Technology
Bibliometric Analysis of Single-Atom Catalysis: A Scoping Review
Single-Atom Catalysts (SACs) are heterogeneous catalysts that demonstrate exceptional efficiency and selectivity due to the use of individual metal atoms at the atomic scale. The substantial number of patents filed on SACs underscore their commercial and technological importance highlighting their potential across various industries. SACs are increasingly applied in areas such as energy generation environmental applications and chemical synthesis reflecting their growing scientific and technical importance.
The objective of this study was to conduct a comprehensive evaluation of existing literature on SACs and the use of bibliometric analysis to identify scientific output and topic patterns of research on SACs.
A bibliometric analysis was performed on 488 papers related to SACs utilizing the Web of Science database of data collection. Analysis of Co-occurrence of keywords trending research topics Citation analysis Publication areas the five-year record of Publications and funding sources were examined using VOS viewer R software and Microsoft Excel.
The analysis indicates a steady growth in publication on SACs in recent years with China leading in research output followed closely by the USA. The highlighting of the global impact and the collaborative nature of SAC research. The study reveals a diverse range of applications and emphasizes the increasing scientific and technical focus on this subject.
This study highlights the essential role of SACs in advancing catalytic science and maps key trends collaborations and applications within the field. The bibliometric insights provide valuable guidance for the researchers pointing to potential applications in energy storage environmental remediation and sustainable chemical synthesis. Emerging challenges such as stability scalability and the development of new materials call for further investigation to unlock the full potential of SACs. These insights support future innovation and exploration in the expanding field of SAC research.
Fabrication with Characterization of Single-Walled Carbon Nanotube Thin Film Transistor (CNT-TFT) by Spin Coating Method for Flat Panel Display
Thin Film Transistors (TFTs) are increasingly prevalent electrical components in display products ranging from smartphones to diagonal flat panel TVs. The limitations in existing TFT technologies such as high-temperature processing carrier mobility lower ON/OFF ratio device mobility and thermal stability result in the search for new semiconductor materials with superior properties.
The main objective of this present work is to fabricate the efficient Single-Walled Carbon Nanotube Thin Film Transistor (TFT) for flat panel display.
Carbon Nano-Tubes (CNTs) are a promising semiconductor material for TFT devices due to their one-dimensional structure and exceptional characteristics. In this research work the CNT-TFTs have been fabricated using nano-fabrication techniques with a spin process. The fabricated devices have been characterized for structural morphological and electrical characteristics.
The 20 µm channel length and 30 µm channel width fabricated device produces about 1.3 nA which lies in the practical range of operating TFTs reported previously. Compared to reported patents and published works this demonstrates a significant improvement.
Further guidelines and limitations of this fabrication method are also discussed for future efficient device fabrication.
Development of Stabilized and Aqueous Dissolvable Nanosuspension Encompassing BCS Class IV Drug via Optimization of Process and Formulation Variables
Nanosuspension has emerged as an effective lucrative and unequalled approach for efficiently elevating the dissolution and bioavailability of aqueous soluble drugs. Diverse challenges persist within this domain demanding further comprehensive investigation and exploration.
This study aims to design develop optimise formulation and process variables and characterise the stabilised aqueous dissolvable nanosuspension using chlorthalidone as a BCS class-IV drug.
Nanosuspensions of the chlorthalidone drug were prepared using a combination of top-down and bottom-up approaches. Various polymers such as Pluronic L-64 F-68 F-127 and Synperonic F-108 were used as stabilisers in this research. All important processes and formulation variables such as ultrasonication intensity and time the concentration of the drug organic solvent and stabilisers that may critically influence the characteristics of the nanosuspensions were optimised. Formulation screening was performed using the optimisation of process and formulation variables and the optimised nanosuspension formulation was assessed for particle size PDI surface charge morphology in vitro drug release and stability.
To select an optimised nanosuspension formulation the effects of formulation and process variables were investigated. These variables critically influence the development of a stabilised nanosuspension. The outcomes revealed that the nanosuspension formulation containing pluronic F-68 as a stabiliser in 0.6% w/v concentration and the drug in 4 mg/ml concentration were optimized. The particle size and zeta potential of the optimised preparation were 110 nm and -27.5 mV respectively. The in-vitro drug release of chlorthalidone drug from the optimised nanoformulation was increased up to 3-fold approximately (88% in 90 min) compared with pure chlorthalidone drug (27% in 90 min) because of the decrease in particle size. Moreover stability studies indicated that the crafted nanoformulation was stable at cold (4°C) as well as normal room temperature (25°C) for six months.
