No description available.

No description available.

The combined effect of films of various gas barrier properties, various gas packaging atmospheres (air, vacuum and gas packaging, oxygen absorbents) and storage temperatures (4 and 12$ sp circ$C) were investigated on the color stability and shelf-life of fresh beef. Meat color was described by reflectance measurements and by reading the color coordinates L* (lightness), a* (redness), b* (yellowness), C* (chroma) and h (hue angle) in the CIE-LAB system. All packaged beef was regarded as unacceptable when reflectance differences values at 630 and 580 nm i.e., due to oxymyoglobin (MbO$ sb2)$ were $ sim$30-35. Based on these standards, aerobic packaging of beef in polyvinylchloride (PVC) film had a shelf-life of $ sim$5 d and 1 d at 4 and 12$ sp circ$C respectively. Beef packaged in both low gas-moisture barrier films resulted in black discoloration after only 2 d at 4$ sp circ$C due to increased moisture loss. Longer extensions in both color and microbial shelf-life of fresh beef were possible by packaging products under modified atmospheres using high gas barrier Cryovac$ sp circler$ bags. Both vacuum packaging (VP) and vacuum skin packaging (VSP) resulted in a shelf-life of $ sim$35 d at 4$ sp circ$C. Gas packaging using high levels of CO$ sb2$ (100%) in conjunction with Ageless-SS$ sp circler$ oxygen absorbent, delayed discoloration for $ sim$42 d at 4$ sp circ$C. (Abstract shortened by UMI.)

Superhydrophobic surfaces, which display water contact angles of larger than 150°, have attracted more and more attention due to their importance in both fundamental research and practical applications. This dissertation is mainly focused on the fundamental understanding and exploring applications of superhydrophobic surfaces. First, some specific examples of superhydrophobic surface fabrication were given, which include superoleophobic Si surface, robust superhydrophobic SiC surface, and reversible wettability nanocomposite films. Based on the study of superhydrophobic surfaces, the application of superhydrophobic surfaces in electronic packaging were explored. Superhydrophobic silica/epoxy nanocomposite coating serves as an encapsulant to improve the electronic device reliability. Such superhydrophobic coating showed good stability under humidity at elevated temperatures and was applied on the triple track resistors test coupons. In addition, the applications of superhydrophobic surfaces in solar cells were studied. Two multi-functional hierarchical structure solar cells with self-cleaning, low reflection and high efficiency properties were built up by coating or etching methods.

Silver nanowires (Ag NWs) have a wide range of applications in the electronic industry and are attracting growing world-wide interest because of their unique thermal, chemical, electrical and mechanical properties. Understanding of mechanical properties of Ag NWs and joining processes for them at a nano scale is urgently needed to support exploitation of their applications. Particularly, study of processing-structure-property relationships is of much significance. In the present thesis, the following research works were conducted. Ag NWs were synthesized using the polyol method. Joining of individual Ag NWs in an end-to-end orientation at room-temperature without assistance of external pressure was investigated. Selective surface activation of Ag NWs provided surface free of protective organic layers for metallurgical joining. A similar crystal orientation was maintained between the NWs, and diffusion along the boundary contributed to the nanojunction formation. Monocrystalline V-shaped or zig-zag silver prisms were formed after nanojoining, terminated by twin boundaries and free surfaces. The feasibility of room-temperature pressure-free joining of copper (Cu) substrates using Ag NW paste was conducted and demonstrated for flexible electronic packaging applications. The organic content in water-based Ag NW pastes was largely reduced by a repeated washing process to decrease the joining temperature. The formation of end-to-side or side-to-side joints between Ag NWs was observed concurrently with those joined end-to-end. The mechanical and electrical properties of Ag NW joints were examined. It was found that self-generated local heating within the Ag NW paste and Cu substrate system promoted the joining of Ag-to-Ag and Ag-to-Cu without any external energy input. The localized heat energy could be delivered in-situ to the interfaces and promoted atomic diffusion and metallic bond formation while the bulk component temperature maintaining near room-temperature. The organic layer on the side surfaces of the Ag NWs could be broken down through consumption of the residual PVP by a CuO-PVP reaction and which produced localized heating, increasing activated surface sites dramatically and making three-dimensional networks feasible. Ag NWs were introduced into Ag nanoparticle (NP) matrices joined at low-temperature. Joining was facilitated by solid state sintering of the Ag nanomaterials and metallic bonding at Cu-Ag interfaces. It was found that Ag NWs in a Ag NP matrix acted as a second reinforcement phase. In addition to improving the fracture toughness of joints, the introduction of Ag NWs affected the path of fracture propagation, where necking, breakage and pullout of Ag NWs occurred during loading.

No description available.

