79 research outputs found
Sound absorption capacity of garnet partial replacement in mortar
Sound absorptive materials are generally used to counteract the undesirable effects of sound reflection in the room. The research aims to develop sound absorbent mortar with inclusion of waste materials in effort to improve the acoustic quality of the room. One method to increase the acoustic quality would be covering part of concrete wall with a new mortar which has high sound absorption. The objective of the research is to determine both non-acoustic properties and evaluate acoustic performance of mortar containing waste garnet as partial garnet aggregate replacement. Three new mortar with i) a series of garnet replacement 10 to 40% of sand to normal mortar (1 sand :3 cement), ii) a series of perlite mortar (1 cement: 4 perlite) with waste garnet replacement up to 30%, and iii) a series perlite mortar with garnet replacement and cotton fiber were developed to have such high sound absorption. Waste garnet, an industrial waste obtained from the shipyard industries were used for the purpose of greener production.. At 7 days age garnet replacing sand of 20% in normal mortar demonstrated highest average sound absorption of 0.221 which implies that the capacity of 22% in absorbing sound in room, thus not achieving the target of 0.8. The inclusion of garnet in perlite mortar and addition of cotton fiber do not posses good effect in 7 days age of mortar. However, overall, garnet increased the sound absorption of mortar
Diagnostic utility of fine needle aspiration cytology in thyroid lesions
Background: Thyroid fine needle aspiration cytology (FNAC) is an important screening tool and thereby dictates clinical management. The exclusion of non-invasive follicular variant of papillary carcinoma (NIFVPTC) from thyroid malignancies and its reclassification as non-malignant entity i.e., non-invasive follicular thyroid neoplasm with papillary like nuclear features (NIFTP) has added a new dimension. Aim of this study was to study the role of fine needle aspiration cytology in screening thyroid lesions by correlation with histopathological examination and to calculate diagnostic accuracy of FNAC considering NIFTP as non-malignant and compare it with pre NIFTP era.Methods: It was an observational study done over a period of 2 years (2017-2018). It included the cases where FNAC was followed subsequently by histopathology. FNAC results were correlated with histopathological diagnosis established thereof.Results: A total of 107 patients were included in this study. Considering NIFTP as non-malignant, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 92.97%, 100%, 100%, 92.73% and 96.23% respectively, that is significantly higher if authors considered NIFTP as malignant.Conclusions: FNAC plays an indispensable role in making preliminary diagnosis in thyroid lesions. There is a notable increase in diagnostic accuracy of FNAC in thyroid lesions and significant decrease in risk of malignancy by considering NIFTP as non-malignant
Bone marrow involvement as a rare manifestation of relapsed choroidal melanoma
Choroidal Melanoma is the most common primary intra-ocular malignancy. Incidence of primary choroidal melanoma is about 6 cases per 1 million population. It disseminates hematogenously. The most common site of metastasis is liver. Metastatic melanoma involving the bone marrow is rare, occurring in 5% of patients with disseminated disease. However, Choroid melanoma with bone marrow involvement is very rare. Only a few case reports are published in literature. Authors present a case of bone marrow metastasis from choroid melanoma in 55 years old female who has been treated for primary choroidal melanoma by enucleation of left eye three years back. In the evaluation of symptomatic anemia, features suggestive of bone marrow infiltration by choroidal melanoma were observed on bone marrow aspiration and biopsy. The diagnosis was confirmed by positivity of immune-histochemistry markers HMB-45 and Melana
Correlation of prothrombin time and activated partial thromboplastin time with serum immunoglobulin and M-band in newly diagnosed multiple myeloma patients
Background: Multiple myeloma is the second most frequent malignancy which constitute 13% of hematologic cancers. Thrombotic and hemorrhagic complications have been frequently observed in multiple myeloma patients.
Methods: The study was conducted in the department of pathology, Government medical college Srinagar. A total of fifty (50) patients were recruited for the study. The patients were advised coagulation profile and complete myeloma profile.
