Cleaning Methods Research Articles

Exploring sources of inaccuracy and irreproducibility in the CDC bottle bioassay through direct insecticide quantification

BackgroundThe Centers for Disease Control and Prevention (CDC) bottle bioassay is a commonly used susceptibility test for measuring insect response to insecticide exposure. However, inconsistencies and high variability in insect response when conducting CDC bottle bioassays have been reported in previous publications. We hypothesized that the CDC bottle bioassay results may be compromised when expected and actual insecticide concentrations in the bottles are not equivalent and that inadequate bottle cleaning and/or loss during insecticide introduction and bottle storage steps could be responsible. We explored this hypothesis by quantifying insecticides using gas chromatography tandem mass spectrometry (GC-MS/MS) in bottles that had been cleaned, prepared, and stored according to the CDC guidelines.MethodsWe investigated the bottle cleaning, preparation, and storage methods outlined in the CDC bottle bioassay procedure to identify sources of irreproducibility. We also investigated the effectiveness of cleaning bottles by autoclaving because this method is commonly used in insecticide assessment laboratories. The two insecticides used in this study were chlorpyrifos and lambda-cyhalothrin (λ-cyhalothrin). Insecticides were removed from glass bioassay bottles by rinsing with ethyl-acetate and n-hexane and then quantified using GC-MS/MS.ResultsThe CDC bottle bioassay cleaning methods did not sufficiently remove both insecticides from the glass bottles. The cleaning methods removed chlorpyrifos, which has higher water solubility, more effectively than λ-cyhalothrin. Chlorpyrifos experienced significant loss during the bottle-coating process whereas λ-cyhalothrin did not. As for bottle storage, no significant decreases in insecticide concentrations were observed for 6 h following the initial drying period for either insecticide.ConclusionsThe CDC bottle bioassay protocol is susceptible to producing inaccurate results since its recommended bottle cleaning method is not sufficient and semi-volatile insecticides can volatilize from the bottle during the coating process. This can lead to the CDC bottle bioassay producing erroneous LC50 values. High levels of random variation were also observed in our experiments, as others have previously reported. We have outlined several steps that CDC bottle bioassay users could consider that would lead to improved accuracy and reproducibility when acquiring toxicity data.Graphical

PREVALENCE OF ASYMPTOMATIC BACTERIURIA AND ITS MICROBIOLOGICAL PROFILE IN PREGNANCY AT TERTIARY CARE HOSPITAL, JABALPUR

Objective: To determine the prevalence of asymptomatic bacteriuria (ASB), microbiological profile, and pregnancy outcome in asymptomatic pregnant women. Methods: Pregnant women attending outpatient clinic were selected randomly. Urine sample by clean catch method collected and battery of tests were performed. Prevalence of ASB and pregnancy outcome studied. Results: Total 114 pregnant women were studied, out of which 6 cases were positive for urine culture. Prevalence rate in our study found to be 5.3%. Study depicted that 33.4% women with asymptomatic bacteriuria had premature rupture of membranes, 16.7 % women had pre-eclampsia and 16.7% had severe anemia. 50 % babies were premature, 33.4% had fetal growth restriction and 16.7% developed acute respiratory distress syndrome. Conclusion: Urinary tract infections are common during pregnancy. Asymptomatic bacteriuria can progress to pyelonephritis and may result in adverse pregnancy outcome. Prevalence rate found to be 5.3%. Premature rupture of membranes and premature births were major adverse pregnancy outcome. E. coli was most common bacterial isolate found in the study and was highly sensitive to cefuroxime sodium. Pregnancy complications may be avoided by using regular screening with urine cultures.

Deciphering the Mechanisms and Biotechnological Implications of Nanoparticle Synthesis Through Microbial Consortia.

