scholarly journals Electrocharged facepiece respirator fabrics using common materials

2020 ◽  
Vol 476 (2243) ◽  
pp. 20200469
Author(s):  
M. M. Bandi
Keyword(s):  
Design Principles ◽  
Simple Design ◽  
Design Rules ◽  
Global Pandemic ◽  
Practical Design ◽  
Cotton Candy ◽  
Set Up ◽  
Filtration Properties ◽  
Plastic Containers

Face masks in general, and N95 filtering facepiece respirators (FRs) that protect against SARS-Cov-2 virion in particular, have become scarce during the ongoing COVID-19 global pandemic. This work presents practical design principles for the fabrication of electrocharged filtration layers employed in N95 FRs using commonly available materials and easily replicable methods. The input polymer is polypropylene or polystyrene, and can include discarded plastic containers of these materials, and the fabrication set-up is based on the cotton candy (CC) principle. The primary parameters underlying the CC principle are translated to simple design rules that allow anyone to construct their own fabrication system from common parts, or employ a commercial CC machine with minimal modifications. Finally, basic characterization results for structural and filtration properties of electrocharged fabrics made using the CC principle are detailed.

scholarly journals Licorice: A Potential Herb in Overcoming SARS-CoV-2 Infections

2021 ◽  
Vol 26 ◽  
pp. 2515690X2199666
Author(s):  
Swee Li Ng ◽  
Kooi-Yeong Khaw ◽  
Yong Sze Ong ◽  
Hui Poh Goh ◽  
Nurolaini Kifli ◽  
...  
Keyword(s):  
Treatment Guidelines ◽  
Food Ingredient ◽  
Active Immunisation ◽  
Reference Guide ◽  
Global Pandemic ◽  
Biological Potential ◽  
Set Up ◽  
Surprising Fact ◽  
Epidemic Diseases ◽  
Roll Out

The management of the global pandemic outbreak due to the coronavirus disease (COVID-19) has been challenging with no exact dedicated treatment nor established vaccines at the beginning of the pandemic. Nonetheless, the situation seems to be better controlled with the recent COVID-19 vaccines roll-out globally as active immunisation to prevent COVID-19. The extensive usage and trials done in recent outbreak in China has shown the effectiveness of traditional Chinese Medicines (TCM) in improving the wellbeing of COVID-19 patients. Therefore, COVID-19 Prevention and Treatment guidelines has listed a number of recommended concoctions meant for COVID-19 patients. Licorice, more commonly known as Gancao in Chinese Pinyin, is known as one of the most frequently used ingredients in TCM prescriptions for treatment of epidemic diseases. Interestingly, it is deemed as food ingredient as well, where it is normally used in Western cuisines’ desserts and sweets. The surprising fact that licorice appeared in the top 10 main ingredients used in TCM prescriptions in COVID-19 has drawn great attention from researchers in revealing its biological potential in overcoming this disease. To date, there are no comprehensive review on licorice and its benefits when used in COVID-19. Thus, in this current review, the possible benefits, mechanism of actions, safety and limitations of licorice were explored in hope to provide a quick reference guide for its preclinical and clinical experimental set-up in this very critical moment of pandemic.

scholarly journals Overcoming the Realization Problems of Wideband Matching Circuits

2018 ◽  
pp. 31-36
Author(s):  
Balázs Matolcsy ◽  
Attila Zólomy
Keyword(s):  
Design Process ◽  
Circuit Simulation ◽  
Impedance Matching ◽  
Microwave Circuit ◽  
Design Rules ◽  
Analytical Design ◽  
Calculation Technique ◽  
Matching Networks ◽  
Practical Design

During the analytical design process of wideband impedance matching major problems may arise, that might lead to non-realizable matching networks, preventing the successful impedance matching. In this paper two practical design rules and a simplified equation is presented, supporting the design of physically realizable impedance matching networks. The design rules and calculation technique introduced by this paper is summarized, and validated by microwave circuit simulation examples.

scholarly journals Eco-Solutioning: The Design and Evaluation of a Curricular Unit to Foster Students’ Creation of Solutions to Address Local Socio-Scientific Issues

