PHOTOSYNTHESIS IN ALGAE: II. GREEN ALGAE WITH SPECIAL REFERENCE TO DUNALIELLA SPP. AND TETRASELMIS SPP.

1966 ◽  
Vol 44 (10) ◽  
pp. 1247-1254 ◽  
Author(s):  
J. S. Craigie ◽  
J. McLachlan ◽  
W. Majak ◽  
R. G. Ackman ◽  
C. S. Tocher
Keyword(s):  
Hydrogen Sulfide ◽  
Special Reference ◽  
Green Algae ◽  
Photosynthetic Rates ◽  
High Level

The photosynthetic fixation of14CO2was studied in 10 species of chlorophycean algae and in 9 isolates of prasinophycean algae of the genus Tetraselmis.Green seaweeds had photosynthetic rates of 2.2 to 4.4 mg CO2 × h−1 × g−1, accumulated starch, glucose, fructose, and sucrose, and excreted very little recent photosynthate.Dunaliella spp. were distinguished by a high level of organic excretion (to 29.2% of the14C fixed in 2 hours), the production of glycerol and hydrogen sulfide, and the absence of dimethyl-β-propiothetin.Tetraselmis spp. excreted relatively small amounts of photosynthate in 2 hours, and produced mannitol and dimethyl-β-propiothetin but not hydrogen sulfide.

NIROSTA 4002

Alloy Digest ◽  
2002 ◽  
Vol 51 (6) ◽  
Keyword(s):  
Hydrogen Sulfide ◽  
High Temperature ◽  
Physical Properties ◽  
Structural Steel ◽  
Oil Industry ◽  
Heat Treating ◽  
Mineral Oil ◽  
Chromium Steel ◽  
Temperature Performance ◽  
High Level

Abstract NIROSTA 4002 is an apparatus structural steel with 13% Cr. It is used for crack-resistant installations in the mineral oil industry because it has a high level of resistance against hydrogen and hydrogen sulfide. This chromium steel requires a smoothened surface free from residues in order to achieve optimal resistance to corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SS-856. Producer or source: ThyssenKrupp Nirosta GmbH.

Cellular Photosynthetic Rate of Fully and Partially Pigmented Chlamydomonas reinhardtii as a Function of Irradiance

2011 ◽  
Author(s):  
Thomas E. Murphy ◽  
Halil Berberog˘lu
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Algae ◽  
Photosynthetic Rate ◽  
Wild Strain ◽  
Experimental Setup ◽  
Light Penetration ◽  
Photosynthetic Rates ◽  
Planktonic Algae ◽  
Mass Cultures ◽  
Increase Productivity

This paper reports the cellular photosynthetic rates of the green algae Chlamydomonas reinhardtii wild strain and its truncated chlorophyll antenna transformant, tla1, as a function of local irradiance. It is hypothesized that reduction in the pigmentation of algae cells can enhance light peneration in mass cultures and increase productivity. Thus, an experimental setup was designed to expose each cell within planktonic algae cultures to a nearly uniform irradiance. An oxygen microsensor was used to monitor the photosynthetic rate as the irradiance onto the sample was varied. The results showed that the cellular photosynthetic rate of the wild strain, CC125, was greater than that of tla1 at all irradiances, by a factor that ranged from 1.7 to 4. Photoinhibition was observed in both strains, although the effect was more pronounced in CC125. Although less pigmented cells enable deeper light penetration in photobioreactors, their reduced phosotynthetic rate can negate this benefit.

scholarly journals Evaluation of Low-Cost Hydrogen Sulfide Monitors for Use in Livestock Production

2017 ◽  
Vol 23 (4) ◽  
pp. 265-279 ◽  
Author(s):  
Jessica M. Beswick-Honn ◽  
Thomas M. Peters ◽  
T. Renée Anthony
Keyword(s):  
Hydrogen Sulfide ◽  
High Risk ◽  
Low Cost ◽  
Agricultural Workers ◽  
Direct Reading ◽  
Alarm Reaction ◽  
And Performance ◽  
One Year ◽  
High Level ◽  
Manure Gas

