Dry Procedure Research Articles

Microstructural properties and water penetration resistance of cementitious binder combined with water-dispersible polyurethane

To avoid the re-degradation of repaired regions and ensure the service lives of infrastructures, cementitious materials used for repair applications should possess excellent water penetration resistance. Organic polymers are widely used to enhance water resistance. In this study, the microstructural properties and water uptake of a cementitious material containing a newly developed water-dispersible polyurethane (PU) polymer were investigated. The results showed that the water uptake decreased significantly in the presence of PU. Microscopic observations and gas sorption isotherms indicated that submillimeter and capillary pores and the surfaces of calcium silicate hydrate were partially hydrophobized and/or blocked upon PU addition, which could contribute to the prevention of liquid water uptake. Nevertheless, based on a drying procedure performed prior to the water penetration tests, the specimens with and without PU exhibited similar water vapor uptakes owing to the eliminated difference in the volumes of their micro- and mesopores.

Hardened wood as a renewable alternative to steel and plastic

Hardened wood as a renewable alternative to steel and plastic

Selective dry etching of UV-nanoimprinted resin passivation masks for area selective atomic layer deposition of aluminum oxide

To demonstrate area selective atomic layer deposition (ALD) using UV-nanoimprinted resin patterns as physical passivation masks, we investigated the removal of UV-cured resin films subjected to sequential mutual doses of trimethylaluminum (TMA) and H2O by using dry etching procedures. On the basis of the removal of a residual layer characteristic from imprint resin patterns by anisotropic oxygen reactive ion etching (O2 RIE), oxidatively etched UV-cured films were modified with TMA and H2O in an ALD-like cyclic manner. Atomic force microscopy and time-of-flight secondary ion mass spectrometry [time-of-flight secondary ion mass spectrometry (TOF-SIMS)] analysis suggested that the combination of physical Ar ion milling and subsequent chemical O2 RIE enabled the elimination of oxidized UV-cured resin masks modified with 5-cycle TMA doses. By contrast, Ar ion milling or O2 RIE left organic or inorganic residues on silicon surfaces, respectively. A TMA-modified hybridized resin layer was etched by physical Ar ion milling; subsequently, the organic residual resin layer was removed by chemical O2 RIE in the case of 5-cycle modification with TMA. The mapping image of Al+ visualized by TOF-SIMS suggested that line patterns of aluminum oxide were left selectively on unmasked silicon substrate surfaces by site-selective dry etching of TMA-modified imprint resin passivation masks with 500 nm linewidth.

Energy-based indicators of soil structure by automatic dry sieving

Numerous methodological approaches and fractionation procedures contribute to the continuation of discussions about soil aggregate formation. This study aims to justify the dry sieving procedure and suggest an optimal sieving regime for automatic shakers for soil samples. For this approach to calculating total sieving energy, using oscillation frequency, vibration amplitude, and time was proposed. Retisol, Phaeozem, and Chernozem topsoil samples from agricultural and native ecosystems were analyzed using a sieving test, in which 50-kg soil samples were divided into 500–700 g subsamples and sieved with a constant oscillation frequency (50 Hz), but with varying vibrational amplitudes (0–2.5 mm), for sieving times that ranged from 1 to 5 min. We found that the optimal sieving regime is characterized by total sieving energy of 1850 J kg−1, reached during 2 min of sieving with a 50 Hz frequency and a 2.5 mm amplitude. Based on results of the dry sieving test, we have proposed the indicators of mechanical stability of soil structure: index of soil structure stability (SS) which characterize the degree of change in the soil aggregates size during sieving with minimal and optimal sieving energy, and modified the soil friability index (F4), that characterizes the rate of change in the soil aggregates size under mechanical load by dry sieving. The proposed formula of total sieving energy calculation allows comparing results between soil studies. Our meta-analysis showed that most (26 of 34) studies used insufficient sieving energy, where the aggregate size distribution did not reach the equilibrium state. A detailed protocol for soil dry sieving analysis is provided.

