Types Of Waxes Research Articles

The influence of integrated Micro-ZnO and Nano-CuO particles/paraffin wax as a thermal booster on the performance of heat pipe evacuated solar tube collector

The research aims to investigate the possibility of enhancing the functionality of a heat pipe evacuated tube collector (HPETC) with a new method of, one or both an evacuated tube (ET) and two separate storage tanks, incorporating nano or micro-enhanced phase change materials as a thermal energy storage system (TESS). In the proposed systems, the (ET) was filled with enhanced medical paraffin wax, while the two separated tanks were filled with enhanced paraffin wax (grade-A). These two types of paraffin wax were enhanced with 5wt% CuO nanoparticle (NP-CuO) or ZnO microparticles (MP-ZnO). In this study, Six tests were carried out to do the investigation. Three tests were done to investigate the effect of the integration of enhanced-PCM in the only (ET) of HPETC. While the other three tests performed to investigate the effect of enhanced-PCM integrated into both (ET) of HPETC and two additional storage tanks. The main advantage of this new system is that it improved solar water heater efficiency by minimizing hot water temperature fluctuations. Thereby, the efficiently thermal isolation of the (ET) and storage tanks and the efficient energy accumulation in PCM which enables the system to supply hot water even when there is no solar radiation at night or in overcast weather. The results showed that the integration of enhanced-paraffin wax with NP-CuO and MP-ZnO in both the (ET) and the separated tanks gives an efficiency improvement range of (36.8-50%) and (25.43-41.4%) respectively, While the integration of enhanced-paraffin wax with NP-CuO and MP-ZnO in the only (ET) led to an increase in the efficiency with a range of (33.8-45.7%) and (23.8-26.7%) respectively, compared with a typical reference collector without PCM. Also, the NP-CuO enhanced paraffin wax integrated with the ET gave a better improvement in the evaporation & condensation coefficients in the evaporator and condenser sections where their values were (401 and 2366.4 W/m2·°C) respectively at a flow rate of 1L/h.

Genetic Analysis of the Unique Epicuticular Wax Profile of ‘Odourless Greenleaf’ Onion

The amounts and types of epicuticular waxes on onion (Allium cepa) leaves affect the severity of feeding damage by onion thrips (Thrips tabaci), a serious insect pest of onion. Onion plants with light green leaves are referred to as “glossy” and accumulate less epicuticular wax relative to the blue–green (“waxy”) foliage of wild-type onion. The onion cultivar Odourless Greenleaf (OGL) has visually glossy foliage, shows resistance to thrips feeding damage, and has the unique profile of accumulating waxes with 28 or fewer carbons. Plants of glossy OGL were crossed with the glossy inbred B9885 and waxy inbred lines DH2107, DH066619, and B8667. Hybrid progenies from glossy OGL by waxy plants had waxy foliage, indicating recessiveness of the glossy OGL phenotype relative to the waxy phenotype. Hybrids from the cross of glossy OGL with glossy B9885 were also waxy, revealing different genetic bases for the glossy phenotype in these two onions. Hybrid plants were self-pollinated and segregations in F2 families from OGL × waxy crosses fit the expected 3:1 ratio for the single locus at which the homozygous recessive genotype conditions glossy foliage. Segregations in F2 families from crosses of glossy 9885 × glossy OGL fit the 9:7 ratio, supporting two independently segregating loci, where the recessive genotype at either locus conditions the glossy phenotype. Amounts and types of epicuticular waxes on leaves of F2 progenies from crosses of OGL × waxy B8667 and glossy B9885 × OGL were determined using gas chromatography-mass spectrometry. Single-nucleotide polymorphisms were genotyped and genetic maps were constructed. The visually glossy phenotype from OGL and its unique profile of epicuticular waxes were conditioned by one locus on chromosome 6, for which we propose the name glogl. Onion populations such as OGL with unique epicuticular wax profiles will be important germplasms for the development of onion cultivars that suffer less feeding damage from onion thrips compared with waxy onion.

