Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran concentrations in Xingyun Lake sediment close to the pulp mill region of Jiangchuan (China): a typical case study

Sediment cores from Xingyun Lake close to the pulp mill region of Jiangchuan (China), earlier found to be highly contaminated by pulping at least from the 1990s, were analyzed by HRGC/HRMS for the concentrations of 17 polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). Regarding the contribution of individual congeners, PCDD/F levels ranged from ND (non-detectable) to 82.05 pg g-1 dw (from ND to 0.16 pg WHO-TEQ g−1 dw) in 0–20 cm of sediment and from ND to 45.61 pg g-1 dw (from ND to 0.67 WHO-TEQ g−1 dw) in 20–40 cm of sediment for 17 PCDD/Fs (WHO-TEQ: WHO-endorsed toxic equivalents). Major PCDD/Fs identified and confirmed were high-chlorinated congeners including OCDD/Fs and HpCDD/Fs in the two depths. For high-chlorinated PCDD/Fs such as O, Hp-CDD/Fs across the depth of sediment, sediment had a higher proportion in 0–20 cm than that in 20–40 cm. On the contrary, for low-chlorinated PCDD/Fs such as T, Pe, Hx-CDD/Fs, the lower proportion was found in 0–20 cm. The results demonstrated that PCDD/Fs loads in the sediment of Xingyun Lake were very low compared to loads in the other regions about 8 years after closedown of a majority of pulp production with chlorine, which indicated that pulp production was an important emission source of dioxins.

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Biorefinery implementation for recovery debottlenecking at existing pulp mills- Part II: Techno-economic evaluation

TAPPI Journal ◽

10.32964/tj11.8.17 ◽

2012 ◽

Vol 11 (8) ◽

pp. 17-24 ◽

Cited By ~ 1

Author(s):

HAKIM GHEZZAZ ◽

LUC PELLETIER ◽

PAUL R. STUART

Keyword(s):

Cost Estimation ◽

Process Model ◽

Black Liquor ◽

Pulp Mill ◽

Value Added ◽

Economic Assessment ◽

Extraction Process ◽

Estimation Methods ◽

Precipitation Process

The evaluation and process risk assessment of (a) lignin precipitation from black liquor, and (b) the near-neutral hemicellulose pre-extraction for recovery boiler debottlenecking in an existing pulp mill is presented in Part I of this paper, which was published in the July 2012 issue of TAPPI Journal. In Part II, the economic assessment of the two biorefinery process options is presented and interpreted. A mill process model was developed using WinGEMS software and used for calculating the mass and energy balances. Investment costs, operating costs, and profitability of the two biorefinery options have been calculated using standard cost estimation methods. The results show that the two biorefinery options are profitable for the case study mill and effective at process debottlenecking. The after-tax internal rate of return (IRR) of the lignin precipitation process option was estimated to be 95%, while that of the hemicellulose pre-extraction process option was 28%. Sensitivity analysis showed that the after tax-IRR of the lignin precipitation process remains higher than that of the hemicellulose pre-extraction process option, for all changes in the selected sensitivity parameters. If we consider the after-tax IRR, as well as capital cost, as selection criteria, the results show that for the case study mill, the lignin precipitation process is more promising than the near-neutral hemicellulose pre-extraction process. However, the comparison between the two biorefinery options should include long-term evaluation criteria. The potential of high value-added products that could be produced from lignin in the case of the lignin precipitation process, or from ethanol and acetic acid in the case of the hemicellulose pre-extraction process, should also be considered in the selection of the most promising process option.

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The Effects of an Aided Augmentative System on Communication and Speech in a Preschool Child with Developmental Delay: A Case Study

Australasian Journal of Special Education ◽

10.1017/s1030011200024490 ◽

1999 ◽

Vol 23 (1) ◽

pp. 25-46

Author(s):

Mark Carter

Keyword(s):

Preschool Children ◽

Developmental Delay ◽

Communication System ◽

Lower Proportion ◽

Graphic Symbol ◽

Symbol Use ◽

Alternating Treatment Design ◽

Treatment Design ◽

Sustained Increase

The effect of an aided graphic augmentative communication system on communication and speech in a 4‐year 7‐month‐old child with developmental delay was evaluated in this case study. An alternating treatment design was used across 2 mealtime settings (morning tea and lunch) over a 6‐week period with counterbalancing of aided and unaided conditions. Once graphic symbol use emerged, there were slightly higher levels of unprompted communication and requests in the aided condition and a lower proportion of acts contained nonsymbolic communication. There was also a higher number of different words + symbols used in the aided condition. The introduction of the graphic symbols did not appear to have detrimental effects on speech but there was no evidence of sustained increase in frequency of speech or spoken vocabulary in the aided condition. Substantial increases were noted in the number of unprompted communicative turns and range of total vocabulary over the course of the study in both conditions. The need for further research on the effects of AAC on speech and communication in preschool children is highlighted.

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The Use of Aluminium for Commercial Vehicle Structures—A Feasibility Study

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1978_192_009_02 ◽

1978 ◽

Vol 192 (1) ◽

pp. 81-92

Author(s):

B. B. Hundy ◽

S. Broadstock

Keyword(s):

Structural Analysis ◽

Aluminium Alloy ◽

Feasibility Study ◽

Commercial Vehicle ◽

Load Capacity ◽

Typical Case ◽

Extra Cost ◽

Manufacturing Processes ◽

Structural Components

The use of aluminium alloy instead of steel for the structural components of a 32 ton articulated lorry has been examined. The probable manufacturing difficulties have been assessed and shown to be minimal. The savings in weight possible by using aluminium have been calculated from a structural analysis of the cab, tractor chassis and trailer and from this and an assessment of the manufacturing processes the extra cost of manufacturing in aluminium has been determined. A typical case study shows that this extra cost can be easily recovered by utilising the increased load capacity of the vehicle during the first few years of its life.

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Behavior and Design of Post-Installed Rebar Connections under Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.711.783 ◽

2016 ◽

Vol 711 ◽

pp. 783-790 ◽

Cited By ~ 6

Author(s):

Giovanni Muciaccia ◽

Andrea Consiglio ◽

Gianpaolo Rosati

Keyword(s):

Bond Strength ◽

Safety Margin ◽

Typical Case ◽

Design Criteria ◽

Bond Properties ◽

Anchorage Length ◽

Testing Conditions ◽

Experimental Campaign ◽

Eurocode 2

Typical applications for post-installed rebar connections consist in overlapping joints with existing reinforcement or anchoring of the reinforcement at a slab or beam support. At cold state it may be shown by testing that a post-installed rebar system can develop the same bond resistance with the same safety margin as cast-in-place rebar. Consequently, anchorage length and lap length for post-installed rebars can be calculated as for cast-in-place according to the Eurocode 2 provisions. However, when subjected to temperature, the decay in bond properties for post-installed systems is significantly more dramatic than for cast-in-place rebars. The paper presents the result of an experimental campaign carried out on a post-installed connection using a vinylester polymer, investigating the effects on the bond strength both of the temperature and of different testing conditions. Finally, design criteria are provided and applied to a typical case study consisting in a post-installed solid slab.

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