Heterogeneous acid catalysts and a biocatalyst were tested as catalysts for esterification of the polyol, trimethylolpropane with fatty acids to produce biolubricants for low temperature ...applications. For long chain fatty acids, the biocatalytic process was comparable to that of chemically catalysed process, and moreover provided a process with least environmental impact and better quality product.
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► Efficient synthesis of TMP-estersunder mild conditions by heterogeneous catalysts ► Acid silica and immobilized lipase are promising catalysts for synthesis of TMP-oleate.
Biolubricants derived from vegetable oils are environmentally compatible products due to their low toxicity and good biodegradability. Synthetic esters based on polyols and fatty acids possess suitable properties for lubricant applications, even at extreme temperatures. In this work, synthesis of esters from trimethylolpropane (TMP) and carboxylic acids from C5 to C18 has been studied and compared using different heterogeneous catalysts (silica–sulphuric acid, Amberlyst-15, and immobilised lipase B from
Candida antarctica). Silica–sulphuric acid was found to be the most efficient catalyst followed by Amberlyst-15, especially when using short chain carboxylic acids. The reaction efficiency decreased with increasing alkyl chain length. On the other hand, the immobilised lipase (Novozym
®435) did not exhibit any activity with C5 acid and the activity increased with increase in length of the fatty acid chain. For synthesis of C18-ester, the biocatalytic production turned out to be comparable to silica–sulphuric acid, and moreover led to a better quality of the final product. The products showed suitable cold-flow properties for application at low temperature. A general trend of increasing pour point (−75
°C to −42
°C) and viscosity index (80–208) with increase in alkyl chain of the carboxylic acid from C5 to C18 was observed. The synthesis of TMP-trioleate using the solid acid catalysts and the biocatalyst was compared using the freeware package EATOS (environmental assessment tool for organic synthesis) and showed the enzymatic route to have the least environmental impact.
Precarious employment and mental health Rönnblad, Torkel; Grönholm, Erik; Jonsson, Johanna ...
Scandinavian journal of work, environment & health,
01/2019, Letnik:
45, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Objectives Precarious employment (PE) is a term used to describe non-standard employment forms characterized by low security that may have negative effects on mental health. The objective of this ...review was to systematically review the evidence for effects of PE on mental health and identify important areas for further research. Methods A protocol was developed following PRISMA-P guidelines. Web of Science, PubMed and PsycINFO were searched up to 4 September 2017. All unique records were assessed for eligibility and quality by at least two reviewers. Data from included studies were summarized in forest plots and meta-analyses using a random-effects model. Evidence quality was rated using the GRADE method. Results We obtained 3328 unique records, of which 16 studies of sufficient quality met the inclusion criteria. Moderate quality evidence (GRADE score 3 of 4) was found for an adverse effect of job insecurity on mental health; summary odds ratio (OR) 1.52 95% confidence interval (CI) 1.35-1.70. There was very low quality (GRADE 1 of 4) evidence for effects of temporary employment or unpredictable work hours on mental health. Five studies on multidimensional exposures all showed adverse effects, weighted average OR 2.01 (95% CI 1.60-2.53). Conclusions Research on PE and mental health is growing, but high-quality prospective studies are still scarce. Job insecurity likely has an adverse effect on mental health. A clear multi-dimensional definition of PE is lacking, and harmonization efforts are needed. Further single-variable observational studies on job insecurity or temporary employment should not be prioritized.
Objectives The lack of a common definition for precarious employment (PE) severely hampers the comparison of studies within and between countries, consequently reducing the applicability of research ...findings. We carried out a systematic review to summarize how PE has been conceptualized and implemented in research and identify the construct's dimensions in order to facilitate guidance on its operationalization. Methods According to PRISMA guidelines, we searched Web of Science and Scopus for publications with variations of PE in the title or abstract. The search returned 1225 unique entries, which were screened for eligibility. Exclusion criteria were (i) language other than English, (ii) lack of a definition for PE, and (iii) non-original research. A total of 63 full-text articles were included and qualitative thematic-analysis was performed in order to identify dimensions of PE. Results We identified several theory-based definitions of PE developed by previous researchers. Most definitions and operationalizations were either an accommodation to available data or the direct result of qualitative studies identifying themes of PE. The thematic-analysis of the selected articles resulted in a multidimensional construct including the following three dimensions: employment insecurity, income inadequacy, and lack of rights and protection. Conclusions Despite a growing number of studies on PE, most fail to clearly define the concept, severely restricting the advancement of the research of PE as a social determinant of health. Our combined theoretical and empirical review suggests that a common multidimensional definition could be developed and deployed in different labor market contexts using a variety of methodological approaches.
