Computerized synthesis of the structure of geared kinematic chains

The paper presents for the first time a fully computerized method for structural synthesis of geared kinematic chains which can be used to derive epicyclic gear drives. The method has been formulated on the basis of representing these chains by their graphs, the graphs being in turn represented algebraically by their vertex-vertex incidence matrices. It has thus been possible to make advantageous use of concepts and results from graph theory to develop a method amenable for implementation on a digital computer. The computerized method has been applied to the structural synthesis of single-freedom geared kinematic chains with up to four gear pairs, and the results obtained thereform are presented and discussed.

Improving Knowledge and Practices in Mango Supply Chains

Mangoes consigned to domestic markets suffered from fruit quality problems from 1997 to 2000. A high incidence of disease breakdown and green-ripe fruit resulted in loss of confidence by marketers, and reduced profits for everyone from grower to retailer. The ‘Better Mangoes’ project was initiated to identify where, and why quality was being lost, and to use this information to improve the knowledge and practices of supply chain businesses.

Conformational Dynamics in Alkyl Chains of an Anchored Bilayer: A Molecular Dynamics Study

Molecular dynamics (MD) simulations are reported for an anchored bilayer formed by the intercalation of cetyl trimethyl ammonium (CTA) and CH3(CH2)15N+(CH3) ions in a layered solid, CdPS3. The intercalated CTA ions are organized with the cationic headgroups tethered to the inorganic sheet and the hydrocarbon tails arranged as bilayers. Simulations were performed at three temperatures, 65, 180, and 298 K, using an isothermal−isobaric ensemble that was subsequently switched once macroscopic parameters had converged to a canonical isothermal−isochoric ensemble. The simulations are able to reproduce the experimental features of this system, including the formation of the bilayer and layer-to-layer separation distance. An analysis of the conformation of the chains showed that at all three temperatures a fraction of the alkyl chains retained a planar all-trans conformation, and that gauche bonds occurred as part of a “kink” (gauche+−trans−gauche−) sequence and not as isolated gauche bonds. Trans−gauche isomerization rates for the alkyl chains in the anchored bilayer are slower than those in lipid bilayers at the same temperature and show a progressive increase as the torsion numbers approach the tail. A two-dimensional periodic Voronoi tessellation analysis was performed to obtain the single-molecular area of an alkyl chain in the bilayer. The single-molecular area relaxation times are an order of magnitude longer than the trans−gauche isomerization times. The results indicate that the trans−gauche isomerization is associated with the creation and annihilation of a kink defect sequence. The results of the present MD simulation explain the apparent conflicting estimates of the gauche disorder in this system as obtained from infrared and 13C nuclear magnetic resonance measurements.

Developing improved supply chains for temperate fruits in transitional Asian economies of Thailand and Vietnam.

Asia's increasing demand for both tropical and temperate fruit is projected to grow significantly. Compared with most developed countries, the production of temperate fruits (peach, nectarine, plum and apple) has expanded rapidly in China over the past 20 years. In contrast, current production of plums and peaches in neighbouring countries (Thailand and Vietnam) is very low but their fruit enters the market earlier. Thailand and Vietnam have enormous potential to satisfy a market window in the northern hemisphere period from March to May inclusive when there is little or no stone fruit on the Asian market. In Vietnam, fruit is harvested in an immature state to avoid disease and fruit fly problems and consequently lacks size and flavour. Approximately 30-40% of locally produced fruit in Vietnam does not reach market due to disease and poor handling during picking and transport. In Thailand, much of the infrastructure needed to transport, store, process and market temperate fruits successfully are now in place. However, there are currently no cool chain management or quality assurance systems to ensure a fresh product reaches the consumer with minimal deterioration. In Vietnam, growing stone fruit under the traditional system with little or minimal inputs, the farmer may receive between AUD3,000-5,000 per ha. In comparison, under higher input systems incorporating fertiliser, irrigation and pest and disease management, net returns can be increased seven-fold. Strengths and weaknesses of the current supply chains in these two countries are discussed.