Free-standing tantalum pentoxide waveguides for gas sensing in the mid-infrared

Typical applications of integrated photonics in the mid-infrared (MIR) are different from near-infrared (telecom) range and, in many instances, they involve chemical sensing through MIR spectroscopy. Such applications necessitate tailored designs of optical waveguides. Both cross-sectional designs and processing methods of MIR waveguides have been a subject of extensive research, where material transparency and substrate leakage of guided modes have been the most common challenges. Both these challenges can be solved simultaneously with air-suspended waveguides. In this paper, tantalum pentoxide (Ta2O5, tantala) thin films deposited on silicon were tested for two different dry under-etching procedures, XeF2 and SF6 plasma, with both of them facilitating selective removal of silicon. We analyze the advantages and limitations of these two methods and optimize the processing for fabricating membranes with arbitrary length and cross-sectional aspect ratio over 300. The performance of these high-aspect-ratio membranes as a framework for single-mode waveguides is rigorously analyzed at 2566 nm wavelength. With tantala being transparent up to 10 µm wavelength, such waveguides are particularly well suited for gas sensing in MIR.

SEM Characterization and Tensile Properties of Alkali Treated Single Coir Fiber with Drying Procedure Variation

This study has aimed to analyze the effect of alkali treatment and drying method on the surface morphology and tensile properties of single coir fibers. The treatments of the coir fibers have been configured on the concentration of alkali solution, the soaking period, and the drying method. Furthermore, they have been soaked in 2 wt% and 6 wt% sodium hydroxide solution at room temperature for 1- and 2-hours soaking periods. The drying procedures adopted have been air, oven, and sun-drying. Observations with a scanning electron microscope (SEM) show that the coir surface is coarser, especially on fibers treated with 6 wt% sodium hydroxide solution. The properties such as tensile strength and strain, as well as tensile modulus of the different samples have been measured. The results have showed that the treated coir fiber with the 2 wt% concentration alkali solution has lower tensile strength than the untreated one. The treated coir with 6 wt% sodium hydroxides has the most considerable tensile strength. The effect of the soaking period on the tensile properties has been influenced by the drying method. Therefore, the appropriate combination of the soaking period and the drying method increase single coir fibers tensile properties. Slow drying (air-drying) has generated better tensile properties than the fast method (oven and sun-drying).

Effects of vacuum and multiflash drying on the microbiota and colour of dried yellow mealworm (Tenebrio molitor)

Larvae ofTenebrio molitor (yellow mealworm; YM) are an alternative to conventional animal protein as food and feed thanks to their high nutritional value and low environmental impact for production. Since some studies have reported high water activity (aw ) with different microbial contamination levels, blanching and drying can be employed to reduce microbial load, enzymatic activity, moisture content, and water activity, ensuring safety and preserving YM for longer periods. This study applied rinsing or blanching followed by vacuum- or multiflash drying, aiming to preserve YM by reducingaw and the microbial load, enabling its use as food and feed. The processing impact on YM colour was evaluated, and they were also subjected to anEscherichia coli contaminated wheat bran to perform a challenge test to evaluate the effectiveness of the decontamination. Drying curves were determined for each situation. Multiflash drying procedure was faster than vacuum drying for reducing YM moisture. Additionally, blanched samples required a shorter period to reach the targeted water activity (0.2-0.3) than rinsed samples. Blanching plus vacuum drying reduced more than 5 logE. coli load in YM in the challenge test. Vacuum drying preserved YM brightness the most. In conclusion, this study showed that drying could provide shelf-stable YM. Besides, only 15 s of blanching before drying gives better brightness and leads to a greater microbial reduction after a relatively short drying time.

Scanning electron microscopy preparation of the cellular actin cortex: A quantitative comparison between critical point drying and hexamethyldisilazane drying.

