scholarly journals Application of the Proposed Fiber Optic Time Differential BOCDA Sensor System for Impact Damage Detection of a Composite Cylinder

2021 ◽  
Vol 11 (21) ◽  
pp. 10247
Author(s):  
Bo-Hun Choi ◽  
Dae-Cheol Seo ◽  
Yong-Seok Kwon ◽  
Il-Bum Kwon

An optical-fiber-embedded composite cylinder was fabricated using the filament winding process with an interval of 12 mm in the longitudinal direction of the cylinder. The optical fiber was wound 160 turns around the cylinder, and the straight length was about 125 m. After a total of twelve impact events of 5, 10, 15, and 20 J, the residual strain in the cylinder was measured using the proposed time differential BOCDA sensor system. This method makes the traditionally used optical delay unnecessary while increasing the degrees of freedom of using the modulation rate, which determines the spatial resolution of this measurement system. The modulation rates of optical light in the system were applied up to 16 Gbps, which is an eight-fold increase compared to our previous experiments. Damage maps were obtained by mapping the measured residual strain onto the structure of the cylinder, and compared using three spatial resolutions of 20, 10, and 6.25 mm. In the measured damage map, expansion deformation due to impact was measured at all impact points, and the impact location on the map and the actual location on the cylinder were exactly the same. The map measured from the composite showed a clear point-symmetrical shape with an increase in sharpness as the measurement resolution increased. At the highest resolution, material expansion and compression were observed to alternate with respect to the center of impact, like the surface deformation of a liquid caused by a thrown object. Furthermore, considered together with our previous experiments, we confirmed that this phenomenon propagated from the surface of the composite material to the interior, where the optical fiber was embedded. The total amount of residual strain formed around each impact point was linearly proportional to the applied external impact energy.


2020 ◽  
Vol 12 ◽  
Author(s):  
Sai Akilesh M ◽  
Ashish Wadhwani

: Infectious diseases have been prevalent since many decades and viral pathogens have caused global health crisis and economic meltdown on a devastating scale. High occurrence of newer viral infections in the recent years, in spite of the progress achieved in the field of pharmaceutical sciences defines the critical need for newer and more effective antiviral therapies and diagnostics. The incidence of multi-drug resistance and adverse effects due to the prolonged use of anti-viral therapy is also a major concern. Nanotechnology offers a cutting edge platform for the development of novel compounds and formulations for biomedical applications. The unique properties of nano-based materials can be attributed to the multi-fold increase in the surface to volume ratio at the nano-scale, tunable surface properties of charge and chemical moieties. Idealistic pharmaceutical properties such as increased bioavailability and retention times, lower toxicity profiles, sustained release formulations, lower dosage forms and most importantly, targeted drug delivery can be achieved through the approach of nanotechnology. The extensively researched nano-based materials are metal and polymeric nanoparticles, dendrimers and micelles, nano-drug delivery vesicles, liposomes and lipid based nanoparticles. In this review article, the impact of nanotechnology on the treatment of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) viral infections during the last decade are outlined.



2020 ◽  
Vol 41 (S1) ◽  
pp. s111-s112
Author(s):  
Mohammed Alsuhaibani ◽  
Mohammed Alzunitan ◽  
Kyle Jenn ◽  
Daniel Diekema ◽  
Michael Edmond ◽  
...  

Background: Surveillance for surgical site infections (SSI) is recommended by the CDC. Currently, colon and abdominal hysterectomy SSI rates are publicly available and impact hospital reimbursement. However, the CDC NHSN allows surgical procedures to be abstracted based on International Classification of Diseases, Tenth Revision (ICD-10) or current procedural terminology (CPT) codes. We assessed the impact of using ICD and/or CPT codes on the number of cases abstracted and SSI rates. Methods: We retrieved administrative codes (ICD and/or CPT) for procedures performed at the University of Iowa Hospitals & Clinics over 1 year: October 2018–September 2019. We included 10 procedure types: colon, hysterectomy, cesarean section, breast, cardiac, craniotomy, spinal fusion, laminectomy, hip prosthesis, and knee prosthesis surgeries. We then calculated the number of procedures that would be abstracted if we used different permutations in administration codes: (1) ICD codes only, (2) CPT codes only, (3) both ICD and CPT codes, and (4) at least 1 code from either ICD or CPT. We then calculated the impact on SSI rates based on any of the 4 coding permutations. Results: In total, 9,583 surgical procedures and 180 SSIs were detected during the study period using the fourth method (ICD or CPT codes). Denominators varied according to procedure type and coding method used. The number of procedures abstracted for breast surgery had a >10-fold difference if reported based on ICD only versus ICD or CPT codes (104 vs 1,109). Hip prosthesis had the lowest variation (638 vs 767). For SSI rates, cesarean section showed almost a 3-fold increment (2.6% when using ICD only to 7.32% with both ICD & CPT), whereas abdominal hysterectomy showed nearly a 2-fold increase (1.14% when using CPT only to 2.22% with both ICD & CPT codes). However, SSI rates remained fairly similar for craniotomy (0.14% absolute difference), hip prosthesis (0.24% absolute difference), and colon (0.09% absolute difference) despite differences in the number of abstracted procedures and coding methods. Conclusions: Denominators and SSI rates vary depending on the coding method used. Variations in the number of procedures abstracted and their subsequent impact on SSI rates were not predictable. Variations in coding methods used by hospitals could impact interhospital comparisons and benchmarking, potentially leading to disparities in public reporting and hospital penalties.Funding: NoneDisclosures: None



