16 research outputs found
Small-scale postharvest practices among plantain farmers and traders: a potential for reducing losses in rivers state, Nigeria
High postharvest losses (PHLs) caused by poor postharvest management of perishable staple foods is a serious food security problem in Nigeria. Adoption of suitable postharvest management techniques is necessary to maintain produce quality and minimize avoidable losses by relevant stakeholders. The challenge is that most popular postharvest technologies are unsuitable for small scale farmers and traders who are a majority in the Nigerian food supply chains. This paper proposes the adoption of small-scale friendly postharvest techniques in the form of small-scale postharvest practices (SSPPs). To justify this proposal, the impact of SSPPs adoption on self-reported losses were investigated in Rivers State Nigeria. The factors influencing plantain farmers and traders intention to use SSPPs were also studied. Multistage and snowball sampling techniques were used to obtain data from farmers and traders, respectively. Data were obtained via face-to-face interviews using structured questionnaire. The data were analysed using descriptive statistics, correlation analysis, chi-square test of independence and multiple linear regression analyses. The results indicate that farmers adoption of SSPPs was negatively correlated with quantitative losses (r = - 0.142) and qualitative losses (r = - 0.412). Gender, education level, occupation, amount of produce harvested, and information access were significantly associated with farmers adoption of SSPPs. From the regression analysis, attitudes (β = 0.523, p < 0.05), awareness knowledge (β = 0.100, p < 0.05) and perceptions (β = 0.293, p < 0.05) of farmers significantly predicted their intention to use SSPPs. The regression model was significant (R2 = 0.552, F(3, 308 =126.264, p < 0.05)), with attitudes, awareness and perceptions explaining 55.2% of the variation in the dependent variable, intention. Based on the results, we recommend that plantain farmers and traders should integrate small scale postharvest practices in their operations because it will help them maintain produce shelf life and minimize avoidable losses. Policy makers, food security proponents and relevant institutions should take the necessary action by formulating tailored intervention programs that would facilitate adoption of SSPPs at farm and market levels. These recommendations will positively impact food security efforts in the country
Computational study of Klang Valley's urban climatology, and urbanisation of Putrajaya city, Malaysia
Urbanisation is associated with physical modifications of land surfaces and climate of a given area. Studies of urbanisation effect on urban climate of Klang Valley region is below par. This research aims to bridge the gap by using a coupled Weather Research and Forecasting (WRF) model with the NOAH Land Surface Model (NOAH) and Urban Canopy Model (UCM) – WRF/NOAH/UCM to investigate the urban climatology of Klang Valley and the urbanisation of Putrajaya over a decade. In addition, evaluation of the garden city concept adopted in the development of Putrajaya city is also conducted. The model is first validated against a network of meteorological observations in the region to determine its suitability for urban climate investigations. Climatological variables (near-surface temperature, relative humidity, and wind speed) along with land use and land cover (LULC) changes; planetary boundary layer height (PBLH), and urban heat/cool islands (UHI/UCI) of the area are also investigated. The model evaluation shows good performance over the region. LULC changes demonstrates strong influence in thermal climatology variations. A mean maximum UHI intensity of ~4.2 ºC was observed in the urban canopy-layer of the Klang Valley.
Results reveal that urbanisation of Putrajaya leads to 2-m temperature increase at the rate of ~1.66 ºC per decade, with the area experiencing a mean UHI intensity of ~2.1 ºC per day. Other climatological variables vary accordingly with the urbanisation processes.
