scholarly journals Understanding and optimizing Evolon® CR for varnish removal from oil paintings

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Lambert Baij ◽  
Chun Liu ◽  
Jesse Buijs ◽  
Alba Alvarez Martin ◽  
Dorien Westert ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Saturated Fatty Acids ◽  
Paint Film ◽  
Fold Increase ◽  
Mechanical Action ◽  
Laser Speckle ◽  
Dominant Factor ◽  
Solvent Exposure ◽  
Oil Paintings ◽  
Solvent Retention

AbstractEvolon$$^\circledR$$ ® CR is increasingly used in paintings conservation for varnish removal from oil paintings. Its key benefits over traditional cotton swabs are limiting solvent exposure and reducing mechanical action on the paint surface. However, this non-woven microfilament textile was not originally engineered for conservation use and little is known about its chemical stability towards organic solvents. Moreover, the physical processes of solvent loading and release by Evolon$$^\circledR$$ ® CR, as well as solvent retention inside paint after cleaning, have not been studied. These three topics were investigated using a multi-analytical approach, aiming for an improved understanding and optimized use of Evolon$$^\circledR$$ ® CR for varnish removal. Our results show that the tissue is generally chemically and physically stable to organic solvents when exposed on timescales that are typical in conservation practice. However, a pre-treatment step of Evolon$$^\circledR$$ ® CR is necessary to avoid the release of unwanted saturated fatty acids into the paint during varnish removal. We show that the primary mechanism of solvent uptake by the fibers is adsorption rather than absorption and that the dominant factor dictating the maximum solvent load is the volume of the voids between the fibers. Finally, solvent induced dynamics after application of solvent-loaded Evolon$$^\circledR$$ ® CR within the paint film was monitored using portable laser speckle imaging on model paints. A method to quantify solvent-retention in real-time was developed and revealed that the presence of varnish on paintings results in lower dynamics of solvents within the paint in comparison to unvarnished paint. Comparing various solvents, it was found that cleaning with acetone resulted in a roughly six-fold increase in dynamics compared to ethanol and isopropanol.

Extraction of Material from Oil Paints by Solvents

2002 ◽  
Vol 712 ◽  
Author(s):  
David Erhardt ◽  
Roland H. Cunningham ◽  
Sirpa Räsänen
Keyword(s):  
Fatty Acids ◽  
Saturated Fatty Acids ◽  
Paint Film ◽  
Short Chain Fatty Acids ◽  
Solvent Exposure ◽  
Crosslinking Process ◽  
Oil Paints ◽  
Paint Films ◽  
Hydrolysis Of ◽  
Soluble Material

ABSTRACTDrying oils used to formulate oil paints consist primarily of polyunsaturated triglycerides, along with smaller amounts of mono- and diglycerides, free fatty acids, and other compounds such as sterols. The drying of oils occurs through an oxidative crosslinking process that also produces smaller scission products such as short chain fatty acids and diacids. Compounds that are not attached to the crosslinked oil matrix include glycerin, the unreactive free saturated fatty acids and their glycerides, soaps of fatty acids produced by reaction with metal ions from the pigment, and scission products. As the oil ages, additional soluble material is produced by hydrolysis of glyceride esters. These relatively low molecular weight compounds can be extracted by exposure to solvents, as occurs during the cleaning of paintings. Excessive extraction of material canembrittle the paint film and affect the appearance of the paint. This paper examines the types and amounts of compounds extracted from oil paint films as a function of solvent, exposure time, pigment, and age of the paint. The results indicate that solvents vary more in the speed that they extract material than in their selectivity. The composition of the extracts is consistent with predictions based on the mechanisms of the drying and aging processes. These results confirm the importance of using the least polar solvent possible to clean paintings and to formulate varnishes.

Static and dynamic characterization of micro-electro-mechanical system repulsive force actuators

2019 ◽  
Vol 26 (13-14) ◽  
pp. 1216-1231 ◽  
Author(s):  
Mohammadreza Zamanzadeh ◽  
Saber Azizi
Keyword(s):  
Mechanical System ◽  
Natural Frequency ◽  
Fold Increase ◽  
Micro Electro Mechanical System ◽  
Linear Increase ◽  
Repulsive Force ◽  
Dominant Factor ◽  
Dynamic Characterization ◽  
High Tunability