The cellular cortex is an approximately 200-nm-thick actin network that lies just beneath the cell membrane. It is responsible for the mechanical properties of cells, and as such, it is involved in many cellular processes, including cell migration and cellular interactions with the environment. To develop a clear view of this dense structure, high-resolution imaging is essential. As one such technique, electron microscopy, involves complex sample preparation procedures. The final drying of these samples has significant influence on potential artifacts, like cell shrinkage and the formation of artifactual holes in the actin cortex. In this study, we compared the three most used final sample drying procedures: critical-point drying (CPD), CPD with lens tissue (CPD-LT), and hexamethyldisilazane drying. We show that both hexamethyldisilazane and CPD-LT lead to fewer artifactual mesh holes within the actin cortex than CPD. Moreover, CPD-LT leads to significant reduction in cell height compared to hexamethyldisilazane and CPD. We conclude that the final drying procedure should be chosen according to the reduction in cell height, and so CPD-LT, or according to the spatial separation of the single layers of the actin cortex, and so hexamethyldisilazane.

Variation of Total Mercury Concentrations in Different Tissues of Three Neotropical Caimans: Implications for Minimally Invasive Biomonitoring.

Mercury (Hg) is a global environmental contaminant that affects ecosystems. It is known to biomagnify through food webs and to bioaccumulate especially in the tissues of top predators. Large-scale comparisons between taxa and geographic areas are needed to reveal critical trends related to Hg contamination and its deleterious effects on wildlife. Yet, the large variety of tissues (keratinized tissues, internal organs, blood) as well as the variability in the units used to express Hg concentrations (either in wet- or dry-tissue weight) limits straightforward comparisons between studies. In the present study, we assessed the moisture content that could influence the total Hg (THg) concentrations measured in several tissues (claws, scutes, total blood, and red blood cells) of three caiman species. We evaluated the moisture content from the different tissues to provide information on THg concentrations in various matrices. Our results show a difference of THg concentrations between the tissues and intra- and interspecific variations of moisture content, with the highest THg values found in keratinized tissues (scute keratinized layers and claws). For the three species, we found positive relationships between body size and THg concentration in keratinized tissues. In the blood, the relationship between body size and THg concentration was species-dependent. Our results emphasize the need for a standardized evaluation of THg concentration and trace elements quantification based on dry weight analytical procedures. In addition, the use of both blood and keratinized tissues offers the possibility to quantify different time scales of THg exposure by non-lethal sampling.

Evaluation of Methods of Enrichment and Compositing of Environmental Samples for Detection of Listeria monocytogenes

Various methods exist for the enrichment and detection of Listeria spp. and Listeria monocytogenes from environmental samples. Procedures for the compositing of environmental samples are not as well defined. In this study, different enrichment procedures involving buffered Listeria enrichment broth (BLEB), University of Vermont medium (UVM), and Fraser broth (FB) were evaluated to determine the limits of detection (LODs) for L. monocytogenes from culture and from swabs of stainless steel and to assess the efficacy of composite sampling by wet (pooling of primary enrichments) and dry (pooling of swabs) procedures. For detection of cells in pure culture, the computed values for the LOD at 95% probability (LOD95) using a single-step BLEB or two-step UVM-FB enrichment were 0.33 and 0.49 CFU/225 mL enrichment, respectively. No significant differences in detection were observed for procedures using either two-step BLEB-FB or UVM-FB enrichments for swabs of stainless steel when L. monocytogenes was inoculated at 2 to 6 log CFU; the LOD95 values were 3.82 and 3.62 log CFU per 4-in2 area, respectively. Wet compositing of L. monocytogenes from culture with and without romaine lettuce wash resident microbiota was conducted using BLEB-FB and UVM-FB enrichment methods; both allowed detection of the pathogen at ratios of 1:1, 1:2, 1:4, and 1:7 (1 positive sample to x negative samples) with no loss in sensitivity. From swabs of stainless steel, L. monocytogenes was detected similarly for both wet and dry composites of up to eight samples (1:7) with romaine lettuce wash. However, the BLEB-FB method allowed significantly faster detection (after 24 h of FB incubation) in composites of 1:4 and 1:7 samples compared with the UVM-FB method under the conditions tested. The results of this study provide data to evaluate the efficacies of the different enrichment procedures and aid in assessing the use of wet and dry compositing of environmental samples for use as part of a Listeria control plan in food production and processing facilities.