Results: Our findings indicate that prolonged PT is associated with high serum IgG levels. A mild to moderate correlation was seen with kappa-free light chains and an inverse correlation was seen between PT and lmbda-free light chains.
Conclusions: Screening of multiple myeloma for hemostatic abnormalities at the diagnosis should improve prognosis in such cases
A bibliometric review of corporate environmental disclosure literature
Purpose
The study aims to identify and discuss influential aspects of corporate environmental disclosure (CED) literature, including key streams, themes, authors, keywords, journals, affiliations and countries. This review also constructs agendas for future CED research.
Design/methodology/approach
Using a bibliometric review approach, the authors reviewed 560 articles on CED from 215 journals published between 1982 and 2020.
Findings
The authors' insights are three-fold. First, the authors identified three core streams of CED research: “legitimization of environmental hazards via environmental disclosures,” “the role of environmental accounting in achieving corporate environmental sustainability” and “integrating environmental social and governance (ESG) reporting into the global reporting initiatives (GRI) guidelines”. Second, the authors also deployed a thematic map that classifies CED research into four themes: niche themes (e.g. institutional theory and environmental management system), motor themes (e.g. stakeholder engagement), emerging/declining themes (e.g. legitimacy theory) and basic/transversal themes (e.g. voluntary CED, environmental reporting and corporate social responsibility). Third, the authors highlighted important CED authors, keywords, journals, articles, affiliations and countries.
Research limitations/implications
This study assists researchers, journal editors and consultants in the corporate sector to comprehensively understand various dimensions of CED research and practices and suggests potential emerging research areas. Although this paper appears to have been thoroughly conducted, using authors' keywords to identify themes was a key limitation. Thus, the authors call upon using a more comprehensive data mining technique that uses keywords in abstracts, titles and the whole body of papers and then identifies inclusive trends in CED literature.
Originality/value
The authors contribute to the extant accounting literature by investigating the organizational-level CED, both mandatory and voluntary, using a systematic and bibliometric literature review model to summarize the key research streams, themes, authors, journals, affiliations and countries. By doing so, the authors construct a future research agenda for CED literature
A Wideband Bear-Shaped Compact Size Implantable Antenna for In-Body Communications
Biomedical implantable antennas play a vital role in medical telemetry applications. These types of biomedical implantable devices are very helpful in improving and monitoring patients' living situations on a daily basis. In the present paper, a miniaturized footprint, thin-profile bear-shaped in-body antenna operational at 915 MHz in the industrial, scientific, and medical (ISM) band is proposed. The design is a straightforward bear-shaped truncated patch excited by a 50-W coaxial probe. The radiator is made up of two circular slots and one rectangular slot at the feet of the patch, and the ground plane is sotted to achieve a broadsided directional radiation pattern, imprinted on a Duroid RT5880 roger substrate with a typical 0.254-mm thickness ( er = 2.2, tan d = 0.0009). The stated antenna has a complete size of 7 mm x 7 mm x 0.254 mm and, in terms of guided wavelength, of 0.027lg x 0.027lg x 0.0011lg. When operating inside skin tissues, the antenna covers a measured bandwidth from 0.86 GHz to 1.08 GHz (220 MHz). The simulations and experimental outcomes of the stated design are in proper contract. The obtained results show that the calculated specific absorption rate (SAR) values inside skin of over 1 g of mass tissue is 8.22 W/kg. The stated SAR values are lower than the limitations of the federal communications commission (FCC). Thus, the proposed miniaturized antenna is an ultimate applicant for in-body communications.This project received funding from Universidad Carlos III de Madrid and the European
Union’s Horizon 2020 research and innovation program, under the Marie Sklodowska-Curie Grant
801538. It also received partial funding from the Researchers Supporting Project number (RSP-