Thermal performance of a V-Corrugated serpentine solar air heater with integrated PCM: A comparative experimental study

The present study conducts a comparative experimental study on the dynamic thermal response and performance of a conventional SAH and SAH equipped with PCM using paraffin packs. Various scenarios were investigated to assess the impacts of PCM usage, PCM melting point, and arrangements of PCM slabs with different melting points on the dynamic thermal response of SAHs. To this aim, two V-type corrugated serpentine SAH prototypes, including conventional and PCM-integrated ones, were simultaneously constructed and tested under field conditions. Two types of paraffin wax with different melting temperatures, 40 °C and 50 °C, with four PCMs arrangements, were installed on a SAH. The experimental runs were carried out in Kerman, Iran, for two air mass flow rates of 0.006 kg/s and 0.01 kg/s. The acquired results illustrated that utilizing PCM improves daily thermal performance from 53.1% to 62.6%. Using PCMs with higher melting point temperature results in increasing the outlet temperature of SAHs almost 5 °C, as well as the daily performance of SAHs by approximately 3%. Furthermore, experimental runs prove that an arrangement with equally distributed PCM types with different melting points has the optimal daily thermal performance and shows approximately 5% improvement in thermal performance.

Modulation and Characterization of Wax-Based Olive Oil Organogels in View of Their Application in the Food Industry.

Olive oil has recognized health benefits but lacks structural resilience to act in a similar fashion as do the typically used triglycerides (TAGs) when applied in food manufacturing. Therefore, olive oil structuring is critical to widening its use as a healthier alternative in spreadable products. Foreseeing the development of an application for the food industry, three types of natural waxes were used as organogelators, generating olive oil organogels with distinct properties. Retail-simulated storage conditions were used to mimic real-life industrial and commercial use. Organogel systems were evaluated according to their oxidation stability and textural and rheological properties. Textural and rheological parameters increased in response to increasing gelator concentration, while oxidation values (below 1.5 meq O2·kg−1) remained within legal limits. Organogels displayed similar textural properties to those of commercially available spreadable products, while displaying a low critical gelation concentration. In short, it was shown that tailoring the physicochemical properties of organogels towards specific applications is possible. The produced organogels showed similar properties to the ones of commercially available spreadable products, revealing favourable oxidative profiles. Therefore, an industrial application can be easily foreseen, building on the natural characteristics of olive oil as a healthier alternative to current spreadable products.

Identities of and Phenotypic Variation for Epicuticular Waxes among Leaves and Plants from Inbred Onion Populations

The amounts and types of epicuticular waxes on onion (Allium cepa) leaves affect feeding damage by onion thrips (Thrips tabaci). This study used gas chromatography mass spectrometry (GCMS) to establish the identities of waxes and measure over time wax amounts on leaves of inbred onion plants with glossy, semiglossy, and waxy foliage. Nine waxes were detected on leaves of all inbreds, and higher coefficients of variation (cv) were observed for less abundant waxes on foliage of doubled haploid onions. Older leaves had higher amounts of waxes compared with younger leaves on the same plant. Except for one minor wax, amounts of individual waxes on leaves were not significantly different for plants of different ages. There was a significant inbred by sampling date interaction due to lower amounts of waxes on the leaves of older plants from the semiglossy inbred. These results indicate that there is little advantage to multiple samplings of leaves over time from the same plant and resources may be better used to evaluate more plants. The relatively large cvs for amounts of specific waxes may reduce response to selection for unique epicuticular wax profiles to develop onion populations that suffer less feeding damage by onion thrips.

The Economic Impact of Paraffin Type and Substrate Mixture on the Production of Grafted Vines—Case Study Muscat Ottonel

The study focussed on a nursery by analyzing its strategic choices to obtain the best profit on grapevine planting material. The production of grapevine grafts involves high labor and material costs. In this study, Muscat Ottonel grape variety grafted on Oppenheim Sellection 4 rootstock was paraffined with different types of wax: standard wax (SW), paraffin with 8-chinolinol (8C) and paraffin with oxiquinolein (OX) (before callusing), and silver color (S), blue color (B) and standard (SW) paraffin (after grafting callusing and before planting in field nursery). After uprooting from the field nursery, all variants were paraffined with red paraffin for storage. The unit cost price was calculated based on total expenses and the yield of grafts obtained in the vine field nursery. The lowest price per unit cost was recorded for the 8C/S variant, directly related to the first quality yield after uprooting from the nursery. The highest profit rate was for the 8C/S variant, while the lowest was registered to the SW/SW variant. The grafts of the 8C/S variant were potted in three rooting mixtures. Variant B (forest ground 60% + black peat 25% + river sand 10% + conifer sawdust 5%) generated the highest yield of the potted grafted vine with a rate of profit of over 170%, due to the lower production cost and high yield of potted vines, while variant C (forest ground 70% + river sand 15% + conifer sawdust 15%), determinate the lowest yield. Results may be useful in orienting the small-to-medium grapevine planting materials producers to choose the best cooperative strategies, which nurseries might implement to enhance their competitiveness and survive in the long-run.

