PEG at compositions of 10, 15 and 20 g were added into the initial formulation of hydrogel L, which was composed of
6 g low molecular weight chitosan (LMC) and 14 g poly (vinyl pyrrolidone) in 100 g of 2% lactic acid. The mixtures
were moulded and exposed to γ radiation at 7 kGy. The hydrogels obtained were characterized in term of gel fraction,
swelling property, syneresis effect, FTIR, XRD and cross section morphology. The results indicated PEG reduces almost
27% crosslinking density of the LMC-PVP hydrogel yet increased hydrogel’s water holding capacity from 450% and 480%
to 750% and 650% in phosphate buffer solution (PBS) at pH5.5 and pH7.0, respectively. Also PEG enhanced the ability
of LMC-PVP hydrogel to retain its moisture from dehydration at body temperature. The morphological study showed PEG
developed thick pores wall and reduced the pores size of the hydrogels’ network.
Rambutan fruit is an exotic fruit and is getting popular worldwide. However, there is usually a glut of rambutan fruit
every year which leads to wastage, especially those from underutilized wild types. Transforming the fruit into various
products could reduce the wastage. Before doing so, the characteristics of the fruit should be available. Hence, the main
aim of this study was to investigate the physicochemical properties of various cultivars of rambutan. The results showed
that rambutan fruit comprises between 38.6-70.8% peel, 19.1-45.9% pulp and 8.3-20.3% seed. On average, it has a pH,
titratable acidity and total soluble solids of 4.18-5.44, 0.10-0.52% as citric acid and 13.78-16.67 °Brix, respectively.
The fruit contains high sugar contents, mainly contributed by sucrose (5.38-10.01%), fructose (1.75-3.18%) and glucose
(1.72-2.43%). Citric acid was the major organic acid found in the fruit and wild type, WT1, contained the highest level.
Some rambutan cultivars including Clone R3, WT1 and wild type, WT2, possess greater concentrations of ascorbic acid
compared to other tropical fruits. With these findings, various types of food products could be derived from rambutan
fruit based on their physicochemical properties.
The use of biodegradable material in membrane technology will be a great solution in reducing non-biodegradable
waste in the landfill. Membranes can often be useful as the recycle stream can usually be much cleaner than with other
techniques. This article describes the preparation of poly(l-lactic acid)-poly(ethylene glycol) (PLLA-PEG) free standing flat
sheet membranes with the presence of 5 wt. % activated carbon filler. PLLA-PEG crosslinked copolymer was synthesized
using PLLA with different molecular weight PEG prepolymers i.e. 4000, 6000 and 10000 g/mol; and excess hexamethylene
diisocyanate to form urethane linkages between the polymers. The reaction was carried out in a dichloromethane/
tetrahydrofuran dual-solvents system. The PLLA-PEG/AC membranes in the weight ratio of 7:3:0.5 were then fabricated
using solution casting and phase inversion techniques. The performance of the membranes was evaluated in terms of
permeation water flux (PWF), palm oil mill effluent (POME) permeation, flux decline and contact angle. It was found that
membrane containing 10000 g/mol PEG has the highest total mean in PWF, POME flux and hydraulic permeability with
values of 100.9 L/m2
.h, 51.45 L/m2
.h and 64.9º;62.9º, respectively, due to high porosity. All of the membranes were more
stable towards the flux decline of POME compared to water. At the same time, addition of AC to the copolymer considerably
enhances the texture and porosity of the fabricated membranes.
[BMIM]OTf and alcohol-based DES combination with a selected organic solvent (acetone and acetonitrile) have
been proven to efficiently extracting rotenone (isoflavonoid biopesticide) compound compared to individual organic
solvents. Their efficiency builds up interest to study the solvent-solute interaction that occurs between both selected
solvent systems with rotenone. The interaction study was analyzed using FTIR, 1D-NMR and 2D- NMR (NOESY, HMBC).
