Acetone Bath Research Articles

Polymethylmethacrylate (PMMA) deposition and removal optimization in CVD-grown graphene transfer: A Taguchi technique study

The conventional method of graphene transfer involving Polymethylmethacrylate (PMMA) often results in residual PMMA, negatively impacting the optical and electrical properties of the transferred graphene layer. This study employs the Taguchi optimization technique to minimize PMMA contamination during the graphene transfer process. The quality of the transferred graphene layer was evaluated utilizing atomic force microscopy (AFM), Raman spectroscopy, and Hall Effect measurement. The optimized conditions identified were a PMMA concentration (P) of 4.5 %, a spin rotation (S) speed of 3000 rpm, an acetone bath temperature (A) at 40 °C, and a dissolution duration (T) of 60 min. These parameters achieved a promising surface coverage of 3.42 %. Interestingly, further characterization highlighted that sample #8, prepared with different parameters (P = 12 %, S = 3000 rpm, A = 24 °C, T = 60 min), exhibited a surface coverage of 5.10 % and superior properties, including high transparency, exceptional film quality, low electrical resistance (8691 Ω), and an ID/IG ratio of 0.13. These findings suggest that the optimized conditions are suitable for applications prioritizing surface coverage, while the parameters for sample #8 are recommended for achieving minimal electrical resistance, high transparency, and superior film quality. This research contributes insights into PMMA-assisted graphene transfer, offering practical guidance for tailored processes.

Enhancing mechanical properties of cellulose acetate/carbon black nanofibers for oil spill cleanup

Oil contamination caused by various oil-related industries and domestic usage is one of the major global challenges that threaten the environment. Therefore, employing efficient and environmentally friendly methods for oil removal from oily water is crucial. Nanofibers offer suitable mediums for such applications due to their low fiber diameter and high surface area. Herein, mechanically enhanced carbon black (CB) loaded-cellulose acetate (CA) nanofiber mats were developed for oil removal applications. Initially, CA/CB nanofibers were fabricated from 15% wt. CA solutions containing 2% wt. CB. To improve the mechanical properties, the samples were treated in an ethanol:acetone bath for 2 and 4h. Increasing post-treatment duration increased the nanofiber diameters from 438 nm to 601 nm and decreased porosities from 75% to 66%. The post-treatments improved the mechanical properties of the samples and the highest modulus was achieved as 20.85 MPa. The water and oil contact angles increased from 86° to 102° and 61° to 80°, respectively. The liquid absorption and retention capacities of the samples were evaluated by immersing them in water, seawater, waste oil, and their emulsions. Despite their lower initial oil absorption compared to the non-treated one, post-treated samples still retained large amounts of oil at the end of 24 h.

Evaluation of Elnady preserved tissues as a teaching aid for undergraduate animal science courses

Abstract The use of tissue specimens for undergraduate instruction is a very valuable tool. However, fresh tissue specimens are not always available and many common preservation techniques can result in discoloration, offensive odors, and/or dangerous chemical residues. The Elnady Technique was developed as a means to produce tissue specimens that “are realistic, durable, have no offensive odor, and are dry, soft and flexible” (Elnady, F.A. 2016 The Elnady Technique: An innovative, new method for tissue preservation. Altex. 33:237-242. doi:10.14573/altex.1511091). Briefly for soft tissue, specimens were preserved by fixing in formalin. The tissue specimen was then dehydrated with a series of acetone baths. Once the tissue was fully dehydrated, the specimen was impregnated in glycerin. Excess glycerin was then removed by draining followed by immersion in cornstarch. Cornstarch residue was removed with a soft brush, and the specimen was stored in a plastic bag. Multiple specimens (including female reproductive tract of the cat, goat, horse, and sow; digestive tract of cat, chicken, and dog; one day old lamb stomach; goat rumen, reticulum, omasum, and abomasum; and sheep heart and kidney) have been preserved and used in various animal science course laboratories (126 laboratory sections and 1696 students at Berry College). Some of the specimens have been in use for seven years and are still in usable condition. Anonymously surveyed Berry College Animal Science Faculty strongly agreed or agreed Elnady preserved tissues are a useful teaching aid (n = 5). The Elnady Technique has proven to be a useful means of preserving tissue samples used in undergraduate animal science courses.