Leaflet blade epidermis and its taxonomic significance in 13 species of Bignonieae (Bignoniaceae) from Pico do Jabre, Paraíba, northeast of Brazil

Bignonieae is the largest tribe of Bignoniaceae, with 21 genera and 393 species of lianas and shrubs that are 1–3-foliolate with the terminal leaflet modified as tendrils. We examined the micromorphologies of the epidermis from the leaflet blade of 13 species of Bignonieae belonging to Amphilophium, Anemopaegma, Bignonia, Cuspidaria, Dolichandra, Fridericia, Pyrostegia, Tanaecium, and Xylophragma, from Pico do Jabre, Paraíba, Brazil. These are lianas except for Tanaecium parviflorum (shrub). We sought to identify the epidermal leaflet parameters to support their taxonomy, subject to great similarities between their vegetative characters, mainly in species of the same genus and related genera. Analyses were performed using light and scanning electron microscopy, and showed five types of epicuticular waxes, four cuticle types, three epidermal cell anticlinal wall types, and nonglandular and glandular trichomes. Hypostomatic leaves showed 10 different types of stomata, with stomatal indices from 6.21% (Bignonia ramentacea) to 23.52% (Tanaecium parviflorum), and stomatal densities from 76 stomata/mm2 (Pyrostegia venusta) to 752.9 stomata/mm2 (T. parviflorum). The presence of raphides in Amphilophium crucigerum and styloids in Fridericia pubescens constitute the first records for these genera. Epidermal micromorphology provided a set of distinctive characters with which to separate these species, representing an additional tool to support their taxonomies, as well as that of tribe Bignonieae.

THEORETICAL INVESTIGATION OF THE EFFECTS OF WAX CONTENT ON THE FUNCTIONING OF BITUMEN AND ASPHALT PAVEMENT

This paper reviews effect of wax content to performance of bitumen and asphalt pavement. Negative influence of wax content is known from literature reviews, which effects elasticity of binder and causes sensitivity to low temperatures and increases cracking. There is lack information of methods to evaluate wax content in bitumen. This paper presents literature review of variety of wax types, separation wax as saturated hydrocarbons by studying fractional composition and methodology for determination of wax content in bitumen and negatively effect of crystallization.

Effect of quality of carnauba wax (Copernica cerífera) on microstructure, textural, and rheological properties of soybean oil-based organogels

This work was designed to elaborate soybean oil organogels structured with three different types (T-I, T-III, and T-IV) of carnauba wax, aiming to find the best wax type and concentration for application in foods. Carnauba wax T-I and T-III produced gels Type 5 (firm and no oil release) at lower concentration (4.5% w/w) in comparison to T-IV (5.0% w/w). Thermal stability of wax T-III at 4% w/w organogel was higher in comparison to T-I and T-IV; however, all waxes at >5.5% w/w formed organogel type 5. Color parameters L*, a*, and b* were directed related to wax type. The polarized light microscopy revealed that organogels formed two different crystal morphologies post-crystallization as a result of Ostwald ripening. Organogels stored for 24 h showed a condensed display of crystals, whereas those stored for 2 months cluster crystalline particles. The hardness of 24 h stored organogels was the same (p < 0.05) for all carnauba waxes (T-I = 0.13 N, T-III = 0.18 N, and T-IV = 0.06 N) whereas counterparts stored for 2 months the hardness values were significantly (p < 0.05) higher (T-I = 0.22 N, T-III = 0.28 N, and T-IV = 0.10 N). Carnauba wax T-III at 4% w/w showed excellent properties for diverse food applications.