Nanomaterial synthesis is a growing study area because of its extensive range of uses. Nanoparticles' high surface-to-volume ratio and rapid interaction with various particles make them appealing for diverse applications. Traditional physical and chemical methods for creating metal nanoparticles are becoming outdated because they involve complex manufacturing processes, high energy consumption, and the formation of harmful by-products that pose major dangers to human health and the environment. Therefore, there is an increasing need to find alternative, cost-effective, dependable, biocompatible, and environmentally acceptable ways of producing nanoparticles. The process of synthesizing nanoparticles using microbes has become highly intriguing because of their ability to create nanoparticles of varying sizes, shapes, and compositions, each with unique physicochemical properties. Microbes are commonly used in nanoparticle production because they are easy to work with, can use low-cost materials, such as agricultural waste, are cheap to scale up, and can adsorb and reduce metal ions into nanoparticles through metabolic activities. Biogenic synthesis of nanoparticles provides a clean, nontoxic, ecologically friendly, and sustainable method using renewable ingredients for reducing metals and stabilizing nanoparticles. Nanomaterials produced by bacteria can serve as an effective pollution control method due to their many functional groups that can effectively target contaminants for efficient bioremediation, aiding in environmental cleanup. At the end of the paper, we will discuss the obstacles that hinder the use of biosynthesized nanoparticles and microbial-based nanoparticles. The paper aims to explore the sustainability of microorganisms in the burgeoning field of green nanotechnology.

Suitable promotion scope of different clean heating technology paths in northern China

The Chinese government has implemented a clean heating policy to alleviate the severe air pollution and high energy consumption associated with winter heating in northern China. However, the promotion of clean heating technology paths (CHTPs) is limited by the problems of rising energy prices and insufficient supply capacity. To quantitatively study the promotion scope of each CHTP, this paper adopts the K-means clustering method in machine learning to analyze the clean heating methods suitable for the characteristics of each region in northern China based on 37 pilot cities. The results show that the 10 CHTPs based on coal, electricity and natural gas as energy, the most widely applied is Air-source heat pump technology, accounting for 86.7 % in cities. The least number of cities suitable for application are water-source heat pumps and sewage-source heat pumps due to economic constraints, with a proportion of 44 %. The 3 kinds of CHTPs applying solar, biomass and geothermal energy, accounted for more than 60 %, among them, ground-source heat pumps are recommended to promote the smallest scope, concentrated in Hebei, Henan, Shandong, and Heilongjiang provinces. This study is of great significance in guiding the selection of CHTPs on a large spatial scale.

Effects of magnetic intensity on the machining quality and tool damage in nickel-based superalloys subjected to magnetic-assisted cutting

Nickel-based superalloys are widely used in engine components due to their excellent high-temperature strength. However, their low plasticity and low thermal conductivity pose significant challenges in machining, leading to poor quality of machined parts and severe tool wear. Magnetic-assisted machining has received considerable attention as a clean and effective machining method, but its application to nickel-based superalloys is rarely reported, necessitating further exploration of its potential. This study focuses on GH4169 alloy and explores the effects of magnetic-assisted cutting (MAC) with varying intensities on the machining quality and tool wear. The experimental results indicate that the introduction of a magnetic field improves the machining quality by reducing tool wear and built-up edge adhesion. Additionally, both the plasticity and thermal conductivity of GH4169 alloy are improved under the effect of magnetic field, resulting in an 11.4 % decrease in cutting temperature. However, when the magnetic intensity ranges from 0.03 T to 0.12 T, secondary serration of the chip edges manifests, resulting in notch wear on the tool nose and a deterioration of surface quality. This secondary serration is attributed to the combined effect of tool nose radius and material plasticity under the magnetic field. As the magnetic field intensity increases further, the secondary serration gradually diminishes, and the surface roughness can be reduced by 26.5 % compared to traditional cutting. This study analyzed the relationship between machined surface, tool wear, chip morphology and magnetic field, and revealed the reasons for the differences in machining quality at different magnetic field intensities. These findings provide more possibilities for future applications of magnetic-assisted cutting to improve the machining quality of nickel-based superalloys and other difficult-to-machine metals.

Studies on Recovery of Performance of Fouled Nanocomposite Ultrafiltration Membranes on Cleaning after Treatment of Oil–Water Emulsions

Herein, we discussed the pure water flux recovery of carbon based nanofillers embedded polyvinyl chloride nanocomposite membranes after physical cleaning through backwashing & flushing with flow reversal and after chemical cleaning using hydrochloric acid and caustic soda. The water flux recovery by backwashing is more than that by forward flushing for all the membrane but it is more effective in carbon black (CB) & graphitized carbon black (GCB) carbon-based membranes than relatively hydrophilic multiwalled carbon-nanotube (MWCNT) & carboxylated multiwalled carbon-nanotube (CMWCNT) based nanocomposite membranes. The highest water flux recovery was found ~96% for nanocomposite membranes by backwashing and caustic soda cleaning. The combination of backwashing and caustic soda cleaning could be the most effective method of cleaning of oil-water fouled membranes to restore the maximum water flux.

