System Volume Compensating for Environmental Noise

Generally, the present disclosure is directed to an audio system for compensating for ambient environmental noise. In particular, in some implementations, the systems and methods of the present disclosure can include or otherwise leverage one or more machine-learned models to predict a comfortable volume level based on an intensity of ambient noise

Analysis of cocaine adulterants and their metabolites in real patient urine samples

Thesis (M.S.)--Boston UniversityCocaine is one of the most common drugs of abuse in the United States today, but street-quality cocaine is decreasing in purity each year. This change in purity requires a shift in the focus of cocaine analysis in forensic laboratories. In recent years, many federal agencies have begun testing and profiling for the adulterants and diluents present in cocaine samples submitted as evidence. By analyzing the compounds present in the street-quality samples, forensic chemists may be able to track the cocaine back to its source, based on the unique identities of certain adulterants. Many of the adulterants currently being added to cocaine are dangerous on their own, even though they may enhance the effects of the cocaine. For this reason many doctors and forensic pathologists are interested in the identities of the adulterants present. Often times, a sample of the cocaine ingested may not be available for testing. Thus, there is a need for the development of methods to test for these adulterants and their metabolites in biological samples. The objective of this research is to develop extraction and instrumental analysis methods for several common cocaine adulterant metabolites, in an effort to create a geographical profile of human urine samples that tested positive for benzoylecgonine, a cocaine metabolite, and exploring the possible trends

Condition monitoring of pharmaceutical powder compression during tabletting using acoustic emission

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research project aimed to develop a condition monitoring system for the final production quality of pharmaceutical tablets and detection capping and lamination during powder compression process using the acoustic emission (AE) method. Pharmaceutical tablet manufacturers obliged by regulatory bodies to test the tablet's physical properties such as hardness, dissolution and disintegration before the tablets are released to the market. Most of the existing methods and techniques for testing and monitoring these tablet's properties are performed at the tablet post-compression stage. Furthermore, these tests are destructive in nature. Early experimental investigations revealed that the AE energy that is generated during powder compression is directly proportional to the peak force that is required to crush the tablet, i. e. crushing strength. Further laboratory and industrial experimental investigation have been conducted to study the relationship between the AE signals and the compression conditions. Traditional AE signal features such as energy, count, peak amplitude, average signal level, event duration and rise time were recorded. AE data analysis with the aid of advanced classification algorithm, fuzzy C-mean clustering showed that the AE energy is a very useful parameter in tablet condition monitoring. It was found that the AE energy that is generated during powder compression is sensitive to the process and is directly proportional to the compression speed, particle size, homogeneity of mixture and the amount of material present. Also this AE signal is dependent upon the type of material used as the tablet filler. Acoustic emission has been shown to be a useful technique for characterising some of the complex physical changes which occur during tabletting. Capping and lamination are serious problems that are encountered during tabletting. A capped or laminated tablet is one which no longer retains its mechanical integrity and exhibit low strength characteristics. Capping and lamination can be caused by a number of factors such as excessive pressure, insufficient binder in the granules and poor material flowabilities. However, capping and lamination can also occur randomly and they are also dependent upon the material used in tabletting. It was possible to identify a capped or laminated tablet by monitoring the AE energy level during continuous on-line monitoring of tabletting. Capped tablets indicated by low level of AE energy. The proposed condition monitoring system aimed to set the AE energy threshold that could discriminate between capped and non-capped tablets. This was based upon statistical distributions of the AE energy values for both the capped and non-capped tablets. The system aims to minimise the rate of false alarms (indication of capping when in reality capping has not occurred) and the rate of missed detection (an indication of non capping, when in reality capping has occurred). A novel approach that employs both the AE method and the receiver operating characteristic (ROC) curve was proposed for the on-line detection of capping and lamination during tabletting. The proposed system employs AE energy as the discriminating parameter to detect between capped and non-capped tablets. The ROC curve was constructed from the area under the two distributions of both capped and non-capped tablet. This curve shows a trade-off between the probabilities of true detection rate and false alarm rate for capped and non-capped tablet. A two-graph receiver operating characteristic (ROC) curve was presented as a modification of the original ROC curve to enable an operator to directly select the desired energy threshold for tablet monitoring. This plot shows the ROC co-ordinate as a function of the threshold value over the entire threshold (AE energy) range for all test outcomes. An alternative way of deciding a threshold based on the slope of the ROC curve was also developed. The slope of the ROC curve represents the optimal operating point on the curve. It depends upon the penalties cost of capping and the prevalence of capping. Sets of guidelines have been outlined for decision making i.e. threshold setting. These guidelines take into account both the prevalence of capping in manufacturing and the cost associated with various outcomes of tablet formation. The proposed condition monitoring system also relates AE monitoring to non-AE measurement as it enable an operator predicting tablet hardness and disintegration form the AE energy, a relationship which was established in this research

INVESTIGATION OF CHEMICAL DIFFERENCES IN MEDICATIONS OBTAINED FROM DIVERSE SOURCES USING NOVEL SPECTROSCOPIC AND STATISTIC APPROACHES