Correlation portrayed by NOESY and HMBC of [BMIM]OTf - standard rotenone mixture predicted probable hydrogen
bonding between the oxygen of rotenone with acidic proton C2-H of [BMIM]OTf. While for the alcohol-based DESrotenone
mixture, the correlation shows probable interaction to occur between methyl and methoxy group rotenone
with the hydroxyl group of 1,4-butanediol. In conclusion, potential hydrogen bonding that occurs between solvent
and solute aid towards the solvent efficiency in extracting rotenone compound while emphasizing on the low cost and
green mediated solvent systems.
C-4-phenacyloxy phenyl calix[4]resorcinarene (CPPCR) was synthesized by acidic condensation of 4-hydroxybenzaldehyde
and resorcinol. The adsorption of CPPCR for Pb(II), Cd(II) and Cr(III) has been studied by measuring the metal
concentration in aqueous solution using Atomic Absorption Spectrophotometry (AAS). The effects of solution pH, contact
time and initial concentration of metal ions on the adsorption capacity of CPPCR were investigated. The adsorption kinetic
of all the ions obeyed the Ho and McKay pseudo 2nd order rate law and the adsorption isotherm profile matched very well
with Langmuir model. The separation factor (RL
) of CPPCR for Pb(II), Cd(II) and Cr(III) were 0.190, 0.017, and 0.065,
respectively, indicating the formation of monolayer behaviour. The Gibb free energy (ΔG) of the adsorption for all the
metal ions have negative values indicating the adsorption process of Pb(II), Cd(II) and Cr(III) by CPPCR are spontaneous.
Malaysian economy relies on palm oil industries as a driver for rural development. However, palm oil mill effluent
(POME) that is generated from palm oil processing stages causes major environmental challenges. Before being
released to the environment, POME treatment is crucial to comply with standard discharge limit. Microalgae have
demonstrated excellent potential for phycoremediating POME and capturing CO2
. In this study, local microalgae isolate
such as Chlamydomonas sp. UKM 6 and Chlorella spp. UKM 8 were used for POME treatment in 21 days with different
inoculum sizes (5%, 10% and 15%). In addition, an integrated treatment process was performed by taking the treated
POME supernatant for cultivation of Chorella spp. UKM 2, Chorella sorokiniana UKM 3 and Chlorella vulgaris for CO2
sequestration study. Different CO2
concentrations (5%, 10% and 15%) were used and the experiments were carried
out in 10 days under continuous illumination. The results showed that among two species involves in POME treatment,
Chlamydomonas sp. UKM 6 showed a great potential to remove pollutant such as COD (56%), nitrogen (65%) and
phosphorus (34%). The biomass after POME treatment and CO2
biofixation content high lipid (90 mg lipid/g biomass)
which can be the potential source for biodiesel production. In CO2
sequestration study, C. sorokininana UKM3 able
to takes up to 15% CO2
with CO2
uptake rate of 273 mgL-1d-1. In this study, the integrated system of POME treatment
and CO2
sequestration were feasible using microalgae.
In a 90-day feeding trial, twenty four (24) Saanen lactating does were assigned to four treatment group. The treatments
were feeding: basal diet only as a control (T1), basal diet with urea molasses multi-nutrient block (UMMB) (T2), basal
diet with medicated urea molasses multi-nutrient block (MUMB) (T3) and basal diet with commercial mineral block (CMB)
(T4). There were significant differences (p<0.05) between T2, T3 and T4 on the fecal egg count (FEC). Animals in T2
and T3 showed moderate level of parasite infestation i.e. at 750 epg and 950 epg, respectively, while animals in T1 and
T4 showed severe parasite load at 4917 epg and 1850 epg, respectively. There were no significant differences (p>0.05)
between treatments on WBC, LYM, MON, GRA, RBC, HCT, MCV, MCH, PLT, MPV and PCT. However, significant effects (p<0.05)
on HBG, MCHC, RDW and PDW were observed in T2 and T3. This research showed that UMMB and MUMB were effective
in controlling parasite infestation in Saanen lactating dairy goats apart from improving their blood hematological
parameters. Comparison with CMB showed that it is practical to be used for parasite control.