Chicken plastination: its role in teaching avian anatomy

This paper describes the preparation of six plastinated chicken dissections for Veterinary Anatomy teaching at the University of Pretoria, South Africa. Specimens were fixed in 10% formalin for seven to ten days, depending on the size of the specimen. Room temperature acetone baths were used for dehydration over a period of six weeks. Impregnation in S10 took place over a period of three weeks at -16 °C. The specimens were cured with S6. A peristaltic pump was used during preparation to ensure the intestines were rinsed properly, and the chemicals penetrated the whole specimen. In the curing phase, a compressor was used to inflate the duodenum and small intestines to show the digestive and reproductive tracts. The plastinated specimens were then labelled. Three chicken hearts in different stages of dissection (one intact, one from the ventrum/cranial, one from the dorsum/caudal aspect) were prepared. A muscle dissection was carried out on a whole chicken with its intestines intact. It was found to be preferable to carry out the dissection while the specimen was stored in the acetone bath. When the dissection was complete, the body wall of the chicken was cut through with an oscillating saw before impregnation in S10. Another adult chicken was used for the skeleton. All the muscle was removed, and the skeleton placed in formalin for fixation. After a week, the skeleton was placed in acetone for dehydration. The aim with this skeleton was to show how the ligaments maintain skeletal integrity. The ovary and reproductive tract were also dissected. The plastinated specimens are now available to the students in the anatomical museum. Now students, at their own pace, may study and learn the anatomy of the chicken more intensely.

Anatomical evaluation and preparation procedure of a cross-sectioned kidney plastination of a thoroughbred horse with local polyester resin

This study aimed to develop a protocol for the thin section plastination of the kidney with local polyester resin and examine the anatomical details of this specimen. The sample was fixed with 10% formalin fixation solution and then sectioned into 3 mm slices. The four stages of the polyester plastination technique were used. Firstly, the samples were kept in 99.5% acetone baths at -25ºC for the dehydration. After this process, the sections were placed in polyester resin and the impregnation process was started at room temperature (20ºC) under vacuum. Following the forced impregnation, the curing chambers were constructed and the curing process was continued under ultraviolet light. The data of each applied stage were recorded carefully and the protocol for polyester plastination of kidney sections was successfully established. The specimens were observed from a different point of view with a thin cross-sectional appearance. The anatomical morphology and the structures of the sections of the kidney such as renal parenchyma and circulatory components were preserved well. The final products could be used as educational samples for cross-sectional anatomical training of kidneys.

A Novel, Rapid Response Renewable Biopolymer Neutron and Gamma Radiation Solid-State Detector for Dosimetry and Nuclear Reactor Flux-Power Mapping

