title: A quick, reliable solution for modelling cheese chilling process

authors: Hoang, Duy

subjects: Modelling

abstract: Optimisation of the refrigerating system for cheese processing requires an accurate prediction of chilling time, product temperature distributions and heat flow. Many existing CFD models can provide the best predictions by directly solving the three-dimensional heat transfer problem within the product and for air flow around the product; however, they are time-consuming and not suitable for routine use. A one-dimensional numerical solution proposed by Ghraizi, Chumak, Onistchenko, and Terziev (1996) has been used to provide the quick answer to food processing engineers with a good accuracy. In this method, the partial differential equation describing one-dimensional non-linear unsteady heat conduction inside the product has been solved by a finite difference technique. The method can take into account the temperature-dependence of thermal properties of foods and a general shape factor was used to reflect the product geometry. The model was applied to a single block of cheese, and agar. Predicted results are compared to experimentally-measured temperature profiles as well as to results generated by the Food Product Modeller, FPM, software.

text: A quick, reliable solution for modelling cheese chilling process Optimisation of the refrigerating system for cheese processing requires an accurate prediction of chilling time, product temperature distributions and heat flow. Many existing CFD models can provide the best predictions by directly solving the three-dimensional heat transfer problem within the product and for air flow around the product; however, they are time-consuming and not suitable for routine use. A one-dimensional numerical solution proposed by Ghraizi, Chumak, Onistchenko, and Terziev (1996) has been used to provide the quick answer to food processing engineers with a good accuracy. In this method, the partial differential equation describing one-dimensional non-linear unsteady heat conduction inside the product has been solved by a finite difference technique. The method can take into account the temperature-dependence of thermal properties of foods and a general shape factor was used to reflect the product geometry. The model was applied to a single block of cheese, and agar. Predicted results are compared to experimentally-measured temperature profiles as well as to results generated by the Food Product Modeller, FPM, software.

year: 2018

title: Cellulose nanocrystal treatment of aligned short hemp fibre mats for reinforcement in polypropylene matrix composites

authors: Sunny, Tom

abstract: Oriented short hemp fibre mats were produced using dynamic sheet forming (DSF) incorporating cellulose nanocrystals (CNCs) to improve their integrity. The CNCs were found to act as a binder and improve mechanical strength of the mats as well as the strength of polypropylene matrix composites produced with the mats. Improved thermal stability was also obtained for composites by using CNC treatment of fibre mats.

text: Cellulose nanocrystal treatment of aligned short hemp fibre mats for reinforcement in polypropylene matrix composites Oriented short hemp fibre mats were produced using dynamic sheet forming (DSF) incorporating cellulose nanocrystals (CNCs) to improve their integrity. The CNCs were found to act as a binder and improve mechanical strength of the mats as well as the strength of polypropylene matrix composites produced with the mats. Improved thermal stability was also obtained for composites by using CNC treatment of fibre mats.

year: 2021

title: A late-Holocene and prehistoric record of environmental change from Lake Waikaremoana, New Zealand

authors: Newnham, Rewi M.

subjects: Palynology

abstract: Further evidence in support of a late pre-European (Polynesian) settlement of New Zealand is provided by an 1850-year-long tephropalynological record from a remote region in New Zealand's North Island. The earliest unequivocally anthropogenic forest clearance is estimated from sedimentation rates to have occurred c. 375 14C years BP (c. ad 1523–1631), although the radiocarbon chronology, shown by tephrochron ology to be erroneous due to hard-water effects, suggested this occurred c. 900 years earlier. Delineation of the anthropogenic era, and the distinction between human activity and other agents of environmental change in the pollen/spore diagram, are supported by cluster analysis and detrended correspondence analysis. Two distinct phases of forest clearance are evident during the pre-European era, reflecting local changes either in population pressure or settlement patterns. We note that the lull between the two phases of forest clearance coincides with the maximum of the ‘Little Ice Age’ within the period c. late ad 1600s to early 1800s.

text: A late-Holocene and prehistoric record of environmental change from Lake Waikaremoana, New Zealand Further evidence in support of a late pre-European (Polynesian) settlement of New Zealand is provided by an 1850-year-long tephropalynological record from a remote region in New Zealand's North Island. The earliest unequivocally anthropogenic forest clearance is estimated from sedimentation rates to have occurred c. 375 14C years BP (c. ad 1523–1631), although the radiocarbon chronology, shown by tephrochron ology to be erroneous due to hard-water effects, suggested this occurred c. 900 years earlier. Delineation of the anthropogenic era, and the distinction between human activity and other agents of environmental change in the pollen/spore diagram, are supported by cluster analysis and detrended correspondence analysis. Two distinct phases of forest clearance are evident during the pre-European era, reflecting local changes either in population pressure or settlement patterns. We note that the lull between the two phases of forest clearance coincides with the maximum of the ‘Little Ice Age’ within the period c. late ad 1600s to early 1800s.

year: 1998