Trace metal elements in phosphate rock wastes from the Djebel Onk mining area (Tébessa, eastern Algeria): A geochemical study and environmental implications

Algeria is one of the phosphate-rich countries where many deposits are found in the Tébessa region which are currently being mined from the Kef Essenoun quarries. The processing of run-off-mine, to increase P2O5 grads in the commercial product, includes the use of wet and dry procedures which in turn leads to the production of large amounts of wastes. The present study focuses on tracking the amount of trace metal elements (TMe) in the phosphate rock wastes resulting from the processing of phosphate run-of-mine. The representative samples of solid rejects and sludge wastes from both processing ways were collected and analysed using SEM and FTIR to characterise the materials, whereas ICP-AES and ICP-MS were used to determine major and TMe compositions, respectively. The results showed that the analysed wastes are P-enriched (P2O5 = 20 wt% - 27 wt %) together with similar mineralogy such as natural phosphorites (carbonate fluor-apatite), but they displayed an enhancement in matrix phases. Moreover, the overall tendency showed that the concentrations of TMe are relatively increased with a decrease in grain size diameter where higher contents of V, Cr, Co, Ni, Cu, Zn, As, Zr, Nb and Cd have been recorded in sludge and fine fraction from the wet way process (Rw −0.08 mm) when compared to other samples. The fine fractions generally contain the matrix that enhances almost all of TMe except for Sr and U which are hosted in apatite. Risk assessment of TMe showed that both raw phosphorites and their wastes, as all worldwide sedimentary phosphorites, yield some hazardous TMe exceeding the standards for soils (e.g., U, Cd, Cr, Mo, V and Tl). Hence, owing to the waste exposure and mobilisation of the finest particles by wind and rainfall, these hazardous metals could have harmful effects on the environment as well as human health.

Handling wine pomace: The importance of drying to preserve phenolic profile and antioxidant capacity for product valorization.

Four different wine grape pomaces (GP) (Vitis vinifera) varieties, Auxerrois, Pinot Blanc, Gamay and Pinot Noir, and obtained from white, rosé or red wine vinification, were considered for possible valorization in food supplement industry. Stabilization of GP by drying is paramount prior to further processing in the valorization chain, as GP might suffer spoilage over time. The objectives of this work were therefore to: evaluate the effect of microbiological spoilage and drying on the polyphenol profile and antioxidant capacity of GP; define a drying procedure by comparing kinetics of freeze-drying (FD) and vacuum oven (VO) (at 60 °C and 40 °C). Microbiological spoilage led to significant losses (P <0.01) of antioxidant capacity (40% to 87%) and total phenolic content (70% to 90%), while drying had no significant effect. FD and VO at 60 °C drying kinetics exhibited similar drying curves, and a dry weight (DW) plateau was reached by 48 hr. In contrast VO at 40 °C required 170 hr to reach similar DW values, pointing out the importance of temperature when opting for VO technology. Antioxidant capacity of GP extracts did not differ between drying methods. Interestingly, GPs from white and rosé wines (AUX, PB, and GAM) had up to 3.5 times higher content (P < 0.001) of total polyphenols compared to PN, obtained from red wine. These results reinforce the importance of drying of GP as a pretreatment, which otherwise could result in significant product degradation. Additionally, we propose white and rosé GP as more interesting sources for valorization, with higher phenolic content, compared to red wine GP.

