title: Improving energy recovery in milk powder production through soft data optimisation

authors: Walmsley, Timothy Gordon

abstract: Milk powder production is highly energy intensive and can benefit from the application of Pinch analysis techniques to develop better methods for integrating the process. In this study, process stream data is extracted from an industrial plant and Pinch analysis applied to calculate utility and heat recovery targets. Some of process data is also varied, within small ranges that do not harm product quality or violate environmental regulation, to minimise utility use targets. Using the Pinch design method and the targets as a guide, Maximum Energy Recovery (MER) networks are developed for two cases, where the condenser in the evaporator section of the plant may be directly or indirectly integrating into the reminder of the process. The two MER networks are compared to two heat exchanger network structures commonly found in industry. Results show that there is potential to increase specific heat recovery by over 30%, while reducing total cost by almost 10%, in the best case. To achieve maximum energy recovery, spray dryer exhaust air heat recovery is necessary and should be matched to preheat the dryer inlet air stream.

text: Improving energy recovery in milk powder production through soft data optimisation Milk powder production is highly energy intensive and can benefit from the application of Pinch analysis techniques to develop better methods for integrating the process. In this study, process stream data is extracted from an industrial plant and Pinch analysis applied to calculate utility and heat recovery targets. Some of process data is also varied, within small ranges that do not harm product quality or violate environmental regulation, to minimise utility use targets. Using the Pinch design method and the targets as a guide, Maximum Energy Recovery (MER) networks are developed for two cases, where the condenser in the evaporator section of the plant may be directly or indirectly integrating into the reminder of the process. The two MER networks are compared to two heat exchanger network structures commonly found in industry. Results show that there is potential to increase specific heat recovery by over 30%, while reducing total cost by almost 10%, in the best case. To achieve maximum energy recovery, spray dryer exhaust air heat recovery is necessary and should be matched to preheat the dryer inlet air stream.

year: 2013

title: Caldolase: an alkaline serine protease from Thermus strain TOK₃

authors: Saravani, G.A.

