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Colourimetric determination of features of an air sampling technique optimal for detection of surfactants

Nur Hazimah Abdul Halim, Norfazrin Mohd Hanif, Mohamed Rozali Othman, Mohd Talib Latif

Sains Malaysiana, 2010;39:175-179.

Surfactants in the atmosphere may act as cloud condensation nuclei, with a potentially negative impact on the global climate. Therefore, accurate determination of surfactants is crucial in order to investigate the possible effects of surfactants on the atmosphere. The aim of this study was to identify the optimum sampling method for measuring the maximum quantity of surfactants present in ambient air. Air samples were collected using a range of air sampling pumps that were made to vary in terms of flow rate, storage period, type of absorbing solution and the characteristics of the impinger tube. Samples obtained were analysed by colourimetry for anionic and cationic surfactants as methylene blue-active substances (MBAS) and disulphine blue-active substances (DBAS), respectively. Absorbance was measured at 650 nm for MBAS and 628 nm for DBAS using UV-visible spectrophotometer. We found that the optimum sampling method consisted of an absorbent solution (deionised water, buffer solution and methylene blue/disulphine blue solution) with the flow rate of 1.0 L/min. The concentration of surfactants in all sampling methods remained constant regardless of the storage period (1 day and 4 days), indicating that surfactants in the absorbing solution are quite stable. Covering the impinger tube was shown to influence the amount of both anionic and cationic surfactants detected.

Matched MeSH terms: Atmosphere
Life cycle inventory of institutional medium-scaled co-composting of food waste and yard waste in tropical country

Chee Guan Ng, Sumiani Yusoff

Sains Malaysiana, 2015;44:517-527.

The main objective of the present study was to provide a comprehensive LCI of medium scale composting of food waste
and yard waste at institutional level, based on substance flow analysis (SFA). A secondary objective was to present the
composition and assess the quality of the final compost product from composting of typical Asian organic waste (food
waste and yard waste). The experiments were designed to represent a batch situation in an institutional medium size
composting scenario with input material of food waste mixed with grass clippings and dried leaves. Two composting
runs were carried out with the intention to showcase the heterogeneity of organic waste and study the effect of windrow
size on the performance of the process. The input and output material were sampled and characterized in order to
quantify the substance balance of the process. SFA was performed by means of the mass balance model STAN 2.5 to
compute unknown parameters (gaseous emissions). SFAs have been performed for C, N, K, P, Cd, Cr, Cu, Ni and Pb. The
composting windrows were fed with 212.4 and 393 kg, respectively. VS content reduction is greater in composting pile
with larger size (Run 2). The loss of C during composting was recorded in the range of 0.146-0.166 kg/kg ww. The C
losses via leachate were insignificant (0.02% of the total input C). The total N loss during the process was 0.005-0.012
kg/kg ww. The leachate generation was measured as 0.012-0.013 kg/kg ww. The flows of selected heavy metals were
assessed. Heavy metals were of minor significance due to low concentrations in the inputs (food waste and yard waste).
Heavy metals were found to be released to the atmosphere. However, majority of heavy metals remain in the finished
compost. The C/N reduction during the process was in the range of 10-23%. In general, the compost composition was
considered to be within the ranges previously reported in literature and thus ready for application in gardening. The LCI
presented in the present study can be used as a starting point for making environmental assessments of medium-scale
co-composting of food waste and yard waste in tropical environment. No major environmental problems were identified
from the process, except for the emissions of GHGs.

Matched MeSH terms: Atmosphere
Effect of monoethanolamine loading on the physicochemical properties of amine-functionalized Si-MCM-41

Anita Ramli, Sohail Ahmed, Suzana Yusup

Sains Malaysiana, 2014;43:253-259.