Ultraclean Suspended Graphene by Radiolysis of Adsorbed Water.

Access to intrinsic properties of a 2D material is challenging due to the absence of a bulk that would dominate over surface contamination, and this lack of bulk also precludes effective conventional cleaning methods that are almost always sacrificial. Suspended graphene and carbon contaminants represent the most salient challenge. This work has achieved ultraclean graphene, attested by electron energy loss (EEL) spectra unprecedentedly exhibiting fine-structure features expected from bonding and band structure. In the cleaning process in a transmission electron microscope, radicals generated by radiolysis of intentionally adsorbed water remove organic contaminants, which would otherwise be feedstock of the notorious electron irradiation induced carbon deposition. This method can be readily adapted to other experimental settings and other materials to enable previously inhibited undertakings that rely on the intrinsic properties or ultimate thinness of 2D materials. Importantly, the method is surprisingly simple and robust, easily implementable with common lab equipment.

Surface Cleaning of Oil Contaminants Using Bulk Nanobubbles.

The removal of oil from solid surfaces, such as textiles and plates, remains a challenge due to the strong binding affinity of the oil. Conventional methods for surface cleaning often require surfactants and mechanical abrasion to enhance the cleaning process. However, in excess, these can pose adverse effects on the environment and to the material. This study investigated how bulk nanobubble water can clean oil microdroplets deposited on surfaces like glass coverslips and dishes. Microscopy imaging and further image analysis clearly revealed that these microdroplets detached from both hydrophobic and hydrophilic surfaces when washed with bulk nanobubble water within a fluidic microchannel. Oil contaminant cleaning was also conducted in water as mobile phase to mimic the circumstances that occur in a dishwasher and washing machine. Cleaning on a larger scale also proved very successful in the removal of oil from a porcelain bowl. These results indicate that nanobubble water can easily remove oil contaminants from glass and porcelain surfaces without the assistance of surfactants. This is in stark contrast to negligible results obtained with a control solution without nanobubbles. This study indicates that nanobubble technology is an innovative, low-cost, eco-friendly approach for oil removal, demonstrating its potential for broad practical applications.

Beyond the shot: Exploring secondary transfer of gunshot residue on common surfaces and the impact of hand cleaning methods

Understanding the presence, transfer dynamics and depletion of gunshot residues (GSR) on various surfaces is crucial for preserving evidence, reconstructing shooting incidents, and linking suspects to crime scenes. This study aims to explore the transfer and loss of GSR on commonly encountered surfaces such as ceramic, glass, metal, paper, and plastic, as well as the influence of different common hand cleaning methods on secondary transfer. Using scanning electron microscopy (SEM) combined with energy dispersive X-ray analysis (EDX) and automated detection software, we quantified highly indicative three-component characteristic particles (lead, barium, and antimony) on cups made from ceramic, glass, metal, paper, and plastic. Furthermore, we evaluated the amount of secondary transferred particles on these surfaces following various post-discharge hand cleaning methods: washing with water and soap, washing with only water, wiping with wet wipes, or using paper towels.The results demonstrate that counts of secondarily transferred GSR particles vary significantly among surfaces. Specifically, the transferred GSR count was highest on paper, followed by plastic, ceramic, metal, and glass respectively. Post-discharge hand cleaning methods, including washing with water and soap, washing with only water, cleaning with wet wipes, or with paper towel, resulted in substantial loss of GSR count on transferred surfaces. Among these methods, washing with water and soap showed the highest depletion. The empirical evidence provided by our results underscores the importance of considering surface properties, post-shooting activities, and the methods of sample collection and analysis when interpreting transferred GSR analysis. Despite challenges, these insights enhance our ability to link suspects to shooting crimes through careful consideration of the entire context.