Objectives The aims of this position paper are to (i) summarize research on precarious employment (PE) in the context of occupational health; (ii) develop a theoretical framework that distinguishes ...PE from related concepts and delineates important contextual factors; and (iii) identify key methodological challenges and directions for future research on PE and health. Methods This position paper is the result of a working group consisting of researchers from the EU, Turkey and the USA, who have discussed the issue over the course of six months (October 2018-April 2019), meeting both online and face-to-face on several occasions. Results The lack of a common theoretical framework of PE hinders it from becoming an established part of occupational and public health research. There are also issues regarding operationalization in surveys and registers. Further, previous research on PE and health suffers from methodological limitations including inadequate study designs and biased assessments of exposure and outcomes. PE is highly dependent on contextual factors and cross-country comparison has proven very difficult. We also point to the uneven social distribution of PE, ie, higher prevalence among women, immigrants, young and low educated. We propose a theoretical framework for understanding precarious employment as a multidimensional construct. Conclusions A generally accepted multidimensional definition of PE should be the highest priority. Future studies would benefit from improved exposure assessment, temporal resolution, and accounting for confounders, as well as testing possible mechanisms, eg, by adopting multi-level and intersectional analytical approaches in order to understand the complexity of PE and its relation to health.
Synthetic esters based on polyols and fatty acids possess suitable technical and ecological properties for applications as biolubricants, and can replace the mineral oil based lubricants in several ...applications. In this work, the synthesis of trimethylolpropane (TMP) esters with oleic acid using immobilised lipase B from Candida antarctica (Novozym®435) has been studied. TMP-trioleate has suitable properties for use as hydraulic fluids, especially at extreme temperatures. The effect of different reaction parameters on the reaction efficiency has been evaluated. The study showed that the formation of the triester product was facilitated at high temperature and biocatalyst concentration, as well as stoichiometric amounts of oleic acid and TMP. The product with the highest triester content exhibited the lowest pour point (−42°C). The stability of the biocatalyst was however limited at high temperature and polyol concentration. Loss of activity during recycling of the biocatalyst at 70°C was reduced to some extent by washing it with 2-propanol prior to subsequent run.
High-quality longitudinal evidence exploring the mental health risk associated with low-quality employment trajectories is scarce. We therefore aimed to investigate the risk of being diagnosed with ...common mental disorders, substance use disorders, or suicide attempt according to low-quality employment trajectories.
A longitudinal register-study based on the working population of Sweden (N=2 743 764). Employment trajectories (2005-2009) characterized by employment quality and pattern (constancy, fluctuation, mobility) were created. Hazard ratios (HR) were estimated using Cox proportional hazards regression models for first incidence (2010-2017) diagnosis of common mental disorders, substance use disorders and suicide attempt as dependent on employment trajectories.
We identified 21 employment trajectories, 10 of which were low quality (21%). With the exception of constant solo self-employment, there was an increased risk of common mental disorders (HR 1.07-1.62) and substance use disorders (HR 1.05-2.19) for all low-quality trajectories. Constant solo self-employment increased the risk for substance use disorders among women, while it reduced the risk of both disorders for men. Half of the low-quality trajectories were associated with a risk increase of suicide attempt (HR 1.08-1.76).
Low-quality employment trajectories represent risk factors for mental disorders and suicide attempt in Sweden, and there might be differential effects according to sex - especially in terms of self-employment. Policies ensuring and maintaining high-quality employment characteristics over time are imperative. Similar prospective studies are needed, also in other contexts, which cover the effects of the Covid-19 pandemic as well as the mechanisms linking employment trajectories with mental health.
