• Journal of Ecology and Environment
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• v.32 no.4
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• pp.257-265
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• 2009

We estimated monthly and annual secondary productivity of pelagic zooplankton in Lake Paldang and Lake Cheongpyong. Secondary productivity was calculated by combining estimated zooplankton biomass and biomass-specific productivity for each site and depth from March to November 2008. In addition to somatic production, we measured production of eggs and exuviae for three dominant species: Daphnia galeata, Bosmina longirostris, Cyclops sp. In terms of biomass, B. longirostris was dominant in Lake Paldang in April and May, B. longirostris showed explosive biomass growth, especially in May. In June and July, B. longirostris and D. galeata were both dominant. Lake Cheongpyeong showed much lower zooplankton biomass than Lake Paldang. In August, there was little or no biomass in both lakes probably due to heavy rain. The Gyeongan River contributed most of the secondary productivity and B. longirostris contributed the most secondary productivity in Lake Paldang. D. galeata also contributed in the Gyeongan River, the South Han River and at the Paldang Dam in spring and fall. Overall, Lake Cheongpyeong showed lower secondary productivity than Lake Paldang. B. longirostris made the largest contribution to secondary productivity in the Cheongpyeong Dam area while D. galeata contributed the most near Nami Island. Somatic production constituted ~80% of the total secondary productivity (the sum of somatic, egg and exuvia production) for D. galeata and B. longirostris. Although production-to-biomass (P/B) ratios were usually <<1 B. longirostris sometimes showed very high P/B ratios, probably due to fish predation. D. galeata showed much lower P/B ratios than B. longirostris after the summer at most sites.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.298-306
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• 2010

We estimated aboveground primary productivity of Salix nipponica based on biomass using allometry and basal area at Janghang wetland in Han River estuary. In addition, we estimated secondary production of sesarmine crab (Sesarma dehaani) living under the Salix community to interpret relationships between Salix nipponica and Sesarma dehaani. Salix nipponica showed primary productivity of 4,777 g DW $m^{-2}yr^{-1}$, which appear to be the highest primary productivity in South Korea. The estimated amount of autochthonous organic matter from S. nipponica and allochthonous organic matter from the Han River into sediment was 359 g C $m^{-2}yr^{-1}$ and 347 g C $m^{-2}yr^{-1}$, respectively. The secondary productivity of Sesarma dehaani was 100.2 g FW $m^{-2}yr^{-1}$, which was 2.1% of the primary productivity of S. nipponica. The biomass of Sesarma dehanni was average 140 g FW $m^{-2}$, which consumed their prey of approximately 2,140 g FW $yr^{-1}$, which is equivalent to approximately 208 g C $m^{-2}yr^{-1}$.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.125-129
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• 2008

To predict Daphnia secondary productivity along a trophic gradient indexed as total phosphorus (TP) concentration, we estimated energy transfer efficiencies from food quality for Daphnia such as eicosa-pentaenoic acid (EPA) or docosahexaenoic acid (DHA) content. Eleven flow-through Daphnia magna growth experiments were conducted with seston from 9 lakes, ponds and river waters. Primary productivities were estimated from food supply rates in the flow-through experiments, producing energy transfer efficiencies from seston to D. magna. We found DHA content was the best predictor of energy transfer efficiencies among the essential fatty acids. An asymptotic saturation model explained 79.6% of the variability In energy transfer efficiencies. Based on empirical data in this study and empirical models from literature, we predict that Daphnia productivity would peak in mesotrophic systems by decreasing food quality and Increasing food quantity along trophic gradient.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1278-1279
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• 2006

New product line with additional secondary operation of oil pump rotor was built in necessity of increasing capacity. This new line includes steam treatment process after sizing. The new line achieved 1.6 times higher performance compared with a conventional line.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.238-244
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• 1994

To investigate the bacterial potentials for utilizing dissolved organic matter in highly eutrophic estuary, the annual fluctuations of microbiological and physicochemical environmental parameters were analyzed in Naktong River Estuary. Total bacterial number ranged from 0.33 to $2.09{\times}10^7$ cells/ml, and correlated with the heterotrophic bacterial numbers in more eutrophic sites, especially. Bacterial biovolume and biomass varied between 0.064 and 0.156 2.09${\mu}m^3$/cell, 0.163 and 1.036 ${\mu}g$-C/ml, respectively. Bacterial secondary productivity ranged from 0.24 to 60.86 ${\mu}g$-C/l/h, and showed high correlations with the environmental parameters of pollution indicator. The seasonal variation pattern of bacterial productivity in freshwater sites was high in winter and low in summer, which was interpreted as the results of pollution loads varied with the amount of rainfall. In seawater site, the pattern was different from those of freshwater sites; high in summer and low in winter. In this site, the values of bacterial productivity showed positive correaltions with chlorophyll a, heterotrophic bacterial number, and temperature (r>0.5, p<0.05). These results suggested that the main source of organic matter which influences the bacterial productivity may be allochthonous materials in the upper freshwater zone of Naktong River Barrage, and autochthonous algal excretory products in the lower seawater zone of Naktong River Barrage.