A novel solid-state neutron and gamma radiation monitor-dosimeter based on biopolymer polylactic acid (PLA) is presented. The resulting detector (PLAD) technology takes advantage of property changes of the renewable PLA resin when subject to ionizing nuclear radiation. A simple yet rapid and accurate (±10%) low-cost (<$0.01/detector) mass loss upon dissolution (MLD) technique was successfully developed; MLD is based on a simple mass balance for discerning neutron and/or gamma doses using small (40 mg, ~4 mm diameter) ultra-low-cost (<$0.01) resin beads via dissolution in acetone. The GammaCellTM Co-60 irradiator, and the PUR-1 12 kW fission nuclear research reactor were utilized, respectively. Irradiation absorbed doses ranged from 1 to 100 kGy. Acetone bath temperature was varied from ~40 °C to ~54 °C. Results revealed a strong dependence of MLD on acetone bath temperature between neutron and gamma photon dose components; this allowed for the unique ability of PLAD to potentially perform as both a neutron-cum-gamma or as a gamma or neutron radiation dosimeter and intensity level detector. A linear trend is found for combined neutron and gamma radiation doses from 0 to 40 kGy when dissolution is conducted above 50 °C. The important potential ability to distinguish neutron from gamma radiation fields was scoped and found to be feasible by determining MLD at 45 °C. The potential was studied for simultaneous use as an in-core neutron and gamma monitor of an operating 3 GWt light-water reactor (LWR). Scoping tests were conducted with the pre-irradiated (@ 20 °C) PLAD resin beads followed by heating to in-core LWR coolant (300 °C) conditions for ~30 s corresponding to the time to reach ~40 kGy total doses in a typical 3 GWt LWR. MLD results were unaffected, indicating the exciting and unique potential for in situ (low-cost, accurate and rapid) simultaneous mapping of neutron and gamma radiation fluxes, related dosimetry, and fission power level monitoring.

Plastination: A Novel Way of Preservation of Cadaveric Specimens for Teaching and Learning Human Anatomy

Plastination is a preservation method of anatomical specimens, which can be used for long-term educational purposes both in basic and clinical sciences. Dr. Gunther von Hagens first developed this technique in 1977 in Heidelberg, Germany. There are several plastination methods that are currently used in different countries. Room-temperature silicone plastination using ‘North Carolina technique’ is assumed as the best suited for our institutions considering our country’s climate and feasibility in terms of limited resources. In general, plastination methods involve four stages: i) fixation and specimen preparation; ii) dehydration and defatting; iii) plastic permeation or force impregnation by plastic material; and iv) hardening or curing. Fixation involves addition of formalin to the specimen for preventing decay and bacterial growth. Then dehydration is done by submerging the specimen in acetone baths. Thereafter, the specimen is kept in a vacuum chamber, where plastic permeation or forced impregnation occurs. Polymers penetrate the tissues of the specimen while removing acetone. After leaving the specimen in an airtight chamber maintaining a specific temperature, hardening or curing process follows. Plastination technique has several advantages like making cadaveric specimens easy to handle, easy storage of viscera, prolonged preservation, odourless, dry, non-irritant, nontoxic presentation and ability to present more anatomical details than ever before. Some important drawbacks are that the process is very costly, time consuming, limited size of the impregnation chamber, health and environmental hazards of the chemicals used. Plastination seems to have a great future in all fields of teaching, training and research not only in anatomy education but also in other disciplines in medical, biomedical, veterinary and health science institutions across the globe. Plastinates have opened several new windows to the world of anatomical sciences. Mediscope 2023;10(1): 31-37

A Minimalistic Technique for Neural Tissue Preservation and Neuroanatomical Education: Quantitative Study of the Elnady Technique on Human Cadaveric Specimens.

Cadaveric shortages have been a challenge to anatomy education; as access remains low in many parts of the world, institutions are relying on plastinated specimens. Plastination typically requires the use of complex equipment and patented chemicals. While models solve cost and toxicity issues, in neuroanatomical education, the rigidity prevents deep-brain structure exploration and visual-spatial learning. The Elnady technique (ET) developed by Dr. Fawzy Elnady is an alternative method that solves the limitations of traditional plastination while maintaining the advantages previously developed in animal models. The superficial temporal artery (STA), brain stem, cerebellum, right hemisphere, and latex-injected cortex were previously embalmed, drained of their original solution, dehydrated in acetone baths, and hydrometer readings were taken. Specimens were placed in a glycerol bath, immersed in cornstarchand cured. Quantitative and qualitative data of weight (grams), size (millimeters), color, texture, and odor were obtained before and after processing the samples. Overall, specimens showed a change of 6.5% in weight, 8.5% in height, 4.8% in width, and 8.9% in length (millimeters) after the preservation process. The products had pliable texture, no change in color grossly and no detectable odor. The measurement of weight (grams) ranges from 0-15.7%, height from 0-12.3%, width from 0-11.1%, and length from 1.7-5.9%. The ET is an effective method for the preservation of human cadaveric specimens that produces quality samples from embalmed specimens. Preservation can be done without patented chemicals and special storage methods are usually required for plastination. It is an ideal technique for basic and/or low-resource settings and could resolve expenses related to acquiring and maintaining cadaveric brain specimens.

