The Tailored Production of Small Diameter Fibres and Their Applications in Wound Healing

Thinner fibres benefit from a high surface area to volume ratio which is valuable in many biomedical applications ranging from tissue engineering to drug delivery and wound healing. Fibre forming technologies such as electrospinning and pressurised gyration rely on the careful manipulation of solution properties as well as working parameters to obtain the most optimal fibre morphology for their intended applications. In deeply understanding how these fibre manufacturing technologies work, there can be highly optimised and tailored production of polymeric biomaterials. Natural substances represent a class of materials that fail to be forgotten for use in health-related applications. Honey and cinnamon have gained significant interest not only for their physical and chemical properties but also for their antibacterial activity. Manuka Honey UMF 20+ was examined for its antibacterial properties against Escherichia coli and Staphylococcus epidermidis using flow cytometry where the active agent is thought to be the high methylglyoxal content. The inhibitory effect of manuka honey on bacterial growth was evident at concentrations ranging from 10 to 30 v/v%, where higher concentrations benefited from additional honey loading. The incorporation of Manuka honey as an antibacterial agent was explored as a potential route for manufacturing wound dressing components. Using pressurised gyration, scaffolds of sub-micrometre fibres were formed from 10, 20 and 30 v/v% Manuka honey which were incorporated into the polycaprolactone polymer solutions. The composite fibres were analysed for their morphology and topography using scanning electron microscopy. The average fibre diameter of the Manuka honey-polycaprolactone scaffolds was found to be in the range of 437 to 815 nm. The antibacterial activity of the most potent 30 v/v% scaffolds was studied against S. epidermidis. The scaffolds showed strong antibacterial activity with a bacterial reduction rate of over 90%. The results here show that honey composite fibres can be considered a natural therapeutic agent for wound healing applications. Fibrous bandage-like constructs made with incorporated cinnamon extract have been previously shown to have potent antifungal abilities which surpass even the raw material itself. The question remains as to whether these constructs are useful in the prevention of bacterial infections and what the antimicrobial effect means in terms of toxicity to native physiological cells. In this work cinnamon-extracted fibres are tested against Staphylococcus epidermidis to assess their antibacterial capacity; it was found that the fibres were able to successfully kill the bacteria. The constructs were also tested under indirect MTT cytotoxicity tests involving the L929 mouse fibroblast cell line, where they showed no variation from the control groups in terms of toxicity. Additionally, cell viability imaging showed no significant toxicity issues with the fibres, even at their tested highest concentration. Here I present a viable method to produce wound healing products made from non-toxic and abundant naturally occurring materials such as cinnamon. Two fibre forming techniques, pressurised gyration and electrospinning have been combined to create a manufacturing process where advanced wound healing bandages can be created. This new hybrid process leverages the rapid production rate of pressurised gyration to create the bulk portion of the bandages and exploits the precise nature of electrospinning to directly print a bioactive fibrous patch onto the active site of the bandages. Polycaprolactone bandages have thus been created which have a bioactive patch consisting of collagen and chitosan with a poly(ethylene oxide) support. The patches have an average fibre diameter of 173 ± 27 nm and closely resemble the extracellular matrix in its structure, together with the active collagen and chitosan, this will be crucial in their ability to facilitate advanced wound healing. Additionally, synthetic materials such as antimicrobial nanoparticles can be added to the patches which demonstrate that the manufacturing technique is not limited to only using natural materials. Patches with these nanoparticles had an average fibre diameter of 142 ± 31 nm and demonstrated that very uniform and thin fibres could be created with these materials. The process has a great degree of automation and has potential for industrial scalability. The advancement of manufacturing processes needs to be supported by the discovery of novel materials and novel combinations of existing materials. Graphene possesses many properties that have predominately been investigated for commercial applications. For the first time, porous graphene (PG) has been incorporated into polymer matrices produced by a high-output manufacturing process. Graphene and its other derivates such as graphene oxide have been shown to provide an antibacterial surface that can mechanically kill pathogens that encounter it. For this reason, graphene nanopores presents itself as a viable additive for wound healing materials. This overarching work focuses on the production of small diameter fibres via multiple techniques to achieve the most control over the final fibre morphology for uses in advanced wound healing materials

Methods for Identifying Best-Value Bid for Performance-based Maintenance Contracts

Performance-based contracting (PBC) for roadway maintenance is relatively new among various alternative contracting options available at present and is increasingly drawing more attention from state Departments of Transportation (DOTs) and the contracting community. Because performance-based maintenance contracts extend over multiple years (typically 5-7 years) and shift performance risk to contractors, it is critical that contractors be selected based on a form of best-value method rather than on the conventional low-bid method. Currently, highway agencies use various methods for determining the best-value bid based on cost and technical scores. Five best-value bid identification methods that are already in practice by the state transportation agencies in Florida, Virginia, North Carolina, United Kingdom, and New Zealand were used as case studies for this research. These five methods were evaluated in terms of the agency’s willingness to pay for quality and the neutrality of these methods with respect to lowest bid and highest quality. To understand and describe the bid evaluation method, the agency can develop a willingness to pay (WTP) curve. This curve should represent the agency’s needs and budget, reflect their project characteristics, and accommodate associated performance risks. An Excel macro based software tool has been developed that automates these five best-value bid identification methods and also helps customize anyone of these options for any agency