Siliceous mesoporous molecular sieve (Si-MCM-41) material with highly ordered hexagonal pore arrangement was synthesized at 373 K for 8-days duration by hydrothermal method, dried at 393 K and calcined at 823 K in N2 atmosphere. The calcined Si-MCM-41 was later functionalized with 10-50 wt. % monoethanolamine (MEA) by impregnation method and dried in vacuum at 343 K. The MEA-Si-MCM-41 samples were characterized for their physicochemical properties with FTIR, XRD, TGA, HRTEM, FESEM, BET and elemental analysis. XRD results showed that the intensity of the characteristic peaks of Si-MCM-41 reduces with increasing loading of MEA indicating that the MEA molecules are loaded in the pores as well as on the surface of Si-MCM-41. The appearance of FTIR peaks corresponding to N-H, C-N and C-H bonds suggested that Si-MCM-41 has been functionalized with MEA. The presence of Si-O-Si peaks in FTIR spectra of MEA-Si-MCM-41 samples indicates that the hexagonal pore arrangement remains intact and this is supported by HRTEM images. FESEM images show that MEA-Si-MCM-41 samples became agglomerated with increase loading of MEA. TGA analyses show that the MEA-Si-MCM-41 samples are thermally stable up to 528 K. N2 adsorption-desorption isotherms show that the textural properties of Si-MCM-41 material slowly change from a mesoporous material to non-porous material as the MEA loading increases due to pore filling effect during functionalization with MEA. Detection of N, C and H by elemental analysis confirms the presence of MEA in MEA-Si-MCM-41 samples.

Matched MeSH terms: Atmosphere
Fulltext Study domain and its influences on family-work enrichment among Teachers

Safaril, Maadon, Zaiton, Hassan, Mark, Kasa, Ida Juliana, Hutasuhut

Journal of Cognitive Sciences & Human Development, 2019;5(1):19-28.
MyJurnal

Work-Life balance (WLB) studies have investigated heavily on family domain even though
there are sub domains in life. Thus, this study will contribute to the literature by examining
study domain (lifelong learning and organizational learning) and its influence on familywork
enrichment (FWE) among teachers who are currently continuing their education in
Lundu district. A total of 117 teachers responded to the self-administered questionnaire. The
finding revealed that both organizational learning and lifelong learning have a positive significant
relationship with family work enrichment. Therefore, school management should
encourage the culture of lifelong learning and at the same time provide facilities and atmosphere
to support the culture will ensure family-work enrichment among teachers who are
continuing their study.

Matched MeSH terms: Atmosphere
Absolute Photoabsorption Cross-Sections of Methanol for Terrestrial and Astrophysical Relevance

Lange E, Lozano AI, Jones NC, Hoffmann SV, Kumar S, Śmiałek MA, et al.

J Phys Chem A, 2020 Sep 30.
PMID: 32941031 DOI: 10.1021/acs.jpca.0c06615

We investigate the methanol absorption spectrum in the range 5.5-10.8 eV to provide accurate and absolute cross-sections values. The main goal of this study is to provide a comprehensive analysis of methanol electronic-state spectroscopy by employing high-resolution vacuum ultraviolet (VUV) photoabsorption measurements together with state-of-the-art quantum chemical calculation methods. The VUV spectrum reveals several new features that are not previously reported in literature, for n > 3 in the transitions (nsσ(a') ← (2a″)) (1A' ← X̃1A') and (nsσ, npσ, npσ', ndσ ← (7a')) (1A' ← X̃1A'), and with particular relevance to vibrational progressions of the CH3 rocking mode, v11'(a″), mode in the (3pπ(a″) ← (2a″)) (21A' ← X̃1A') absorption band at 8.318 eV. The measured absolute photoabsorption cross-sections have subsequently been used to calculate the photolysis lifetime of methanol in the Earth's atmosphere from the ground level up to the limit of the stratosphere (50 km altitude). This shows that solar photolysis plays a negligible role in the removal of methanol from the lower atmosphere compared with competing sink mechanisms. Torsional potential energy scans, as a function of the internal rotation angle for the ground and first Rydberg states, have also been calculated as part of this investigation.