Alleviation of RO membrane fouling in wastewater reclamation plants using an enhanced acid-base chemical cleaning method

Membrane fouling has always been a critical constraint in the operation of the reverse osmosis (RO) process, and chemical cleaning is essential for mitigating membrane fouling and ensuring smooth operation of the membrane system. This paper presents an optimized chemical cleaning method for the efficient cleaning of RO membranes in full-scale applications. Compared to the regular cleaning method (cleaning with 0.1 % NaOH + 1 % ethylenediaminetetraacetic acid + 0.025 % sodium dodecyl benzene sulfonate followed by 0.2 % HCl), the optimized cleaning method improves the cleaning efficiency by adding sodium chloride to the alkaline cleaning solution and citric acid to the acid cleaning solution. Notably, the membrane flux recovery rate with the optimized cleaning method is 45.74 %, and it improves the cleaning efficiency by 1.65 times compared to the regular cleaning method. Additionally, the optimized cleaning method removes 30.46 % of total foulants (organic and inorganic), which is 2.11 times higher than the regular cleaning method. The removal of inorganic ions such as Fe, Ca, and Mg is significantly improved with the optimized cleaning method. For organic matter removal, the optimized cleaning method effectively removes more polysaccharides, proteins, and microbial metabolites by disrupting the complex structures of organic matter. Furthermore, it also changes the microbial community structure on the RO membrane surface by eliminating microorganisms that cannot withstand strong acids, bases, and high salt environments. However, Mycobacterium can adapt to these harsh conditions, showing a relative abundance of up to 84.13 % after cleaning. Overall, our results provide a new chemical cleaning method for RO membranes in full-scale applications. This method effectively removes membrane foulants and enhances the understanding of the removal characteristics of foulants on RO membrane surfaces by chemical cleaning.

The Distribution of Pc5 Ultralow-frequency Waves at Geostationary Orbit

Using GOES magnetometer data spanning over 30 yr, we study the distribution of Pc5 ultralow-frequency waves at geosynchronous orbit. The CLEAN algorithm was applied to detect narrowband Pc5 waves. This method was first used in astronomical radio interferometry, but has since been applied to many other areas. The algorithm allows for identification of multiple individual peaks within the same power spectral density. We found close to 30,000 events in each magnetic field component in field-aligned coordinates. With some exceptions, results were in agreement with previous studies. Wave occurrence along magnetic local time (MLT) was higher in the 18–23 MLT sector. However, the largest accumulated wave amplitudes were observed on the dayside, peaking close to local noon. As expected, wave amplitudes were larger during more active solar wind conditions. For the radial and parallel components, amplitudes were maximum at the interplanetary magnetic field clock angle of −30° to −45°. The resultant database of Pc5 ultralow-frequency wave events can be used to constrain radiation belt models, while the CLEAN method provides a unique technique to automatically detect narrowband plasma waves in the magnetosphere and beyond.

The combined effect of Weisella cibaria and Fusarium oxysporum nanoparticles on cervical cancer cells

من المتوقع أن يتجاوز عبء السرطان العالمي المتوقع 20 مليون حالة سرطان جديدة بحلول عام 2025. على الرغم من التقدم الأخير في علاج الأورام ، لا يزال علاج السرطان الناجح يمثل تحديًا. يوفر مجال تكنولوجيا النانو الناشئ فرصًا رائعة لتشخيص السرطان ، والتصوير ، وعلاج السرطان. يعتبر التخليق الحيوي لجسيمات الفضة النانوية عن طريق الفطريات طريقة نظيفة وغير سامة بيئيًا مقارنة بالطرق الفيزيائية والكيميائية الأخرىالغرض من هذه الدراسة هو تحديد التأثير التآزري للجسيمات النانوية المركبة من Fusarium oxysporum مع Weisella cibaria ضد خلايا سرطان عنق الرحمأجريت هذه الدراسة من عام 2022 إلى مارس 2023 في معمل ميكروبيولوجيا الغذاء في قسم الأحياء / كلية العلوم / الجامعة المستنصرية. تم عزل بكتيريا حمض اللاكتيك (LAB) من مصادر الغذاء (الشلغم ، اللهانه ، الشوندر والقرنابيط) ، بعد خطوات متسلسلة من كلوريد الصوديوم المعالج ، ثم تم تربيتها في مرق MRS (Man-Rogosa-Sharpe) ، وتم فحصها تحت المجهر. تم الكشف عن النشاط المضاد للبكتيريا في المواد الطافية الخالية من الخلايا (CFS) التي تنتجها هذه العزلات لاختيار الأفضل وتشخيصها عن طريق تسلسل تفاعل البوليميراز المتسلسل والحمض النووي. تم الحصول على الجسيمات النانوية (AgNo3) التي تم إنتاجها من Fusarium oxysporum بالتخليق الحيوي من مختبر الدراسات العليا للفطريات ، وتم إخضاع هذه الفطريات لاختبار السمية. تمت دراسة تأثير التآزر للجسيمات النانوية المختارة من LAB و Fusarium oxysporum ضد خلايا سرطان عنق الرحم. أظهرت هذه الدراسة أن جميع مصادر الغذاء كانت غنية بـ LAB وأن أفضل نشاط مضاد للجراثيم كان مصدر اللفت ووفقًا للتشخيص الجزيئي كان Weisella cibaria والذي سجل في NCBI كـ (MG7865551). أظهر التأثير التآزري لـ Weisella cibaria والجسيمات النانوية انخفاض معدل بقاء خط السرطان بعد 72 ساعة من التعرض لهذا التأثير.

