Simple speed sensorless DTC-SVM scheme for induction motor drives

The paper focuses on the development of a novel DSP based high performance speed sensorless control scheme for PWM voltage source inverter fed induction motor drives. Firstly, two generic torque and flux control methods the Field Oriented Control (FOC) and Direct Torque Control (DTC), are briefly described. For implementation the sensorless scheme DTC with Space Vector Modulation (DTCSVM) has been selected because it eliminates the disadvantages associated with the DTC while keeping the advantages of both FOC and DTC. Secondly, the simple flux vector observer allowing speed sensor elimination is given. The novelty of the presented system lays in combining the DTC-SVM structure with a simple observer for both torque/flux and speed sensorless control. Furthermore, the DTC-SVM structure which operates in speed sensorless and torque control mode is presented. Finally, the description of a 50 kW laboratory drive and experimental results illustrating properties of the system are given

Utilization of Multimedia Services in Libraries for Students with Disabilities

This study has two primary objectives: first, to determine whether or not students with visual impairments make use of multimedia services, and second, to compile a list of the challenges that handicapped face while attempting to use such services. This research was a descriptive qualitative field study that used a qualitative technique of qualitative description. In addition to interviews and written documentation, observation was another method that was used while compiling this data. The study is significant as it shows the availability of media services in schools’ libraries for students with disabilities. According to the findings of this investigation, pupils seem to make effective use of the multimedia services provided by the library for patrons with disabilities. The library offers a variety of services and amenities. Students use of technology, such as laptops and projectors, to get access to material via both visual and audible channels might be seen as evidence that they have achieved this goal. The inadequacy of the service infrastructure and the antiquated nature of the technology makes it difficult to make use of the benefits offered by multimedia services. In addition, there is a severe lack of librarians with experience working with multimedia technology in the worlds educational institutions at the present moment

The Role of Media in Educational Social Construction of Children with Special Needs

This study tries to explore the function that the media plays in supporting the social construction process within the context of inclusive education services. The impact of the media is one of the multiple variables that contribute to the broad adoption of inclusive education. Other contributing aspects include: To be more specific, what part do different kinds of media play in the social construction that makes up inclusive education? It is vital to do qualitative research to shed light on the function that the media plays in building and inviting classrooms to create. The selection of the test population to evaluate the performance of the inclusive education program required a great deal of attention to detail and consideration. The data for this research was gathered using a variety of methods, including observation, interviews, and written records. When looking at the data that was acquired, a descriptive qualitative analysis was performed. It has been found, after considerable discussion, that the speed with which social construction may occur in the classroom is closely tied to the efficacy of the media in aiding student comprehension. This conclusion was reached after much deliberation

Microbiome engineering to combat antimicrobial resistance and upsurge productivity of food animals: a systematic review

Extensive antimicrobial usage in animal farming plays a prominent role in the antimicrobial resistance (AMR) crisis and is repeatedly highlighted as an area needing development under the ‘One Health’ approach. Alternative therapies such as microbiome products can be used as prophylaxis to help avoid infectious disease. However, a limited number of studies have focused on AMR-targeted microbiome products. We conducted this systematic review by using PRISMA guidelines to screen for literature that have evaluated food animals’ health when administrated with microbiome products targeting antimicrobial resistance (AMR) or antibiotic-resistant genes (ARGs). We searched and examined studies from SCOPUS, Web of Science, Embase, and Science direct databases for studies published up to November 2021, restricted to the English language. The findings of this review showed that microbiome products have a promising capability to tackle specific AMR/ARGs coupled with animal’s health and productivity improvement. Furthermore, our study showed that probiotics were the most favorable tested microbiome products, with the most targeted resistance being to tetracycline, macrolides, and beta-lactams. While microbiome products are promising alternatives to antibiotic prophylactics, there is a dearth of studies investigating their efficacy in targeting AMR. Thus, it is highly recommended to further investigate, develop, and improve the microbiome, to better understand its utility and circumvent its limitations.The authors thank Barzan holdings for the financial support