Reflectance Spectroscopy for Non-Destructive Measurement and Genetic Analysis of Amounts and Types of Epicuticular Waxes on Onion Leaves.

Epicuticular waxes on the surface of plant leaves are important for the tolerance to abiotic stresses and plant–parasite interactions. In the onion (Allium cepa L.), the variation for the amounts and types of epicuticular waxes is significantly associated with less feeding damage by the insect Thrips tabaci (thrips). Epicuticular wax profiles are measured using used gas chromatography mass spectrometry (GCMS), which is a labor intensive and relatively expensive approach. Biochemical spectroscopy is a non-destructive tool for measurement and analysis of physiological and chemical features of plants. This study used GCMS and full-range biochemical spectroscopy to characterize epicuticular waxes on seven onion accessions with visually glossy (low wax), semi-glossy (intermediate wax), or waxy (copious wax) foliage, as well as a segregating family from the cross of glossy and waxy onions. In agreement with previous studies, GCMS revealed that the three main waxes on the leaves of a wild type waxy onion were the ketone hentriacontanone-16 (H16) and fatty alcohols octacosanol-1 (Oct) and triacontanol-1 (Tri). The glossy cultivar “Odourless Greenleaf” had a unique phenotype with essentially no H16 and Tri and higher amounts of Oct and the fatty alcohol hexacosanol-1 (Hex). Hyperspectral reflectance profiles were measured on leaves of the onion accessions and segregating family, and partial least-squares regression (PLSR) was utilized to generate a spectral coefficient for every wavelength and prediction models for the amounts of the three major wax components. PLSR predictions were robust with independent validation coefficients of determination at 0.72, 0.70, and 0.42 for H16, Oct, and Tri, respectively. The predicted amounts of H16, Oct, and Tri are the result of an additive effect of multiple spectral features of different intensities. The variation of reflectance for H16, Oct, and Tri revealed unique spectral features at 2259 nm, 645 nm, and 730 nm, respectively. Reflectance spectroscopy successfully revealed a major quantitative trait locus (QTL) for amounts of H16, Oct, and Tri in the segregating family, agreeing with previous genetic studies. This study demonstrates that hyperspectral signatures can be used for non-destructive measurement of major waxes on onion leaves as a basis for rapid plant assessment in support of developing thrips-resistant onions.

Floral Studies inOctomeriaR. BR. (Orchidaceae: Pleurothallidinae)

Octomeriais a well‐represented basal genus in the subtribe Pleurothallidinae, the main myophile group of the Orchidaceae. The systematics of the genus is based in leaf shape and degree of connation of sepals. In this study, we analyse comparatively the flower micromorphology of 15 species through light microscopy, histochemical tests and scanning electron microscopy, including most of the infrageneric groups proposed for the genus. The epidermal structures of sepals and petals are very similar, with oblong or isodiametric cells, stomata and trichome‐like structures adaxially. The lip presents a uniseriate epidermis with ovate to irregular cells and mesophyll with homogeneous parenchyma and idioblasts with raphides. Calluses and grooves in the lip were shown to be secretory regions. Histochemical tests in fresh flowers were positive for starch in the sepals, petals and lip and positive for osmophores in the lip. Three types of waxes were observed; one of them is described for the first time. Our study shows that despite similarities in the perianth, floral micromorphology indicated differences in the lip and column surfaces. Thus, this approach can be an important source of phylogenetic information for the genus.

QUALITY OF NAPOLI CV. EGGPLANT COATED WITH CARNAUBA WAX

The objective of this study was to evaluate the quality of eggplant Napoli cv. coated with Carnauba wax and stored for seven days at room temperature. Treatments consisted of immersion of fruits in two concentrations of two types of commercial wax, totaling four treatments: Meghwax ECF 124 to 9% concentrations (Megh 9%); Meghwax ECF 124 to 18% (Megh 18%), Arua BR 18% (Pomacea canaliculata) Tropical 9% (Arua 9%), and Arua BR 18% Tropical 18% (Arua 18%). The control treatment consisted of fruit without coating with wax and immersed in water. Fruits were analyzed at 0, 3, 6, and 7 days for the outer appearance, weight loss, turgor pressure, titratable acidity (TA), soluble solids (SS), SS/TA ratio, ascorbic acid, and pH. The waxes were effective in reducing weight loss. The turgor pressure showed a decrease during storage, which was more pronounced in the control treatment. The treatments did not differ among themselves for the levels of soluble solids. Fruits immersed in Arua wax at 18% concentration showed higher titratable acidity. The levels were reduced during storage. The control fruits showed higher pH. The ascorbic acid contents decreased by 15.0%, 16.4%, 16.5%, 16.9%, and 34%, considering the control treatments. Fruits subjected to Arua wax at 18% had longer shelf-life; the control fruits showed shorter shelf-life. Thus, it is concluded that 18% Aruá wax was the most effective to increase the shelf life of eggplants when stored at room temperature.