• The Journal of Industrial Distribution & Business
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• v.11 no.10
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• pp.49-58
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• 2020

Purpose: The purpose of this study was to examine the differential effect of workforce diversity on employee productivity and its subsequent impact on customer experience. Research design, data and methodology: A once-off cross-sectional research design was used in this study where the Zimbabwean civil service was targeted. Randomization was used to collect 324 validated responses. The study focused on both primary (age and gender) and secondary (education and political affiliation) dimensions of workforce diversity. Results: The results were confirmatory that workforce diversity is a significant predictor of employee productivity (β = 0.668, P < 0.05), at the same time employee productivity holds explanation to customer experience by 37%. Results also revealed that gender diversity, educational diversity and political diversity were significant determinants of workforce diversity (P < 0.05). However, the study established that age diversity was not a significant factor in enhancing employee productivity (P > 0.05). Conclusions: The study concluded that workforce diversity is a powerful tool in enhancing both customer experience and employee productivity. As such, the latter can be augmented through shrewd workforce diversity practices as championed by management. To that end, the study recommends the development of a workforce diversity framework which promotes inclusivity.

• Clean Technology
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• v.28 no.3
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• pp.258-266
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• 2022

Resource productivity (GDP/DMC) is defined as GDP divided by DMC. However, it has shortcomings when estimating the value-added generated from material processing. In this paper, an energy coefficient is applied to GDP to develop a sub-indicator (referred to as GDPe/DMC). Consequently, South Korea, which is a secondary industry-oriented country, created 1,094.60 USD/ton from input materials and was ranked 4th on the OECD list, which is 10 levels higher than the level estimated by GDP/DMC. However, Luxembourg, which is a tertiary industry-oriented country, is ranked 16th on the OECD list, which is 12 levels lower than the level estimated by GDP/DMC. The resource productivity estimated by the sub-indicator (GDPe/DMC) developed in this study indicates that secondary industry-oriented countries are undervalued in the existing main GDP/DMC calculation. On the other hand, tertiary industry-oriented countries are downgraded due to the industrial features of the GDPe/DMC calculation. As a result of this paper, GDPe/DMC could be considered a more reasonable indicator to directly reflect the material input effect compared to the existing main indicator, GDP/DMC. This means that GDPe/DMC-induced resource productivities could be estimated to be slightly higher than the GDP/DMC-induced resource productivities for secondary industry-oriented countries. It is expected that the sub-indicator, GDPe/DMC, proposed in this study could be useful especially for comparing and analyzing the resource productivities between countries that have different industry structures. This study intended to consider a structurally energy/resource-intensive industry in estimating and analyzing national-level resource productivity. Thus, the sub-indicator, GDPe/DMC, may help minimize the distortion of interpreting national resource productivities in various situations, and be utilized as a more efficient tool when used together with GDP/DMC.

• Journal of Plant Biology
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• v.18 no.3
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• pp.122-128
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• 1975

With the cultivated mulberry plant which feeds silkworm on its leaves in sericulture, the measuring methods of biomass of terrestrial organs were compared and the annual net productivity was estimated. The measurement of the standing crops by means of allometric method on basis of relation between the parameter D230H, square of the diameter of the branch on 30cm high above ground($D{\frac}{2}{30}$) multiplied by its height(H), and the amount of leaves(WL) or of branch (Ws) was more accurate than other methods on basis of correlation between a character of the branch such as H, D30 or D230 and WL or Ws. The estimate of value of the net productivity of terrestrial parts of mulberry was 9.06-12.54 ton/ha.year, which was similar to that obtained from secondary forests in cool temperate zone.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.3-8
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• 2001

The mineral industry of the United States is going through a challenging time. The US as an industrial nation faces with increasing demand in raw materials to fuel various industrial sectors but, at the same time, meeting environmental constraints associated with excavating and extracting these raw materials. In addition, gradual depletion of material resources. and the necessity of handling more complex forms of resources of primary origin have led to a decline in her resource productivity, once a strategic advantage of the U.S. As a result. the United States currently relies heavily upon foreign importation of various materials such as precious and strategic metals. However, since the US is the major consumer of most of these materials, the recovery of these values from scrap would help renew her position as a resource-producing nation, and ultimately help spur its domestic economy. Furthermore. recycling would also help maintain a clean environment and reduce energy consumption. In this paper. the author attempts to discuss opportunities and challenges lied ahead of the US mineral in relation to recovering their much-needed resources from secondary sources. The need and demand in various metals in the US will be reviewed and discussed. The implication of resource recovery from secondary sources will also be discussed. Extraction methods treating secondary sources are inherently different from those for primary sources. There is a need for new technologies which are metallurgically efficient and environmentally benign in treating secondary sources. Ways to meet such a need will be examined and key factors to be considered in approaching these challenges will be discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.138-149
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• 2002

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stage etc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.