In search of conditions for Gd-TiO2 activation by light irradiation in photodynamic treatment of pancreatic cancer cells

With difficulty in early diagnosis, inaccessibility for the surgical approach, and high resistance to radio and chemotherapies, the resulting low treatment success rates are calling for new approaches in treating pancreatic cancer [1]. Photodynamic therapy (PDT), with the use of light or X-rays, is a method that has the potential to help overcome the problems that existing approaches meet [2,3]. Through activation of photo-sensitive particles with irradiation, PDT helps the production of reactive oxygen species, consequently stimulating cell death. We have synthesized and characterized Gadolinium-doped titanium dioxide nanoparticles (Gd-TiO2 NPs) and tested them as photosensitizers on two pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. Different concentrations of NP treatment, irradiation powers, and times of irradiation were trialed as parameters of activation. Cell viability was measured 48h after treatments, and although some results implied a slight decrease in the viability of treated cells, we have met difficulties in obtaining consistency in results. Statistical significance in the decrease of the viability of treated cells in most cases was not attained, suggesting that higher concentrations or irradiation power and longer illumination time might be needed to achieve a positive PDT effect with this NP system.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

Carbon quantum dots/silver based metal organic framework composites in light enhanced wound healing

In recent years researchers have developed new strategies to enhance the effectiveness of wound healing by combining nanoparticles and infra red (IR) light. For example, some studies have shown that nanoparticles can be used to enhance the absorption of near-infrared laser (NIR) light by tissues, leading to increased healing rates [1]. The influence of NIR light on proliferation, collagen production, and wound healing was tested on: keratocytes (HaCaT) and fibroblasts (MRC-5) cells that are used as model systems of human skin equivalents that comprise an epidermal and a dermal compartment of skin. Also, these cells were treated with carbon quantum dots/silver-based metal-organic framework composites (Ag-MoFs-NCDs and Ag-MoFs-SCDs), which previously showed high antibacterial activity [2], without and with laser light. Firstly, we have found the most convenient and effective CW laser intensity (16 mW/cm2) and illumination time (3 minutes), which is not too high and short enough to influence human cells' proliferation and metabolism positively. Additional chemical treatment with Ag-MoFs-NCDs and Ag-MoFs-SCDs results in a further increase in human cell viability. Our measurements showed that the proliferation index in laser-illuminated cells and cells treated with Ag-MoFs-SCDs was at the level of the untreated control. Furthermore, Ag-MoFs-SCDs treatment and laser illumination induced a mild, insignificant increase in cellular proliferation. On the other hand, Ag-MoFs-NCDs treatment led to a more pronounced, albeit not significant increase, in cellular proliferation, while Ag-MoFs-NCDs treatment combined with laser illumination significantly increased proliferation. Also, we have detected a mild change in collagen level estimated by hydroxyproline assay, which may indicate a positive outcome of combined laser illumination and treatment, taking into account that after 48 hours, a change in cell's response to the treatment could be noticed. Finally, based on migration assay, we observe a complete wound closure after 48 hours in fibroblast cells treated with Ag-MoFs-NCDs and near-infrared laser light, Fig. 1.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

Assessment of Indoor Air Quality of Four Primary Health Care Centers in Qatar.