Generic medications are those medicines manufactured by a pharmaceutical company without a license from the company that has first invented and patented the same drug, when the related patent and other exclusivity rights have expired. Only studies of bioequivalence are requested as requirements to introduce a new generic medication in clinics, making easier and financially attractive for many pharmaceutical companies to participate in this typology of market. Organised criminality is strongly attracted by this market both for the high profitability, and for the high similarity to the production and trafficking of illegal controlled substances associated to the extreme difficulties faced by the law enforcement authorities in effectively investigating the online market, because of its anonymity. A significant paradigm continuously frequented in pharmacology is the confliction between views on generic medications that can be used interchangeably with the original medicines. Several clinical studies conducted in certain medical areas have shown as the generic medications present an overlapping therapeutic equivalence to the original ones. On the contrary, for certain other generics, both pharmacokinetics and pharmacodynamics issue have been reported. Also, in some cases issues on the stability of generics have been raised. Despite the numerous research articles and reviews published on the matter of clinical equivalence among generic and original medications, no study to the scientific community has been presented on an analytical evaluation of the chemical composition of the different generic drugs that could shed some lights on the reason of the different clinical performances reported. The main aim of this research was to develop a non-destructive quick qualitative analytical methodology to be able to discriminate differences in the chemical composition from generic medicines that have been reported not presenting similar therapeutic equivalence in clinical comparison studies, obtained from authorised pharmacies and non-authorised online sellers. From the cardio-vascular area, digoxin (with the related cardiac glycosides digitoxin and digoxigenin) and amlodipine (in its different salts maleate, mesylate and besylate used in therapies). In the gastroenterology area, omeprazole both in its racemic and isomeric forms, have been selected as samples to be analysed. In the antihistamine area, cetirizine, in its racemic and isomeric forms, equally for the same reasons as before, have been considered. As starting analytical approaches, voltammetry, FT-IR, Raman spectroscopies and NMR have been considered and a statistical data analysis approach of the analytical data obtained based on multivariate analysis such as principal component analysis, cross validation, correlation scatter plots and factor loadings has been implemented. This work has matched the aims initially set, generating novel methods of analysis to investigate differences in the chemical composition within different groups of generic medications. This study has led to the creation and interpretation of new knowledge, through a systematic acquisition and understanding of a substantial body of scientific literature and through original research, and adjusting the project design in the light of unforeseen problems, conceptualizing, designing and implementing the research project for the generation of novel knowledge

A Comprehensive Approach to WSN-Based ITS Applications: A Survey

In order to perform sensing tasks, most current Intelligent Transportation Systems (ITS) rely on expensive sensors, which offer only limited functionality. A more recent trend consists of using Wireless Sensor Networks (WSN) for such purpose, which reduces the required investment and enables the development of new collaborative and intelligent applications that further contribute to improve both driving safety and traffic efficiency. This paper surveys the application of WSNs to such ITS scenarios, tackling the main issues that may arise when developing these systems. The paper is divided into sections which address different matters including vehicle detection and classification as well as the selection of appropriate communication protocols, network architecture, topology and some important design parameters. In addition, in line with the multiplicity of different technologies that take part in ITS, it does not consider WSNs just as stand-alone systems, but also as key components of heterogeneous systems cooperating along with other technologies employed in vehicular scenarios

Sample Preparation-Quo Vadis

Sample preparation is and will always be the most important step in chemical analysis. Numerous techniques, methods, methodologies, and approaches are published in the literature offering a wide range of analytical tools to the lab practitioner. Analytical scientists all over the world are trying to develop protocols for a plethora of analytes in various sample matrices. In the last decade, sample pre-treatment advances have followed green chemistry and green analytical chemistry demands, focusing on miniaturization and automation, using the least possible amount of organic solvents. The question is how far we have been till now, and what the future perspectives are. To answer this question, analytical chemists were invited to share their experience in the field and report on the recent advances in sample-preparation approaches. The outcome of our invitation was eleven excellent manuscripts, including four review articles and seven original research articles in the first edition of the Special Issue “Sample Preparation-Quo Vadis: Current Status of Sample Preparation Approaches”.The second edition is a collection of ten significant contributions to the field of sample preparation. It includes two highly interesting and comprehensive review articles and eight innovative research articles

Optimizing Powder Metallurgy Methods: Carbon Nanotube Metal Composites

Since their discovery in 1991, CNTs have revolutionized the composites industries and continue to show great promise as exotic reinforcers in a variety of materials. Extensive studies have been carried out by researchers to impart the unique physical properties of CNTs in metal systems and understand their interfacial interactions. However, the thermal, electrical and mechanical advantages of CNTs in metal systems are limited because of their tendency to aggregate together in rope-like bundles. The objective of this research is two-fold: 1) optimize carbon nanotube (CNT) dispersal mechanisms in the fabrication of aluminum carbon nanotube metal-matrix composites (Al-CNT/MMCs) via the powder metallurgy method (PM), 2) characterize the effects of CNT morphology on the physical properties of Al-CNT/MMCs

Technologies for safe and resilient earthmoving operations: A systematic literature review

Resilience engineering relates to the ability of a system to anticipate, prepare, and respond to predicted and unpredicted disruptions. It necessitates the use of monitoring and object detection technologies to ensure system safety in excavation systems. Given the increased investment and speed of improvement in technologies, it is necessary to review the types of technology available and how they contribute to excavation system safety. A systematic literature review was conducted which identified and classified the existing monitoring and object detection technologies, and introduced essential enablers for reliable and effective monitoring and object detection systems including: 1) the application of multisensory and data fusion approaches, and 2) system-level application of technologies. This study also identified the developed functionalities for accident anticipation, prevention and response to safety hazards during excavation, as well as those that facilitate learning in the system. The existing research gaps and future direction of research have been discussed