Abstract. Direct-reading gas monitors warn workers of the risk of potentially fatal hydrogen sulfide (H2S) exposures that may arise during manure handling. Low-cost, low-maintenance H2S monitors are available from many manufacturers, but differences in their features and performance make selection challenging for farmers. Moreover, little information is available on the practical maintenance and performance of these devices in agricultural environments. The objective of this study was to provide information to agricultural workers to aid in the selection, maintenance, and use of low-cost H2S monitors. This laboratory study evaluated the performance of several low-cost monitors over a simulated period of use of one year in a swine barn. Four models were exposed to H2S concentrations of 1 to 10 ppm over 18 weeks to examine the drift in reported concentration and changes in the alarm reaction time. Over the simulated barn year, the performance of alarm-only monitors declined faster than that of monitors displaying the H2S concentration. Of concern was the high-level (20 ppm) alarm failures after an equivalent of 139 days (Altair) and 289 days (BW Clip) in a swine barn, well within the monitor’s reported shelf-life. Models displaying concentration exhibited fewer failures but were inaccurate in the displayed concentration when challenged with 20 ppm of H2S. The T40 Rattler provided consistently higher readings (+2.3 ppm), and the Pac 3500 showed consistently lower readings (-3.4 ppm) when challenged with 20 ppm. This study confirms the need for routine bump tests for these low-cost monitors to ensure that the monitor reacts to the presence of H2S, even if the manufacturer does not recommend this procedure. Most importantly, agricultural workers should inspect and bump test these monitors prior to any potentially high-risk activity, such as manure agitation, pumping, or pressure washing, to ensure that the monitor appropriately detects and warns users. Keywords: Calibration, Direct-reading monitors, H2S, Hydrogen sulfide monitors, Manure gas, Safety, Sensors.

scholarly journals To Study the Socio-Economic Status of Small and Marginal Farmers with Special Reference to Schedule Caste and Schedule Tribe Farmers of Kamrup District of Assam

2021 ◽  
Vol 8 (8) ◽  
pp. 147-162
Author(s):  
Deeptangshu Sarma ◽  
Jahanara Jahanara
Keyword(s):  
Special Reference ◽  
Economic Status ◽  
Annual Income ◽  
Schedule Caste ◽  
Socio Economic Status ◽  
Medium Level ◽  
Food And Nutritional Security ◽  
High Level ◽  
Mass Media Exposure ◽  
Schedule Tribe

SES (socio-economic status) is a measurement of an entity's economic and social position in comparison to others in society. It has an impact on resource accessibility, livelihood patterns, food and nutritional security, and so on. Knowledge, attitude, perception, adoption, change-proneness, level of aspiration, economic motivation and other psychological and behavioural components of a sample are frequently predicted. The present study tried to investigate about the socio economic status of the marginal and small farmers with special reference to Schedule caste and schedule tribe farmers in Kamrup district of Assam. Descriptive research design has been used . Data of 120 respondents were collected with the help of pre-structured questionnaire and personal interview. The study was conducted in 5 villages in Kamrup district of Assam in the year 2021.Thirteen variables were selected viz. category Gender, age, caste, education, annual income, occupation, social participation, types of house, land holding , Mass media exposure, farm power, material possessed, Extension contact were taken into account. Equal numbers of respondents were taken from SC and ST. 64.2% of the respondents were male. Majority of them were under 30 years old. Majority of the percentage had primary level of education, along with medium annual income. The overall SES category was medium level with 48.3% and low level 32.5% of SES category, 19.2% high level.

Monophyly of Genera and Species of Characeae based on rbcL Sequences, with Special Reference to Australian and European Lychnothamnus barbatus (Characeae: Charophyceae)

1999 ◽  
Vol 47 (3) ◽  
pp. 361 ◽  
Author(s):  
Richard M. McCourt ◽  
Michelle T. Casanova ◽  
Kenneth G. Karol ◽  
Monique Feist
Keyword(s):  
Maximum Likelihood ◽  
Special Reference ◽  
Green Algae ◽  
Large Subunit ◽  
Australian Population ◽  
Sexual Systems ◽  
Limited Variation ◽  
Multiple Species ◽  
Paraphyletic Assemblage ◽  
Rbcl Sequences

Sequences for the chloroplast-encoded large subunit of the Rubisco gene (rbcL) were used to test the monophyly of multiple isolates within species, and multiple species within genera, of green algae in the Characeae (Class Charophyceae). Parsimony and maximum likelihood analyses supported the monophyly of genera and most species, with the exception of a paraphyletic assemblage comprising isolates of two ‘species’, dioecious Chara connivens Salzm. ex A.Br. and monoecious C. globularis Thuill., which together constitute a monophyletic group. The rbcL data support the independent evolution of either monoecious or dioecious sexual systems in the two connivens-globularis, clades. Comparisons of disjunct isolates of the monotypic Lychnothamnus barbatus (Meyen) Leohn. revealed nearly identical rbcL sequences in isolates from Croatia, Germany and Australia, although all three sequences were unique. The variation exhibited by these isolates was similar to variation between isolates within species of Chara and Lamprothamnium from different continents. The limited variation may be due to dispersal of thalli or oospores between continents; however, the rarity of known intercontinental transfers of Characeae in the last two centuries suggests that the Australian population is probably not an exotic from Europe. Lychnothamnus barbatus populations in Australia and elsewhere thus merit continued protected status.

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