Airborne bacteria pose a potential risk to human health upon inhalation in the indoor environments of health care facilities. Airborne bacteria may originate from various sources, including patients, workers, and daily visitors. Hence, this study investigates the quantity, size, and identification of airborne bacteria indoors and outdoors of four Primary Health Care Centers (PHCC) in Doha, Qatar. Air samples were collected from the lobby, triage room, and outside environment of the centers, including, Qatar University (QU-HC), Al-Rayyan (AR-HC), Umm-Ghuwailina (UG-HC), and Old Airport (OA-HC) between August 2020 and March 2021, throughout both the hot and the cold seasons. Samples were collected using an Anderson six-stage cascade impactor. The mean of the total colony-forming units was calculated per cubic meter of air (CFU/m). QU-HC had the lowest mean of total bacterial count compared with other centers in the indoor and outdoor areas with 100.4 and 99.6 CFU/m, respectively. In contrast, AR-HC had the highest level, with 459 CFU/m indoors, while OA-HC recorded the highest bacterial concentration of the outdoor areas with a total mean 377 CFU/m. In addition, 16S rRNA sequencing was performed for genera identification. , , , and were the four most frequently identified bacterial genera in this study. The abundance of airborne bacteria in the four health centers was higher in the cold season. About 46% of the total airborne bacterial count for three PHCC centers exceeded 300 CFU/m, making them uncompliant with the World Health Organization's (WHO) recommendation for indoor settings. Consequently, an IAQ standards should be shaped to establish a baseline for measuring air pollution in Qatar. Additionally, it is crucial to understand seasonal fluctuations better so that hospitals can avoid rising and spreading infection peaks.This research was funded partially by Primary Health Care Corporation, grant number PHCC/RC/18/06/002

Anti-cancer and imaging potential of fluorescent black carrot Carbon Dot nanoparticles

Carbon Dots (CDs) are biocompatible, fluorescent, water-soluble, and stable nanoparticles with a high potential to be used for vast biomedical applications [1,2]. We explore the application of CDs produced from natural sources, black carrots, as anti-cancer and imaging agents. These nanoparticles suppress cell growth of three different cancer cell lines, cervical (HeLa), pancreatic (PANC-1), and melanoma (A375) cell lines in vitro. However, the cytotoxic effect against A375 cells stands out, with only 20% of viable cells left after treatment (Fig.1(a)), antimetastatic potential, and a selectivity index higher than two, which indicates that the efficacy against melanoma cells is significantly greater than the toxicity against non-malignant cells (MRC-5). Furthermore, after the cellular uptake, green fluorescence was visible in the cytosol of A375 cells (Fig. 1 (b)). On the other hand, the DAPI stain for DNA was visible as a blue light in the cell nucleus. Moreover, cells with a higher intensity of green fluorescence in the nucleus, Fig. 1 (c) indicated with arrows, were the cells with condensed chromatin in the mitotic phase of the cell cycle (Fig. 1 (d) and (e)), which indicates that CDs interact with chromatin and that they could be used as a marker of cells mitosis and proliferation. In summary, we have demonstrated the great anti-cancer potential of black carrot CDs, for image-guided anti-cancer therapy of melanoma that can be used to recognize cell proliferation.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

Cement degradation in CO2 storage sites: a review on potential applications of nanomaterials

© 2018 The Author(s) Carbon capture and sequestration (CCS) has been employed to reduce global warming, which is one of the critical environmental issues gained the attention of scientific and industrial communities worldwide. Once implemented successfully, CCS can store at least 5 billion tons of CO2per year as an effective and technologically safe method. However, there have been a few issues raised in recent years, indicating the potential leakages paths created during and after injection. One of the major issues might be the chemical interaction of supercritical CO2with the cement, which may lead to the partial or total loss of the cement sheath. There have been many approaches presented to improve the physical and mechanical properties of the cement against CO2attack such as changing the water-to-cement ratio, employing pozzolanic materials, and considering non-Portland cements. However, a limited success has been reported to the application of these approaches once implemented in a real-field condition. To date, only a few studies reported the application of nanoparticles as sophisticated additives which can reinforce oil well cements. This paper provides a review on the possible application of nanomaterials in the cement industry where physical and mechanical characteristics of the cement can be modified to have a better resistance against corrosive environments such as CO2storage sites. The results obtained indicated that adding 0.5 wt% of Carbon NanoTubes (CNTs) and NanoGlass Flakes (NGFs) can reinforce the thermal stability and coating characteristics of the cement which are required to increase the chance of survival in a CO2sequestrated site. Nanosilica can also be a good choice and added to the cement by as much as 3.0 wt% to improve pozzolanic reactivity and thermal stability as per the reports of recent studies