Flexible Wrapper Research Articles

Effective Enhancement of Post-Harvest Tomato Storage through Wrapping Using Deacetylated Chitin Nanofibril-Plasticized Honey Films

As one of the most grown seasonal fruit, tomato is widely consumed for making food products, drugs and ornaments. However, poor post-harvest handling system, transport and storage facilities deteriorate the quality of tomato fruits resulting into post-harvest losses. These problems have been addressed by the use of nanotechnology in this study. The combination of a chitosan surface and the core shell chitin results into novel deacetylated chitin nanofibril (DeChNF) with good biological activity and mechanical strength. The effectiveness of the DeChNF films for food preservation as an alternative material to chitosan is investigated. The DeChNF with degree of acetylation (DA) = 60.2% and chitosan (DA = 7.1%) were obtained from crab shells. Two appraches were employed to store freshly matured tomatoes harvested at a breaker stage. The tomatoes were coated with the colloidal suspension and wrapped in the films. Flexible wrapping films were prepared from the colloidal suspension through solution casting using bees honey (35%) and compared to those with glycerol (25%) as plastisizers. The main output storage parameters analysed include colour development, surface spoilage, and weight loss over 20 days at a 73% relative humidity. Tomatoes covered with DeChNF-honey and chitosan-honey films remained in good condition after 20 days, while the coated samples lasted for up to 15 days, except those coated with DeChNF, and those covered with a polyethylene films or stored in a refrigerator at 9 °C. The samples covered with DeChNF films plasticized with honey showed the best resistance against weight loss. The tensile strength of the DeChNF-honey films (strength = 21.32 MPa) and the chitosan-honey films (strength = 21.86 MPa) were higher than the polyethylene films (10.9 MPa). The current work increases understanding on DeChNF as an alternative material, with additional of honey as a plasticizer, over the superior chitosan, or commercial films based on fossil resources.

Low Code Coding Approach for ofdm Systems Coded with the Progressive Transmission

Orthogonal Frequency Division Multiplexing (OFDM) offers several benefits such as flexible wrapping, mail sign interference, reduced complexity and more. The only way to match parallel channels is to have genetic diversity in multipath channels. Various coded of OFDM systems reported using some form of channel coding or pre-coding to improve system performance. The execution of irrational orthogonal frequency division multiplexing (OFDM) on blurred channels is usually better than introducing some coding. Various coding schemes for off-OFDM have been reported in the literature.

Effects of Nano Carbon Conductive Additives on the Electrochemical Performance of LiCoO2 Cathode for Lithium Ion Batteries

Carbon black(CB), multi-walled carbon nanotubes(CNTs) and graphene nanosheets(GNs) were employed as carbon conductive additives for LiCoO2(LCO). X-ray diffraction, transmission electron microscopy and scanning electron microscopy were used to characterize the crystal structure and morphology of samples. And the specific surface area and porosity structure of the three kinds of carbon conductive additives were measured by N2 adsorption-desorption. To investigate the effect on the electrochemical reaction activity, galvanostatic discharge-charge experiments showed that the composite of LCO-GNs exhibited the highest specific capacity of 167mAh/g at 0.1C and 123 mAh/g at 1 C rate. The flexible wrapping of GNs and bridging nearby LCO particles together were found to enhance electrical conductivity most effectively.

Flexible chemiresistor sensors: thin film assemblies of nanoparticles on a polyethylene terephthalate substrate