abstract: The object of this investigation was the isolation of extreme thermophiles producing extracellular proteases, and the biochemical characterisation of a stable, chelator-insensitive protease. 
Two plate assay systems were developed for the initial screening of proteases. The first involved the incorporation of various protease inhibitors (particularly chelating agents) in casein agar plates, the second the inclusion of a variety of native and chromogenic proteins in the agar plates. In conjunction, these methods provided a basis for screening extreme thermophiles for particular proteases, and enabled the identification of fourteen new proteases. Included amongst them was an extracellular serine protease from a Thermus strain designated Tok₃, which was selected for further study.
The protease was purified to homogeneity by ammonium-sulphate precipitation followed by ion exchange on DEAE-cellulose and QAE-Sephadex, affinity chromatography on CBZ-phe-TETA-Sepharose-4B, gel filtration chromatography on either Sephadex G-75 or TSK G3000 SW using HPLC system and finally Polyacrylamide gel electrophoresis.
For convenience the protease was assigned a trivial name, and the term Caldolase was chosen. The prefix Caldo- is derived from Latin Caldo (hot) and the suffix ‘ase’ is a general term for enzymes. 
The specific activity of the pure enzyme was estimated to be 38,000 proteolytic units per mg (PU mg ml⁻¹) at 75°C using casein as the substrate. The purified enzyme had a pH optimum of 9.5 with an isoelectric point of 8.9. Caldolase demonstrated greatest stability between pH 7 and 10. The molecular weight of the protease was estimated by exclusion chromatography on Sephadex G-75 and TSK G3000 SW to be 25,000 daltons.
The enzyme was inhibited by serine inhibitors (DFP, PMSF and di-phenyl carbamyl chloride), partially inhibited by heavy metal (CUCl₂), but not inhibited by metal chelators (EDTA, EGTA, 0-phenanthroline, and NEPIS), Cysteine inhibitors (PCMB, iodo-acetamide, and N-ethylmaleimide) or trypsin inhibitors. These results indicate that Caldolase is an alkaline serine protease. 
Neither Ca²⁺ nor Zn²⁺ ions were detected in the highly purified protease. The presence of four disulphide bonds per molecule of the enzyme was indicated with dithionitro-benzoate. No free sulphydryl groups were found. The purified protease contained approximately 10% carbohydrate. The amino acid composition of Caldolase was determined. 
The enzyme exhibited strong substrate inhibition when using casein, azo-casein, and azo-albumin as substrates. No substrate inhibition was observed when low-molecular weight synthetic substrates were used, indicating that substrate inhibition using casein and azo-albumin substrates may be due to steric hindrance rather than binding to the active site of the enzyme.
The Arrhenius plots for both casein and peptide substrates were curved, but without any clearly marked discontinuity. It is concluded that the effect of temperature on the enzyme conformation is continuous rather than occurring at a particular temperature. No significant differences were observed in Kₘ values at various temperatures between 45° and 85°C.
Caldolase hydrolysed several protein substrates, including casein, albumin, ovalbumin, haemoglobin, collagen, fibrin and elastin, and a number of synthetic chromogenic peptides. It also possessed esterase activity. The enzyme was not able to hydrolyse peptides possessing fewer than four groups (amino acid residues and terminal blocking group). Caldolase did not hydrolyse Bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-phe-Arg). In contrast enzyme hydrolysis of insulin B chain resulted in a very complex pattern, suggesting a low degree of specificity. 
The enzyme was very thermostable. Half-life values were: 100°C, 5 min; 90°C, 45 min; and 80°C, 840 min. Caldolase was stable in denaturing agents (GuHCl, urea) at 22°C, but not at 85°C. Exposure of the enzyme to various organic solvents caused no significant loss of catalytic activity.
Ionic strength had a marked effect on enzyme stability. The combination of low salt concentration (below 0.3M NaCl) and low temperatures (under 75°C) results in reversible enzyme denaturation. However, at high temperatures (above 80°C) this phenomenon is rapidly followed by autolysis by the remaining active enzyme.