From the obtained results it was concluded that the combination of top-down and bottom-up approaches employed for the fabrication of oral nanosuspension is a remunerative and lucrative approach to successfully resolve the perplexities associated with the dissolution rate of poorly aqueous soluble BCS class-IV drug moieties such as chlorthalidone. Moreover various patents have been granted over this novel technology which have also summarized in the manuscript for the better understanding of readers.
Recent Advancements, Patents, and Scientific Insights into the Biomedical Soft Robots Using Nanomaterials and Nanotechnology
This study investigates the most recent advancements in the field of biomedical soft robotics with a primary emphasis on the integration of nanomaterials and nanotechnology. It underscores the biocompatibility flexibility and performance of soft robots by emphasizing critical advancements in nanomaterials robotics and biomedical applications. Nanomaterials can improve the biocompatibility and mechanical qualities of soft robots used in tissue engineering and regenerative medicine. Nanotechnology enables the development of flexible and elastic electronics which may be integrated into soft robotics. This study also analyzes recent patents offering a viewpoint on emerging technologies and their potential impact on medical diagnostics therapeutic delivery systems and minimally invasive procedures. The scientific developments and patents with the functioning and operating mechanisms of soft robots as well as the problems of constructing biomedical soft robots with nanomaterials and nanotechnology are examined in this critical study. Moreover it also examines current advancements patents technological challenges and future trends in nanomaterials and nanotechnology used in biomedical soft robotics.
Progress on One-dimensional Vanadium Pentoxide-based Nanomaterials for Advanced Energy Storage
One-dimensional (1D) vanadium-based nanostructures have advantageous properties and are showing emerging critical applications in the fields of catalysis smart devices and electrochemical energy storage. We herein timely gave an overview of the 1D vanadium pentoxide (V2O5)-based nanomaterials for these promising applications especially regarding the merits of different synthetic methods structures and properties combined with recent research frontiers and patents in advanced energy storage including batteries supercapacitors and the like. The high capacity high rate and flexibility of 1D V2O5-based nanomaterials endow them with great potential in high-energy-density high-power energy devices and specific/harsh environments. Finally some major directions and suggestions are provided for further development of this emerging and promising field.
AI-based Nanotechnology: Breakthroughs, Applications, Challenges, and the Road Ahead
This article examines the emerging field of AI-based nanotechnology highlighting its potential to revolutionize various industries and drive patent innovations that bridge cutting-edge science and practical applications. The article expounds on the synergistic relationship between artificial intelligence's data-processing capabilities and nanotechnology's manipulation at the nanoscale. Within the medical field for instance this synergy has the potential to facilitate precise cancer treatment and early disease detection with promising patent-worthy breakthroughs in diagnostic tools and therapeutic delivery systems. The field of manufacturing stands to benefit from the optimization of nanomaterial production where AI-driven processes are generating novel methodologies that are eligible for patent protection. The article continues by exploring the potential of AI-based 3D printing and MEMS applications highlighting the capabilities that these technologies enhance. It is noteworthy that a significant number of these technologies are currently undergoing the patenting process which is expected to expedite their commercialization. Notwithstanding the challenges including data misuse and integration issues that are both ethically and technically complex the potential benefits such as fostering a robust patent landscape justify the risks. The article advocates for collaboration among scientists policymakers and industry to promote responsible research and development ensuring that the transformative potential of this combination is harnessed through strategic patent management and innovation thereby offering solutions to global challenges.
Enhancing Tribological Characteristics of Titanium Grade-5 Alloy through HVOF Thermal-Sprayed WC-Co Nano Coatings by TOPSIS and Golden Jack Optimization Algorithm
Thermal spray coatings have emerged as a pivotal technology in materials engineering primarily for augmenting the characteristics related to wear and tribology of metallic substrates.