This paper presents the static and dynamic response characterization of an electrostatic micro-electro-mechanical system mirror driven by repulsive force. The experimental analysis of the static response in different seasons of the year indicates that the capillary force caused by the thin layer of water underneath the mirror is the dominant factor for variation in the lifting threshold of the applied voltage. Dynamic characterization of the mirror reveals a large natural frequency of 2.6 kHz at the increasing rate of 8 Hz/V, indicating a four-fold increase compared to a previous design. This high natural frequency with an almost linear increase is desired for fast speed scanners and interferometers with high tunability benefited from the simplified signal processing circuit. Since the amplitude of the repulsive force micro-structure is no longer restricted to any geometrical limitation, the non-dimensionalizing parameters are chosen so that the nonlinear terms are small enough in order that the perturbation method is applicable in the vicinity of both primary and principal parametric resonances. The analytical analysis shows the way for inserting a bookkeeping parameter in a simple manner based on the evaluation of the magnitude of order in which the pre-assumed value is further validated by experimental results. The results of our investigations can be used to analytically evaluate the static and dynamic behavior of the system and have important applications in the design of various devices such as filters, interferometers, and switches.

scholarly journals Organic solvents as chemical risk factors of the work environment in different branches of industry and possible impact of solvents on workers' health

2010 ◽  
Vol 64 (1-2) ◽  
pp. 25-32
Author(s):  
Mārīte Ārija Baķe ◽  
Maija Eglīte ◽  
Žanna Martinsone ◽  
Inita Buiķe ◽  
Anita Piķe ◽  
...  
Keyword(s):  
Risk Factors ◽  
Organic Solvent ◽  
Work Environment ◽  
Organic Solvents ◽  
Risk Level ◽  
Exposure Index ◽  
Solvent Exposure ◽  
Chemical Risk ◽  
Worker Health ◽  
Organic Solvent Exposure

Organic solvents as chemical risk factors of the work environment in different branches of industry and possible impact of solvents on workers' health The aim of our study was to investigate organic solvents as chemical risk factors of the work environment in different branches of the industry in Latvia during 1998-2006 and to evaluate the possible impact of solvents to worker health according to the exposure index. The work conditions were studied in 116 enterprises of different branches of industries in Latvia. The analysis of 1790 measurements showed that organic solvents in the work environment have different degrees of exposure probability risk on worker health. The exposure levels in workplaces differ. More than half of surveyed workplaces (56.7%) had a low organic solvent exposure probability level, in 25.2% workplaces it was medium, and in 18.1% workplaces high. The most widely used organic solvents were aromatic hydrocarbons, which was recorded in 35% of the measurements made during assessment of aromatic hydrocarbon group organic solvent exposure in the work environment. In most workplaces several solvents were present simultaneously. Since solvents have a one-way effect on the human body, the actual exposure risk level is higher than shown when evaluating the exposure index of a single solvent only.

scholarly journals Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Deepthy Alex ◽  
Anju Shainu ◽  
Ashok Pandey ◽  
Rajeev K. Sukumaran
Keyword(s):  
Organic Solvents ◽  
Enzyme Production ◽  
Fold Increase ◽  
Methanol Concentration ◽  
Crude Enzyme ◽  
Biodiesel Production ◽  
Original Activity ◽  
Acyl Acceptor ◽  
Polar Organic Solvents

Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol.

scholarly journals Neurobehavioral Effects of Organic Solvents Exposure Among Wood Furniture Makers in Ile-Ife, Osun State, Southwestern Nigeria

2019 ◽  
Vol 9 (22) ◽  
Author(s):  
Patrick Ayodeji Akinyemi ◽  
Caleb Aderemi Adegbenro ◽  
Temitope Olumuyiwa Ojo ◽  
Olanrewaju Elugbaju
Keyword(s):  
Organic Solvents ◽  
Comparison Group ◽  
Verbal Learning ◽  
Small Scale ◽  
Exposure Index ◽  
Total Volatile ◽  
Solvent Exposure ◽  
Significant Difference ◽  
Volatile Organic ◽  
Comparison Groups

Background. Furniture making industries are small scale businesses that commonly use organic solvents. There has been minimal focus on the health effects of this chemical hazard on the nervous system among furniture makers in Nigeria. Objectives. The present study aimed to assess the association between organic solvents exposure and neurobehavioral status of furniture makers, using electronic technicians as a comparison group. Methods. A comparative cross-sectional study design was employed. A sample size of 108 was calculated for each group. A semi-structured interviewer-administered questionnaire was used to obtain data on the socio-demographic variables and use of personal protective equipment (PPE). A proforma was developed to collect neurobehavioral assessment data. A checklist was used to assess the furniture makers' workshops. Air was sampled from all of the workshops in both the study and comparison groups to determine the concentration of total volatile organic compounds (TVOCs). Results. The use of PPE was poor in both the study and comparison groups, with no significant difference between them (34.4% and 37.7% respectively). Total volatile organic compound and formaldehyde (HCHO) concentrations were significantly higher at the furniture makers' workshops compared with electronic technicians (p<0.001) for both chemicals. The 8-hour time-weighted average of TVOC was also higher in the furniture makers' workshops (4.4±0.6 mg/m3) compared with the control group (0.3±0.3 mg/m3). The neurobehavioral symptoms score was significantly higher among the study group relative to the comparison group (p<0.001). There was a significant difference in the outcome of the auditory verbal learning test, total recall (p=0.005), and delayed recall (p=0.003). There was no significant association between solvent exposure index and findings from the simple reaction time test Conclusions. Poor compliance with the use of PPE among furniture makers may increase their exposure to organic solvents. There were more neurobehavioral changes in the furniture makers with a higher exposure index. Measures are needed to educate artisans about workrelated chemical hazards and ensure compliance with basic occupational safety and hygiene standards. Participant Consent. Obtained Ethics Approval. Ethics approval was obtained from the Health Research and Ethics Committee of the Institute of Public Health, Obafemi Awolowo University (IPH/OAU/12/1049). Competing Interests. The authors declare no competing financial interests.

