Reactive Chemical Agents Research Articles

Effect of Parameters of Chemical Mechanical Polishing (CMP) for Improving Surface Roughness for Semiconductor Material Kind Silicon

Chemical Mechanical Polishing (CMP) is the polishing process where the top surface of a wafer is smoothed using a slurry containing abrasive grit as well as reactive chemical agents. The polishing process is partly mechanical and partly chemical. The mechanical element's main advantage is that it is achieved without great effort to manufacture and supplies good-quality general mechanical and electrical properties. In the current study, the invention reckons on the chemical and mechanical properties of the composition particles (abrasive slurry) utilized to polish silicon surfaces traveling through chemical-mechanical polishing (CMP). MINITAB 17 software was used to estimate the influence of the (CMP) input variables on the surface roughness (Ra) of the silicon workpiece. Other process input variables were disk speed (rpm), the dose of abrasive, the grain size of the abrasive, and the type of slurry. In order to get the best response surface roughness, the current findings show that the constant coefficient of determination (R2) is 95.80%. Furthermore, the effects of disk speed (X1), abrasive dose (X2), abrasive grain size (X3), and type of slurry (X4) on achieving a superior surface roughness finish were 21.05%, 4.34%, 50.00%, and 24.59%, respectively.

Applications of Adductomics in Chemically Induced Adverse Outcomes and Major Emphasis on DNA Adductomics: A Pathbreaking Tool in Biomedical Research.

Adductomics novel and emerging discipline in the toxicological research emphasizes on adducts formed by reactive chemical agents with biological molecules in living organisms. Development in analytical methods propelled the application and utility of adductomics in interdisciplinary sciences. This review endeavors to add a new dimension where comprehensive insights into diverse applications of adductomics in addressing some of society’s pressing challenges are provided. Also focuses on diverse applications of adductomics include: forecasting risk of chronic diseases triggered by reactive agents and predicting carcinogenesis induced by tobacco smoking; assessing chemical agents’ toxicity and supplementing genotoxicity studies; designing personalized medication and precision treatment in cancer chemotherapy; appraising environmental quality or extent of pollution using biological systems; crafting tools and techniques for diagnosis of diseases and detecting food contaminants; furnishing exposure profile of the individual to electrophiles; and assisting regulatory agencies in risk assessment of reactive chemical agents. Characterizing adducts that are present in extremely low concentrations is an exigent task and more over absence of dedicated database to identify adducts is further exacerbating the problem of adduct diagnosis. In addition, there is scope of improvement in sample preparation methods and data processing software and algorithms for accurate assessment of adducts.

A Painful Trp Can Be a Bonding Experience

The receptive field of the TRPA1 nociceptor is remarkably expansive when compared to other chemodetectors such as odorant receptors. The identification of a unique mechanism utilized by TRPA1 helps clarify how this protein can efficiently alert the cell to an array of reactive chemical agents, regardless of their structure.

Multimodal Strategies for Resuscitating Injured Cells

Our cells and tissues are challenged constantly by exposure to extreme conditions that cause acute and chronic stress. Wounding at the cellular level is a common event, and results from cell exposure to supra-physiologic forces, or is the consequence of action by reactive chemical agents. An individual cellular wound results from either the alteration of protein or DNA structure, or the disruption of molecular assemblies, the most important of which is the cell's membranes. Tissue healing at the macroscopic level is a complex and coordinated process involving many different cell types while, in contrast, the wounds of individual cells heal primarily via biomolecular interactions. Like tissue wound healing, cellular wound healing involves the upregulation or acceleration of processes that are constitutively expressed in routine physiologic repair of cellular structures In addition, recent advances have been made in the identification of pharmaceutical strategies to aid the cellular repair response. Many of these strategies offer promise for augmenting the already present cellular repair mechanisms.

Formation of water-resistant hyaluronic acid nanofibers by blowing-assisted electro-spinning and non-toxic post treatments

A unique blowing-assisted electro-spinning process has been demonstrated recently to fabricate hyaluronic acid (HA) nanofibers. In this article, effects of various experimental parameters, such as air-blowing rate, HA concentration, feeding rate of HA solution, applied electric field, and type of collector on the performance of blowing-assisted electro-spinning of HA solution were investigated. With the assistance of air-blowing, the solution-feeding rate could be increased to 40 μl/min/spinneret and the applied electric field could be decreased to 2.5 kV/cm. The optimum conditions for consistent fabrication of HA (with a molecular weight of ∼3.5 million) nanofibers involved the use of an air-blowing rate of around 70 ft 3/h and a concentration range between 2.5 and 2.7% (w/v) in aqueous solution. Two benign methods to fabricate water-resistant HA nanofibrous membranes without the use of reactive chemical agents were demonstrated: (a) the exposure of HA membranes in hydrochloric acid (HCl) vapor, followed by a freezing treatment at −20 °C for 20–40 days; and (b) the immersion of HA membranes in an acidic mixture of ethanol/HCl/H 2O at 4 °C for 1–2 days. Although both methods could produce hydrophilic, substantially water-resistant HA nanofibrous membranes (the treated membranes could keep their shape intact in neutral water at 25 °C for about 1 week), the immersion method (6) was shown to be more versatile and effective. IR spectroscopy was used to investigate this ‘cross-linking’ mechanism in the solid HA membrane. Viscosity studies of acidic HA solutions under varying freezing conditions were also carried out. It was found that when the freezing time exceeded 8 h, the HA solution became gel-like and exhibited a large increase in the hydrogen-bond concentration. Thus, the resistance to water solubility could be due to the high density of hydrogen bonds in the solid HA membranes that were treated by the ‘freezing’ approach.

Cytoprotection by stabilization of cell membranes.

The major constraint that limits tissue storage is the accumulation of cellular damage or wounding by the storage conditions and consequential loss of tissue viability. The noun wound is used in the medical field to refer to a disruption of tissue integrity that follows trauma. Subsequent wound healing results from exposure to supraphysiological forces or is the consequence of action by reactive chemical agents.1,2 Cell wounding results from exposure to supraphysiological forces or is the consequence of action by reactive chemical agents. Cell wounds result from alteration of cellular moleculary structure or disruption of molecular assemblies such as membranes. Unlike tissue healing, the healing of cellular wounds occurs by neighboring biomolecular interactions. Like tissue wound healing, cellular wound healing involves accelerated processes that are constitutively expressed in routine physiologic repair of cellular structures.3 This discussion relates to pharmaceutical strategies that are useful for augmenting the cellular healing response.

Emergency response and hazardous chemical management: principles and practices

Management of hazardous chemicals and materials--particularly during emergency release situations--is a critical part of routine training required for workers and professionals in the chemical, petroleum and manufacturing industries. Proper storage of highly reactive chemical agents, correct choice of protective clothing, safety issues in confined spaces are vital to operating facilities. This book provides a concise reference for management and workers on the important issues regarding the use and management of hazardous chemicals as well as the critical issues in the emergency response management to uncontrolled releases of hazardous agents. This book combines practical information on hazardous chemical response and environmental management with scientific and management issues important in the development of sound chemical management planning. Important current topics such as hazardous chemical management in confined spaces are also covered in detail.