Seasonal changes in the standing crop of two montane sedges

1973 ◽  
Vol 51 (6) ◽  
pp. 1097-1108 ◽  
Author(s):  
Eville Gorham ◽  
Maureen Gibson Somers
Keyword(s):  
Life Span ◽  
Production Rate ◽  
Late Summer ◽  
Dry Weight ◽  
Early Spring ◽  
Pure Stand ◽  
Carex Aquatilis ◽  
Maximum Production ◽  
Carex Rostrata ◽  
Maximum Production Rate

Aboveground green biomass of a montane pure stand of Carex rostrata varies from about 125 g/m2 (air-dry weight) at the end of November to about 640 g/m2 in early August. The maximum production rate of about 6 g/m2 per day occurs in May. For a nearby stand of Carex aquatilis with a prominent moss layer the aboveground green biomass of sedge material varies from about 40 g/m2 in February to about 380 g/m2 in mid-August. The maximum production rate for sedge material is about 4 g/m2 per day in July. Both species exhibit two main populations of shoots, one emerging in late summer and the other through winter and early spring. The winter and spring shoots of Carex rostrata flower and die after about 18 months, while the late summer shoots, which do not mature vegetatively until the following summer, have a life-span of about 2 years. The late summer shoots of Carex aquatilis mature vegetatively before winter, and flower and die within about 12 months; while the winter and spring shoots live through the next winter, and flower and die the following summer after a life-span of about 18 months.

Economics of Multitool Lathe Operations

1963 ◽  
Vol 85 (4) ◽  
pp. 402-404 ◽  
Author(s):  
E. M. McCullough
Keyword(s):  
Production Rate ◽  
Tool Life ◽  
Cycle Time ◽  
Minimum Cost ◽  
Spindle Speed ◽  
Maximum Production ◽  
Maximum Production Rate

The formulas for calculation of tool life for maximum production rate and tool life for minimum cost are expanded to include multitool operations and cases in which the total cycle time controlled by the spindle speed is greater than the cutting time. A modification is made to avoid use of conventional overhead rates, which are shown to be invalid in this instance.

scholarly journals Studies on British Laminariaceae. I. Growth in Laminaria Saccharina (L.) Lamour

1948 ◽  
Vol 27 (3) ◽  
pp. 651-709 ◽  
Author(s):  
Mary Parke
Keyword(s):  
Life Span ◽  
Late Summer ◽  
Early Spring ◽  
Laminaria Saccharina ◽  
Sublittoral Zone ◽  
British Coast

The production, longevity, growth, regeneration and reproduction of Laminaria saccharina (L.) Lamour. on the Devon and Argyll coasts are described.Bathymetric zone and habitat control the fertility and longevity of the gametophyte and consequently the production of the sporophyte. Sporophytes develop at the higher levels during the winter, early spring, late summer and autumn, and at the lower levels during spring, summer and autumn.Longevity of the sporophyte depends on season of germination, bathymetric zone and habitat. Winter sporophytes rarely persist to maturity. Spring sporophytes form the bulk of all L. saccharina populations except on very sheltered coasts in the sublittoral zone where summer sporophytes may be equally numerous. On the British coast the life-span of a L. saccharina sporophyte does not exceed 3 years.

Evaluation of Medium Composition and Fermentation Parameters on Pullulan Production by Aureobasidium pullulans

2011 ◽  
Vol 17 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Kuan-Chen Cheng ◽  
Ali Demirci ◽  
Jeffrey M. Catchmark
Keyword(s):  
Production Rate ◽  
Batch Fermentation ◽  
Aureobasidium Pullulans ◽  
Fed Batch ◽  
Maximum Production ◽  
Fed Batch Fermentation ◽  
Initial Ph ◽  
Fermentation Parameters ◽  
Maximum Production Rate ◽  
Ph Profiles

The goal of this study was to enhance pullulan production by evaluating the effects of different fermentation parameters. Various carbon sources and their concentrations, yeast extract (YE) concentrations, fermentation temperatures and various pH profiles were examined. The optimal growth condition for pullulan production by Aureobasidium pullulans has been found as 75 g/L of sucrose as carbon source, 3 g/L of YE and cultivation temperature at 30 °C. Under these conditions with an initial pH at 5, 20.7 g/L of final pullulan concentration and 0.22 g/L/h maximum production rate were obtained. Later on, various pH profiles, agitation speeds, aerations and fed-batch fermentation were evaluated. The results demonstrated that pullulan production was enhanced to 25.8 g/L after 7-day cultivation with a 0.68 -g/L/h maximum production rate. There was no significant improvement of pullulan production from fed-batch fermentation. The optimal kinetics parameters were as follows: initial pH at 2.0, switched to pH 5.0 after 72 h and kept constant; agitation speed at 200 rpm; aeration at 1.5 vvm. The quality analysis demonstrated that the pullulan content produced from optimal conditions was 94.5% and its viscosity was 2.3 centipoise (cP). Fourier transform infrared spectroscopy also suggested that pullulan dominated the produced exopolysaccharide.

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