Matched MeSH terms: Atmosphere
Fulltext Roles and mechanisms of stem cell in wound healing

Ayavoo T, Murugesan K, Gnanasekaran A

Stem Cell Investig, 2021;8:4.
PMID: 33829056 DOI: 10.21037/sci-2020-027

Wound healing phases comprise of highly synchronized process that begins due to a damage and restores the integrity of the injured tissues. Wound healing reduces the damage in tissue and supply sufficient oxygen and tissue perfusion, provide proper nourishment and humid wound healing atmosphere to re-establish the essential status of exaggerated parts. The untreated wound becomes susceptible for pus development, bacterial infection and complications like sepsis. Traditional and modern approaches are in practice to treat acute, open and chronic injuries, however, present wound care management has met with challenges and minimal positive effects. Stem cells have possible wound healing capability to overwhelm restrictions of the current wound care practices as it produces faster tissue regeneration in wound repair. Stem cells are unspecialized cells derived from adult body tissues and embryos that differentiate into any cell of an organism and capable of self-regeneration. The understanding on molecular mechanisms of stem cells has become the central and promising field in scientific study. This review focuses on the pre-existing traditional and modern treatments for wound healing, and types and roles of stem cells in wound care management. This review also focuses on the fundamental molecular characterization and factors influencing the molecular mechanisms of stem cells in wound healing.

Matched MeSH terms: Atmosphere
Fulltext Influence of oxalate ligand functionalization on Co/ZSM-5 activity in Fischer Tropsch synthesis and hydrodeoxygenation of oleic acid into hydrocarbon fuels

Ayodele OB

Sci Rep, 2017 Aug 30;7(1):10008.
PMID: 28855545 DOI: 10.1038/s41598-017-09706-z

Achieving high degree of active metal dispersions at the highest possible metal loading and high reducibility of the metal remains a challenge in Fischer Tropsch synthesis (FTS) as well as in hydrogeoxygenation (HDO).This study therefore reports the influence of oxalic acid (OxA) functionalization on the metal dispersion, reducibility and activity of Co supported ZSM-5 catalyst in FTS and HDO of oleic acid into paraffin biofuel. The Brunauer-Emmett-Teller (BET) results showed that cobalt oxalate supported ZSM-5 catalyst (CoOx/ZSM-5) synthesized from the incorporation of freshly prepared cobalt oxalate complex into ZSM-5 displayed increase in surface area, pore volume and average pore size while the nonfunctionalized cobalt supported on ZSM-5 (Co/ZSM-5) catalyst showed reduction in those properties. Furthermore, both XRD and XPS confirmed the presence of Co° formed from the decomposition of CoOx during calcination of CoOx/ZSM-5 under inert atmosphere. The HRTEM showed that Co species average particle sizes were smaller in CoOx/ZSM-5 than in Co/ZSM-5, and in addition, CoOx/ZSM-5 shows a clear higher degree of active metal dispersion. The FTS result showed that at CO conversion over Co/ZSM-5 and CoOx/ZSM-5 catalysts were 74.28% and 94.23% and their selectivity to C5+ HC production were 63.15% and 75.4%, respectively at 4 h TOS. The HDO result also showed that the CoOx/ZSM-5 has higher OA conversion of 92% compared to 59% over Co/ZSM-5. In addition CoOx/ZSM-5 showed higher HDO and isomerization activities compared to Co/ZSM-5.

Matched MeSH terms: Atmosphere
Fulltext Undergraduate Medical Students' Perceptions on Feedback-Seeking Behaviour

Oktaria D, Soemantri D

Malays J Med Sci, 2018 Feb;25(1):75-83.
PMID: 29599637 DOI: 10.21315/mjms2018.25.1.9

Background: The concept of feedback-seeking behaviour has been widely studied, but there is still a lack of understanding of this phenomenon, specifically in an Indonesian medical education setting. The aim of this research was to investigate medical students' feedback-seeking behaviour in depth in one Indonesian medical school.
Methods: A qualitative method was employed to explore the feedback-seeking behaviour of undergraduate medical students in the Faculty of Medicine at Universitas Lampung. Focus group discussions (FGDs) were conducted with four student groups and each group consisted of 7-10 students from the years 2012, 2013 and 2014. Data triangulation was carried out through FGDs with teaching staff, and an interview with the Head of the Medical Education Unit.
Results: Study findings indicated that the motivation of students to seek feedback was underlain by the desire to obtain useful information and to control the impressions of others. Students will tend to seek feedback from someone to whom they have either a close relationship or whose credibility they value. The most common obstacle for students to seek feedback is the reluctance and fearfulness of receiving negative comments.
Conclusions: Through the identification of factors promoting and inhibiting feedback-seeking behaviour, medical education institutions are enabled to implement the appropriate and necessary measures to create a supportive feedback atmosphere in the learning process.