This study aims to develop into applying High-Velocity Oxygen Fuel (HVOF) thermal-sprayed WC-Co nanocoatings on Titanium Grade-5 alloy (Ti64). The coating process utilizing nano-sized WC-Co powder undergoes systematic optimization of HVOF parameters encompassing the flow rate of carrier gas powder feed rate and nozzle distance. Experimental assessments via Pin-on-Disc (PoD) tests encompass Loss of Wear (WL) Friction Coefficient (CoF) and Frictional Force (FF). Later an exhaustive optimization of responses is conducted using the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) method and the golden jack optimization algorithm (GJOA).
Outcomes show a substantial increase in WL CoF and FF with a rise in the carrier gas and powder feed rate. However with increasing spraying distance of powder the WL CoF and FF tend to lower due to higher bonding which leads to increased wear resistance. The ideal parametric settings achieved from TOPSIS and GJOA are 245 mm of spray distance 30 gpm rate of powder feed and 11 lpm of carrier gas flow rate. The powder feed rate contributes 88.99% to the control action as seen from ANOVA.
The confirmation experiment presents that the WL CoF and FF output responses are 42.33 27.97 and 9.38% less than the mean of experimental data. These results highlight the HVOF process in spraying WC-Co nanocoatings to fortify the durability and performance of Ti64 alloy that can be patented for diverse engineering applications.
Improved Thermal Performance and Distillate of Conventional Solar Still via Copper Plate, Phase Change Material and CuO Nanoparticles
The world is currently facing a growing concern regarding freshwater scarcity which has arisen as a result of a complex interplay of various factors. Renewable energy-powered water desalination is a feasible solution to address freshwater scarcity.
This patent study presents a comprehensive investigation of the performance of a conventional solar still (CSS) and its modified versions such as a still with copper plates a still with PCM and a still with PCM and 3 wt% CuO nanoparticles blend. The experiments were carried out concurrently under identical circumstances for the CSS and the proposed stills. Prior to usage the CuO nanoparticles and their blend with PCM were characterized through various analyses.
The investigation showcased the copper plate attached solar still with 3 wt% CuO nanoparticles blended with PCM significantly improved the distillate production achieving approximately 6.85 kg/m2/day. This represents an increment of approximately 23.42% compared to the still with copper plate and PCM and 69.14% related to the CSS.
Moreover the solar still with 3 wt% CuO nanoparticles blended with PCM demonstrated a thermal efficiency of 74.23% and an exergy efficiency of 9.75%. The production cost of distillate for all four stills remained at $0.03 per kg. These findings highlight the effectiveness of the proposed copper plate attached solar still with 3 wt% CuO nanoparticles blended with PCM as a viable method for producing potable water.
A Detailed Study on using Novel LM 25 Aluminium Alloy Hybrid Metal Matrix Nanocomposite for Nuclear Applications
This article describes the use of graphite (Gr) and boron carbide (B4C) as multiple nanoparticle reinforcements in LM25 aluminum alloy. Because boron carbide naturally absorbs neutron radiation aluminium alloy reinforced with boron carbide metal matrix composite has gained interest in nuclear shielding applications. The primary goal of the endeavor is to create composite materials with high wear resistance high microhardness and high ultimate tensile strength for use in nuclear applications. Patents on Gr and B4C can cover a wide range of subjects including the synthesis and production methods of structural armor materials abrasives and nuclear shielding.
Science and Technology have brought a vast change to human life. The human burden has been minimized by the use of innovation in developing new and innovative technologies. To improve the quality of human life fresh lightweight and creative materials are being used which play a vital role in science and technology and reduce the human workload. Composite materials made of metal are being used because they are lightweight. Neutron absorption high ultimate strength high wear resistance high microhardness high thermal and electrical conductivity high vacuum environmental resistance and low coefficient of thermal expansion under static and dynamic conditions are all demands for the hybrid metal matrix composites utilized in nuclear applications.
Stir casting is used to create the novel LM 25 aluminum alloy/graphite and boron carbide hybrid nanocomposites. The mechanical properties such as ultimate tensile strength yield strength percentage of elongation microhardness and wear behavior are calculated. Three analyses are performed: microstructure worn surface analysis and fracture analysis of the tensile specimen.
(1) Stir casting process. (2) Tensile hardness wear test. (3) Materials characterization – FESEM optical microscopy EDS.
The mechanical properties values are 308.76 MPa 293.51 MPa 7.8 169.2 VHN and 0.01854 mm3/m intended for ultimate tensile strength yield strength percentage of elongation microhardness and wear behavior respectively. This implies that the synthesized composite may be used in nuclear applications successfully.