Selected mechanical properties of human cancellous bone subjected to different treatments: short-term immersion in physiological saline and acetone treatment with subsequent immersion in physiological saline

BackgroundPhysiological saline (0.9% NaCl) and acetone are extensively used for storage (as well as hydration) and removal of bone marrow, respectively, of cancellous bone during preparation and mechanical testing. Our study aimed to investigate the mechanical properties of cancellous bone subjected to short-term immersion in saline and acetone treatment with subsequent immersion in saline.MethodsCylindrical samples (Ø6 × 12 mm) were harvested from three positions (left, middle, and right) of 1 thoracic vertebral body, 19 lumbar vertebral bodies, and 5 sacral bones, as well as from 9 femoral heads. All samples were divided into two groups according to the different treatments, (i) samples from the left and middle sides were immersed in saline at 4℃ for 43 h (saline-immersed group, n = 48); (ii) samples from the respective right side were treated with a combination of acetone and ultrasonic bath (4 h), air-dried at room temperature (21℃, 15 h), and then immersed in saline at room temperature (21℃, 24 h) (acetone and saline-treated group, n = 38). All samples were subjected, both before and after treatment, to a non-destructive compression test with a strain of 0.45%, and finally destructive tests with a strain of 50%. Actual density (ρact), initial modulus (E0), maximum stress (σmax), energy absorption (W), and plateau stress (σp) were calculated as evaluation indicators.ResultsBased on visual observation, a combination of acetone and ultrasonic bath for 4 h failed to completely remove bone marrow from cancellous bone samples. The mean values of ρact, σmax, W, and σp were significantly higher in the femoral head than in the spine. There was no significant difference in E0 between non-treated and saline-immersed samples (non-treated 63.98 ± 20.23 vs. saline-immersed 66.29 ± 20.61, p = 0.132). The average E0 of acetone and saline-treated samples was significantly higher than that of non-treated ones (non-treated 62.17 ± 21.08 vs. acetone and saline-treated 74.97 ± 23.98, p = 0.043).ConclusionShort-term storage in physiological saline is an appropriate choice and has no effect on the E0 of cancellous bone. Treatment of cancellous bone with acetone resulted in changes in mechanical properties that could not be reversed by subsequent immersion in physiological saline.

Dual Triplet Sensitization Strategy for Efficient and Stable Triplet–Triplet Annihilation Upconversion Perovskite Solar Cells

Dual Triplet Sensitization Strategy for Efficient and Stable Triplet–Triplet Annihilation Upconversion Perovskite Solar Cells