Amounts and Types of Epicuticular Leaf Waxes among Onion Accessions Selected for Reduced Damage by Onion Thrips

Onion thrips (Thrips tabaci) is the main insect pest of onion (Allium cepa), and feeding damage routinely causes serious yield losses. Lower amounts of epicuticular waxes on onion leaves have been associated with fewer onion thrips and less feeding damage, and research is needed to assess the relationships between amounts and composition of epicuticular waxes and feeding damage by onion thrips. This study used gas chromatography mass spectroscopy to determine amounts and types of epicuticular waxes on the foliage of onion accessions that had been field-selected for lower damage from onion thrips. Hentriacontanone-16 (H16), octaconasol-1, and triacontanol-1 were the most prevalent waxes on the foliage of these selections. Amounts of H16 were significantly lower on selections visually classified as having glossy or semiglossy foliage. Semiglossy selections were identified with similar amounts of total epicuticular wax as waxy phenotypes, due primarily to lower amounts of H16 and higher amounts of other waxes. These semiglossy selections suffered significantly less feeding damage from onion thrips in a field evaluation, supporting the identification of unique wax profiles toward the development of thrips-resistant onion.

Genetic Analyses of Epicuticular Waxes Associated with the Glossy Foliage of ‘White Persian’ Onion

Onion (Allium cepa) plants with lower amounts of epicuticular waxes on foliage suffer less damage from the insect pest Thrips tabaci (onion thrips). Glossy onion accumulates significantly less epicuticular wax compared with wild-type “waxy” onion, and a single recessive locus (gl) has been proposed to condition this phenotype. Genetic analyses of types and amounts of epicuticular waxes were completed using two segregating families from the cross of the glossy inbreds B9885 and B9897 (both originally selected from the onion cultivar White Persian) with waxy inbred B8667 and semiglossy (intermediate amounts of waxes) inbred B5351, respectively. F2 progenies were grown in greenhouses and scored visually for foliar phenotypes, and amounts and types of epicuticular waxes were determined using gas chromatography-mass spectrometry (GCMS). For one F2 family from the cross of glossy B9885 by waxy B8667, visually scored glossy vs. waxy foliage fit a 1:3 ratio and the phenotype mapped to chromosome 8 of onion. This same region on chromosome 8 was significantly associated with amounts of the ketone hentriacontanone-16 (H16) and fatty alcohols 1-octacosanol (Oct1) and 1-triacontanol (Tri1). Visually scored F2 progeny from the cross of glossy B9897 × semiglossy B5351 did not fit expected models for one or two recessive loci. Significant quantitative trait loci (QTL) were revealed on chromosomes 5 and 8 controlling amounts of H16. Epistasis was detected between regions on chromosomes 1 and 8, and a 100-fold increase of H16 was conditioned by homozygous genotypes for the B5351 region on chromosome 1 and the B9885 region on chromosome 8. The three QTL model explained 41% of the phenotypic variation for amounts of H16 at logarithm of odds of 16.6. Amounts of Oct1 and Tri1 in the B9897 × B5351 family were associated with a major QTL on chromosome 1, explaining 37% to 46% of the phenotypic variation, respectively. This research demonstrates that glossy foliage of ‘White Persian’ onion is conditioned by a recessive locus on chromosome 8 for which we propose the name glwp. These results are important for selection of onion with unique profiles of epicuticular waxes to reduce losses resulting from onion thrips.