Does the Correlation between 2MRS Galaxies and the CMB Indicate an Unmodeled CMB Foreground?

We revisit the claimed detection of a new cosmic microwave background (CMB) foreground based on the correlation between low-redshift Two Micron All Sky Survey Redshift Survey (2MRS) galaxies and CMB temperature maps from the Planck and Wilkinson Microwave Anisotropy Probe missions. We reproduce the reported measurements but argue that the original analysis significantly underestimated the uncertainties. We cross-correlate the 2MRS galaxy positions with simulated CMB maps and show that the correlation measured with the real data for late-type spiral galaxies at angular scales θ ≥ 0.°1 and redshift cz < 4500 km s−1 is consistent with zero at the 1.7σ level or less, depending on the exact CMB map and simulation construction. This was the sample that formed the basis for the original detection claim. For smaller angular separations the results are not robust to galaxy type or CMB cleaning method, and we are unable to draw firm conclusions. The original analysis did not propose a specific, falsifiable physical correlation mechanism, and it is impossible to rule out any contribution from an underlying physical effect. However, given our calculations, the lack of signal from expanding the redshift range, and the lack of corroboration from other galaxy surveys, we do not find the evidence for a new CMB foreground signal compelling.

Do Precipitation and Temperature Influence Perceptions of Urban Cleanliness?

Abstract This study explores the correlation between weather and the perception of urban cleanliness across the 47 largest cities in Spain. Utilizing survey data conducted by the national Consumers and Users Organization (OCU) in 2015, 2019, and 2023 to assess cleanliness perceptions, we analyze potential associations with precipitation and temperature recorded by weather stations of the Spanish Meteorological Agency. Additionally, we consider computed values of the De Martonne aridity index. The OCU data reveal regional disparities in perceived cleanliness quality. Higher cleanliness scores are obtained in cities located in the northern and north-central regions of Spain, characterized by humid and superhumid climates according to the De Martonne index. Conversely, lower cleanliness ratings are given to cities in the southern and eastern regions of Spain, where a Mediterranean climate and lower aridity index values prevail. In conducting a statistical analysis on the perception of cleanliness and variables related to precipitation and temperature, the results of the chi-square and linear correlation tests found no strong statistical correlation, although a tendency is observed. Cities with higher annual precipitation and lower values of average annual temperature tend to receive better cleanliness ratings, while drier and warmer cities exhibit the worst values of perceived urban cleanliness. Furthermore, our findings indicate that the Gompertz model effectively captures a strong statistical correlation in the relationship between cleanliness perception and the De Martonne index: As aridity increases, cleanliness perception decreases. These results are relevant for the development of future cleaning methods and systems, particularly in light of the climate change scenarios that are anticipated in the Mediterranean region due to warmer and drier conditions and, consequently, an increase in aridity.

Clinical study of cervical caries treatment the effectiveness by assessing composite restorations condition