Paraffin Fixed Human Trabecular Bone Specimens for Study of Osteoporosis

Examining and quantifying specific measures of trabecular bone to investigate the progression of osteoporosis presents a challenge. Specifically, the development of analytical and computational strategies to interpret computed tomography (CT) generated data sets requires gross anatomical specimens that closely approximate the intraosseous matrix of the marrow while maintaining the structural integrity of the trabecular network. Moreover, these specimens must be durable, easily transported, and stored at room temperature (e.g., do not require freeze/thaw cycles). Here we investigated if paraffin impregnated bone specimens maintained the trabecular network and bone density of prepared fresh‐frozen specimens used in imaging studies for osteoporosis. Standardized fresh‐frozen human distal tibia specimens (n = 12), from the institution’s Deeded Body Program, were scanned using multi‐row detector computed tomography (MDCT) and micro computed tomography (micro‐CT) imaging at different times in the preparation process to evaluate and quantify the preservation of microstructure and continuity of cortical and trabecular bone constituents. Once scanned, the specimens were placed in a series of acetone baths to remove water and marrow. With the de‐marrowing procedure complete, four specimens were rescanned using MDCT and micro‐CT. De‐marrowed specimens were then impregnated, under vacuum controlled conditions, with either a silicone polymer, gelatin matrix solution, or paraffin wax. After impregnation and curing, the specimens were re‐scanned. Analysis demonstrated a high correlation in the region of interest (ROI) for trabecular bone network area density from micro‐CT data sets of the preprocessed and de‐marrowed states (r = 0.99). Quantitatively, wax impregnated specimens demonstrated congruence in MDCT bone volume fraction (r = 0.92) and trabecular network area (r = 0.94) measures when the preprocessed and impregnated states were correlated. Results were more robust in the micro‐CT data in the bone volume fraction (r = 0.97) and the trabecular network area (r = 0.99). MDCT analysis at the (ROI) corresponding to 14‐16% length measured from the distal aspect of specimens demonstrated an increased estimate of bone mineral density (BMD) relative to scans acquired with the unmodified tissue (polymer +160 mg/cc; gelatin +58 mg/cc), whereas the paraffin wax condition slightly underestimated BMD (‐21 mg/cc). Of the impregnating procedures, paraffin wax provided the best qualitative specimens for handling, storage, and processing time. Together these data suggest that the trabecular structure is preserved through the de‐marrowing procedure and demonstrates that specimens can be transferred away from cold storage. Impregnating bone specimens with paraffin wax effectively provides a space occupying matrix that protects the delicate trabecular network without altering the ability to quantify important biomechanical measures in clinical CT as well as micro‐CT imaging for assessing bone integrity for the study of osteoporosis. This procedure creates specimens that are easily stored and transported, can be scanned across various imaging modalities, and effectively retain the trabecular micro‐structure.

Carbon Nanotubes: Synthesis via Flame Fragment Deposition (FFD) Method from Liquefied Petroleum Gas

The current study uses the flame fragment deposition (FFD) method to synthesize carbon nanotubes (CNTs) from Iraqi liquefied petroleum gas (LPG), which is used as a carbon source. To carry out the synthesis steps, a homemade reactor was used. To eliminate amorphous impurities, the CNTs were sonicated in a 30 percent hydrogen peroxide (H2O2) solution at ambient temperature. To remove the polycyclic aromatic hydrocarbons (PAHs) generated during LPG combustion, sonication in an acetone bath is used. The produced products were investigated and compared with standard Multi-walled carbon nanotube MWCNTs (95%), Sigma, Aldrich, using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), Raman spectroscopy, scanning electron spectroscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Transmission Electron Microscopy (TEM). Under the applied experimental circumstances, the obtained characterization data confirm the synthesis of multi-wall carbon nanotubes (MWCNTs) with portion from few wall carbon nanotubes (FWCNTs). The average diameter of synthesized Carbon nanotubes ranged from 31.26 to 78.00 nm, with a purity of more than 65 percent.

PSII-B-24 Use of the Elnady technique of tissue preservation to preserve specimens for use in undergraduate animal science courses

Abstract The use of tissue specimens for undergraduate instruction is a very valuable tool. However, fresh tissue specimens are not always available and many common preservation techniques can result in discoloration, offensive odors, and/or dangerous chemical residues. The Elnady Technique was developed as a means to produce tissue specimens that “are realistic, durable, have no offensive odor, and are dry, soft and flexible” (Elnady, F.A. 2016 The Elnady Technique: An innovative, new method for tissue preservation. Altex. 33:237–242. doi:10.14573/altex.1511091). Briefly for soft tissue, specimens were preserved by fixing in formalin for one week. The tissue specimen was then dehydrated with a series of acetone baths changed weekly. Once the tissue was fully dehydrated, the specimen was impregnated in glycerin by full immersion in a glycerin bath for one to two weeks. Excess glycerin was then removed by draining followed by immersion in cornstarch for one to two weeks. Cornstarch residue was removed with a soft brush, and the specimen was stored in a plastic bag. Multiple specimens (including female reproductive tract of the cat, goat, horse, and sow; digestive tract of barred owl, cat, chicken, and dog; one day old lamb stomach; goat rumen, reticulum, omasum, and abomasum; deer testicle; and sheep heart and kidney) have been preserved and used in various animal science course laboratories (75 laboratory sections and over 1000 students at Berry College). Some of the specimens have been in use for five years and are still in usable condition. The Elnady Technique has proven to be a useful means of preserving tissue samples used in undergraduate animal science courses.