scholarly journals Acute Vertigo in a Patient with Long-Term Organic Solvent Exposure: Importance of a Comprehensive Audio-Vestibular Test Battery

2020 ◽  
Vol 31 (05) ◽  
pp. 363-368
Author(s):  
Maxime Maheu ◽  
François Champoux ◽  
Adrian Fuente
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Vestibular System ◽  
Semicircular Canals ◽  
Vestibular Evoked Myogenic Potentials ◽  
Head Impulse Test ◽  
Solvent Exposure ◽  
Vestibular Evoked Myogenic Potential ◽  
Vestibular Tests ◽  
Organic Solvent Exposure

Abstract Background Ototoxicity induced by organic solvents has been identified in several groups of workers. Little is known, however, about the effects of organic solvents on the vestibular system. Purpose The aim of the study was to comprehensively assess the vestibular system and auditory functions in a worker exposed to organic solvents. Research Design Both behavioral and physiological auditory and vestibular evaluations were performed. Results No auditory-related findings associated with solvent exposure were found. The vestibulo-ocular reflex gain was abnormal for all semicircular canals with significant catch-up saccades, as measured by the video head impulse test. The cervical vestibular evoked myogenic potentials was absent in the right ear and small but replicable in the left ear. Ocular vestibular evoked myogenic potential were bilaterally absent. Conclusions The results suggest a case of vestibulotoxicity induced by a long history of organic solvent exposure. We suggest that solvent-exposed individuals should be evaluated with a comprehensive battery of auditory and vestibular tests.

Four Cases of Progressive Supranuclear Palsy in Patients Exposed to Organic Solvents*

1989 ◽  
Vol 34 (9) ◽  
pp. 934-936 ◽  
Author(s):  
E. Mccrank ◽  
K. Rabheru
Keyword(s):  
Organic Solvent ◽  
Progressive Supranuclear Palsy ◽  
Organic Solvents ◽  
Subsequent Development ◽  
The Other ◽  
Multiple Exposure ◽  
Solvent Exposure ◽  
Industrial Firm ◽  
Environmental Toxin

Four cases are described in which Progressive Supranuclear Palsy (PSP) is associated with the use of organic solvents. Two of them are a housewife and an ex-banker who had multiple exposure to insecticides (with organic solvent base), followed years later with a diagnosis of PSP. The other two are of lithographers, both of whom worked at the same industrial firm where solvent exposure took place with subsequent development of PSP. The hypothesis that PSP is linked to an environmental toxin is supported by these cases.

scholarly journals Is palmitate truly proinflammatory? Experimental confounders and context-specificity

2018 ◽  
Vol 315 (5) ◽  
pp. E780-E794 ◽  
Author(s):  
Kikumi D. Ono-Moore ◽  
Michael L. Blackburn ◽  
Sean H. Adams
Keyword(s):  
Saturated Fatty Acids ◽  
Fold Increase ◽  
Receptor Activation ◽  
Sodium Palmitate ◽  
Metabolic Dysfunction ◽  
Toll Like Receptor ◽  
Cell Type ◽  
Experimental Conditions ◽  
Context Specific ◽  
Map Kinase Pathways