The subsequent explanation was drawn from this investigative work: The LM 25/B4C/Gr hybrid nanocomposite was successfully manufactured by employing the stir casting technique. For nuclear shielding applications these composites were prepared with three different weight percentages of nanoparticle reinforcements in 246% Boron carbide and constant 4 wt.% graphite. The microhardness values of the three-hybrid nanocomposite fabricated castings were determined to be 143.4VHN 156.7VHN and 169.2VHN respectively. The hybrid nano composite's microstructure revealed that the underlying LM 25 aluminum alloy matrix's fine-grained evenly dispersed nanoparticles of graphite and boron carbide were present. The microtensile test was carried out and it was found that the ultimate tensile strength yield strength and percentage of elongation values are 281.35MPa 296.52MPa 308.76MPa 269.43 274.69 293.51 and 3.4 5.7 7.8 respectively. Deformation caused the hybrid LM 25/B4C/Gr nanocomposite to fracture in ductile mode. Dimples and cavities are seen in the fracture because of the nanoparticle reinforcements and the matrix's tight connection. The wear loss of nanocomposite based on the input parameter applied load sliding velocity and sliding distance values are 0.02456 0.02189 0.01854 0.02892 0.02586 0.02315 and 0.02682 0.02254 0.02015 mm3/m respectively. The LM 25 alloy's elemental analysis displays the aluminum alloy phase as the largest peak and the remaining elements as smaller peaks; also the spectral analysis reveals the presence of boron (B) graphite (C) silicon and ferrous in the aluminum alloy LM 25. Through worn surface FESEM investigation it was shown that under sliding and high load situations debris delamination and groove develop. Further rupture fine and continuous grooves were seen when low stress and sliding circumstances were applied to the LM 25/B4C/Gr and stir cast specimen. This result implies the presence of mild adhesive and delamination wear processes.
Two-phase Hybrid Thermal Interface Alkali-treated E-Glass Fiber/MWCNT/Graphene/Copper Oxide Nanocomposites for Electronic Gadgets
Two-phase hybrid mode thermal interface materials were created and characterized for mechanical properties thermal conductivity and wear behaviour. Therefore the ultimate goal of this current research was to use alkali-treated glass fibre and other allotropes to produce high-performance two-phase thermal interface materials that can be patented for engineering applications.
Three different polymer composites were prepared to contain 20 vol.% alkalies (NaOH) treated e-glass fibre (E) and epoxy as a matrix with varying proportions of multi-walled carbon nanotube (MWCNT) graphene (G) copper oxide (C). The one-phase material contained epoxy+20%e-glass+1%MWCNT (EMGC1) the two-phase hybrid composite contained epoxy+20%e-glass+1%MWCNT+1%graphene+1%CuO (EMGC2) and two-phase material contained epoxy+20%e-glass+1%graphene+1%CuO (EMGC3). Vacuum bagging method was used for fabricating the composites.
The higher thermal conductivity observed was 0.3466 W/mK for EMGC2 the alkali-treated glass fibre/hybrid mode nanofillers epoxy matrix composite was mechanically tougher than the other two composites (EMGC1 & EMGC3). Scanning electron microscopy analysis revealed the fine filler dispersion and homogenous interaction with the glass fibre/epoxy resin composite of the upper and lower zone which also revealed the defective zone fibre elongation fibre/filler breakages and filler leached surfaces.
Finally it was concluded that the hybrid mode two-phased structure EMGC2 epoxy matrix composite replicated the maximum thermal conductivity mechanical properties and wear properties of the other two specimens.
A Patent Analysis on Nano Drug Delivery Systems
A nano drug delivery system is an effective tool for drug delivery and controlled release which is used for a variety of medical applications. In recent decades nano drug delivery systems have been significantly developed with the emergence of new nanomaterials and nanotechnologies.
This article aimed to provide insight into the technological development of nano drug delivery systems through patent analysis.
3708 patent documents were used for patent analysis after retrieval from the Incopat patent database.