A quantitative evaluation of color changes occurring in the muscle tissue during the stages of S10 silicone plastination technique

There are many preservation techniques that are used to ensure that the changes (odor, color, and elasticity) in the characteristics of the animal or human bodies after death are minimized in the field of anatomy. One of the most modern anatomic specimen preparation methods is the plastination technique. Therefore, primary plastination stages were applied to the muscle tissue in this study. The aim of the current study is to present color changes in muscle tissue quantitatively by using a colorimeter device in every stage of the standard silicone plastination technique until the last product is obtained. Color analyses were performed on the muscle tissue after each stage of the plastination. Throughout the whole process, it was observed that the stage when the value of color change from green to red in the product was the closest to the fresh tissue was the 1st acetone bath. The value of color change from blue to yellow was closest to the fresh tissue at the gas curing and hardening stage. Furthermore, the closest values to the fresh tissue were recorded after the impregnation stage when the variations in plastinates were evaluated in terms of brightness. Color changes in plastinates, which have been described as close to the natural color up to today, were determined through statistical data in this study. Moreover, as a result of this dissertation, it was asserted that colorimeter can be effectively used in the field of anatomy due to the advantages it holds.

Poe in Richmond: Conserving Poe's Papers

Poe in Richmond: Conserving Poe's Papers

Purification for Carbon Nanotubes Synthesized by Flame Fragments Deposition via Hydrogen Peroxide and Acetone.

Carbon nanotubes (CNTs) are synthesized by the flame fragment deposition (FFD) technique using Iraqi liquefied petroleum gas (LPG) as a source of carbon in a hand-made reactor at a low temperature (160 °C) without using a catalyst. Purification of the multi-walled carbon nanotubes (MWCNTs) is carried out using a two-step process consisting of sonication in 30 wt.% hydrogen peroxide (H2O2) solution at room temperature to remove amorphous impurities adhering to the walls of the CNTs and carbon nanoparticles (CNPs), followed by sonication in an acetone bath to remove the polyaromatic hydrocarbons (PAH) formed during the LPG gas burning. Comprehensive characterizations such as X-ray diffraction (XRD), atomic force microscopy (AFM), thermo-gravimetric analysis (TGA), and transmission electron microscopy (TEM) were conducted to verify the efficiency of the purification process. The results clearly demonstrated that this process is promising for the purification of the synthesized CNTs.

Poly(methyl methacrylate) Coating of Titanium Workpieces to Reduce Burrs in Micro-drilling.

A technique to reduce burr height in titanium micro-drilling is presented: a poly (methyl methacrylate) coating was applied before machining on the upper and lower surfaces of a titanium specimen (0.5-mm thick). After drilling, a cleaning process (acetone bath) was executed to eliminate the coating, and holes with less burr were obtained. The coating process was executed with a spin-coating machine. To test the efficacy of the technique, two different coating thicknesses (7.9 and 5.4 μm) and two drill bits (0.25- and 0.5-mm diameter) were evaluated. Qualitative and quantitative analyses of the holes obtained were performed with scanning electron microscopy and three-dimensional microscopy, respectively. The results highlight the efficacy of the technique to reduce the burr height by 70% in coated titanium relative to that in an uncoated titanium sheet.

Coloring plastinated specimens.