Kappaphycus alvarezii kaya dengan karagenan yang banyak digunakan dalam industri makanan sebagai agen pemekat
dan penstabil. Penggunaan gelatin ikan dan ayam dalam produk makanan dapat menggantikan gelatin lembu yang
mempunyai banyak isu terutamanya berkaitan halal dan penyakit lembu gila (BSE). Penyelidikan ini adalah untuk
menentukan kesan penambahan Kappaphycus alvarezii, gelatin ikan dan gelatin kaki ayam terhadap ciri-ciri kualiti
sosej ayam. Dua formulasi optimum T1 (10% Kappaphycus alvarezii, 3.81% gelatin ikan, 7.63% gelatin kaki ayam)
dan T2 (2.57% Kappaphycus alvarezii, 5% gelatin ikan, 7.63% gelatin kaki ayam) telah diperoleh daripada Kaedah
Respon Permukaan (RSM) dalam kajian awalan. Kualiti sosej ayam dikaji berdasarkan analisis proksimat dan ujian
jangka hayat (pH, nilai TBA dan warna). Ujian jangka hayat dijalankan selama 3 minggu pada suhu penyimpanan 4
± 1°C Penambahan Kappaphycus alvarezii, gelatin ikan dan gelatin kaki ayam meningkatkan (p<0.05) kandungan
protein dan abu tetapi menurunkan (p<0.05) kandungan lemak. Nilai pH bagi sampel T1 dan T2 lebih tinggi berbanding
dengan C semasa tempoh penyimpanan. Nilai TBA bagi sampel T1 dan T2 adalah rendah dibandingkan dengan C
semasa tempoh penyimpanan. Penambahan Kappaphycus alvarezii, gelatin ikan dan gelatin kaki ayam mengubah
warna bagi sampel T1 dan T2 sepanjang tempoh penyimpanan. Penambahan Kappaphycus alvarezii, gelatin ikan dan
gelatin kaki ayam mengubah warna sosej ayam sepanjang tempoh penyimpanan. Kajian ini menunjukkan penambahan
campuran Kappaphycus alvarezii, gelatin ikan dan gelatin kaki ayam pada tahap optimum menghasilkan sosej ayam
yang lebih berkualiti.
A 50Hz glow discharge He/CH4
plasma was generated and applied for the glass surface modification to reduce the powder
adhesion on wall of spray dryer. The hydrophobicity of the samples determined by the water droplet contact angle and
adhesion weight on glass, dependent on the CH4 flow rate and plasma exposure time. The presence of CH3
groups and
higher surface roughness of the plasma treated glass were the factors for its hydrophobicity development. Response
surface methodology (RSM) results using central composite rotatable design (CCRD) showed that optimal responses
were obtained by the combination of parameters, CH4
gas flow rate = 3 sccm and exposure time = 10 min. In optimum
conditions, the contact angle increased by 47% and the weight of the adhesion reduced by 38% (w/w). The plasma
treatment could enhance the value of the contact angle and thus reduced the adhesion on the spray dryer glass surface.
MeSH terms: Body Fluids; Glass; Powders; Water; Hydrophobic and Hydrophilic Interactions
Levulinic acid (LA) is one of biomass derived building block chemicals with various applications. Catalytic esterification
of LA with alkyl alcohol produces levulinate ester which can be applied as fragrance, flavouring agents, as well as fuel
additives. In this study, a series of sulfated silica (SiO2
) catalyst was prepared by modification of SiO2
with sulfuric acid
(H2
SO4
) at different concentrations; 0.5 M to 5 M H2
SO4
. The catalysts were characterized, and tested for esterification
of LA with ethanol to ethyl levulinate (EL). The effect of various reaction parameters including reaction time, catalyst
loading and molar ratio of LA to ethanol on esterification of LA to EL were inspected. The catalyst with high concentration
of acid sites seemed suitable for LA esterification to EL. Among the sulfated SiO2
catalysts tested (0.5 M-SiO2
, 1 M-SiO2
,
3 M-SiO2
and 5 M-SiO2
), 3 M-SiO2
exhibited the highest performance with the optimum EL yield of 54% for reaction
conducted at reflux temperature for 4 h, 30% 3 M-SiO2
loading and LA to ethanol molar ratio of 1:20. Besides, the
reusability of 3 M-SiO2
catalyst for LA esterification with ethanol was examined for five cycles. Esterification of LA with
methanol and 1-butanol were also carried out for methyl levulinate (ML) and butyl levulinate (BL) productions with 69%
and 40% of ML and BL yields, respectively. This study demonstrates the potential of sulfated SiO2
catalyst for levulinate
ester production from LA at mild process condition.
