41 research outputs found
Vapor grown carbon nanofiber based cotton fabrics with negative thermoelectric power
Vapor grown carbon nanofiber (CNF)
based ink dispersions were used to dip-coat woven
cotton fabrics with different constructional parameters, and their thermoelectric (TE) properties studied
at room temperature. Unlike the positive thermoelectric power (TEP) observed in TE textile fabrics
produced with similar carbon-based nanostructures,
the CNF-based cotton fabrics showed negative TEP,
caused by the compensated semimetal character of the
CNFs and the highly graphitic nature of their outer
layers, which hinders the p-type doping with oxygen
groups onto them. A dependence of the electrical
conductivity (r) and TEP as a function of the woven
cotton fabric was also observed. The cotton fabric with
the largest linear density (tex) showed the best
performance with negative TEP values around
- 8 lV K-1
, a power factor of 1.65 9 10-3
lW m-1 K-2
, and a figure of merit of 1.14 9 10-6
.
Moreover, the possibility of a slight e- charge transfer
or n-doping from the cellulose onto the most external
CNF graphitic shells was also analysed by computer
modelling. This study presents n-type carbon-based
TE textile fabrics produced easily and without any
functionalization processes to prevent the inherent
doping with oxygen, which causes the typical p-type
character found in most carbon-based TE materialsFEDER funds through
COMPETE and by national funds through FCT – Foundation for
Science and Technology within the project POCI-01-0145-
FEDER-007136. E. M. F. Vieira is grateful for financial support
through FCT with CMEMS-UMinho Strategic Project UIDB/
04436/202
Macroscopic kinetics of hydrate formation of mixed hydrates of hydrogen/tetrahydrofuran for hydrogen storage
10.1016/j.ijhydene.2013.01.123International Journal of Hydrogen Energy38114587-4596IJHE
Hydrogen storage in clathrate hydrates: Current state of the art and future directions
10.1016/j.apenergy.2014.01.063Applied Energy122112-132APEN
Torso kinematics and low back disorder risk as a function of pallet orientation
The objective of this study was to assess the affect of pallet location on torso kinematics during lifting. Participants transferred 11.3 kg boxes to pallets at two orientations and two distances from a constant lift origin. When reorienting the pallet from 180° to 90°, torso twist, lateral and sagittal torso kinematics increased when palletizing to various locations on the pallet when keeping the pallet distance far. Torso flexion increased slightly at the lowest level on the pallet independent of the pallet distance. When keeping the pallet distance close, torso twist kinematics decreased only when palletizing to the highest and closest position of the pallet. When reorienting the pallet from 180° to 90° adjacent to the lift origin, the best strategy to reduce torso kinematics appears to be to eliminate the transferring of loads to the lowest level of the pallet, and keeping the pallet close to the lift origin. © 2004 - IOS Press and the authors. All rights reserved
The effect of pallet distance on torso kinematics and low back disorder risk.
Intervention research for prevention of occupational low back injuries has focused on the effects of reducing extreme torso flexion and the external moment. Little is known about prevention strategies for torso twisting and lateral bending. The objective of this study was to assess the effect of pallet distance with regard to a constant lift origin on the torso kinematics and a measure of low back disorder risk. Fifteen male participants transferred 11.3 kg boxes from a constant origin to six different regions on a pallet. Two pallet distances with regard to the lift origin were investigated. ANOVA indicated that increasing the pallet distance resulted in increases in torso kinematics (velocities and accelerations) as well as a measure of risk of low back disorder. The increases in torso kinematics (e.g. twisting and lateral awkward postures and bending velocities) occurred mostly at the lower height regions on the pallet. It is concluded that increasing the pallet distance with regard to the lifting origin, with the intention to influence the participant to take a step during a palletizing task does not appear to be an effective intervention strategy to reduce the risk of low back disorder associated with torso kinematics
Kinetic promotion of mixed methane-THF hydrate by additives: Opportune to energy storage
10.1016/j.egypro.2019.01.647Energy Procedia1585287-529
Hydrate phase equilibrium of ternary gas mixtures containing carbon dioxide, hydrogen and propane
10.1016/j.jct.2013.02.003Journal of Chemical Thermodynamics6158-63JCTD
An ergonomic evaluation of manual Cleco plier designs: Effects of rubber grip, spring recoil, and worksurface angle
The present study evaluated two design modifications (rubber grip and torsion spring) to the conventional manual Cleco pliers by electromyography (EMG), hand discomfort, and design satisfaction. This study also surveyed workers' satisfaction with selected design features of the pliers for ergonomic improvement. A two-way (plier design x worksurface angle) within-subject (nested within gender and hand size) design was employed. Eleven workers simulated the plier task in an adjustable workstation for different plier designs and worksurface angles (0 degrees, 60 degrees, and 90 degrees). Lower EMG values were obtained for the pliers with rubber grip and at 60 degrees of worksurface angle. EMG values varied significantly between the participants, but showed low correlations (Spearman's rank correlation = -0.27 similar to-0.58) with their work experience with the pliers. The hand discomfort and design satisfaction evaluations identified that the grip span (max = 14.0 cm) and grip force requirement (peak = 220.5 N) of the current pliers need ergonomic modification. The present study shows the needs of both the ergonomic design of a hand tool and the training of a proper work method to control work-related musculoskeletal disorders at the workplace. (c) 2005 Elsevier Ltd. All rights reserved.X1112sciescopu
Benefits and Challenges of Lung Cancer Screening in Older Adults
© 2018 Elsevier HS Journals, Inc. Purpose: Lung cancer screening with low-dose computed tomography has been shown to significantly reduce lung cancer–related mortality in high-risk patients. However, patients diagnosed with lung cancer are typically older and often have multiple age- and smoking-related comorbidities. As a result, cancer screening in older adults remains a complex decision, requiring careful consideration of patients’ risk characteristics and life expectancy to ensure that the benefits outweigh the risks of screening. In this review, we evaluate the evidence regarding lung cancer screening, with a focus on older patients. Methods: PubMed was searched to identify relevant studies evaluating the clinical outcomes of lung cancer screening. The key words used in our search included non–small cell lung cancer (NSCLC), screening, older, comorbidities, computed tomography, and survival. While we primarily looked for articles specific to older patients, we also focused on subgroup analysis in older patients in larger studies. Finally, we reviewed all relevant guidelines regarding lung cancer screening. Findings: Guidelines recommend that lung cancer screening be considered in adults aged 55 to 80 years who are at high risk based on smoking history (ie, 30-pack–year smoking history; having smoked within the past 15 years). Patients who fit these criteria have been shown to have a 20% reduction in lung cancer–related mortality with the use of low-dose computed tomography versus chest radiography. High rates of false-positive results and potential overdiagnoses were also observed. Therefore, screening is generally not recommended in adults with severe comorbidities or short life expectancy, who may experience limited benefit and higher risks with screening. However, several studies have shown a benefit with continued lung cancer screening with appropriate selection of older individuals at the highest risk and with the lowest comorbidities. Implications: Older patients experience the highest risk for lung cancer incidence and mortality, and stand to be the most likely to benefit from lung cancer screening. However, careful consideration must be given to higher rates of false-positives and overdiagnosis in this population, as well as tolerability of surgery and competing risks for death from other causes. The appropriate selection of older individuals for lung cancer screening can be greatly optimized by using validated risk-based targeting