Evaluation of the garden city concept indicates that the adopted concept causes a reduction in 2-m air temperature of the Putrajaya area, amounting to ~0.53 ºC per day; with vegetation contributing more (~0.39 ºC) to the daily reduction relative to water bodies (~0.14 ºC). Location of the city in the tropics accustomed with high intensity of daily solar radiation masked the cooling potentials of the concept to some extent
Effect of vegetation and waterbody on the garden city concept: an evaluation study using a newly developed city, Putrajaya, Malaysia
The garden city concept was adopted in the development of a new tropical city, Putrajaya, aimed at mitigating the effect of urban thermal modification associated with urbanisation, such as urban heat island (UHI). WRF/Noah/UCM coupled system was used to estimate the urban environment over the area and the individual thermal contributions of natural land use classes (vegetation and waterbody). A control experiment including all land use types describing the urban conditions of Putrajaya city agreed well with the observations in the region. A series of experiments was then conducted, in which vegetation and waterbody were successively replaced with an urban land use type, providing the basis for an assessment of their respective effect on urban thermal mitigation. Surface energy components, 2-m air temperature (T2m) and mixing ratio (Q2m), relative humidity (RH) and UHI intensity (UHII) showed variations for each land use class. Overall, an increase in urban surfaces caused a corresponding increase in the thermal conditions of the city. Conversely, waterbody and vegetation induced a daily reduction of 0.14 and 0.39 °C of T2m, respectively. RH, UHI and T2m also showed variations with urban fractions. A thermal reduction effect of vegetation is visible during mornings and nights, while that of water is minimally shown during daytime. However, during nights and mornings, canopy layer thermal conditions above waterbody remain relatively high, with a rather undesirable effect on the surrounding microclimate, because of its high heat capacity and thermal inertia
Conceptual framework for estimating postharvest losses in food supply chains: the case of plantain fruits in Nigeria
Postharvest losses which refer to the measurable quantitative and qualitative food losses in any agro-food supply chain account for significant amounts of food loss. Lack of consistent information on exact amount of losses and assessment methods further complicate the problems and makes solutions very difficult. Plantain also known as cooking banana is an important staple food and cash crop in Nigeria with observed high postharvest losses. The current study proposes a conceptual framework for directly estimating postharvest losses and identifying causative factors using a commodity system approach
Computational study of Klang Valley's urban climatology, and urbanisation of Putrajaya city, Malaysia
Urbanisation is associated with physical modifications of land surfaces and climate of a given area. Studies of urbanisation effect on urban climate of Klang Valley region is below par. This research aims to bridge the gap by using a coupled Weather Research and Forecasting (WRF) model with the NOAH Land Surface Model (NOAH) and Urban Canopy Model (UCM) – WRF/NOAH/UCM to investigate the urban climatology of Klang Valley and the urbanisation of Putrajaya over a decade. In addition, evaluation of the garden city concept adopted in the development of Putrajaya city is also conducted. The model is first validated against a network of meteorological observations in the region to determine its suitability for urban climate investigations. Climatological variables (near-surface temperature, relative humidity, and wind speed) along with land use and land cover (LULC) changes; planetary boundary layer height (PBLH), and urban heat/cool islands (UHI/UCI) of the area are also investigated. The model evaluation shows good performance over the region. LULC changes demonstrates strong influence in thermal climatology variations. A mean maximum UHI intensity of ~4.2 ºC was observed in the urban canopy-layer of the Klang Valley.
Results reveal that urbanisation of Putrajaya leads to 2-m temperature increase at the rate of ~1.66 ºC per decade, with the area experiencing a mean UHI intensity of ~2.1 ºC per day. Other climatological variables vary accordingly with the urbanisation processes.
Evaluation of the garden city concept indicates that the adopted concept causes a reduction in 2-m air temperature of the Putrajaya area, amounting to ~0.53 ºC per day; with vegetation contributing more (~0.39 ºC) to the daily reduction relative to water bodies (~0.14 ºC). Location of the city in the tropics accustomed with high intensity of daily solar radiation masked the cooling potentials of the concept to some extent
The uncharacteristic occurrence of the June 2013 biomass-burning haze event in Southeast Asia: effects of the Madden-Julian oscillation and tropical cyclone activity.