The number of patents on nano drug delivery systems has shown a rapid growth trend in the past two decades. At present China and the United States have obvious contributions to the number of patents. According to the patent data the nanomaterials used in nano drug delivery system are mainly inorganic nanomaterials lipid-based nanomaterials and macromolecules. In recent years the highly cited patents (≥14) for nano drug delivery systems mainly involve lipid-based nanomaterials indicating that their technology is mature and widely used. The inorganic nanomaterials in drug delivery have received increasing attention and the number of related patents has increased significantly after 2016. The number of highly cited patents in the United States is 250 which is much higher than in other countries.
Even after decades of development nano drug delivery systems remain a hot topic for researchers. The significant increase in patents since 2016 can be attributed to the large number of new patents from China. However according to the proportion of highly cited patents in total China's patented technologies in nano drug delivery systems are not advanced enough compared to developed countries including the United States Canada Germany and France. In the future research on emerging nanomaterials for nano drug delivery systems such as inorganic nanomaterials may focus on developing new materials and optimising their properties. The lipid-based and polymer-based nanomaterials can be continuously improved for the development of new nanomedicines.
Nano-Rutin: A Promising Solution for Alleviating Various Disorders
Rutin often known as vitamin P is a natural flavonoid compound which offers a broad spectrum of therapeutic potentials. Rutin is metabolised to different compounds by the gut bacteria after consumption therefore very little is absorbed. Higher plants contribute to rutin synthesis in large quantities and it may also be found in many fruits and fruity rinds particularly citrus fruits and berries.
The present paper highlights several studies and patents conducted on rutin along with its nanoformulations regarding its broad spectrum of therapeutic potentials.
Numerous electronic databases including Springer PubMed Science Direct Pubchem Google Patents etc. were searched to extract relevant published literature demonstrating rutin effectiveness in various ailments.
The reviewed literature showed that rutin and related flavonoids possess a variety of physiological properties that protects human beings plants and animals. Antioxidant anti-inflammatory anti-allergic cytoprotective vasoprotective anticarcinogenic neuroprotective cardioprotective antibacterial antiviral antiprotozoal antitumor anti-hypertensive antiplatelet antispasmodic and hypolipidemic activities. Nanotechnology has been implemented for the improvement of the bioavailability of rutin using novel drug-delivery carriers.
The study concludes that the development of rutin nanoformulations for multiple therapeutic approaches contributes towards enhanced aqueous solubility as well as tailored pharmacokinetics compared to conventional delivery of rutin. However more investigations should be conducted to confirm the improved bioavailability of the rutin nanoformulations.
Critical Review on the Effect and Mechanism of Realgar Nanoparticles on Lymphoma: State of the Art on In-vitro Biomedical Studies
Lymphoma is a malignant tumor caused by abnormal proliferation of lymphocytes in the lymphatic system. Conventional treatments for lymphoma often have limitations and new therapeutic strategies need to be explored. Realgar is an ancient Chinese medicine that has been used for centuries to treat a variety of ailments due to its therapeutic potential for various diseases including cancer. However it is a time-consuming waste and has a low absorption rate in the gastrointestinal tract so it has the disadvantages of oral dose potential toxicity and low bioavailability. Recently the development of nanotechnology has promoted the nanization of realgar particles which have better physicochemical properties and higher bioavailability. The antitumor activity of Realgar nanoparticles against lymphoma has been demonstrated in preclinical studies. Realgar nanoparticles exhibit cytotoxic effects by inducing apoptosis and inhibiting the growth and proliferation of lymphoma cells. Moreover these nanoparticles exert immunomodulatory effects by enhancing the activity of immune cells and promoting the cytotoxicity of T lymphocytes against lymphoma cells. Additionally realgar nanoparticles have been shown to inhibit tumor angiogenesis thereby restricting the blood supply and nutrient availability to lymphoma cells as exhibited in this patent comprehensive review. Despite promising preclinical data further research on the role and mechanism of realgar nanoparticles in the treatment of lymphoma remains to be studied. Moreover the translation of these findings into clinical practice requires rigorous evaluation through well-designed clinical trials. Realgar nanoparticles hold great potential as a novel therapeutic approach for lymphoma and their development may contribute to the advancement of precision medicine in the field of oncology.