THE SYSTEMATIC SIGNIFICANCE OF LEAF EPIDERMAL MICROMORPHOLOGY OF TEN NEPENTHES SPECIES (NEPENTHACEAE) FROM PENINSULAR MALAYSIA

GHAZALLI, M. N., TAMIZI, A. A., ESA, M. I. M., BESI, E. E., NIKONG, D., NORDIN, A. R. M. &amp; ZAINI, A. Z. 2019. The systematic significance of leaf epidermal micromorphology of ten Nepenthes species (Nepenthaceae) from Peninsular Malaysia. Reinwardtia 18(2): 81−96. — The pitcher plants of Malaysia belong to the genus Nepenthes and can be found thriving in swampy areas, along the roadside, on hillslopes and in mountainous terrains depending on species and their ecological preferences. In this study, cuticle micromorphology of ten species of Nepenthes (Nepenthaceae) collected from Peninsular Malaysia was intensively studied through scanning electron microscopy (SEM) to characterise and investigate diagnostic characters of cuticle micromorphology that can be useful in Nepenthes classification. A total of eleven characters from the inner and outer cuticles were enumerated in details and these characters have a value either for infrageneric classification or for diagnostic identification of the species. Characters observed and analysed were related to the epidermal cells, subsidiary cells, stomatal complex i.e type of waxes on both epidermal surfaces, abaxial and adaxial cuticular ornamentation, stomata characteristics, stomata formation, stomata frequency, cuticular ornamentation on stomata, shape of the stomata, stomata size, trichome existence and type of trichomes. Nepenthes ampullaria is clearly distinguished from the other species by markedly different types of tufted and multicellular trichomes of the epidermal cells on both leaf epidermal surfaces. For N. alba, its cuticular feature showed groovy cuticular pattern on the abaxial and adaxial surface, hence, can serve as a diagnostic cuticular pattern for this species. From these findings, the species delimitation based on cuticular features show a clear resolution, however some species might be individually distinct based on the combination of characters examined.

Measurement of damping properties of beeswax and cosmetic wax using Oberst beam method

Damping treatment is a standard practice in many industries for controlling excessive vibration at resonance. Different damping materials are available for various engineering applications. Wax is one of them, and it’s mostly used in musical instruments. There are two types of wax are available namely beeswax (natural wax) and cosmetic wax. The aim of the present study is to measure damping properties of these two types of wax using Oberst Beam Method (OBM). The effects of damping material’s thickness and bare sample on damping loss factor are studied.

Constructing functional cuticles: analysis of relationships between cuticle lipid composition, ultrastructure and water barrier function in developing adult maize leaves.

Background and AimsPrior work has examined cuticle function, composition and ultrastructure in many plant species, but much remains to be learned about how these features are related. This study aims to elucidate relationships between these features via analysis of cuticle development in adult maize (Zea mays L.) leaves, while also providing the most comprehensive investigation to date of the composition and ultrastructure of adult leaf cuticles in this important crop plant.MethodsWe examined water permeability, wax and cutin composition via gas chromatography, and ultrastructure via transmission electron microscopy, along the developmental gradient of partially expanded adult maize leaves, and analysed the relationships between these features.Key ResultsThe water barrier property of the adult maize leaf cuticle is acquired at the cessation of cell expansion. Wax types and chain lengths accumulate asynchronously over the course of development, while overall wax load does not vary. Cutin begins to accumulate prior to establishment of the water barrier and continues thereafter. Ultrastructurally, pavement cell cuticles consist of an epicuticular layer, and a thin cuticle proper that acquires an inner, osmiophilic layer during development.ConclusionsCuticular waxes of the adult maize leaf are dominated by alkanes and alkyl esters. Unexpectedly, these are localized mainly in the epicuticular layer. Establishment of the water barrier during development coincides with a switch from alkanes to esters as the major wax type, and the emergence of an osmiophilic (likely cutin-rich) layer of the cuticle proper. Thus, alkyl esters and the deposition of the cutin polyester are implicated as key components of the water barrier property of adult maize leaf cuticles.