2021 ◽  
Vol 6 ◽  
Author(s):  
Nancy Butler Songer ◽  
Guillermo D. Ibarrola Recalde
Keyword(s):  
Engineering Design ◽  
Materials Science ◽  
Design Principles ◽  
Urban Neighborhoods ◽  
Instructional Materials ◽  
Stem Learning ◽  
Instructional Unit ◽  
Global Pandemic ◽  
Research Cycle ◽  
College Programs

The global pandemic and climate change have led to unprecedented environmental, social, and economic challenges with interdisciplinary STEM foundations. Even as STEM learning has never been more important, very few pre-college programs prepare students to address these challenges by emphasizing socio-scientific issue (SSI) problem solving and the engineering design of solutions to address local phenomena. The paper discusses the design and evaluation of a pre-college, SSI curricular unit where students expand their learning by creating solutions to increase biodiversity within local urban neighborhoods. The learning approach, which we call eco-solutioning, builds from current vision and policy documents in STEM education emphasizing phenomenon-centric instructional materials, science investigations, and engineering design. The paper outlines design principles for creating an eco-solutioning instructional unit that guides young students to: collect and analyze data on local organisms, use an engineering design approach to craft solutions to increase local biodiversity, and present their solutions to local city planners and community members. Two cycles of research studies evaluated student learning using paired t-tests. Results demonstrated significant pre-post learning outcomes in both research cycles. A third research cycle in the form of a summer extension program supported students as they implemented their local solutions. Conclusions highlight design principles for the successful creation of SSI curricular units centered on local environmental issues of interest to students, teachers, and stakeholders.

Operational Readiness Case Study for Accessibility and Mobility of Wells Real Time Centre System and Applications During Movement Control Order

2021 ◽  
Author(s):  
Mohd Ridzuan Hamid ◽  
Meor M. Meor Hashim ◽  
Lokman Norhashimi ◽  
Muhammad Faris Arriffin ◽  
Azlan Mohamad
Keyword(s):  
Real Time ◽  
Movement Control ◽  
Time Data ◽  
Work From Home ◽  
Global Pandemic ◽  
Machine Learning Applications ◽  
Full Capacity ◽  
Set Up ◽  
Control Order ◽  
Remote Operations

Abstract The recent global pandemic is an unprecedented event and took the world by storm. The Movement Control Order (MCO) issued by Malaysia's government to halt the spread of the deadly infection has changed the landscape of work via a flexible working arrangement. The Wells Real Time Centre (WRTC) is not an exception and is also subjected to the change. WRTC is an in-house proactive monitoring hub, built to handle massive real-time drilling data, to support and guide wells delivery effectiveness and excellence. The functionality of the WRTC system and applications are embedded in the wells delivery workflow. The centre houses drilling specialists who are responsible for observing the smooth sailing of well construction and are tasked to intervene when necessary to avoid any unintended incidents. WRTC is equipped with myriads of engineering applications and drilling software that are vital for the operations. Such applications include monitoring software, machine learning applications, engineering modules, real-time data acquisition, and database management. These applications are mostly cloud-based and Internet-facing, hence it is accessible and agile as an infrastructure that is ready to be deployed anytime anywhere when it is required. The strategy for WRTC mobility started as soon as the MCO was announced. This announcement mandated the WRTC to operate outside of the office and required the staff to work from home. The careful coordination and preparation to transform and adapt WRTC to a new norm was greatly assisted by the infrastructure readiness. All of these factors contributed greatly to a successful arrangement with zero to minimal downtime where a workstation was set up in each personnel's home, running at full capacity. This transformation was done within one day of the notice and completed within hours of activation. Despite the successful move, few rooms for improvements such as redundancy of VPN use to access applications and limited access to some proprietary software can be enhanced in the future. WRTC is ready to be mobile and agile to support the drilling operations remotely either in the office or from home. The quick turnaround is a major indicator that WRTC infrastructure and personnel are ready and capable for remote operations without interruption.