Glycerol, the main by-product in biodiesel manufacturing, is a useful and environment-friendly solvent for many organic
and inorganic substrates. This study investigates the effects of soaking using glycerol, silicone oil, dimethyl sulfoxide
(DMSO) and Organosolv (1:1 water: ethanol) on energy consumption in the process of grinding kempas wood and on
the particle size of ground kempas. Kempas wood chips were soaked in various solvents at 90°C for 1 h. The structural
characterisation of untreated and treated kempas was analysed using CHNS, ATR-FTIR and XRD. Meanwhile, the grinding
energy was calculated based on power per unit time while particle size was analysed using nested column sieves. Glycerol
has high stability, good compatibility with other chemicals and is environmentally friendly. Glycerol-soaked kempas
consumed less energy which led to energy saving of up to 0.015 W h and exhibited the smallest average particle size
(263 µm) close to that of untreated kempas due to glycerol lubricating properties. Therefore, glycerol can be used as
an alternative to conventional solvents in reducing the grinding energy consumption and particle size of lignocellulosic
biomass.
Poly(ethylene glycol)-polydimethylsiloxane (PEG-PDMS) crosslinked copolymers with mol ratios PEG:PDMS:Glycerol
of 5:3:2, 6:2:2 and 7:1:2 have been prepared and characterized. The synthesis of the copolymers was carried out
by the reaction between hydroxyl groups of PEG, PDMS and glycerol with isocyanate groups of 1,6-hexamethyelene
diisocyanate (HMDI). In the reaction, glycerol was acted as the cross linker. The copolymers were then characterized
by FTIR spectroscopy. The thermal behaviour was investigated by DSC and TGA. Based on FTIR results, the crosslinked
structure of the copolymers was confirmed by the presence of absorption peak at 3350 and 1710 cm-1 which indicated
the (-N-H) stretching and carbonyl (-C=O) correspond to urethane links. This showed that the hydroxyl groups of PEG,
PDMS and glycerol have reacted to isocyanate groups of HMDI. The copolymers showed melting temperature (Tm) of PEG
segments from 22°C to 27°C and glass transition temperature (Tg
) from -11°C to -6°C. Meanwhile, the PDMS segment
showed values from -53°C to -56°C for Tm, and Tg
from -118°C to -122°C. Data obtained from the thermal analysis
indicate that thermal stability increases with increasing PDMS mol ratio.
The role of heat shock protein in reproduction is widely known as a molecular chaperone in aiding and repairing protein
formation when stress occurred. The present objectives were to evaluate the effect of different thawing temperature and
time on the expression of HSP70 gene expression and the capacitation status in cryopreserved bovine spermatozoa. Briefly,
fresh ejaculates were obtained from three different adult bulls. The semen then underwent a sperm washing technique
known as Magnetic Activated Cell Sorting System (MACS) and later on, cryopreserved. The sperm- containing straws
were then thawed at five different thawing temperatures and time post-cryostorage; 20°C for 13 s, 37°C for 30 s, 40°C
for 7 s, 60°C for 6 s and 80°C for 5 s. The RNA was extracted from each of the sperm’s pellets and converted to cDNA
prior to the qPCR process. Capacitation status was then determined by means of CTC assay. The results showed that after
the process of amplification, there is a significant different of HSP70 gene expression in MACS process samples when the
thawing process was performed at 37°C for 30 s, with p<0.05. Furthermore, the CTC assay also showed that thawing at
the same temperature gave less capacitated spermatozoa with p<0.05. As a conclusion, MACS yield spermatozoa with a
better expression of HSP70 gene and less capacitated spermatozoa when thawing was done at 37°C for 30 s.