Design of Roll‐In Margarine Analogous by Partial Drying of Monoglyceride‐Structured Emulsions

AbstractA novel process is proposed to turn soft gelled emulsions containing saturated monoglyceride (MG), sunflower oil, and water into a fat material with the typical water content (20 g/100 g) and rheological properties of roll‐in margarine. A gentle drying procedure at 30 °C is proposed to allow partial water removal from the emulsions, without causing phase separation. Upon water removal, the soft emulsion, initially stabilized by a highly hydrated liquid crystalline lamellar phase of MG, converts into a high internal phase oil–water emulsion (HIPE) stabilized thanks to the presence of MG crystals around gelled oil particles, which are interconnected via polar groups of MG. HIPE at the highest MG content (13.7 g/100 g) shows rheological properties (Gʹ = 4.6 × 105 Pa, critical stress = 634 Pa) comparable to those of commercial roll‐in margarine and is successfully used in baking trials of puff pastry.Practical Applications: The last years have seen an increasing demand for strategies for the nutritional improvement of lipid‐containing foods, due to the emerging health concern related to the consumption of unbalanced saturate/unsaturated fats. Moreover, sustainability issues have arisen due to the abundant use of tropical fats in foods. However, the unique technological and sensory properties of fats make this task very challenging, especially considering the production of laminated products requiring the use of plastic fat materials with peculiar rheological properties. The results obtained in this study are very promising, as they show that the novel fat can be used as an alternative to traditional laminating margarine.

Maize grain moisture content correction: From nonstandard to standard system

The accurate determination and estimation of grain moisture content is important for maize (Zea Mays L.) production, processing and drying studies. However, different drying procedures are often adopted by different operators to determine the grain moisture content, making it difficult to compare results with each other. In this study, different drying temperatures and times were used to create different drying conditions, and the differences in the estimated grain moisture content of maize were analysed. The results showed that, compared to the standard system, an insufficient drying temperature and time contributed to a lower apparent moisture content of maize grain, but the low drying temperature could be compensated by a longer drying time, and vice versa. Additionally, a correction method for maize grain moisture content was built. This method can correct the apparent moisture content (nonstandard system) under different drying procedures to the specified standard system, and the accuracy of model validation and the stability of deviation are very satisfactory. This method is very suitable for the rapid conversion of the grain moisture content of maize between different drying methods. It is especially helpful for re-evaluating the differences and controversies of some conclusions caused by different drying procedures adopted by different researchers, and provides a reference method for moisture content correction of other foods and cereals.

Validity of a Sham Dry Needling Technique on a Healthy Population

BackgroundVarious methods of sham procedures have been used in controlled trials evaluating dry needling efficacy although few have performed validation studies of the sham procedure.Hypothesis/PurposeThe purpose of this study was to examine the validity of a sham dry needling technique on healthy, active subjects.Study DesignValidation studyMethodsRunners capable of completing a half-marathon or marathon race and were randomized to receive true (using an introducer and needle) or sham (using an introducer and fixed, blunted needle) dry needling. Blinded subjects were asked to identify if they received sham or true dry needling following the procedure. Proportions of those who correctly identified their needling were also examined on the basis of past experience of receiving dry needling.ResultsFifty-three participants were included in this study, with 25 receiving the true dry needling procedure and 28 receiving the sham. Of those who had received dry needling in the past (n = 16), 11 (68.8%) correctly identified their respective groups. For those who had not previously received dry needling (n = 37), 13 (35.1%) accurately identified their group. Most importantly, 94.1% of dry needling-naïve participants were unable to identify they received the sham procedure (p < 0.001).ConclusionsThis study shows that a fixed needle in an introducer tube is a simple, inexpensive, effective sham procedure in patients who have never received dry needling before. This technique may be useful for randomized controlled trials in the future.Levels of Evidence2

Event-related potentials accompanying performance of computer mouse pointing task in the long-term dry immersion model of microgravity

