S , Yusop A F , Ali M H
Published: March 2020

Butanol is a second-generation biofuel which obtained from the biomass feedstock sources to improve the fuel properties and performance of the recent fuels. However, there are certain grey aspects in the combustion characteristics of butanol blends in various operating speeds and loads. This work investigates the use of mineral diesel (D), palm biodiesel (B), butanol (10%)-diesel (90%) (DBu10) and butanol (10%)-palm biodiesel (90%) (BBu10) fuels. The objectives of this study are to investigate the cyclic combustion variations of cylinder pressure profiles and peak cylinder pressure, Pmax and analyse the combustion stabilities using recurrence plot (RP) on tested fuels using a diesel engine. The results showed that higher peak cylinder pressures were observed for butanol blends with full load at 1100 rpm. Higher cylinder pressure cyclic variability occurred at high load and speed for all test fuels, especially DBu10 with higher COVPmax values. Thus, in this case, DBu10 produced the most chaotic combustion irregularities and higher cyclic variations for the time series in those conditions. In conclusion, cylinder pressure variations in the time series were found to be affected by the fuel composition of butanol in the blends and types of fuel in engine operation.
Preparation of Reduced Graphene Oxide (RGO) Modified Titanium Dioxide Nanotube (TNTs) as Visible Light Effective Catalyst for the Conversion of CO2 to CH4
Authors: Khatun F , Aziz A A , Sim L C
Published: March 2020

In this study, a modified visible light active photocatalyst has been prepared where titanium dioxide nanotube (TNTs) was coupled with reduced graphene oxide (RGO) through a facile synthesis process. The photoactivity of the RGO-TNTs has been evaluated by converting CO2 to CH4 under visible light irradiation. In order to justify the photo-effectivity of the catalysts, physical and optical characterization were performed through FESEM, EDX, UV-Vis absorption spectra and PL spectra. The morphological analysis shows homogeneous RGO distribution on the TiO2 nanotube whereas elemental compositional analysis revealed the presence of all elements in the prepared catalyst. Visible light enhancement activity of the prepared catalyst after the incorporation of RGO was exposed by UV-Vis analysis due to its enhanced light absorption properties. Improved electron-hole separation rate was investigated for the RGO incorporated TNTs through PL analysis. The fruitful incorporation of the RGO with TNTs further affirmed by the increased photocatalytic activity by converting CO2 to CH4 that acquired enhanced CH4 production (9.27%) which is 1.81 times higher than the CH4 production rate obtained through TNTs (5.12%). Thus, this study induces a simple synthesis procedure to modify TNTs as a visible light active photocatalyst with the integration of RGO. Moreover, RGO-TNTs enhanced visible light activity were evaluated through the conversion of CO2 to CH4.
Ni–supported palm oil fuel ash catalyst (Ni–POFA) from in situ glycine-nitrate combustion for methane cracking
Authors: Hanifa N H E , Ideris A , Ismail M
Published: March 2020

Metal-supported catalysts synthesized using a conventional impregnation method are usually suffered from non-uniform distribution and agglomeration of catalyst particles. In this work, in situ glycine-nitrate combustion method has been explored to synthesize Ni catalyst supported on palm oil fuel ash (Ni–POFA). The properties and performance of the catalyst were compared with one produced using impregnation method. Effects of pre-treatment and catalyst preparation method have been investigated and characterizations of POFA and Ni–POFA catalysts were performed using XRF, XRD, BET surface area, FESEM and TGA. Catalytic activity of the catalysts was evaluated for methane cracking at 550 °C. Results showed that pre-treatment has improved the composition of SiO2 in POFA from 42.4 to 72.0%. Ni–POFA catalyst synthesized using in situ glycine-nitrate combustion method exhibited a good catalytic performance during the methane cracking with an initial H2 yield of 6.4%. This was attributed to high Ni metal dispersion on POFA support. Nevertheless, the degradation of CH4 conversion for this particular catalyst was more significant than one produced using impregnation method. Catalyst prepared using in situ glycine-nitrate combustion was active towards carbon formation, thus led to an obvious formation of carbon on the catalyst surface. Additionally, catalyst preparation method influenced the type of carbon formed on the spent Ni–POFA catalysts.
High degradation of BIVO4 nanoparticle for organic dyes under visible light irradiation mediated by S2O8
Authors: Cao V D , Nong L X , Nguyen V H , Tran T V , Vu H T , Nguyen C V , Do S T
Published: March 2020

In this study, we have successfully synthesized BiVO4 materials by hydrothermal method. The degradation of methylene blue (MB) under LED visible light mediated by S2O8/BiVO4/Vis system. The obtained BiVO4 catalyst was characterized by X-ray diffraction (XRD), Raman, scanning electron microscope (SEM), and UV-visible diffuse reflectance spectrum (UV-vis DRS). We investigated the effect of S2O8 concentrate, pH value and initial concentration on the removal rate of MB. The results of XRD spectra showed that the BiVO4 fragment has a crystalline structure in moneblinite monoclinic phase alone. The degradation of MB concentration under visible light mediated S2O8/BiVO4/Vis was 78% after 100 minutes of irradiation. The band gap (Eg) of BiVO4 was estimated to be 2.39 eV. Therein, the presence of Na2SO4 anions decrease concentration of MB with compared to the original using S2O8/BiVO4 system alone.
Synthesis and characterization of MSU-2 synthesized by using tetraethylorthosilicate and Triton X-100
Authors: Lee X Y , Chew T L , Oh P C , Jawad Z A , Ho C D
Published: March 2020

Adsorption technology is one of the well-established gas separation techniques as it can minimize cost and energy requirement for CO2 separation. Mesoporous silicas such as MSU-2 appears to be a good adsorbent as it comprises of three-dimensional (3D) wormhole framework structures that are highly interconnected which minimize the diffusion resistance of CO2 through its pore structure. Current study focus on the preparation of MSU-2 and investigation on the CO2 adsorption on the synthesized MSU-2. In this study, MSU-2 was prepared by using tetraethylorthosilica (TEOS) as a source of silica in the presence of non- ionic polyethyleneoxide (PEO)-based surfactants under an acidic condition where the pH is 2 at 55 °C for 48 hours via the fluoride-assisted two-step synthesis process. The two main steps involved are hydrolysis of TEOS and condensation of silica. The morphology, crystallinity, functional groups and pore characteristics of MSU-2 were investigated by using characterization method of Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray (EDX) Spectrometry, X-ray Diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). The synthesized MSU-2 was well crystallized and possessed a uniform monodisperse microspherical morphology with BET surface area, pore volume and pore size of 964 m2/g, 0.98 cm3/g and 4.1 nm, respectively. All the characterization results showed that MSU-2 was successfully synthesized via solution precipitation method. In conclusion, the high BET surface area of the synthesized MSU-2 shows that MSU-2 is a very potential candidate as a good adsorbent for gases.