text: Caldolase: an alkaline serine protease from Thermus strain TOK₃ The object of this investigation was the isolation of extreme thermophiles producing extracellular proteases, and the biochemical characterisation of a stable, chelator-insensitive protease. 
Two plate assay systems were developed for the initial screening of proteases. The first involved the incorporation of various protease inhibitors (particularly chelating agents) in casein agar plates, the second the inclusion of a variety of native and chromogenic proteins in the agar plates. In conjunction, these methods provided a basis for screening extreme thermophiles for particular proteases, and enabled the identification of fourteen new proteases. Included amongst them was an extracellular serine protease from a Thermus strain designated Tok₃, which was selected for further study.
The protease was purified to homogeneity by ammonium-sulphate precipitation followed by ion exchange on DEAE-cellulose and QAE-Sephadex, affinity chromatography on CBZ-phe-TETA-Sepharose-4B, gel filtration chromatography on either Sephadex G-75 or TSK G3000 SW using HPLC system and finally Polyacrylamide gel electrophoresis.
For convenience the protease was assigned a trivial name, and the term Caldolase was chosen. The prefix Caldo- is derived from Latin Caldo (hot) and the suffix ‘ase’ is a general term for enzymes. 
The specific activity of the pure enzyme was estimated to be 38,000 proteolytic units per mg (PU mg ml⁻¹) at 75°C using casein as the substrate. The purified enzyme had a pH optimum of 9.5 with an isoelectric point of 8.9. Caldolase demonstrated greatest stability between pH 7 and 10. The molecular weight of the protease was estimated by exclusion chromatography on Sephadex G-75 and TSK G3000 SW to be 25,000 daltons.
The enzyme was inhibited by serine inhibitors (DFP, PMSF and di-phenyl carbamyl chloride), partially inhibited by heavy metal (CUCl₂), but not inhibited by metal chelators (EDTA, EGTA, 0-phenanthroline, and NEPIS), Cysteine inhibitors (PCMB, iodo-acetamide, and N-ethylmaleimide) or trypsin inhibitors. These results indicate that Caldolase is an alkaline serine protease. 
Neither Ca²⁺ nor Zn²⁺ ions were detected in the highly purified protease. The presence of four disulphide bonds per molecule of the enzyme was indicated with dithionitro-benzoate. No free sulphydryl groups were found. The purified protease contained approximately 10% carbohydrate. The amino acid composition of Caldolase was determined. 
The enzyme exhibited strong substrate inhibition when using casein, azo-casein, and azo-albumin as substrates. No substrate inhibition was observed when low-molecular weight synthetic substrates were used, indicating that substrate inhibition using casein and azo-albumin substrates may be due to steric hindrance rather than binding to the active site of the enzyme.
The Arrhenius plots for both casein and peptide substrates were curved, but without any clearly marked discontinuity. It is concluded that the effect of temperature on the enzyme conformation is continuous rather than occurring at a particular temperature. No significant differences were observed in Kₘ values at various temperatures between 45° and 85°C.
Caldolase hydrolysed several protein substrates, including casein, albumin, ovalbumin, haemoglobin, collagen, fibrin and elastin, and a number of synthetic chromogenic peptides. It also possessed esterase activity. The enzyme was not able to hydrolyse peptides possessing fewer than four groups (amino acid residues and terminal blocking group). Caldolase did not hydrolyse Bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-phe-Arg). In contrast enzyme hydrolysis of insulin B chain resulted in a very complex pattern, suggesting a low degree of specificity. 
The enzyme was very thermostable. Half-life values were: 100°C, 5 min; 90°C, 45 min; and 80°C, 840 min. Caldolase was stable in denaturing agents (GuHCl, urea) at 22°C, but not at 85°C. Exposure of the enzyme to various organic solvents caused no significant loss of catalytic activity.
Ionic strength had a marked effect on enzyme stability. The combination of low salt concentration (below 0.3M NaCl) and low temperatures (under 75°C) results in reversible enzyme denaturation. However, at high temperatures (above 80°C) this phenomenon is rapidly followed by autolysis by the remaining active enzyme.

year: 1985

title: Incorporating New Zealand indigenous views into community resilience frameworks for the built environment

authors: Boston, Megan

abstract: Community resilience lacks a standardized definition and methodology to quantify. Many governments and organizations have attempted to construct frameworks for improving community resilience, particularly as related to the built environment. However, few of these frameworks explicitly consider the values and cultural aspects of marginalized communities that are potentially negatively disadvantaged due to colonialization or socio-economic deprivation. To date, little research has worked on integrating Maori cultural views into these resilience frameworks. Using survey results investigating Maori and New Zealand European cultural views on resilience and aspects of the built environment, it has been found that Maori value unity and community cohesion as aspects of resilience more than New Zealand Europeans. Further, communities can increase community cohesion and unity through adapting Maori Marae’s or communal gathering places to increase community resilience following a disaster.

text: Incorporating New Zealand indigenous views into community resilience frameworks for the built environment Community resilience lacks a standardized definition and methodology to quantify. Many governments and organizations have attempted to construct frameworks for improving community resilience, particularly as related to the built environment. However, few of these frameworks explicitly consider the values and cultural aspects of marginalized communities that are potentially negatively disadvantaged due to colonialization or socio-economic deprivation. To date, little research has worked on integrating Maori cultural views into these resilience frameworks. Using survey results investigating Maori and New Zealand European cultural views on resilience and aspects of the built environment, it has been found that Maori value unity and community cohesion as aspects of resilience more than New Zealand Europeans. Further, communities can increase community cohesion and unity through adapting Maori Marae’s or communal gathering places to increase community resilience following a disaster.

year: 2022-07-01