Matched MeSH terms: Atmosphere
Fulltext Long-term carbon sink in Borneo's forests halted by drought and vulnerable to edge effects

Qie L, Lewis SL, Sullivan MJP, Lopez-Gonzalez G, Pickavance GC, Sunderland T, et al.

Nat Commun, 2017 12 19;8(1):1966.
PMID: 29259276 DOI: 10.1038/s41467-017-01997-0

Less than half of anthropogenic carbon dioxide emissions remain in the atmosphere. While carbon balance models imply large carbon uptake in tropical forests, direct on-the-ground observations are still lacking in Southeast Asia. Here, using long-term plot monitoring records of up to half a century, we find that intact forests in Borneo gained 0.43 Mg C ha-1 per year (95% CI 0.14-0.72, mean period 1988-2010) above-ground live biomass. These results closely match those from African and Amazonian plot networks, suggesting that the world's remaining intact tropical forests are now en masse out-of-equilibrium. Although both pan-tropical and long-term, the sink in remaining intact forests appears vulnerable to climate and land use changes. Across Borneo the 1997-1998 El Niño drought temporarily halted the carbon sink by increasing tree mortality, while fragmentation persistently offset the sink and turned many edge-affected forests into a carbon source to the atmosphere.

Matched MeSH terms: Atmosphere
Effect of irradiance on the emission of short-lived halocarbons from three common tropical marine microalgae

Lim YK, Keng FS, Phang SM, Sturges WT, Malin G, Abd Rahman N

PeerJ, 2019;7:e6758.
PMID: 31041152 DOI: 10.7717/peerj.6758

Marine algae have been reported as important sources of biogenic volatile halocarbons that are emitted into the atmosphere. These compounds are linked to destruction of the ozone layer, thus contributing to climate change. There may be mutual interactions between the halocarbon emission and the environment. In this study, the effect of irradiance on the emission of halocarbons from selected microalgae was investigated. Using controlled laboratory experiments, three tropical marine microalgae cultures, Synechococcus sp. UMACC 371 (cyanophyte), Parachlorella sp. UMACC 245 (chlorophyte) and Amphora sp. UMACC 370 (diatom) were exposed to irradiance of 0, 40 and 120 µmol photons m-2s-1. Stress in the microalgal cultures was indicated by the photosynthetic performance (Fv/Fm, maximum quantum yield). An increase in halocarbon emissions was observed at 120 µmol photons m-2s-1, together with a decrease in Fv/Fm. This was most evident in the release of CH3I by Amphora sp. Synechococcus sp. was observed to be the most affected by irradiance as shown by the increase in emissions of most halocarbons except for CHBr3 and CHBr2Cl. High positive correlation between Fv/Fm and halocarbon emission rates was observed in Synechococcus sp. for CH2Br2. No clear trends in correlation could be observed for the other halocarbons in the other two microalgal species. This suggests that other mechanisms like mitochondria respiration may contribute to halocarbon production, in addition to photosynthetic performance.

Matched MeSH terms: Atmosphere
Effects of debinding and sintering atmosphere on properties and corrosion resistance of powder injection molded 316 L - stainless steel

Raza MR, Sherazi I, Muhammad Aslam, Ahmad F, Abu Bakar Sulong, Muhamad Norhamidi, et al.

Sains Malaysiana, 2017;46:285-293.

316L stainless steel is a common biomedical material. Currently, biomedical parts are produced through powder injection molding (PIM). Carbon control is the most critical in PIM. Improper debinding can significantly change the properties of the final product. In this work, thermal debinding and sintering were performed in two different furnaces (i.e. laboratory and commercially available furnaces) to study the mechanical properties and corrosion resistance. Debounded samples were sintered in different atmospheres. The samples sintered in inert gas showed enhanced mechanical properties compared with wrought 316L stainless steel and higher corrosion rate than those sintered in the vacuum furnace. The densification and tensile strength of the hydrogen sintered samples increased up to 3% and 51%, respectively, compared with those of the vacuum-sintered samples. However, the samples sintered in inert gas also exhibited reduced ductility and corrosion resistance. This finding is attributed to the presence of residual carbon in debonded samples during debinding.