One of the worst haze events to ever hit Peninsular Malaysia occurred in June 2013 due to smoke from Riau, Central Sumatra. While biomass-burning in the region is common, the early occurrence of a haze episode of this magnitude was uncharacteristic of the seasonality of extreme fire events, which usually occur between August and October in the Maritime Continent (MC). This study aims to investigate the phenomenology of the June 2013 haze event and its underlying meteorological forcing agents. The aerosol and meteorological environment during the event is examined using the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire hotspot detections and aerosol optical thickness retrievals, satellite-based precipitation retrievals, and meteorological indices. These datasets are then supported by a WRF-Chem simulation to provide a comprehensive picture of the event's meteorology and aerosol transport phenomenology. While extreme fire events are more characteristic of El Nino years, the MODIS fire count over the MC in June for the years 2001–2015 was highest in 2013 when neutral El Nino/Southern Oscillation (ENSO) conditions prevailed. Although, the mean daily precipitation for June 2013 was below average for June 2003–2015. An early active tropical cyclone (TC) season occurred in 2013, and results show that the combined induced subsidence and flow enhancement due to TC Bebinca and the dry phases of a strong Madden–Julian Oscillation (MJO) event contributed to the event intensification. Results also show that Bebinca induced a decrease in surface relative humidity of at least 10% over Riau, where fire hotspots were concentrated
Upgrading of Napier grass pyrolytic oil using microporous and hierarchical mesoporous zeolites: products distribution, composition and reaction pathways
Reaction pathways in ex-situ catalytic upgrading of pyrolytic oil towards formation of specific products
such as hydrocarbons are still not well established due to the presence of many different organic components in the raw pyrolytic oil. Currently, only a few studies are available in literature particularly with regards to application of hierarchical mesoporous zeolite in the refinement of sample pyrolytic oil. This study provides the first experimental investigation of ex-situ catalytic upgrading of pyrolytic oil derived from Napier grass using microporous and hierarchical mesoporous zeolites. Two hierarchical mesoporous zeolites were synthesized by desilication of microporous zeolite using 0.2 and 0.3 M solution of sodium hydroxide. Upgrading over microporous zeolite produced 16.0 wt% solid, 27.2 wt% organic phase and 23.9 wt% aqueous phase liquid while modified zeolites produced 21e42% less solid and 15e16% higher organic phase liquid. Higher degree of deoxygenation of pyrolytic oil was achieved with the modified zeolites. Analysis of organic phase collected after catalytic upgrading revealed high
transformation of oxygenates into valuable products. Bulk zeolite produced cyclic olefins and polyaromatic
hydrocarbons while mesoporous zeolites were selective toward cycloalkanes and alkylated monoaromatic production, with significant reduction in the production of polyaromatic hydrocarbon. Result of gas analysis showed that hierarchical mesoporous zeolite favoured decarboxylation and decarbonylation reactions compared to the parent zeolite, which promoted dehydration reaction. Mesoporous zeolite produced with 0.3 M sodium hydroxide solution was found to be the best-performing catalyst and
its reusability was tested over four consecutive cycles. This study demonstrated that pyrolytic oil derived
from Napier grass can be transformed into high-grade oil over hierarchical mesoporous zeolite
Recovery of clean energy precursors from Bambara groundnut waste via pyrolysis: Kinetics, products distribution and optimisation using response surface methodology
This study presents first comprehensive thermochemical analysis of Bambara groundnut shell. Pyrolysis
characteristics was examined under non-isothermal degradation in nitrogen atmosphere at different
heating rates (10, 15 and 20 �C/min) using single-step global model kinetic model. The single-step global
model average apparent activation energy was found to be 142.64 ± 5.7 kJ/mol. Pyrolysis was conducted
in a fixed bed reactor. Effects of pyrolysis temperature (450e750 �C), heating rate (20e50 �C/min) and
nitrogen flow rate (5e25 L/min) were investigated collectively. The process variables were optimized
using response surface methodology with central composite design. Optimum bio-oil yield of 36.49 wt%
was recorded at 600 �C, 50 �C/min and 11 L/min. The bio-oil, bio-char and non-condensable gas collected
were comprehensively characterised. Energy analysis of the products was also evaluated. This study
revealed that Bambara groundnut shell, a residue from food crop, is a potential source of energy precursors
for development of a sustainable bioenergy system and biomaterial
Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16
Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP
Potential of adopting small scale postharvest practices towards reducing plantain supply chain food losses in Rivers State, Nigeria
Postharvest losses (PHLs) is the most significant contributor of food losses in
developing countries. High PHLs in food staples like plantain pose a threat to food
security in Nigeria; therefore, viable strategies to reduce PHLs in agri-food supply
chains is in dire need. Conventional postharvest technologies used in modern agrifood
supply chains in developed countries require high capital investments and
technological competence; most of which is lacking in Nigeria. Although,
sophisticated postharvest technologies may not be within the reach of farmers and
traders who operate in traditional supply chains, small-scale postharvest practices
(SSPPs) such as shade-cooling, hydro-cooling, use of protective transport materials
are simpler alternatives to help maintain produce quality, prolong shelf-life and
consequently reduce PHLs.