scholarly journals OVIPOSITION PREFERENCE AND BIOLOGY OF FRUIT FLIES (DIPTERA: TEPHRITIDAE) ON GRAPE VINE GENOTYPES

2018 ◽  
Vol 31 (4) ◽  
pp. 850-859 ◽  
Author(s):  
SABRINA CRISTINA CORRÊA ◽  
CLEITON LUIZ WILLE ◽  
HADSON HOFFER ◽  
MARI INÊS CARISSIMI BOFF ◽  
CLÁUDIO ROBERTO FRANCO
Keyword(s):  
Oviposition Preference ◽  
Fruit Flies ◽  
Choice Test ◽  
Transparent Plastic ◽  
Grape Vine ◽  
Grape Berries ◽  
Randomized Design ◽  
Set Up ◽  
Plastic Containers

ABSTRACT Grape orchards are highly affected by oviposition of fruit flies on grape berries, which compromises the productivity and quality of the grapes. The goal of this study was to evaluate the susceptibility of American, European, and hybrid grape genotypes to Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae) under laboratory conditions (25 ± 2ºC, 60 ± 10% RH, and 14-hour photophase). The assays were conducted by evaluating oviposition preference through choice and no-choice (antibiosis) tests. The choice test was set up using circular arenas (diameter: 300 mm) with 10 grapes per genotype. The no-choice test was set up using 150 grapes per genotype which were placed inside plastic boxes (417 x 297 x 289 mm). After exposure of the grapes to one or two couples of fruit flies per genotype in choice and no-choice tests, respectively, the grapes were transferred to transparent plastic containers (750 mL). The number of eggs per grape and its viability were evaluated. The no-choice test also evaluated the biological cycle of the fruit flies. The assays were conducted in a completely randomized design with 15 replicates. The most preferred grapes for oviposition by A. fraterculus were Cabernet Sauvignon, Niagara Rosada, and BRS Cora, while C. capitata mainly preferred Isabel Precoce grapes. We observed the complete development of fruit flies in the Moscato Embrapa grapes, but this only occurred with C. capitata. All genotypes evaluated were considered susceptible to A. fraterculus and C. capitata. However, the fruit flies expressed differences in preference for oviposition and host quality.

scholarly journals Resistor Geometry Comparison With Respect to Current Noise and Trim Sensitivity

1977 ◽  
Vol 4 (2) ◽  
pp. 63-68 ◽  
Author(s):  
W. Ulbrich
Keyword(s):  
Finite Difference ◽  
Current Distribution ◽  
Current Noise ◽  
Total Resistance ◽  
Sheet Resistivity ◽  
Design Rules ◽  
Optimal Geometry ◽  
Practical Design ◽  
Finite Difference Solution ◽  
Resistance Value

The paper deals with laser trimming of film resistors. The finite-difference solution of the electric field calculated by a digital computer gives the total resistance and the inhomogeneous current distribution within the resistor area. The current noise voltage was found to be proportional to the sum of reciprocal subareas wherein the current density is approximately constant. Resistor trimming is modelled by finite increments of cut length to obtain the resistance trim rate and the trim sensitivity.Known and new resistor geometries and cut configurations are compared (based on the same resistor area and the same initial tolerance of ± 20%) to find the optimal geometry depending on the ratio of the nominal resistance value to the sheet resistivity. Diagrams are given leading to practical design rules not only for resistance trimming but also for deterministic and functional tuning.

scholarly journals Design Optimization of Coulomb Blockade Devices

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 193-198
Author(s):  
H.-O. Müller ◽  
D. A. Williams ◽  
H. Mizuta
Keyword(s):  
Quantum Dots ◽  
Statistical Analysis ◽  
Design Optimization ◽  
Coulomb Blockade ◽  
Rectangular Array ◽  
Design Rules ◽  
Practical Design ◽  
Geometric Size ◽  
Device Operation

We investigate the design of a Coulomb blockade device consisting of a rectangular array of quantum dots or ultrasmall metallic islands with regard to its stability against geometric size disorder and offset charges. To simulate the device operation we perform a statistical analysis of the Coulomb blockade voltage which results in practical design rules.

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