Matched MeSH terms: Atmosphere
Fulltext Design, synthesis and biological profile of heterocyclic benzimidazole analogues as prospective antimicrobial and antiproliferative agents

Tahlan S, Kumar S, Ramasamy K, Lim SM, Shah SAA, Mani V, et al.

BMC Chem, 2019 Dec;13(1):50.
PMID: 31384798 DOI: 10.1186/s13065-019-0567-x

Background: Nitrogen containing heterocycles are widely used and investigated by pharmaceutical industry, as they are important in discovery and designing of new drug molecules. Drugs with a benzimidazole nucleus possess exclusive structural features and electron-rich atmosphere, which enable them to bind to a number of biologically important targets and result in a wide range of activities. This has served as the basis of the present study whereby new scaffolds with benzimidazole moiety were designed and synthesized.
Methods: The structures of synthesized compounds were confirmed by physicochemical and spectral means. The synthesized compounds were screened for their antimicrobial and antiproliferative activities by tube dilution and Sulforhodamine B (SRB) assays, respectively.
Results and conclusion: The in vitro biological screening results revealed that compound Z24 exhibited promising antimicrobial and anticancer activities which are comparable to standards.

Matched MeSH terms: Atmosphere
Fulltext C mobilisation in disturbed tropical peat swamps: old DOC can fuel the fluvial efflux of old carbon dioxide, but site recovery can occur

Waldron S, Vihermaa L, Evers S, Garnett MH, Newton J, Henderson ACG

Sci Rep, 2019 08 07;9(1):11429.
PMID: 31391485 DOI: 10.1038/s41598-019-46534-9

Southeast-Asian peat swamp forests have been significantly logged and converted to plantation. Recently, to mitigate land degradation and C losses, some areas have been left to regenerate. Understanding how such complex land use change affects greenhouse gas emissions is essential for modelling climate feedbacks and supporting land management decisions. We carried out field research in a Malaysian swamp forest and an oil palm plantation to understand how clear-felling, drainage, and illegal and authorized conversion to oil palm impacted the C cycle, and how the C cycle may change if such logging and conversion stopped. We found that both the swamp forest and the plantation emit centuries-old CO2 from their drainage systems in the managed areas, releasing sequestered C to the atmosphere. Oil palm plantations are an iconic symbol of tropical peatland degradation, but CO2 efflux from the recently-burnt, cleared swamp forest was as old as from the oil palm plantation. However, in the swamp forest site, where logging had ceased approximately 30 years ago, the age of the CO2 efflux was modern, indicating recovery of the system can occur. 14C dating of the C pool acted as a tracer of recovery as well as degradation and offers a new tool to assess efficacy of restoration management. Methane was present in many sites, and in higher concentrations in slow-flowing anoxic systems as degassing mechanisms are not strong. Methane loading in freshwaters is rarely considered, but this may be an important C pool in restored drainage channels and should be considered in C budgets and losses.

Matched MeSH terms: Atmosphere
Utilization of Malaysia EAF slags for effective application in direct aqueous sequestration of carbon dioxide under ambient temperature

Omale SO, Choong TSY, Abdullah LC, Siajam SI, Yip MW

Heliyon, 2019 Oct;5(10):e02602.
PMID: 31667417 DOI: 10.1016/j.heliyon.2019.e02602

Iron and steel industries are among the contributors of CO2 emission in large volume into the atmosphere, causing detrimental effects to the environment and the ecosystem at large scale. These industries also generate solid wastes in the form of electric arc furnace (EAF) slag during operations which result in about 10-15% slag wastes per ton of steel produced. In this study, the EAF slags from an iron and steel-making factory in Klang, Malaysia was utilized for CO2 sequestration through direct aqueous mineral carbonation. According to the surface area analysis, the fresh EAF slag has a mesoporous structure, its elemental composition shows the presence of 20.91 wt.% of CaO that was used for the sequestration of CO2 through carbonation. The sequestration capacity was found to be 58.36 g CO2/kg of slag at ambient temperature in 3 h, with the liquid/solid (L/S) ratio of 5:1 and using <63μm particle size. Moreover, the shrinking core model (SCM) was used to analyze the solid-fluid reaction in a heterogeneous phase and the CO2 sequestration shows to be controlled by the product layer phase. The EAF slag is demonstrated to have the potential of CO2 sequestration at ambient temperature.