Evaluation of oil-gelling properties and crystallization behavior of sorghum wax in fish oil

Inspired by the potential opportunities offered by sorghum as a natural wax source, the objective of this study was to investigate for the first time the potential of three types of sorghum waxes, namely, sorghum bran wax (SBW), sorghum DDGS wax (SDW), and sorghum kernel wax (SKW), as an oleogelator. All the three sorghum waxes showed good gelation properties with minor differences. Fast cooling rate and ultrasonic treatment favored the oil-gelling capacity and reduced oil loss by reducing the crystal size. All sorghum wax oleogels exhibited two common x-ray diffraction peaks around d-value of 0.415 nm and 0.374 nm, suggesting the evidence of a hexagonal symmetry and β’ crystals. Faster cooling rate resulted in an earlier onset of crystallization and ultrasonic treatment narrowed the melting range. Oxidation of fish oil in the sorghum wax oleogels were delayed considerably compared to free fish oil, while SDW generated the most stable oleogels.

Holocene and Last Interglacial climate of the Faroe Islands from sedimentary plant wax hydrogen and carbon isotopes

The Last Interglacial period (LIG) is Earth's most recent globally warm period and is analogous in some ways to projected future global warming. However, questions remain regarding the state of the climate during the LIG in the North Atlantic, a region that is extremely sensitive to changes in oceanic and atmospheric circulation. Here, we present hydrogen and carbon isotope (δD and δ13C) records from a suite of plant wax biomarkers preserved in Holocene and LIG lacustrine sediments from the North Atlantic Faroe Islands and interpret them as qualitative proxies for temperature and hydroclimate variability. These data are used to directly compare LIG and Holocene climate using the same proxy approaches from the same terrestrial location. Measuring multiple isotopes on multiple types of waxes elucidates the sources of homologous plant waxes. We deduce that the δD values of long-chain n-alkanes (C27–C33) and mid-chain n-alkanes (C23–C25) in these sedimentary archives reflect leaf water and lake water δD values, respectively, while the δD values for both long-chain (C28–C30) and mid-chain n-alkanoic acids (C24–C26) primarily represent lake water δD values. Plant wax-inferred δD values of precipitation during the early Holocene (10,100 to 8,200 cal yr BP) are ∼35‰ more positive than late Holocene values, and decline over the Holocene. δD-inferred hydrologic change and δ13C -inferred plant water use efficiency both indicate that the Faroe Islands became drier throughout the Holocene. Comparison with measurements from LIG plant waxes indicates that late LIG in the Faroe Islands was hydrologically similar to the early-to mid-Holocene (8,200 to 4,000 cal yr BP), with enriched precipitation isotopes and reduced evapotranspiration indicating a warmer, wetter environment.

A comparative study on the artificial UV and natural ageing of beeswax and Chinese wax and influence of wax finishing on the ageing of Chinese Ash (Fraxinus mandshurica) wood surfaces

This study investigated and compared the behaviour of two types of natural waxes, beeswax and Chinese wax, by means of two different ageing tests: an artificial accelerated ageing test using UV light and a simulated natural ageing test (indoors conditions) based on the action of natural, window-filtered light. The same tests were employed to evaluate the influence of wax finishing on the ageing behaviour of Chinese Ash (Fraxinus mandshurica) wood surfaces. Ageing effects were evaluated by direct and microscopic observation, colour measurements in the CIELab system and FTIR investigations. The results yielded by both accelerated UV ageing (72 h) and simulated indoors natural ageing (6 months) indicate that the waxes under analysis here are materials with a good ageing resistance. FTIR investigation revealed only minor chemical changes following ageing, more evident with beeswax than with Chinese wax. Finishing Chinese Ash wood surfaces with the two types of waxes influenced their ageing behaviour in terms of colour and surface chemistry changes. For both UV and natural ageing the maximum colour differences occurred for the samples finished with Chinese wax. The colour differences ΔE after 72 h accelerated UV ageing were in all the cases higher than those occurring after 6 months of indoors simulated natural ageing. Acceleration indexes for UV exposure compared to exposure to natural window-filtered sunlight, of about 40X-60X, were calculated. Both UV accelerated ageing and natural simulated ageing resulted in significant surface chemistry changes for the unfinished Chinese ash wood samples, consisting mostly in lignin degradation and formation of carbonyl containing chromophores. FTIR investigation of wax finish wood samples revealed only very minor chemical changes of the top wax layers, although chemical changes occurring beneath the coating layer on the wood surface are highly probable. Overall, the experiments presented in this paper indicate that Chinese wax seems slightly more resistant to ageing than beeswax.