Black spot development or "melanosis" is a common defect in fresh shrimp which results in product being devalued and rejected by consumers. Currently, sulfiting agents are used to control melanosis in shrimp. However, with increasing regulatory and consumer concerns about the safety of sulphites as a method of melanosis control, the shrimp processing industry is actively seeking alternative methods to control melanosis on, and extend the shelf life of, fresh shrimp. One method which has the potential to fulfill both objectives is glucose oxidase (GOX)/glucose dipping solutions in conjunction with Modified Atmosphere Packaging (MAP). / Preliminary studies have shown that black spot development can be controlled for 14 days at 4$ sp circ$C in white shrimp (Pandalus occidentalis) and pink shrimp (Pandalus borealis) using GOX/glucose or GOX/glucose/ascorbic acid in conjunction with gas packaging (60% CO$ sb2$: 40% N$ sb2$). This dipping/packaging treatment also improves the physical, chemical and microbiological changes in white shrimp compared to samples dipped only in water and air packaged. This study has shown that the combined use of two or more "barriers" can be used to extend the shelf life of, and control melanosis on, fresh shrimp. This novel process of "dipping" shrimp in GOX/glucose solutions in conjunction with MAP will have a significant effect in the area of shrimp hygiene and will have the potential to minimize shrimp spoilage incurred through melanosis.

This research investigates the responsiveness of companies in the Australian packaging supply chain to stakeholder concerns about the environmental impacts of packaging. The National Packaging Covenant (NPC), which was introduced in 1999, is based on the principle of shared responsibility for the 'life cycle' environmental impacts of packaging. This principle is commonly referred to as 'product stewardship' (PS). The primary focus of the thesis is corporate environmental policies and practices, but within a broader institutional framework. The institutionalisation of PS as a relatively new framework for corporate behaviour is occurring within an 'organisational field' at several levels. At the broadest (macro) level it is being institutionalised through the interaction of the state, industry associations and environmental non-government organisations (ENGOs) in policy processes. Within the packaging supply chain (meso level) it is being institutionalised through changes to corporate policy and practice within different sectors of the packaging supply chain, including raw material suppliers, packaging manufacturers, product manufacturers (brand owners) and retailers. Within individual firms (micro level) PS is being institutionalised through the interaction of functional groups with different interests, allegiances and stakeholders. At a macro level the institutionalisation of PS as the solution to the perceived 'packaging problem' is linked to the relative power of the industry coalition in policy negotiations and the deregulatory approach to policy making within federal and state governments. Within this environment, companies have sought to maintain or enhance organisational legitimacy by developing policies and practices that institutionalise PS in the way they do business. The responsiveness of companies in different industry sectors is evaluated by examining the PS policies and practices of 30 large companies in the Australian packaging supply chain. The results show that companies are acting to reduce the environmental impacts of packaging, but most are only doing the minimum required to meet public expectations. The research also found a significant gap between the performance of the beverage and packaging manufacturers and retailers. This reflects, at least in part, the fact that beverage and packaging manufacturers have a longer history of exposure to interest group pressure on this issue. Decision-making within individual companies is also driven by corporate policies on environmental and social responsibility, which in turn appear to be linked to industry sector, company size and country of origin. Most companies are focusing on strategies which achieve both environmental and financial savings. This reflects the competitive nature of the industry and the pressure being imposed on companies, by their customers, to reduce supply chain costs. It is also consistent with the voluntary and flexible nature of the NPC, which allows individual companies to choose strategies that support other business objectives. However, while this approach is likely to achieve incremental improvements, it may not meet the expectations of some government agencies and ENGOs for more rapid and substantial reductions in packaging waste. Companies in the packaging supply chain face a continuing challenge to maintain their legitimacy in the face of ongoing stakeholder concerns about their products.

A bulk export orientated company has to optimise their packaging to be able to compete in a globalised world. Therefore it is important to maximise the container load to save shipping costs. This can be done in different ways, • by changing the product weight, • the packaging material or size, • the pallet/container size or, for some products, • the bulk density. With so many parameters affecting the container load finding the best packaging solution is difficult. To solve the problem an Add-on to for the existing packaging optimisation software Cape Pack called SADIE was developed. SADIE automates the process of data input into Cape Pack and allows browsing of different packaging combinations in a short time. Main feature of SADIE is that it allows testing complete weight and/or bulk density ranges in one Query. For that it takes the weight and the bulk density combination that is going to be tested and calculates the start dimension for a regular slotted case (RSC) with a 2:1:2 ratio, which, for a RSC, is the ratio that uses a minimum quantity of board. Those dimensions are then, with many other parameters, transferred into the Cape Pack Design mode where the new packaging solution is calculated and transferred back to SADIE. The data coming from SADIE was tested for consistency and was also used for physical pack size validations, both successfully. Packaging solutions for products with higher bulk densities could be optimised. A new packaging solution calculated for salted butter could save 231 container per annum. Depending on the destination of the butter cost savings from 184,000 US$ to 577,500 US$ would be possible. The results show that there are improvements in container load possible, especially for products in a higher bulk density range, like butter and cheese. An increase in container load for Whole milk powder (WMP) might be possible if another packaging system is used whereas for Skim milk powder (SMP), with its higher densities compared to WMP, the program can calculate improved container load without a change to the packaging system used.

Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 93-97).