38 research outputs found
Human Arm simulation for interactive constrained environment design
During the conceptual and prototype design stage of an industrial product, it
is crucial to take assembly/disassembly and maintenance operations in advance.
A well-designed system should enable relatively easy access of operating
manipulators in the constrained environment and reduce musculoskeletal disorder
risks for those manual handling operations. Trajectory planning comes up as an
important issue for those assembly and maintenance operations under a
constrained environment, since it determines the accessibility and the other
ergonomics issues, such as muscle effort and its related fatigue. In this
paper, a customer-oriented interactive approach is proposed to partially solve
ergonomic related issues encountered during the design stage under a
constrained system for the operator's convenience. Based on a single objective
optimization method, trajectory planning for different operators could be
generated automatically. Meanwhile, a motion capture based method assists the
operator to guide the trajectory planning interactively when either a local
minimum is encountered within the single objective optimization or the operator
prefers guiding the virtual human manually. Besides that, a physical engine is
integrated into this approach to provide physically realistic simulation in
real time manner, so that collision free path and related dynamic information
could be computed to determine further muscle fatigue and accessibility of a
product designComment: International Journal on Interactive Design and Manufacturing
(IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with
arXiv:1012.432
Chlorpyrifos degradation by the cyanobacterium Synechocystis sp. strain PUPCCC 64
Background, aim, and scope Indiscriminate use of insecticides
leads to environmental problems and poses a great
threat to beneficial microorganisms. The aim of the present
work was to study chlorpyrifos degradation by a rice field
cyanobacterium Synechocystis sp. strain PUPCCC 64 so
that the organism is able to reduce insecticide pollution
in situ.
Material and methods The unicellular cyanobacterium isolated
and purified from a rice field was identified by partial
16S rRNA gene sequence as Synechocystis sp. strain
PUPCCC 64. Tolerance limit of the organism was determined
by studying its growth in graded concentrations (2.5–
20 mg/L) of chlorpyrifos. Chlorpyrifos removal was studied
by its depletion from the insecticide supplemented growth
medium, and its biodegradation products were identified in
the cell extract, biomass wash, and growth medium.
Results and discussion The organism tolerated chlorpyrifos
up to 15 mg/L.Major fraction of chlorpyrifos was removed by
the organism during the first day followed by slow uptake.
Biomass, pH, and temperature influenced the insecticide
removal and the organism exhibited maximum chlorpyrifos
removal at 100 mg protein/L biomass, pH 7.0, and 30°C. The
cyanobacteriummetabolized chlorpyrifos producing a number
of degradation products as evidenced by GC-MS chromatogram.
One of the degradation products was identified as 3,5,6-
trichloro-2-pyridinol.
Conclusion and recommendations Present study reports the
biodegradation of chlorpyrifos by Synechocystis sp. Biodegradation
of the insecticide by the cyanobacterium is
significant as it can be biologically removed from the
environment. The cyanobacterium may be used for bioremediation
of chlorpyrifos-contaminated soils