The thin film assembly of metal nanoparticles on flexible chemiresistor (CR) arrays represents an intriguing way to address the versatility of chemical sensor design. In this work, thin film assemblies of gold nanoparticles in size range of 2–8 nm diameters with high monodispersity (unlinked or linked by molecular mediators) were assembled on a CR array with a polyethylene terephthalate (PET) substrate to demonstrate the flexible chemiresistor characteristics of the nanostructured materials. The correlation between the relative change in electrical conductivity and the change in dielectric medium constant in response to flexible wrapping of the device demonstrated the viability of manipulating the electrical responses in terms of wrapping direction. The responses of the devices in response to volatile organic compounds (VOCs) were analyzed in terms of particle size, interparticle properties, and substrate–film interactions. For molecularly linked films with small particle size and large interparticle spacing, which is characterized by a high percentage of organics and linker molecules, the relatively low electrical conductivity renders the change in interparticle spacing able to play a dominant role in the sensor response to VOCs with small dielectric constants. The combination of a high percentage of linker molecules in the thin film assembly and a high dielectric constant for the VOCs was found to produce a negative response characteristic. In contrast, the response characteristic for the unlinked film via weak interparticle interactions was dominated by the change in interparticle spacing regardless of the percentage of organics in the nanostructure. The delineation between these factors and the sensing characteristics is useful in enabling a rationale design of the nanostructures on flexible chemiresistors.

GRIDCC: A Real-Time Grid Workflow System with QoS

The over-arching aim of Grid computing is to move computational resources from individual institutions where they can only be used for in-house work, to a more open vision of vast online ubiquitous `virtual computational' resources which support individuals and collaborative projects. A major step towards realizing this vision is the provision of instrumentation – such as telescopes, accelerators or electrical power stations – as Grid resources, and the tools to manage these resources online. The GRIDCC project attempts to satisfy these requirements by providing the following four co-dependent components; a flexible wrapper for publishing instruments as Grid resources; workflow support for the orchestration of multiple Grid resources in a timely manner; the machinery to make reservation agreements on Grid resources; and the facility to satisfy quality of service (QoS) requirements on elements within workflows. In this paper we detail the set of services developed as part of the GRIDCC project to provide the last three of these components. We provide a detailed architecture for these services along with experimental results from load testing experiments. These services are currently deployed as a test-bed at a number of institutions across Europe, and are poised to provide a 'virtual lab' to production level applications.

Design and synthesis of an “ultrachelating” ligand based on an 18-membered ring hexaaza macrocycle

Abstract A new ultrachelating ligand, H4PYTA (3,6,14,17,23,24-hexaazatricyclo[17.3.1.1(8.12)]tetracosa-1(23),8,10,12(24),19,21-hexaene-3,6,14,17-tetraacetic acid), has been synthesized by tetracar-boxymethylation of the parent ligand PYAN (3,6,14,17,23,24-hexaazatricyclo[17.3.1.1(8.12)]tetracosa-1(23),8,10,12(24),19,21-hexaene). Both of these ligands are based upon the [18]aneN6 macrocyclic framework in which two trans dimethylamino groups are replaced by 2,6-substituted pyridine. The metal binding constants for PYTA4- (log KML) were measured for sixteen metals and were found to be comparable to those for DTPA5- and DOTA4-. PYTA4- binds well to an extraordinarily large range of metal ions from small Ga3+ to large Pb2+. This behavior is attributable to the flexible wrapping of the PYAN framework and the ability of PYTA4- to be six-coordinate with small metals and ten-coordinate with large metals.

Paper 9: History and Development of Flexible Packaging

This paper deals essentially with flexible wrapping materials and their performance on packaging machinery. The emphasis throughout is on the packaging media but the demands made on them by machines are given prominence. The basic principles of the main types of machine are enunciated and illustrated with simple flow diagrams. These show the passage of the wrapping material through the machine and the text isolates the different sections and the wrapping problems involved. For example, the feeding, forming and closure sections of a machine are examined and such properties as slip, tensile strength, elongation and heat-sealability of wrapping materials are considered in relation to them. The paper opens with an historical survey of packaging, packaging materials and packaging machinery. The economic trends which shaped the packaging industry are presented and general developments in packaging materials and machines are traced from the turn of the century. Some comments on the functions of packaging and its part in the industrial scene are made. The packaging media covered include paper, cellulose films, aluminium foils, plastic films and the main forms and combinations of them. The production, properties and uses of these materials are outlined but the main emphasis, as stated above, is on their machinability. Current developments in wrapping materials and machine principles are discussed and some effort is made to forecast trends in flexible packaging generally.