Based primarily on cell culture results, saturated fatty acids (SFAs) are proposed to promote inflammation and contribute to metabolic dysfunction through Toll-like receptor activation. Studies are often complicated by a requirement for carriers (e.g., BSA) or solvents (e.g., ethanol) to increase SFA solubility. To ascertain whether these factors influence interpretations of SFA-associated inflammation activity, we measured responses of RAW264.7 monocyte/macrophages and C2C12 myotubes to various BSA, ethanol, and cyclodextrin (alternative FA carrier) conditions. Fatty acid-free, low-endotoxin BSA preparations (0.33% to 2% wt/vol) activated whereas 0.5–1.0% ethanol inhibited RAW264.7 TNFα release. Ethanol modestly increased IL-6 secretion in C2C12 myotubes. Cyclodextrins (0.3–6.0 mM) were tested as alternative carriers of palmitate, but their usefulness was limited due to toxicity and solubility issues. Using a lower-inflammation BSA source and no ethanol, ∼24-h sodium palmitate treatment (≤600 µM) failed to trigger RAW264.7 TNFα release and, in fact, significantly dampened BSA-induced inflammation by >50%. In C2C12 myotubes, only high palmitate concentrations (500–600 µM) elicited IL-6 secretion (>2.5-fold increase). Acute palmitate (200 or 500 µM) treatment did not activate MAP kinase pathways above that of fresh BSA-containing media alone in either cell type. These results highlight the importance of experimental conditions in studies exploring SFA inflammation effects. The limited (or even anti-inflammatory) effects of palmitate that we observed indicate that immunomodulatory effects of SFAs are context-specific. Thus, caution is needed when interpreting the literature related to putative proinflammatory effects of SFA.

scholarly journals Non-Hodgkin's lymphoma risk derived from exposure to organic solvents: a review of epidemiologic studies

1998 ◽  
Vol 14 (suppl 3) ◽  
pp. S41-S66 ◽  
Author(s):  
Marco Antônio V. Rêgo
Keyword(s):  
Risk Factors ◽  
Organic Solvents ◽  
Statistical Significance ◽  
Epidemiologic Studies ◽  
Solvent Exposure ◽  
Hair Dyes ◽  
Immunodeficiency Virus ◽  
Hodgkin's Lymphomas ◽  
Lymphoma Risk

The rate of non-Hodgkin's lymphomas (NHL) has increased around the world during the last decades. Apart from the role of the human immunodeficiency virus (HIV) infection in the development of NHL, exposure to chemical agents like phenoxyacetic pesticides, hair dyes, metal fumes and organic solvents are suspected to be involved. The present review evaluates the results of studies that directly or indirectly searched for an association between solvent exposure and NHL. The selected studies comprised those published from 1979 to 1997, designed to investigate risk factors for NHL, whether specifically looking for solvent exposure or for general risks in which solvent exposure could be included. In 25 of the 45 reviewed studies (55.5%), fifty-four statistically significant associations between NHL and solvent exposure related occupations or industries were reported. Statistical significance was more frequently shown in studies where solvent exposure was more accurately defined. In eighteen of such studies, 13 (72.2%) defined or suggested organic solvents as possible risk factors for NHL.

scholarly journals Automobile Paint Reducer Induced Acute Kidney Injury

2021 ◽  
Vol 5 (2) ◽  
pp. 10-13
Author(s):  
Muzamil Latief ◽  
Zhahid Hassan ◽  
Mohd Latief Wani ◽  
Farhat Abbas ◽  
Summyia Farooq
Keyword(s):  
Acute Kidney Injury ◽  
Metabolic Acidosis ◽  
Renal Replacement Therapy ◽  
Replacement Therapy ◽  
Organic Solvents ◽  
Acute Tubular Necrosis ◽  
Kidney Injury ◽  
Solvent Exposure ◽  
The Third ◽  
Tubular Necrosis

The various aspects of the automobile industry also carry with it the risk for occupational health hazards with it. Toluene has also evolved as a commonly used drug by substance abusers. Accidental exposure or self-poisoning with these substances has been reported in literature. These substances can also cause distal renal tubular acidosis (RTA), acute tubular necrosis, glomerulonephritis and interstitial nephritis, rhabdomyolysis and myoglobinemia.In this series, we report about three patients who developed renal manifestations because of organic solvents. Two of the three patients had ingested the paint reducer substance and the third one was addicted to sniffing the toluene based paint reducer. All the patients had in taken these substances with suicidal intent and developed acute kidney injury (AKI) and severe metabolic acidosis. One of the patients had features of rhabdomyolysis as well. The third patient was a substance abuser and had inhaled higher than usual dose and developed severe and refractory acidosis and mild kidney injury and required Renal Replacement Therapy (RRT) for acidosis. All the patients eventually recovered their kidney functions and were doing well during their follow-up.Toluene based organic solvents lead to acute neurological symptoms, accompanied by severe metabolic alterations, organ injury and dysfunc-tion. An association of the development of hypokalemic paralysis and metabolic acidosis with toluene intoxication has been observed. The management of acute toluene toxicity is mainly conservative, consisting of electrolytes correction, acid-base and fluid abnormalities and renal replacement therapy in severe AKI.Organic solvent exposure may result in acute tubular necrosis, rhabdomyolysis, RTA and AKI irrespective of the intake route. Clinical suspicion of organ dysfunction and failure and timely induction of supportive care leads to a good outcome.

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