Matched MeSH terms: Atmosphere
Rainwater chemistry of acid precipitation occurrences due to long-range transboundary haze pollution and prolonged drought events during southwest monsoon season: climate change driven

Payus CM, Jikilim C, Sentian J

Heliyon, 2020 Sep;6(9):e04997.
PMID: 33005801 DOI: 10.1016/j.heliyon.2020.e04997

The purposes of this research were to study the characteristics chemistry of pH, anions and cations in rainwater, and to identify the possible sources that contributing to the acid precipitation during southwest monsoon season with occurrence of extreme drought event. During the southwest monsoon season, it normally occurs along with haze phenomenon that every year will hit Southeast Asia. This condition will aggravate with high acidic particles in the atmosphere due to the prolonged drought. The analysed parameters which involved pH, anions (NO3-, SO42- and Cl-) and cations (Ca2+, Mg2+, Na+ and K+) were analysed using pH meter, Hach DR 2800, argentometric method and ICP-OES. From the findings, it showed that acid rain occurred during the southwest monsoon season with the range of pH values from 4.95 ± 0.13 to 6.40 ± 0.03 and the total average of pH 5.71 ± 0.32. Anions NO3-, SO42- and Cl- were found to be the dominant compositions of the acid rain occurrences with higher concentrations detected. In overall, rural area recorded with higher acidity of precipitation at total average of pH 5.54 ± 0.39 compared to urban area at pH 5.77 ± 0.26. Rural area surprisingly recorded higher frequency occurrences of acid rain with pH lesser than 5.6 and below compared to urban area. As for public health and safety, all rainwater samples during the acid rain event were found exceeded the allowable limits of NWQS and WHO standards, that shown not suitable for skin contact, recreational purposes even for drinking purposes.

Matched MeSH terms: Atmosphere
Fulltext The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

Pastorello G, Trotta C, Canfora E, Chu H, Christianson D, Cheah YW, et al.

Sci Data, 2020 07 09;7(1):225.
PMID: 32647314 DOI: 10.1038/s41597-020-0534-3

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

Matched MeSH terms: Atmosphere
Co-valorization of delayed petroleum coke - palm kernel shell for activated carbon production

Rashidi NA, Yusup S

J Hazard Mater, 2021 02 05;403:123876.
PMID: 33264948 DOI: 10.1016/j.jhazmat.2020.123876

In this study, a binary mixture of petroleum coke and palm kernel shell had been investigated as potential starting materials for activated carbon production. Single-stage potassium carbonate (K2CO3) activation under nitrogen (N2) atmosphere was adopted in this research study. Effect of several operating parameters that included the impregnation ratio (1-3 wt./wt.), activation temperature (600-800 °C), and dwell time (1-2 hrs) were analyzed by using the Box-Behnken experimental design. Influence of these parameters towards activated carbon yield (Y1) and carbon dioxide (CO2) adsorption capacity at an atmospheric condition (Y2) were investigated. The optimum conditions for the activated carbon production were attained at impregnation ratio of 1.75:1, activation temperature of 680 °C, and dwell time of 1 h, with its corresponding Y1 and Y2 is 56.2 wt.% and 2.3991 mmol/g, respectively. Physicochemical properties of the pristine materials and synthesized activated carbon at the optimum conditions were analyzed in terms of their decomposition behavior, surface morphology, elemental composition, and textural characteristics. The study revealed that the blend of petroleum coke and palm kernel shell can be effectively used as the activated carbon precursors, and the experimental findings demonstrated comparable CO2 adsorption performance with commercial activated carbon as well as that in literatures.

Matched MeSH terms: Atmosphere
Fulltext Physico-chemical changes in dabai (Canarium odontophyllum Miq.) fruit during modified atmosphere storage

Ding, P., Diana, J.

