The role of smart packaging system in food supply chain

Food supply chain is a rapidly growing integrated sector and covers all the aspects from farm to fork, including manufacturing, packaging, distribution, storing, as well as further processing or cooking for consumption. Along this chain, smart packaging could impact the quality, safety, and sustainability of food. Packaging systems have evolved to be smarter with integration of emerging electronics and wireless communication and cloud data solutions. Although there are many factors causing the loss and waste issues for foods throughout the whole supply chain of food and there have been several articles showing the recent advances and breakthroughs in developing smart packaging systems, this review integrates these conceptual frameworks and technological applications and focuses on how innovative smart packaging solutions are beneficial to the overall quality and safety of food supply by enhancing product traceability and reducing the amount of food loss and waste. We start by introducing the concept of the management for the integrated food supply chain, which is critical in tactical and operational components that can enhance product traceability within the entire chain. Then we highlight the impact of smart packaging in reducing food loss and waste. We summarize the basic information of the common printing techniques for smart packaging system (sensor and indicator). Then, we discuss the potential challenges in the manufacturing and deployment of smart packaging systems, as well as their cost-related drawbacks and further steps in food supply chain.     

Assessment of extreme and metocean conditions in the Maldives for OTEC applications

The Maldives is a group of tropical atolls, considered globally to be one of the most desirable holiday destinations. There is an urgent requirement to decrease their dependency on fossil fuels that are currently the main source of energy, and a number of renewable energy alternatives are being evaluated. Among these, due to the favorable oceanographic and bathymetric conditions, ocean thermal energy conversion (OTEC) systems represent a viable opportunity for clean and reliable power. However, the stresses the OTEC platform will need to endure during adverse environmental conditions are not well defined. The magnitude of these stresses will then have a direct influence on the design of the OTEC device. In order to overcome this uncertainty, this paper uses hindcast data sets from global weather and ocean models to assess the metocean conditions of the Maldives, with particular reference to extreme conditions. After selecting a suitable location for the deployment of the devices, return values calculated using the peaks‐over‐threshold (POT) methodology are estimated for wind, waves, and currents. The 100‐year return value for the significant wave height is found to be 4.5 m, with a joint occurrence of energy periods between 7.5 and 8.5 seconds, whereas the 100‐year return wind has a velocity of 17.8 m/s and the 100‐year return current of 1.9 m/s. The directionality of these extreme events is also considered, showing the southern and western sub‐quadrants as the prevailing sources, which provides essential information for positioning of the platform. Additional evaluations of tropical revolving storms (TRS) and variations in temperature and salinity patterns are also provided over a 1500‐m water column; temperature varies by approximately 24°C, and salinity by around 2 ppt, showing the suitability of OTEC platforms in the Maldives. This work is therefore of interest to offshore renewable energy stakeholders interested in developing a project in the Maldives or those conducting an analogous analysis in other locations.     

Uncertainty in wave energy resource assessment. Part 1: Historic data

The uncertainty in estimates of the energy yield from a wave energy converter (WEC) is considered. The study is presented in two articles. This first article deals with the accuracy of the historic data and the second article considers the uncertainty which arises from variability in the wave climate. Estimates of the historic resource for a specific site are usually calculated from wave model data calibrated against in-situ measurements. Both the calibration of model data and estimation of confidence bounds are made difficult by the complex structure of errors in model data. Errors in parameters from wave models exhibit non-linear dependence on multiple factors, seasonal and interannual changes in bias and short-term temporal correlation. An example is given using two hindcasts for the European Marine Energy Centre in Orkney. Before calibration, estimates of the long-term mean WEC power from the two hindcasts differ by around 20%. The difference is reduced to 5% after calibration. The short-term temporal evolution of errors in WEC power is represented using ARMA models. It is shown that this is sufficient to model the long-term uncertainty in estimated WEC yield from one hindcast. However, seasonal and interannual changes in model biases in the other hindcast cause the uncertainty in estimated long-term WEC yield to exceed that predicted by the ARMA model.     

Measurements of H2O2 and HCHO by Tunable Diode Laser Absorption Spectroscopy During the 1986 Carbonaceous Species Methods Comparison Study in Glendora,California

An improved, high sensitivity, tunable diode laser spectrometer system designed for tropospheric air measurements (TAMS-150) was employed during the 1986 Carbonaceous Species Methods Comparison Study at Glendora, CA. The TAMS-150 made simultaneous measurements of H₂O₂ and HCHO with a time response of 3 minutes per data point. The minimum detection limits were respectively 0.1 ppbv and 0.15 ppbv for HCHO and H₂O₂ and the estimated accuracies were ± 20% for both species. During the first 5 days of the study H₂O₂ showed little diurnal variation ranging between 0.25 and 0.5 ppbv with maximum values occurring at 15:30 PDT. During the final 4 days H₂O₂ showed stronger diurnal behavior with mixing ratios ranging from below the detection limits during some nighttime periods to as high as 1.8 ppbv during midday maxima which occurred about 15:30 PDT. HCHO showed strong diurnal behavior throughout the study with rapid changes in concentration in the early morning and evening. Mixing ratios were typically in the range 5–20 ppbv with maxima at about 10:00 and 14:00 PDT.     

An atmospheric correction procedure for the ATSR-2 visible and near-infrared land surface data

An atmospheric correction procedure for the solar reflecting channels of the Second Along Track Scanning Radiometer (ATSR-2) is described in which the aerosol optical thickness is retrieved from atmospheric simulations using the top-of-atmosphere (TOA) reflectances. The aerosol optical thickness is obtained when the ratio of the corresponding surface reflectances, in the off-nadir view to the nadir view, for two selected sensor channels, are equal. Directional reflectance models have been used to determine the validity of this approach and to determine suitable channel combinations. Simulations of the procedure for realistic surfaces indicate the retrieval of tau A 550 is better than 0.1 when the aerosol meteorology is known. The accuracy of the retrieval of surface reflectance is significantly affected by deviations from the expected aerosol meteorology. Factors affecting the accuracy of the correction procedure are described.     

Rapid application development (RAD): an empirical review

Rapid application development (RAD) is an approach to information systems (IS) development which is much discussed in the practitioner literature. However, there is comparatively little research data on this topic. This paper forms a report of the results of a multi-disciplinary research project which has been studying this development approach for the last three years. The paper discusses seven case studies of RAD projects and compares each to issues relating to a number of RAD principles as represented in methodologies such as the recent open standard known as dynamic systems development method. We conclude with a discussion of a number of important questions relating to further research on RAD.     

POLICY REVIEW Housing Policy in South Africa: The Challenge of Delivery

The main principles of housing policy in South Africa were established in the period leading up to the first democratic elections in 1994. This paper sets those in the context of development theory and the legacy of apartheid planning. The main aspects of the 1997 Housing Act are discussed as are current housing finance and subsidy systems. The final section of the paper considers some examples of the way in which the housing production and improvement is being delivered and evaluates the state of housing at the end of the ANC's first term of office.     

An improved pencil-of-functions method and comparisons with traditional methods of pole extraction

Prony's method is usually used for the determination of poles from experimental data in the singularity expansion method (SEM) literature, It is the aim here to show that this is not the best method and that Jain's pencil-of-functions (POF) method can be generalized to provide a better method. An example of such a method is given.