A framework for automated quality assessment of software requirement specification based on part-of-speech tagging, multi-agent k-means clustering and case-based reasoning

Software Requirement Specification (SRS) is an imperative process in a Software Engineering (SE) cycle, where its role is to document functional and non-functional requirements and to establish the tasks that a particular system is set to accomplish. Because a badly written SRS has an expensive impact on the entire project, the success or failure of any software product depends on the quality of the SRS document. Recent advancements in the field have explored automated extraction of quality attributes in SRS documents such as the Reconstructed ARM and the Rendex models. However, automating the quality assessment process poses major challenges, which requires advanced Natural Language Processing (NLP) algorithms to extract the quality features, interpreting the context of the features, formulating the assessment metrics, and documenting the shortcomings as well as possible improvements. Recent automated models also attempted to assess the quality of the SRS based on a small number of quality attributes and indicators due to the limitation in extracting quality attributes that require specific indicators from the SRS. To address this gap, this thesis proposes an Automated Quality Assessment of SRS (AQA-SRS) framework by integrating NLP for feature extraction, Multi-Agent System (MAS) with K-means for features clustering, and Case-based Reasoning (CBR) for process management. This framework assessed the SRS documents by automatically extracted 11 quality attributes and their corresponding 11 quality indicators through a deep analysis of the SRS textual content. This process is performed through the Multi-Agent K-means (MA-K-means) model for handling the automatic evaluation of the AQA-SRS framework. The performance of the AQA-SRS framework is evaluated by comparing the results against the state-of-the-art techniques as well as human experts based on two standard SRS datasets. The results showed the AQA-SRS framework reliably handled the assessment of 11 quality attributes and their corresponding 11 quality indicators with Krippendorff’s Alpha 0.78 for the agreement with software engineering experts

Temperature Impact and Efficiency Analysis of Hybrid PVT System

Hybrid photovoltaic thermal (PV/T) systems are a type of solar system that combines the functions of a photovoltaic and a solar thermal in one unit [1]. The PV panels generate electricity from sunlight, while the thermal collection system captures the excess heat produced by the PV panels and uses it to produce warm water or space heating [2]. According to the recent analysis, the efficiency of the solar energy production in particular solar photovoltaic system is still low [3]. There are several factors to be considered that affect the energy production during the operation of hybrid PVT system. There are several internal and external or environmental parameters are responsible for this output disruption. The parameters found to be affecting are solar irradiance, environmental and module surface temperature, humidity, wind speed, shading, dust and many others [3]. Solar irradiance and temperature are the key role-players among all the variables. The light intensity or solar irradiance value is related with PV production as it affects short circuit current of the absorbed photons in the semiconductor material. The most important parameter which is the main concern of this work is the inside and outside temperature of the panel. If there is rise in ambient temperature, then the short circuit current only increases that results in decrease in power output [3-4]. As a result, the maximum power point (MPP) also decreases with the rise of temperature. Temperature is considered as a negative parameter in the panel, but it turns into positive in the proper use of hybrid PVT system. In this work, the impact of temperature rises in the panel and its related power output is shown which clearly identifies the negative result on the panel. Additionally, the MPP output due to temperature rise is also explained in the figure. Afterall, the changes in efficiency due to the temperature rise also analyzed in this work. One of the main advantages of hybrid PVT system is that it helps to regulate the panel temperature that tends to improve its efficiency. The PVT system can keep the panels cooler with high efficiency by capturing and using the excess produced heat. Temperature can be regulated in a PVT panel using several methods which will improve overall efficiency. Thus how, the PVT panel will be cooled producing more electric energy including thermal energy. This work proves that the impact of temperature rise can be mitigated, and efficiency is improved using hybrid PVT system properly

Comparative Analysis of Loss Functions in TD3 for Autonomous Parking

Autonomous parking is a revolutionary technology that has transformed the automotive industry with the rise of deep reinforcement learning, in particular, the Twin-Delayed Deep Deterministic Policy Gradient Algorithm (TD3). Nonetheless, the robustness of TD3 remains a significant challenge due to bias in Q-value estimates when determining how good an Action, A, taken at a particular state, S. To investigate this gap, this paper analyzes different loss functions in TD3 to better approximate the true Q-value, which is necessary for optimal decision making. Three loss functions are evaluated; Mean Squared Error (MSE), Mean Absolute Error (MAE) and Huber Loss via a simulation experiment for autonomous parking. The results showed that TD3 with Huber Loss has the highest convergence speed with the fastest Actor and Critic loss convergence. The Huber Loss function is found to be more robust and efficient than either loss function such MSE or MAE used in isolation, making it a suitable replacement for existing loss functions in the TD3 algorithm. In the future, TD3 with Huber Loss will be used as the base model to solve overestimation problem in TD3 when the estimated Q-values that represent the expected rewards of taking an action in a particular state, are higher than their true values