Strategic Analysis: A key factor in developing horticultural supply chains in transitional Asian economies

Globalisation is set to have a major impact on world horticultural production and distribution of fruit and vegetables throughout the world. In contrast to developing countries such as China, production and consumption of fresh fruit and vegetables in most developed countries is relatively static. For developed countries, we are starting to see consolidation in the number of farms producing fruit and vegetables with falling or static prices and real farm incomes. Global supply chains are now dominated by a few large multi-national retailers supplied by preferred trans-national distribution companies. The major competitive advantages that are emerging are consistency of supply of high quality product over an extended season and the control of genetic resources and their marketing. To capture these new competitive advantages, new strategic analyses and planning processes must be implemented. In the past, strategic analyses and planning has been undertaken on an ad hoc basis without accurate global intelligence. In the future, working ‘on the supply chain’ will become equally, if not more important, than working ‘in the supply chain’. A revised approach to strategic planning, which encompasses and adjusts for the changes caused by globalisation, is urgently needed. A new 6-step strategic analyses process is described.

Improving knowledge and practices in fresh produce chains

A successful supply chain must delivery the right product, value and satisfaction to the end customer, and profitability for its participants. Critical to getting the product right is the practices used to produce and maintain product quality through the supply chain from production to sale to the end customer. This paper describes the approach used by a R&D team to add value to supply chains through improving knowledge and practices. The desired outcome is better produce quality for consumers and more control and less wastage for chain participants. The team worked with specific supply chains to identify areas for improvement and to develop, test and implement improved practices. The knowledge gained was communicated to the industry to gain wider adoption of results. Three conditions were identified as critical for practice change - motivation, knowledge, and capacity for change. For improvement in practices to occur, a business must be motivated and have the knowledge and capacity to improve. Two case studies of working with Australian supply chains (mango and melons) are presented to illustrate our participatory methodology. A key activity is monitoring produce quality and handling practices and conditions to demonstrate to participants the points where quality deterioration occurs in the supply chain. This participatory approach is successful because working with supply chain participants generates knowledge and solutions to real problems. It enables the participants to observe the effect of handling practices and conditions on produce quality, gain knowledge and assess the benefits of improvements. Where existing knowledge is not present, research is conducted to fill the knowledge gaps. IV International Conference on Managing Quality in Chains - The Integrated View on Fruits and Vegetables Quality

A computerized methodology for structural synthesis of kinematic chains: Part 1- Formulation

In an effort to develop a fully computerized approach for structural synthesis of kinematic chains the steps involved in the method of structural synthesis based on transformation of binary chains [38] have been recast in a format suitable for implementation on a digital computer. The methodology thus evolved has been combined with the algebraic procedures for structural analysis [44] to develop a unified computer program for structural synthesis and analysis of simple jointed kinematic chains with a degree of freedom 0. Applications of this program are presented in the succeeding parts of the paper.

A computerized methodology for structural synthesis of kinematic chains: Part 2 - Application to several fully or partially known cases

The reliability of the computer program for structural synthesis and analysis of simple-jointed kinematic chains developed in Part 1 has been established by applying it to several cases for whuch solutions are either fully or partially available in the literature, such as 7-link, zero-freedom chains; 8- and 10-link, single-freedom chains; 12-link, single-freedom binary chains; and 9-link, two-freedom chains. In the process some discrepancies in the results reported in previous literature have been brought to light.

A computerized methodology for structural synthesis of kinematic chains: Part 3 - application to the new case of 10-link, three- freedom chains

The unified computer program for structural synthesis and analysis developed in Part 1 has been employed to derive the new and complete collection of 97 10-link, three-freedom simple-jointed kinematic chains. The program shows that of these chains, 3 have total freedom, 70 have partial freedom and the remaining 24 have fractionated freedom and that the 97 chains yield a total of 676 distinct mechanisms.