Graphene Oxide, a Prominent Nanocarrier to Reduce the Toxicity of Alzheimer’s Proteins: A Revolution in Treatment
Graphene oxide a derivative of graphene has recently emerged as a promising nanomaterial in the biomedical field due to its unique properties. Its potential as a nanocarrier in the treatment of Alzheimer's disease represents a significant advancement. This abstract outlines a study focused on utilizing graphene oxide to reduce the toxicity of Alzheimer's proteins marking a revolutionary approach in treatment strategies. The pathological features of Alzheimer’s disease primarily focusing on the accumulation and toxicity of amyloid-beta proteins have been described in this review. These proteins are known to form plaques in the brain leading to neuronal damage and the progression of Alzheimer's disease. The current therapeutic strategies and their limitations are briefly reviewed highlighting the need for innovative approaches. Graphene oxide with its high surface area biocompatibility and ability to cross the blood-brain barrier is introduced as a novel nanocarrier. The methodology involves functionalizing graphene oxide sheets with specific ligands that target amyloid-beta proteins. This functionalization facilitates the binding and removal of these toxic proteins from the brain potentially alleviating the symptoms of Alzheimer's disease. Preliminary findings indicate a significant reduction in amyloid-beta toxicity in neuronal cell cultures treated with graphene oxide nanocarriers. The study also explores the biocompatibility and safety profile of graphene oxide in biological systems ensuring its suitability for clinical applications. It calls for further research and filing patents for its translational potential and benefits of this nanotechnology paying the way for a new era in neurodegenerative therapy.
Investigation of TiO2 Nanoparticles Influence on Tensile Properties and Thermal Stability of Dry and Wet Luffa-Epoxy Nanocomposites
Recently progress has been made toward understanding the efficiency of polymer composites with natural fibres. With the hope of enhancing the characteristics of polymer composites supplemented with natural fibres in a watery environment TiO2 nanoparticles have been used to improve their performance in the field.
These nanoparticles were filled in luffa-epoxy components at 1 3 and 5% volume fractions. A combination of çx-ray diffraction and Fourier transform infrared spectroscopy was utilized to conduct the structural examinations. The nanoparticle spread was captured by field emission scanning electron microscopy.
Results show that dry nanocomposite's tensile strength and modulus have increased by 74% and 13% 137% and 50% compared with epoxy and 40 vol% luffa-epoxy (E/L) composites respectively. In wet nanocomposites maximum reduction in tensile strength and modulus were observed as 27.4% and 16.54% respectively. The diminished water absorption and thickness swelling percentage of nanocomposites were recorded as 98% and 91.8% respectively. The onset temperature of these nanocomposites was scattered in the range of 379-393°C with a maximum char residue of 38%.
The increase in the percentage of residue indicates the effectiveness of epoxy's flame retardant improved thermal stability diminished water absorption (approximately 2%) and 95% retention of wet composites' tensile properties. These results provided data support for improving the application of nanocomposites in the automobile field and to develop possible patents on the new material development.
Copper Electrodes Modified with Gold Nanoparticles Detect Two Hazardous Contaminants (As, Cd) in Raw Milk
Milk contamination has been a longstanding global concern with Heavy Metals (HM) like lead (Pb) mercury (Hg) arsenic (As) and cadmium (Cd) posing significant risks. These contaminants often infiltrate milk through contaminated water sources or during pasteurization. This petent introduces a novel approach to detecting milk contaminants by analyzing the current–voltage (I-V) characteristics of copper (Cu) electrodes modified with gold nanoparticle (AuNPs).
Leveraging the exceptional conductivity of metal nanoparticles electrons freely traverse the surface facilitating electron movement across the copper substrate. Additionally the nanoparticles serve as binding agents aiding in the comparative detection of contaminants. This method enables the preliminary detection of two HM (As Cd) by evaluating their current gains in milk supernatant samples at varying concentrations.
AuNPs deposited on Cu electrodes exhibited a linear I-V trend with a significant increase in current compared to bare electrodes. Spiked milk supernatant drop cast on the electrode system displayed a current gain which was evaluated towards sensing application of HM ions in milk. The synthesized AuNPs underwent initial characterization using a UV-Vis spectrophotometer revealing a prominent plasmonic peak around 520 nm confirming nanoparticle formation. X-Ray Diffraction (XRD) analysis confirmed the Face-Centred Cubic (FCC) crystal structure.
Notably different concentrations (1 and 10 ppm) and types of HM (As Cd Hg and Pb) in milk supernatant yielded varying current gains providing insights specifically targeting As and Cd contamination.