Nozzle-Pressurized Gyration: A Novel Fiber Manufacturing Process

An innovative development of pressurized gyration is presented, incorporating a directional nozzle system. Thus, nozzle-pressurized gyration is used to prepare polymeric fibers. In this work, three different polymeric fibers (polycaprolactone, polyvinylpyrrolidone, and polyethylene oxide) manufactured by the original pressurized gyration and nozzle-pressurized gyration are compared. Under the same processing parameters (working pressure, rotational speed, and collection distance), nozzle-pressurized gyration is proved to be a highly efficient spinning technology for uniform and uniaxially oriented fiber products. The effects of the spinning vessel geometry on the morphology and alignment of gyrospun fibers are elucidated. This work also reveals the relationship between fiber morphology and collection distance in nozzle-pressurized gyration. Varying the collection distance provides a useful approach to the synthesis of uniform fibers with anisotropic arrangement

Anti-fungal bandages containing cinnamon extract

© 2019 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.Cinnamon-containing polycaprolactone (PCL) bandages were produced by pressurised gyration and their anti-fungal activities against Candida albicans were investigated. It was found that by preparing and spinning polymer solutions of cinnamon with PCL, fibres capable of inhibiting fungal growth could be produced, as observed in disk diffusion tests for anti-fungal susceptibility. Fascinatingly, compared with raw cinnamon powder, the novel cinnamon-loaded fibres had outstanding long-term activity. The results presented here are very promising and may indeed accelerate a new era of using completely natural materials in biomedical applications, especially in wound healing.Peer reviewe

Sand Dunes Stabilization Using Silica Gel and Cement kiln Dust

This research includes the study of adding some available cheap and Local materials to Sand Dunes (SD) such as, Silica Gel (SG) and Cement kiln Dust (CKD) which are used as stabilizers and sand improvement . The Laboratory tests out on (June 2013 to November 2013 .) Some Physical and chemical characteristics of(SD),(SG) and (CKD) were obtained, also Grain Size Distribution(GSD) and chemical composition were obtained. The program was divided into two stages the first one includes preparing four mixtures three of them Silica gel were added to tape water to make solution (2.5%,5% and 7.5%) , then adding to the sand dunes, which is denoted by (m1, m2 and m3) respectively , the fourth mixture represent reference( sand dunes) ,these mixtures aging for (7, 14 and 28 ) days. Pure sand dunes and these three mixtures were tested to determine the wind velocity effects on drifting sand, shear strength force, cohesion and penetration .The second stage includes determining the best results of three previous mixtures, which called typical mixture, and (2.5%,5% and 7.5%) of CKD were added to the typical mixture, which is denoted by (m41, m42 and m43) respectively , these mixtures aging- curing period- for (7, 14 and 28 ) days. Generally, this study showed significant improvement in the performance of sand dunes by using Silica Gel and Cement Kiln Dust, which means that, they can be used as stabilizer and soil improvement as economic and available material

Utilization of waste as a constituent ingredient for enhancing thermal performance of bricks – a review paper

In view of the environmental regulations, practitioners have been inclined to use bricks with higher insulation capability, however with minimal attention to sustainable material composition, let alone waste material. From a research perspective, in the wake of the growing concerns for the environment, the use of waste material to develop bricks which can exhibit suitable characteristics attributed to the material composition has been on the rise. However, the extant literature on utilization of waste materials for brick mix design has neglected to provide detailed literature review on the influence of waste materials on the thermal performance of bricks. Methods: This paper provides detailed review of research conducted on thermal properties of bricks produced from various types of waste. Influence of the method of manufacturing and type of waste on thermal performance of bricks is discussed. A sustainability selection criteria format is provided to assist optimal decision making in considering alternative sustainable waste material. Findings: A sustainability selection criteria format is provided to assist optimal decision making in considering alternative sustainable waste material. Applications: The outcome of this paper can serve as a common reference for practitioners and researchers attempting to seek out solutions for further improving overall quality of thermally insulated waste-incorporated bricks, paving the way for more focused research on waste utilization in the development of more sustainable wall material based on the current brick production process

Effective Communication Protocols for Verification on SoC Using FPGA

ABSTRACT A System on Chip (SoC) is an integrated circuit that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often radio frequency functions all on a single chip substrate. Traditionally, Engineers have employed simulation acceleration, emulation and/or an FPGA prototype to verify and debug both hardware and software for SOC design prior to tape out. So that design effective communication protocols are important for efficient verification on SOC.A serial communication interface based on FPGA (Field Programmable Gate Array) has been designed in this paper, used for data communication with other equipment. It guarantees the realization of the serial communication function under the condition of without any increasing in hardware resources