In quest of a reliable and efficient computational test for detection of isomorphism in kinematic chains

The test based on comparison of the characteristic coefficients of the adjancency matrices of the corresponding graphs for detection of isomorphism in kinematic chains has been shown to fail in the case of two pairs of ten-link, simple-jointed chains, one pair corresponding to single-freedom chains and the other pair corresponding to three-freedom chains. An assessment of the merits and demerits of available methods for detection of isomorphism in graphs and kinematic chains is presented, keeping in view the suitability of the methods for use in computerized structural synthesis of kinematic chains. A new test based on the characteristic coefficients of the “degree” matrix of the corresponding graph is proposed for detection of isomorphism in kinematic chains. The new test is found to be successful in the case of a number of examples of graphs where the test based on characteristic coefficients of adjancency matrix fails. It has also been found to be successful in distinguishing the structures of all known simple-jointed kinematic chains in the categories of (a) single-freedom chains with up to 10 links, (b) two-freedom chains with up to 9 links and (c) three-freedom chains with up to 10 links.

Adoption of environmental assurance in pastoral industry supply chains - Market failure and beyond

This paper describes adoption rates of environmental assurance within meat and wool supply chains, and discusses this in terms of market interest and demand for certified 'environmentally friendly' products, based on phone surveys and personal interviews with pastoral producers, meat and wool processors, wholesalers and retailers, and domestic consumers. Members of meat and wool supply chains, particularly pastoral producers, are both aware of and interested in implementing various forms of environmental assurance, but significant costs combined with few private benefits have resulted in low adoption rates. The main reason for the lack of benefits is that the end user (the consumer) does not value environmental assurance and is not willing to pay for it. For this reason, global food and fibre supply chains, which compete to supply consumers with safe and quality food at the lowest price, resist public pressure to implement environmental assurance. This market failure is further exacerbated by highly variable environmental and social production standards required of primary producers in different countries, and the disparate levels of government support provided to them. Given that it is the Australian general public and not markets that demand environmental benefits from agriculture, the Australian government has a mandate to use public funds to counter this market failure. A national farm environmental policy should utilise a range of financial incentives to reward farmers for delivering general public good environmental outcomes, with these specified and verified through a national environmental assurance scheme.

Self-Organization of n-Alkane Chains in Water: Length Dependent Crossover from Helix and Toroid to Molten Globule

We demonstrate a chain length dependent crossover in the structural properties of linear hydrocarbon (n-alkane) chains using detailed atomistic simulations in explicit water. We identify a number of exotic structures of the polymer chain through energy minimization of representative snapshots collected from molecular dynamics trajectory. While the collapsed state is ring-like (circular) for small chains (CnH2n+2; n <= 20) and spherical for very long ones (n = 100), we find the emergence of ordered helical structures at intermediate lengths (n similar to 40). We find different types of disordered helices and toroid-like structures at n = 60. We also report a sharp transition in the stability of the collapsed state as a function of the chain length through relevant free energy calculations. While the collapsed state is only marginally metastable for C20H42, a clear bistable free energy surface emerges only when the chain is about 30 monomers long. For n = 30, the polymer exhibits an intermittent oscillation between the collapsed and the coil structures, characteristic of two stable states separated by a small barrier.

Improved domestic profitability and export competitiveness of selected fruit value chains in the southern Philippines and Australia program

The goal of the Program is to contribute to economic growth in the Philippines through increased income and improved livelihoods of tropical fruit growers in southern Philippines. The purpose of the Program is to improve the smallholder and industry profitability and export competitiveness of selected tropical fruits industries in the southern Philippines. Fruit crops to be targeted are mango, papaya, durian and jackfruit. The primary audience for the outcomes of this Program are medium to large scale commercial fruit growers and farmers predominantly in the regions of Leyte (VIII), northern Mindanao/Cagayan de Oro (X) and southern Mindanao/Davao (XI).

Computer-aided analysis of the structure of kinematic chains

Using the link-link incidence matrix to represent a simple-jointed kinematic chain algebraic procedures have been developed to determine its structural characteristics such as the type of freedom of the chain, the number of distinct mechanisms and driving mechanisms that can be derived from the chain. A computer program incorporating these graph theory based procedures has been applied successfully for the structural analysis of several typical chains.

Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis.

Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5 years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.