However, the adoption of these SSPPs is low and there is dearth of information in
this regard. This study adopted a quantitative approach to investigate the potential
adoption of selected SSPPs by plantain farmers and traders who operate in a
traditional supply chain in Rivers State, Nigeria. The study intended to determine the
influence of adoption factors on farmers and traders intention to use SSPPs. The data
used in the study were obatained via face-to-face interviews using two structured
questionnaire where one questionnaire was administered to farmers and the other one
administered to the traders. The data were analysed using statistical techniques such
as descriptive analyses, chi-square, mean ranking, T-test, Pearson’s correlation, and
partial least square structural equation modelling. In terms of the losses, the findings of the study revealed that a significant amount of
plantain comodity is entirely lost from the food supply chain; this is regarded as the
quantitative losses. Furthermore, it was observed that more than half of the produce
is reportedly sold at reduced prices due to quality deterioration; this form of losses
was interpreted as the amount of qualitative losses. A correlation analysis revealed
that use of small-scale postharvest practices had a significant negative relationship
with the amount of self-reported quantitative and qualitative losses at both farm and
market levels.
With regards to adoption, the results of the chi-square analyses indicated that gender,
education level, occupation, harvetsed produce and information sources were
significantly associated with farmers adoption whereas experience level and
information sources were the significant factors associated with the traders adoption
of SSPPs. Based on the mean rankings, the respondents were observed to have low
awareness and adoption rates for a majority of the postharvest practices investigated.
In addition, the results of t-tests show that adopters demonstarted more positive
perceptions of the SSPPs than non-adopters.
Furthermore, an exploratory factor analysis (EFA) revealed six and five factors as
representing perceptions towards SSPPs perceptions towards each postharvest
practice as relevant to farmers and traders repectively. This implies that when
respondents evaluated the usefulness and complexity of a particular postharvest
practice, they evaluated the practice as one entity rather than considering the
perceived usefulness and ease of use of the postharvest practice as separate
dimensions. Factor analysis of the items that measured behaviour towards adoption
of SSPPs extracted three factors named as attitudes, motivation and intention. The
EFA factor solutions were further confirmed during confirmatory factor analysis
during which the measurement models were rigourosly assessed to ensure reliability
and validity of constructs and scales.
Assessment of the variables that influence farmers and traders potential to adopt
SSPPs with intention to use postharvest practices as the dependent variable, the
results of the structural equation modelling found that awareness level, perceptions,
attitudes and motivation significantly predicted intention to use SSPPs with 55.4%
and 33.4% of the variances accounted for in the data that were obtained from farmers
and traders repectively. In addition, attitudes significantly mediated the relationships
between plantain farmers and traders intention and their perceptions and motivation
towards using SSPPs. A rigourous assessment of the structural models showed that
the hypothesized model was supported by empirical data. The model had acceptable
predictive relevance and ability to account for moderate to substantial variance in
both data sets.
iii
In conclusion, postharvest interventions that aim to be successful must recognize the
critical role of understanding their target audience. Technology push must be
balanced with an understanding of the potential adopters’ preferences in order to
attain successful and strategic solutions. In this regard it is recommended that future
interventions should ascertain the perceptions held by the potential adopters prior to
dissemination of solutions. The strong positive effect of motivation on behavioral
intention suggests a necessity to identify and utilize peculiar factors in motivating
adoption of postharvest solutions