2021 ◽  
Vol 14 (5) ◽  
pp. 453
Author(s):  
Gabriela Wiergowska ◽  
Dominika Ludowicz ◽  
Kamil Wdowiak ◽  
Andrzej Miklaszewski ◽  
Kornelia Lewandowska ◽  
...  

To improve physicochemical properties of vardenafil hydrochloride (VAR), its amorphous form and combinations with excipients—hydroxypropyl methylcellulose (HPMC) and β-cyclodextrin (β-CD)—were prepared. The impact of the modification on physicochemical properties was estimated by comparing amorphous mixtures of VAR to their crystalline form. The amorphous form of VAR was obtained as a result of the freeze-drying process. Confirmation of the identity of the amorphous dispersion of VAR was obtained through the use of comprehensive analysis techniques—X-ray powder diffraction (PXRD) and differential scanning calorimetry (DSC), supported by FT-IR (Fourier-transform infrared spectroscopy) coupled with density functional theory (DFT) calculations. The amorphous mixtures of VAR increased its apparent solubility compared to the crystalline form. Moreover, a nearly 1.3-fold increase of amorphous VAR permeability through membranes simulating gastrointestinal epithelium as a consequence of the changes of apparent solubility (Papp crystalline VAR = 6.83 × 10−6 cm/s vs. Papp amorphous VAR = 8.75 × 10−6 cm/s) was observed, especially for its combinations with β-CD in the ratio of 1:5—more than 1.5-fold increase (Papp amorphous VAR = 8.75 × 10−6 cm/s vs. Papp amorphous VAR:β-CD 1:5 = 13.43 × 10−6 cm/s). The stability of the amorphous VAR was confirmed for 7 months. The HPMC and β-CD are effective modifiers of its apparent solubility and permeation through membranes simulating gastrointestinal epithelium, suggesting a possibility of a stronger pharmacological effect.



Author(s):  
Marta Oliveira ◽  
Sílvia Capelas ◽  
Cristina Delerue-Matos ◽  
Simone Morais

Grilling activities release large amounts of hazardous pollutants, but information on restaurant grill workers’ exposure to polycyclic aromatic hydrocarbons (PAHs) is almost inexistent. This study assessed the impact of grilling emissions on total workers’ exposure to PAHs by evaluating the concentrations of six urinary biomarkers of exposure (OHPAHs): naphthalene, acenaphthene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene. Individual levels and excretion profiles of urinary OHPAHs were determined during working and nonworking periods. Urinary OHPAHs were quantified by high-performance liquid-chromatography with fluorescence detection. Levels of total OHPAHs (∑OHPAHs) were significantly increased (about nine times; p ≤ 0.001) during working comparatively with nonworking days. Urinary 1-hydroxynaphthalene + 1-hydroxyacenapthene and 2-hydroxyfluorene presented the highest increments (ca. 23- and 6-fold increase, respectively), followed by 1-hydroxyphenanthrene (ca. 2.3 times) and 1-hydroxypyrene (ca. 1.8 times). Additionally, 1-hydroxypyrene levels were higher than the benchmark, 0.5 µmol/mol creatinine, in 5% of exposed workers. Moreover, 3-hydroxybenzo(a)pyrene, biomarker of exposure to carcinogenic PAHs, was detected in 13% of exposed workers. Individual excretion profiles showed a cumulative increase in ∑OHPAHs during consecutive working days. A principal component analysis model partially discriminated workers’ exposure during working and nonworking periods showing the impact of grilling activities. Urinary OHPAHs were increased in grill workers during working days.



2021 ◽  
pp. 1-1
Author(s):  
Leticia Avellar ◽  
Gabriel Delgado ◽  
Eduardo Rocon ◽  
Carlos Marques ◽  
Anselmo Frizera ◽  
...  


Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Aleksey V. Tarasov ◽  
Ekaterina I. Khamzina ◽  
Maria A. Bukharinova ◽  
Natalia Yu. Stozhko

In contemporary bioanalysis, monitoring the antioxidant activity (AOA) of the human skin is used to assess stresses, nutrition, cosmetics, and certain skin diseases. Non-invasive methods for skin AOA monitoring have certain advantages over invasive methods, namely cost-effectiveness, lower labor intensity, reduced risk of infection, and obtaining results in the real-time mode. This study presents a new flexible potentiometric sensor system (FPSS) for non-invasive determination of the human skin AOA, which is based on flexible film electrodes (FFEs) and membrane containing a mediator ([Fe(CN)6]3–/4–). Low-cost available materials and scalable technologies were used for FFEs manufacturing. The indicator FFE was fabricated based on polyethylene terephthalate (PET) film and carbon veil (CV) by single-sided hot lamination. The reference FFE was fabricated based on PET film and silver paint by using screen printing, which was followed by the electrodeposition of precipitate containing a mixture of silver chloride and silver ferricyanide (SCSF). The three-electrode configuration of the FPSS, including two indicator FFEs (CV/PET) and one reference FFE (SCSF/Ag/PET), has been successfully used for measuring the skin AOA and evaluating the impact of phytocosmetic products. FPSS provides reproducible (RSD ≤ 7%) and accurate (recovery of antioxidants is almost 100%) results, which allows forecasting its broad applicability in human skin AOA monitoring as well as for evaluating the effectiveness of topically and orally applied antioxidants.



2021 ◽  
Vol 13 (5) ◽  
pp. 874
Author(s):  
Yu Chen ◽  
Mohamed Ahmed ◽  
Natthachet Tangdamrongsub ◽  
Dorina Murgulet

The Nile River stretches from south to north throughout the Nile River Basin (NRB) in Northeast Africa. Ethiopia, where the Blue Nile originates, has begun the construction of the Grand Ethiopian Renaissance Dam (GERD), which will be used to generate electricity. However, the impact of the GERD on land deformation caused by significant water relocation has not been rigorously considered in the scientific research. In this study, we develop a novel approach for predicting large-scale land deformation induced by the construction of the GERD reservoir. We also investigate the limitations of using the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) mission to detect GERD-induced land deformation. We simulated three land deformation scenarios related to filling the expected reservoir volume, 70 km3, using 5-, 10-, and 15-year filling scenarios. The results indicated: (i) trends in downward vertical displacement estimated at −17.79 ± 0.02, −8.90 ± 0.09, and −5.94 ± 0.05 mm/year, for the 5-, 10-, and 15-year filling scenarios, respectively; (ii) the western (eastern) parts of the GERD reservoir are estimated to move toward the reservoir’s center by +0.98 ± 0.01 (−0.98 ± 0.01), +0.48 ± 0.00 (−0.48 ± 0.00), and +0.33 ± 0.00 (−0.33 ± 0.00) mm/year, under the 5-, 10- and 15-year filling strategies, respectively; (iii) the northern part of the GERD reservoir is moving southward by +1.28 ± 0.02, +0.64 ± 0.01, and +0.43 ± 0.00 mm/year, while the southern part is moving northward by −3.75 ± 0.04, −1.87 ± 0.02, and −1.25 ± 0.01 mm/year, during the three examined scenarios, respectively; and (iv) the GRACE-FO mission can only detect 15% of the large-scale land deformation produced by the GERD reservoir. Methods and results demonstrated in this study provide insights into possible impacts of reservoir impoundment on land surface deformation, which can be adopted into the GERD project or similar future dam construction plans.



1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari ◽  
Z. Chen ◽  
Q. Li

ABSTRACTStructurally integrated optical fiber sensors form the basis for smart structure technology. Over the past decade a variety of sensor configurations have been developed for measurement of strains and deformations in structures. Strains and deformations alter the refractive index and the geometry of the optical fiber material. These changes perturb the intensity, phase, and polarization of the light-wave propagating along the probing fiber. The optical perturbations are detected for the determination of strain. The research presented here describes the development of a new optical fiber sensor system for measurement of structural strains based on white light interferometry. An optical switch provides for multiplexing of strain signals from various locations in the structure. Redundant Bragg grating type fiber optic sensors as well as strain gauges were employed for comparison and verification of strain signals as measured by the new system. The system provides capability for distributed sensing of strains in large structures.



1991 ◽  
Author(s):  
Tong Yu ◽  
Qin G. Li ◽  
Rongsheng Chen ◽  
Jin-Li Yan


2015 ◽  
Vol 17 (01) ◽  
pp. 1550003 ◽  
Author(s):  
FRANK VANCLAY

Over 150 forms of impact assessment can be identified using Google searches, with several new forms appearing since 2003. Since then, the popularity of the various members of the impact assessment family has changed, partly in response to legislative and regulatory changes, and general trends in society. The information explosion and expansion of the internet has resulted in a 32 fold increase in the number of hits for "impact assessment", now over 12 million. The conventional methods most frequently mentioned in 2003 had relatively low proportional change over the last 10 years but remain amongst the most frequently mentioned in 2014: risk assessment, public participation, cost-benefit analysis, public involvement, environmental monitoring, and project evaluation. The terms with highest proportional change (i.e. the super-hot topics) were primarily social concerns, including: equality impact assessment, welfare impact assessment, mental health impact assessment, disability impact assessment, human impact assessment, social impact assessment, and social risk assessment. Other terms that had high proportional change included life cycle impact assessment. Information about the relative popularity of the various forms of impact assessment is used in this paper to discuss issues and trends in the broad field of impact assessment.



Sign in / Sign up

Export Citation Format

Share Document