International Food Research Journal, 2013;20(6):3033-3040.
MyJurnal

Dabai or Canarium odontophyllum Miq., from the family Burseraceae, is an important indigenous fruit to Borneo Island. However, it is a highly perishable fruit with short shelf life. Postharvest technology such as modified atmosphere packaging (MAP) can be used to maintain highly perishable fresh fruit quality and increase its shelf life. There is not much work has been carried out to study effect of MAP on dabai fruit. Therefore, this study was conducted to determine the effect of four different types packaging methods on the postharvest quality of dabai fruits. Total of 240 fruit were used for each replication and the experiment was repeated thrice. Fruit were divided equally into four groups with each group packed in low-density polyethylene plastic bag, low-density polyethylene plastic bags lined with tissue paper, low-density polyethylene plastic bag with vacuumed and control (unwrapped). The fruit were then stored in a cold room of 10°C for 8 days. The fruits were analyzed for peel and flesh colour (L*, C* and hue angle), CO2 and C2H4 production, weight loss, firmness, soluble solids concentration (SSC), titratable acidity (TA) and pH at every two days interval. Data were analyzed using analysis of variance and means was separated using Duncan’s multiple range tests. The use of MAP retained peel colour (L*, C* and hue angle values), flesh colour (L*values), SSC and TA of dabai fruit. The CO2 production in MAP fruit was significant lower than control. Although vacuum packed showed lowest weight loss, flesh discolouration, soggy texture and foul sour odour developed during 8 days of storage. Neither packing dabai fruit in low-density polyethylene plastic bag nor bag lined with tissue paper retained better fruit quality. Thus, it is recommended packing dabai fruit in low-density polyethylene plastic bag is sufficient to retain fruit quality during 8 days of storage at 10oC.

Matched MeSH terms: Atmosphere
Effects of reaction conditions on the emission behaviors of arsenic, cadmium and lead during sewage sludge pyrolysis

Han H, Hu S, Syed-Hassan SSA, Xiao Y, Wang Y, Xu J, et al.

Bioresour Technol, 2017 Jul;236:138-145.
PMID: 28399417 DOI: 10.1016/j.biortech.2017.03.112

Sewage sludge is an important class of bioresources whose energy content could be exploited using pyrolysis technology. However, some harmful trace elements in sewage sludge can escape easily to the gas phase during pyrolysis, increasing the potential of carcinogenic material emissions to the atmosphere. This study investigates emission characteristics of arsenic, cadmium and lead under different pyrolysis conditions for three different sewage sludge samples. The increased temperature (within 723-1123K) significantly promoted the cadmium and lead emissions, but its influence on arsenic emission was not pronounced. The releasing rate order of the three trace elements is volatile arsenic compounds>cadmium>lead in the beginning of pyrolysis. Fast heating rates promoted the emission of trace elements for the sludge containing the highest amount of ash, but exhibited an opposite effect for other studied samples. Overall, the high ash sludge released the least trace elements almost under all reaction conditions.

Matched MeSH terms: Atmosphere
Fulltext Production of carbon dioxide using direct pyrolysis-combustion from Aquilariella Malaccensis or karas woods under argon atmosphere

Noraishah Othman, Siti Kartom Kamarudin, Muhd Noor Md Yunus, Abd. Halim Shamsuddin, Siti Rozaimah, Zahirah Yaakob

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

The production of carbon dioxide from Karas woods under argon atmosphere was investigated using a direct pyrolysis-combustion approach. Direct burning was used in this study, using argon for yrolysis and oxygen during combustion to look at the yield of carbon dioxide, produced at different parameters, such as the temperature, retention time and flow rate of argon, as the carrier gas. In this study, a new methodology, 23 response surface central composite design was successfully employed for the experimental design and analysis of results. Central composite experimental design and response surface method were utilized to determine the best operating condition for a maximum carbon dioxide production. Appropriate predictable empirical linear model was developed by incorporating interaction effects of all the variables involved. The results of the analysis revealed that linear equation models fitted well with the experimental for carbon dioxide yield. Nevertheless, the R-Squared obtained using the direct pyrolysis-combustion was 0.7118, indicating that the regression line was not at the best-fitted line.

Matched MeSH terms: Atmosphere

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