Phalaenopsis bellina is an important indigenous fragrant orchid threatened with extinction. In this study, we evaluated
the effect of medium strength, sucrose, nitrogen (NH4
NO3
) and potato extract on proliferation of P. bellina protocormlike
bodies (PLBs) to improve micropropagation in this species. Optimal treatment for PLBs proliferation rate with an
average fresh weight (FW) of 0.97±0.16 g was obtained through culturing on half strength (½) MS medium containing
20 g/L sucrose, 15 mM NH4
NO3
and 20% w/v potato extract supplemented with 0.8 µM 2,4 dichlorophenoxyacetic acid
(2,4-D). The optimal treatment produced large, healthy and greenish PLBs with reduction in the occurrence of culture
browning. In contrast, treatments with high potato extract (>20% w/v) or NH4
NO3
(>30 mM) concentrations tend to
have inhibitory effect and resulted in low PLBs proliferation rate, with an average FW of 0.77±0.15 g and 0.69±0.15 g,
respectively. Plant regeneration of PLBs was achieved on plant growth regulator (PGR)-free ½ MS medium. In total, 60
healthy PLBs from the optimal treatment were successfully regenerated, acclimatized with 100% survival percentage and
grew well in a mixture of soil, sand and vermicompost (8:4:2 (w/w/w)). With the optimal treatment, PLBs proliferation
rate was enhanced by 27.63%. Our findings offer an improved micropropagation protocol of the endangered P. bellina
for conservation and commercial production.
Oxidation of p-Cresol was investigated by using ozonation process. The aim of this research is to assess the effectiveness
of ozonation on oxidation of micropollutant such as p-Cresol. Ozonation performance was evaluated based on p-Cresol
concentration reduction and chemical oxidation demand (COD) reduction. It was found ozonation at pH11 achieved
the highest p-Cresol degradation, with 95.8% of p-Cresol reduced and 96.0% of COD reduced, for an initial 50 mgL-1
of p-Cresol. The degradation of p-Cresol could be expressed by second-order of kinetic model. The second-order rate
constant k increases as the initial pH increased, but decreases with the increasing of initial p-Cresol concentrations.
Besides, the absorption spectra of p-Cresol over ozonation time were analyzed by spectrophotometry. The evolution of
absorption spectra of p-Cresol degradation suggests that the oxidation of p-Cresol follows three stages mechanisms
with cycloaddition as the first step to produce aromatic intermediates followed by ring-opening reactions, degradation
of the intermediates, and subsequently achieved mineralization.
The effects of salinity on the gastric emptying time (GET) and absorption of nutrient along the alimentary tract of tiger
grouper (TG) × giant grouper (GG) (Epinephelus fuscoguttatus × E. lanceolatus) hybrid were studied. Juveniles TG×GG
hybrid grouper (10.0 ± 0.5 cm total length; 50.5 ± 2.0 g) were reared in different salinities (10, 15, 20, 25 and 30 parts per
thousand (ppt)) and fed with commercial pellet diet during the 60-day experimental period. The fish were then slaughtered
sequentially at different time intervals after initial feeding to obtain GET. Our results showed that low salinity (10-20 ppt)
lead to a shorter GET in the hybrid grouper. The shortest and longest GETs were observed in 15 ppt (12 h) and 30 ppt (18
h) treatments, respectively. Apparent digestibility coefficient (ADC) using ash contents was measured to determine the
absorption of nutrient in each treatment. The absorption of macronutrient in TG×GG hybrid grouper was increased as
the salinity decreased. The highest absorption occurred in 15 ppt (72% protein, 75% lipid, 68% carbohydrate and 74%
energy) while the lowest absorption occurred in 30 ppt (59% protein, 64% lipid, 34% carbohydrate and 55% energy).
The findings of this study suggested that 15 ppt salinity facilitates faster digestion and maximize the nutrient absorption
of TG×GG hybrid and may enhance the growth rate of this newly developed grouper species.
This study offers the numerical solutions for the problem of mixed convection stagnation-point flow along a permeable
vertical flat plate in an Oldroyd-B fluid. The present investigation considers the effects of thermal radiation and heat
generation/absorption in the fluid flow. The similarity transformation simplifies the complex model and the bvp4c function
generates the numerical solutions according to the variations in the governing parameters. A higher degree of shrinking
hastens flow separations. The dual solutions are visible in the range of buoyancy opposing flow. The results from this study
may be useful for the scientist to understand the behaviour of the dilute polymer solutions in the industrial applications,
for example, the drag reduction in pipe flows.