In the early days of plastination, plastinate Color was the usual grey/brown familiar to formalin-fixed biological specimens. Initially, trials with Kaiserling's, Klotz, Jore's and McCormick's fixative solutions were disappointing. Vascular injections with Colored epoxy were a great breakthrough in the 1980s. Biodur AC10® stain was the first stain of note to be applied to gross specimens to be plastinated and was applied in the last acetone bath. As plastination became more popular, specimen Color became an important and necessary aspect. Reactivation of the normal Color of red blood cells within a formalin-fixed specimen was introduced as a mechanism to restore Color to plastinated specimens. Painting of plastinated vessels was tried with some success, and finally, a superior new proprietary type of silicone coloration was developed. More recently, a versatile red pigment stain was developed. All of these have added aesthetically to the plastination processes and will certainly be a reality in the years to come. The various methodologies to Color plastinates are presented. Time will tell how effective these may or may not be.

Stable isotope and compositional analysis of Alaska caribou teeth embedded in polymethyl-methacrylate (PMMA)

Stable isotopic analysis (SIA) of incremental dental tissues from archaeological specimens provides unique insight into the paleoecology of animals utilized by humans in the past. Unfortunately, many archaeological specimens are too fragile to survive the mechanical processes necessary to accurately identify and sample incremental dental tissues. Polymethyl-methacrylate (PMMA) is an organic polymer often used to encapsulate and strengthen archaeological specimens for the sectioning, grinding, and polishing necessary to identify incremental tissues. The effects of PMMA embedding on stable carbon and nitrogen isotopes in dental enamel and dentin has not been assessed previously and may be relevant whenever stable isotopic analysis of carbon and nitrogen is to be conducted. We embedded five caribou (Rangifer tarandus) tooth halves in PMMA, sampled these halves and the corresponding non-embedded tooth halves. We found that PMMA embedding has no noticeable effects on the nitrogen values of embedded specimens. PMMA embedding decreased the δ13C values of whole teeth powder by an average of −6.5‰ and increased %C by an average of 8.7%.We then tested two methods to mitigate the impact of PMMA embedding on dental carbon 1) acetone baths to dissolve the PMMA before SIA, and 2) acetone baths combine with a modified Longin method for collagen extraction to remove PMMA prior to SIA. We found that three, four and five acetone baths appear to be equally efficient at removing PMMA introduced carbon from embedded specimens. Acetone baths reduce the standard error of δ13C values of whole tooth dental powder, including enamel, dentin, and cementum, in both embedded and non-embedded specimens. Both methods were successful at reducing the effects of PMMA embedding; however, the most efficient mitigation of PMMA effects on whole tooth carbon was found in collagen extracts coupled with acetone baths. This information may be helpful in future stable isotope assessments of PMMA-encapsulated dental tissues.

Self-cleaning of a hydrophobic surface by a rolling water droplet

A water droplet behavior on a hydrophobic surface is examined relevant to the dust particles removal from the surface. Surface crystallization of polycarbonate is realized in acetone bath and the resulting surface is coated by the functionalized nano-size silica particles towards reducing contact angle hysteresis. This arrangement provides droplet rolling/sliding on the hydrophobic surface. Droplet translational velocity is formulated and predictions are compared with those resulted from the high speed recorded data. Influence of surface inclination angle on droplet dynamics is investigated and the dust removal mechanism on the inclined surface is analyzed. It is found that predictions of droplet translational velocity agree well with those obtained from the experiment. Droplet rolling dominates over sliding on the inclined surface and droplet sliding velocity remains almost 10% of the droplet translational velocity. The main mechanism for the dust particles removal is associated with the droplet fluid cloaking of the dust particles during its transition on the hydrophobic surface. Droplet acceleration, due to increased surface inclination angle, has effect on the rate of dust particles removal from the surface, which is more apparent for large droplet volumes. Increasing droplet acceleration improves the coverage area of the clean surface.