2021/399), King Saud University, Riyadh, Saudi Arabia
X-shaped slotted patch biomedical implantable antenna for wireless communication networks
Biomedical implantable antennas have a major role in biomedical telemetry applications. Therefore, a compact-size low-profile implantable antenna working in industrial, scientific, and medical (ISM) band at 915 MHz is presented. The presented antenna is a simple slotted patch fed with a coaxial probe of 50 Ω impedance. The patch consists of four slotted resonators printed on a flexible Roger Duroid RT5880 substrate (εr = 2:2, tan δ = 0:0009) with the standard thickness of 0.254 mm. The complete volume of the designed antenna is 7 mm × 7 mm × 0:254 mm (0:08λg × 0:08λg × 0:003λg). The antenna covers the bandwidth from 800 MHz to 1 GHz (200 MHz) inside skin tissue. A good agreement between the simulation and measurements of the antenna has been obtained. Finally, the specific absorption rate (SAR) values have also been analyzed through simulations as 8.17 W/kg inside skin over 1 g of mass tissue. The proposed SAR values are less than the limit of the Federal Communications
Commission (FCC). This antenna is miniaturized and an ideal applicant for applications in biomedical implant
SPARCO: Stochastic Performance Analysis with Reliability and Cooperation for Underwater Wireless Sensor Networks
Reliability is a key factor for application-oriented Underwater Sensor Networks (UWSNs) which are utilized for gaining certain objectives and a demand always exists for efficient data routing mechanisms. Cooperative routing is a promising technique which utilizes the broadcast feature of wireless medium and forwards data with cooperation using sensor nodes as relays. Here, we present a cooperation-based routing protocol for underwater networks to enhance their performance called Stochastic Performance Analysis with Reliability and Cooperation (SPARCO). Cooperative communication is explored in order to design an energy-efficient routing scheme for UWSNs. Each node of the network is assumed to be consisting of a single omnidirectional antenna and multiple nodes cooperatively forward their transmissions taking advantage of spatial diversity to reduce energy consumption. Both multihop and single-hop schemes are exploited which contribute to lowering of path-losses present in the channels connecting nodes and forwarding of data. Simulations demonstrate that SPARCO protocol functions better regarding end-to-end delay, network lifetime, and energy consumption comparative to noncooperative routing protocol—improved Adaptive Mobility of Courier nodes in Threshold-optimized Depth-based routing (iAMCTD). The performance is also compared with three cooperation-based routing protocols for UWSN: Cognitive Cooperation (Cog-Coop), Cooperative Depth-Based Routing (CoDBR), and Cooperative Partner Node Selection Criteria for Cooperative Routing (Coop Re and dth)
Adaptive Filtering on GPS-Aided MEMS-IMU for Optimal Estimation of Ground Vehicle Trajectory
Fusion of the Global Positioning System (GPS) and Inertial Navigation System (INS) for navigation of ground vehicles is an extensively researched topic for military and civilian applications. Micro-electro-mechanical-systems-based inertial measurement units (MEMS-IMU) are being widely used in numerous commercial applications due to their low cost; however, they are characterized by relatively poor accuracy when compared with more expensive counterparts. With a sudden boom in research and development of autonomous navigation technology for consumer vehicles, the need to enhance estimation accuracy and reliability has become critical, while aiming to deliver a cost-effective solution. Optimal fusion of commercially available, low-cost MEMS-IMU and the GPS may provide one such solution. Different variants of the Kalman filter have been proposed and implemented for integration of the GPS and the INS. This paper proposes a framework for the fusion of adaptive Kalman filters, based on Sage-Husa and strong tracking filtering algorithms, implemented on MEMS-IMU and the GPS for the case of a ground vehicle. The error models of the inertial sensors have also been implemented to achieve reliable and accurate estimations. Simulations have been carried out on actual navigation data from a test vehicle. Measurements were obtained using commercially available GPS receiver and MEMS-IMU. The solution was shown to enhance navigation accuracy when compared to conventional Kalman filter
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