Background. Cervical caries is a fairly common teeth pathology and its treatment is carried out in complicated clinical conditions. Therefore, increasing the term of functioning of composite restorations is an urgent task. Aim. Identification of the effectiveness of a differential approach to dissection of hard dental tissues depending on the depth of enamel microcracks and implementation of professional hygiene in the treatment of cervical caries in the short- and long-term periods. Materials &amp; Methods. The study involved 50 people (average age [23.28±5.52] years) in whom cervical caries was treated in 72 teeth. All patients were divided into three equal groups based on the number of restorations according to the selected dissection technique and the chara­cteristics of professional hygiene. The dissection technique depended on the depth of the enamel microcracks in Main Group I (MG I), the dissection was carried out within the limits of clinically intact hard dental tissues in Control Group (CG) and Main Group II (MG II). The dental biofilm was removed from the vestibular surface of the teeth by the method of air-abrasive cleaning using the erythritol-based powder in MG I and MG II, the vestibular surface of the tooth was cleaned of dental deposits with a polishing paste without fluoride in CG. The quality of restorations was assessed based on the United States Public Health Service (USPHS) criteria on the day of restoration, 6 and 12 months later. The effectiveness of the prescribed treatment was identified by the dynamic indicators of the dental pulp electroexcitability and the electrical conductivity of the enamel. Results. There were no partial or completely destroyed restorations in all terms of the observation period. Composite restorations were preserved according to the criteria of "anatomical shape" and "color matching". One year later restoration defects were absent in 61 teeth (84.72%): in MG I – in 22 (91.67%), in CG – in 19 (79.17%), in MG II – in 20 (83.33%). Recurrent caries and symptoms of hypersensitivity were not identified in MG I. A slightly greater effectiveness of the treatment was noted in MG II group in comparison with CG (by 4.16%) that confirms the importance of removing the dental biofilm before restoration by the method of air-abrasive clea­ning using erythritol. Conclusions. The analysis of the state of restorations in the long-term period showed that the dissection technique and the features of professional hygiene affected their quality before restoration. The number of high-quality composite restorations was by 10.42% more on average in MG I than in the other groups. The obtained results make it possible to recommend the proposed method for using in practical dentistry. Keywords: electroodontology, electroodontometry, microcracks.

Optimalisasi Produksi Bersih dengan Pendekatan Neraca Air di Pabrik Tahu ABC

Tofu is a food product derived from soybeans. The production process generates waste that can pollute the environment. This study aims to examine clean production methods through direct observation and interviews. The growth of food industry centers, particularly in Wagir, Malang, has intensified competition, often neglecting environmental impacts. Conducted at ABC tofu factory in December 2022, this research investigates the tofu production stages: soaking, washing, grinding, boiling, filtering, coagulating, pressing, molding, and cutting. Notably, ABC factory’s washing process involves flowing water over soybeans soaked for 3 minutes. Water is essential for all stages except molding and is sourced from a well. The factory’s water storage system fills the tank unless manually stopped. At ABC tofu industry, 4350 liters of water are used for 75 kg of soybeans, producing 3813.3 liters of wastewater. Soaking lasts 4-5 hours in a 42 cm diameter and 50 cm height bucket, causing soybeans to swell and soften. Wastewater volume is measured by filtering water from soaked soybeans in a 7-liter bucket; not all soak water is captured during filtration

A novel synthesis route with large-scale sublattice asymmetry in boron doped graphene on Ni(111)

One of the promising ways to functionalize graphene is incorporation of heteroatoms in carbon sp2 lattice, as it is proven to be an efficient and versatile method for controllably tuning chemistry of graphene. We present unique, contamination-free method for selectively doping graphene with B dopants, which are incorporated in layer from a reservoir created in the bulk of Ni(111) single crystal, during standard CVD growth process, leading to clean, versatile and efficient method for creating B-doped graphene. We combine experimental (STM, XPS) and theoretical (DFT, simulated STM) studies to understand structural and chemical properties of substitutional B dopants. Along with previously reported substitutional B in fcc sites, we have observed, for the first time, two more defects, namely substitutional B in top sites and interstitial B in octahedral subsurface sites. Extensive STM investigations confirm presence of low and high concentration regions of B dopants in as-prepared B-doped graphene, indicating non-uniform boron incorporation. Among two substitutional sites, no preference is observed in low-concentration B-doped regions, whereas in high B concentration regions, one of the sublattices is preferred for incorporation, along with alignment of defects. This generates an asymmetric sublattice doping in as-grown B-doped graphene, which is theoretically predicted to result in notable band gap.

Ice-Enabled Transfer of Graphene on Copper Substrates Enhanced by Electric Field and Cu2O.

Graphene films grown by the chemical vapor deposition (CVD) method suffer from contamination and damage during transfer. Herein, an innovative ice-enabled transfer method under an applied electric field and in the presence of Cu2O (or Cu2O-Electric-field Ice Transfer, abbreviated as CEIT) is developed. Ice serves as a pollution-free transfer medium while water molecules under the electric field fully wet the graphene surface for a bolstered adhesion force between the ice and graphene. Cu2O is used to reduce the adhesion force between graphene and copper. The combined methodology in CEIT ensures complete separation and clean transfer of graphene, resulting in successfully transferred graphene to various substrates, including polydimethylsiloxane (PDMS), Teflon, and C4F8 without pollution. The graphene obtained via CEIT is utilized to fabricate field-effect transistors with electrical performances comparable to that of intrinsic graphene characterized by small Dirac points and high carrier mobility. The carrier mobility of the transferred graphene reaches 9090 cm2V-1s-1, demonstrating a superior carrier mobility over that from other dry transfer methods. In a nutshell, the proposed clean and efficient transfer method holds great potential for future applications of graphene.