Objectives This study aimed to explore multidimensional operationalizations of precarious employment (PE) in Swedish register data using two approaches: (i) a typological approach and (ii) a ...dimensional, summative scale approach. It also examined the distribution of sociodemographic and occupational characteristics of precarious employees in Sweden. Method Register data was retrieved on individuals and their employers in the Swedish workforce. Five items corresponding to three dimensions of PE were operationalized: contractual relationship insecurity, contractual temporariness, multiple jobs/sectors, income level, and lack of unionization. First, latent class analysis was applied and a typology of six employment types emerged. Second, a summative scale was constructed by scoring all PE-items. Results Three types of PE were found using the typological approach, which were characterized by direct employment, solo self-employment and multiple job holding, respectively. The summative scale score ranged between -10 and +2 (average: -1.8). Particularly poor scores were seen for solo self-employed, multiple job holders/multiple sectors, and low income. Female gender, young age, low education and foreign origin were prone to precariousness. PE was more frequent among certain economic sectors and occupations. Conclusions Using an existing register of labor market data, two operationalizations of PE were constructed and rendered promising for exposure assessment. Hence, the operationalizations could be of interest for countries with similar data structure. Both approaches highlighted precarious combinations of employment conditions and pointed towards the existence of a wide continuum of precariousness on the labor market. Etiological studies and research assessing trends over time are needed to validate these findings.
This study aimed to examine the effects of low-quality employment trajectories on severe common mental disorders (CMD) according to Swedish and foreign background.
In this longitudinal study based on ...Swedish population registries (N=2 703 687), low- and high-quality employment trajectories were the main exposures observed across five years (2005-2009), with severe CMD as outcome variable (2010-2017). Adjusted hazard ratios (HR) were calculated by means of Cox regression models and stratified according to Swedish and foreign background first-generation (i) EU migrants, (ii) non-EU migrants, (iii) second-generation migrants, (iv) Swedish-born of Swedish background and sex. The reference group was Swedish-born of Swedish background in a constant high-quality employment trajectory.
Second-generation migrants had an increased risk of CMD compared to Swedish-born of Swedish background when following low-quality employment trajectories eg, male in constant low-quality HR 1.54, 95% confidence interval (CI) 1.41-1.68. Female migrant workers, especially first-generation from non-EU countries in low-quality employment trajectories (eg, constant low-quality HR 1.66, 95% CI 1.46-1.88), had a higher risk of CMD compared to female Swedish-born of Swedish background. The risk for CMD according to employment trajectories showed little differences between first- and second-generation migrants.
Low-quality employment trajectories appear to be determinants of risk for CMD in association with Swedish or foreign background of origin and sex. Our study shows a higher risk for severe CMD in second-generation and non-EU migrant compared to Swedish-born of Swedish background in constant low-quality employment. Further qualitative research is recommended to understand the mechanism behind the differential mental health impact of low-quality employment trajectories according to foreign background.
The aim of this case study was to explore the abilities and limitations of trade unions in their response to undeclared work, which has received scant attention in research on working conditions and ...industrial relations. The authors use power resource theory to examine the outcome of a Swedish government initiative aimed to boost the ability of the social partners to tackle undeclared work. The findings confirm previous literature suggesting cross-sectoral differences in the extent and nature of undeclared work and an association between low levels of power resources and high risk of undeclared work. The authors recommend that future initiatives take account of cross-sectoral differences in the nature and extent of undeclared work and available power resources. Future research should consider how different actors can contribute to the ability of the social partners in different sectors to engage in the battle against undeclared work.
Childbirth has been suggested to increase sickness absence (SA) and disability pension (DP). This may vary by occupation; however, knowledge in this field remains limited. We explored SA and DP in ...the years before and after childbirth among women in four occupational groups and those without occupation.
We studied nulliparous women aged 18-39 years, living in Sweden on December 31, 2004 (n = 492,504). Women were categorized into five skill-level based occupational groups and three childbirth groups; no childbirths within 3 years (B0), first childbirth in 2005 with no childbirth within 3 years (B1), and first childbirth in 2005 with at least one more birth within 3 years (B1+). We compared crude and standardized annual mean SA (in spells> 14 days) and DP net days in the 3 years before and 3 years after first childbirth date.
Women in the highest skill level occupations and managers, had less mean SA/DP days during most study years than women in the lowest skill level occupations group. In B1 and B1+, absolute differences in mean SA/DP, particularly in SA, among occupational groups were highest during the year before childbirth. DP was most common in B0, regardless of group and year.
We found that women's mean SA/DP days before and after first childbirth was higher with decreasing skill-level of the occupational group and these differences were most pronounced in the year before childbirth. DP was most common among women not giving birth, regardless of occupational group.
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