MeSH terms: Government; Hot Temperature; Polymers; Convection; Physical Phenomena; Hydrodynamics
Air heating by solar collectors is renewable technology providing hot air for different purposes. The present research
emphasizes on analysis of energy, exergy and efficiency of a flat plate solar air heater. The analysis model was tested
on five different air mass flow rates of 0.5 (Natural), 1.31, 2.11, 2.72 and 3.03 kgs-1 under three different tilt angles of
25, 35 (Recommended) and 50o
. The data was replicated three times making a total of 45 treatments. A two factorial
completely randomized design was used to find if there is any significant difference among the treatments. The results
showed that the solar collector gave better performance at air mass flow of 3.03 kgs-1 under tilt of 35o
. At maximum
air mass flow rate of 3.03 kgs-1and optimum tilt angle of 35o
the maximum energetic efficiency of 51%, while minimum
exergetic efficiency of 24% and maximum overall efficiency of 71% were recorded. It was concluded that to get maximum
thermal efficiencies of 71% from flat plate solar collector used as an air heater must be operated at high air mass flow
rates of 3.03 kgs-1under 35o
tilt angle at Peshawar, Pakistan.
Pulp and paper mill sludge (PPMS) was found to be poorly colonised with thermophilic microorganisms. However,
evidence to support the need for inoculation to facilitate PPMS composting has only been demonstrated in one instance.
In this study, we aimed to: screen and identify PPMS digesting thermophilic bacterial strains; investigate effects of the
mixture of selected thermophilic bacterial strains on PPMS digestion; and utilize this mixture as start inoculum in PPMS
composting and assess the quality of compost product. The results showed that eleven thermophilic bacterial strains were
isolated from Bai Bang PPMS by the enrichment culture method. Among these, three strains which reflected high growth
rates on the plates of Minimal Media Agar supplemented with Bai Bang PPMS and showed hydrolytic and ligninolytic
activities on the agar plates containing appropriate inductive substrates were selected. Based on the morphological,
biochemical characteristics and 16S rRNA gene sequencing, they were identified as Bacillus subtilis. The inoculation
with the mixture of selected strains enhanced remarkably Bai Bang PPMS digestion. The dry weight decrease, volatile
suspended solids removal, dehydrogenase and protease activities in the inoculated sludge were 2.1-, 1.5-, 1.3- and 1.2-
fold higher, respectively, compared to the non-inoculated sludge. The assessment of compost quality based on stability
using the alkaline trap method and maturity using the germination and root elongation test showed that the inoculated
compost was stable and mature while the non-inoculated compost was unstable and immature. These thermophilic
bacterial strains therefore have great potential for Bai Bang PPMS composting.
Dietary study provides understanding in predator-prey relationships, yet diet of tropical forest birds is poorly understood.
In this study, a non-invasive method, next-generation sequencing (Illumina MiSeq platform) was used to identify prey in
the faecal samples of the Rufous-winged Philentoma (Philentoma pyrhoptera). Dietary samples were collected in lowland
tropical forest of central Peninsular Malaysia. A general invertebrate primer pair was used for the first time to assess
diet of tropical birds. The USEARCH was used to cluster the COI mtDNA sequences into Operational Taxonomic Unit (OTU).
OTU sequences were aligned and queried through the GenBank or Biodiversity of Life Database (BOLD). We identified
26 distinct arthropod taxa from 31 OTUs. Of all OTUs, there was three that could be identified up to species level, 20 to
genus level, three to family level and five could not assigned to any taxa (the BLAST hits were poor). All sequences were
identified to class Insecta belonging to 18 families from four orders, where Lepidoptera representing major insect order
consumed by study bird species. This non-invasive molecular approach provides a practical and rapid technique to
understand of how energy flows across ecosystems. This technique could be very useful to screen for possible particular
pest insects consumed by insectivores (e.g. birds and bats) in crop plantation. A comprehensive arthropod studies and
local reference sequences need to be added to the database to improve the proportion of sequences that can be identified.