Rapid and nondestructive watermelon (Citrullus lanatus) seed viability detection based on visible near-infrared hyperspectral imaging technology and machine learning algorithms.

The improper storage of seeds can potentially compromise agricultural productivity, leading to reduced crop yields. Therefore, assessing seed viability before sowing is of paramount importance. Although numerous techniques exist for evaluating seed conditions, this research leveraged hyperspectral imaging (HSI) technology as an innovative, rapid, clean, and precise nondestructive testing method. The study aimed to determine the most effective classification model for watermelon seeds. Initially, purchased watermelon seeds were segregated into two groups: One underwent sterilization in a dehydrator machine at 40°C for 36h, whereas the other batch was stored under favorable conditions. Watermelon seeds' spectral images were captured using an HSI with a charge-coupled device camera ranging from 400 to 1000nm, and the segmented regions of all samples were measured. Preprocessing techniques and wavelength selection methods were applied to manage spectral data workload, followed by the implementation of a support vector machine (SVM) model. The initial hybrid-SVM model achieved a predictive accuracy rate of 100%, with a test set accuracy of 92.33%. Subsequently, an artificial bee colony (ABC) optimization was introduced to enhance model precision. The results indicated that, with kernel parameters (c, g) set at 13.17 and 0.01, respectively, and a runtime of 4.19328s, the training and evaluation of the dataset achieved an accuracy rate of 100%. Hence, it was practical to utilize HSI technology combined with the PCA-ABC-SVM model to detect different watermelon seeds. As a result, these findings introduce a novel technique for accurately forecasting seed viability, intended for use in agricultural industrial multispectral imaging. PRACTICAL APPLICATION: The traditional methods for determining the condition of seeds primarily emphasize aesthetics, rely on subjective assessment, are time-consuming, and require a lot of labor. On the other hand, HSI technology as green technology was employed to alleviate the aforementioned problems. This work significantly contributes to the field of industrial multispectral imaging by enhancing the capacity to discern various types of seeds and agricultural crop products.

A clean, simple, and efficient method for preparing vibration-reducing low-carbon bamboo building materials with high strength

Large-format bamboo panels prepared by bamboo flattening are adhesive-free and retain the natural structure of bamboo, making them ideal materials for interior architecture. However, due to poor dimensional stability and vibration-reducing properties, flattened bamboo easily deforms and vibrates when applied to building walls and floors due to ambient humidity changes or external excitation, impacting both comfort and structural safety. In this work, a clean, efficient, and simple densification process for flattened bamboo is developed to prepare low-carbon bamboo building materials with enhanced vibration reduction. The results indicated that the densification process reduced the vibration intensity of the flattened bamboo under excitation, changed its vibrational modes, avoided low-frequency resonance, and improved its vibration reduction and suppression properties. The dynamic stiffness of the densified bamboo increased to 3.23–3.63 times, while the root mean square (RMS) and transfer function value decreased by 20.84 % and 62.5 %, respectively. The MOE (16.2 GPa) and MOR (276 MPa) increased to 2.73 times and 2.22 times, respectively. The densified bamboo met the dimensional stability requirements of the GB/T 18102–2020 building material standards. Compared with damping, the increased stiffness played the primary role in improving the vibration-reducing properties of densified bamboo. The hydrothermal mechanical treatment changed the structure and composition. From a macroscopic perspective, the gradient structure of the vascular bundles and parenchyma cells was gradually plasticized and homogenized, compacting large capillary pores and channels such as those in parenchyma cells, vessels, and sieve tubes. On a microscopic level, defects such as pits, intercellular spaces, and micropores were filled, and microfibrils between the middle lamellae were tightly stacked, forming a mechanically-interlocked structure. At the molecular scale, there was an increase in the crystallinity and orientation of cellulose molecular chains, accompanied by an increase in hydrogen bond density. The densified bamboo developed in this study shows good application potential for vibration-reduction structures such as buildings and rail transit.