Ten healthy volunteers participated in the ground imitation of a microgravity condition. For three weeks they stayed in the water filled tub without bodily support in supine position while isolated by waterproof material (this procedure is known as dry immersion - DI). During this period, they performed computer mouse pointing task and corresponding brain activity was evaluated by means of EEG: movement related and cognitive event-related potentials as well as resting state electroencephalogram were registered). Pointing task was performed before DI and at the time after initial period of adaptation – at the 5th and 17th days of DI. No deterioration of pointing task performance was found. Movement related potentials were not changed as well as cognitive peak P3, and only N1 peak significantly decreased at the 17th day of DI. Occipital alpha EEG also became significantly more pronounced at the 17th day of DI. Dry immersion procedure is thought to reproduce space flight physiological effects quite well, due to the DI specific feature – support withdrawal. Thus, results obtained indicate that support withdrawal also affects brain functioning in a specific way: increased alpha EEG is accompanied by altered visual processing (as indexed by diminished N1). Although these alterations are not sufficient to disrupt well learned mouse pointing task.

Separation of astatine from irradiated lead targets based on dry distillation in a glass test tube

Astatine was separated from a lead target, irradiated with 7Li ion beams, by dry distillation. Dry distillation was conducted in a glass test tube filled with nitrogen gas by heating the test tube with an electric furnace at 650 °C. The optimized conditions of the dry distillation procedure were studied by monitoring astatine radioactivity with gamma-ray spectrometers. The separation of astatine was accomplished in ~ 10 min. The cooling of the middle portion of the test tube was instrumental in recovering astatine radioactivity in high yields. The adsorption temperature of astatine on the glass surface was ~ 20 °C.

Drying performance, as well as physical and flexural properties of oil palm wood dried via the super-fast drying method

Effects of incising parameters were studied relative to the drying performance and properties of super–fast dried oil palm wood. Different incising depths (1/3, 1/2, 2/3, and 100% of the total thickness) and distance (38 mm and 50 mm) were made on the oil palm wood boards prior to the super-fast drying procedure. All the boards achieved the desired moisture content after drying. Drying defects were minimal, as only two boards indicated end checks and surface checks defects. The board density ranged from 0.44 g/m3 to 0.60 g/m3, and the thickness swelling and water absorption of the boards ranged from 8.3% to 12.5% and 45% to 67%, respectively. The specific modulus of rupture and elasticty ranged from 0.35 N m3/kg mm2 to 0.77 N m3/kg mm2 and from 77.64 N m3/kg mm2 to 118.40 N m3/kg mm2, respectively. It can be concluded that the hole distances did not exert significant effect on the properties, with exception of specific modulus of elasticity. A hole depth of 1/3 mm was preferable, since the surface looked like no incision had been made and the sample had good physical and flexural properties.

COVID-19 global pandemic planning: Dry heat incubation and ambient temperature fail to consistently inactivate SARS-CoV-2 on N95 respirators.

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.

Laboratory quality assessment of candidate gene panel testing for acute myeloid leukaemia: a joint ALLG / RCPAQAP initiative

Accurate classification of acute myeloid leukaemia (AML) has become increasingly reliant on molecular characterisation of this blood cancer. Throughout Australia and New Zealand massively parallel sequencing (MPS) is being adopted by diagnostic laboratories for the routine evaluation of patients with AML. This technology enables the surveying of many genes simultaneously, with many technical advantages over single gene testing approaches. However, there are many variations in wet and dry lab MPS procedures, which raises the prospect of discordant results between laboratories. This study compared the results obtained from MPS testing of ten diagnostic AML bone marrow aspirate samples sent to eight participating laboratories across Australasia. A reassuringly high concordance of 94% was observed with regard to variant detection and characterisation of pathogenicity. The level of discordance observed, although low, demonstrates the need for ongoing assessment of concordance between diagnostic testing laboratories through quality assurance programs.