Formulation Method of Gain Calculation at Marginal Stability of a Linear Invariant Control Systems

The stability analysis of a linear invariant control system is based mainly on its characteristic equation. There are various methods to examine, to do analysis, and to design a control system. Those methods become less effective and more complicated for use when those methods are used for a high order of an open loop transfer function that has several poles and several zeros. In this research work a new method was developed to find the gains at marginal stability and the intersection points with the imaginary axis of a single-input and single-output of a linear invariant control system by using two new formulas. First formula is used to construct a new polynomial where its roots are the intersection points with the imaginary axis of the s-plane, and a second formula is used to calculate the gains at the marginal stability of the system. The coefficients of the characteristic equation’s polynomial of the control system are substituted in the first formula to obtain a new polynomial. The roots of the obtained polynomial are substituted in the second formula to obtain the gains at marginal stability. In this research work the derivation of the polynomial’s construction formula, its mathematical proof, and the derivation of the gains formula at marginal stability are presented. The proposed Formulization method is compared with another three common methods in the solution of three examples. The used methods are the proposed method, Routh-Hurwitz criterion, Root Locus technique, and the complex variable s on the imaginary axis. The chosen examples are three control systems where their transfer functions are different in order and in complexity, going from low to high. The comparison shows that the Formulization method is accurate and needs less mathematical operations by the user. It is applicable for any order of a single-input and single-output of invariant control systems. It is an effective method especially for a higher order and for more complicated transfer functions of the control systems

Development of Cost-Effective Menstrual Absorbent Pad with Eco-Friendly Antimicrobial Finish

Management of menstrual hygiene is a critical problem for Bangladeshi women and girls as the sanitary pads are expensive. Therefore, purchasing sanitary napkins for incredibly poor and middle-class families is very challenging. Many retail sanitary napkins are available on the local market, but most of them are costly. However, poor women’s are unable to purchase or use high-quality sanitary napkins. Thus, a maximum of nine sanitary napkin pad samples with very cheap raw materials (natural fibres) have been produced in this study. Newly manufactured products even undergo antimicrobial treatment with natural antimicrobial agents such as Tulshi and Aloe Vera accompanied by a simple production process, which ultimately makes the product cheaper and safer for the consumer during use. A maximum of nine samples were produced and compared with commercial samples for cost analysis. The primary objective of this research is to develop such a kind of sanitary napkin that will be cheaper as well as user-friendly in contrast to commercial samples. More interestingly, poor women are not used to wear underwear, because of which they are not interested in using pads as commercial sanitary napkins; panty or other underwear is required. For this reason, an adjustable waistband support is used in this experiment to easily attach the sanitary napkin without any gum. Since menstruation is directly linked to the human reproductive process, it is important for women and girls to manage menstruation appropriately. In addition, the material (especially sanitary napkin core forming materials) used in commercial sanitary napkins is synthetic and may lead to accelerated growth of bacteria and germs by long term use of the pad. The goal of this research was to construct an inexpensive sanitized pad that was treated with Aloe Vera and Tulshi extract. Tulshi and Aloe Vera modified non-woven fabrics incorporate antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Therefore, as it can be used without undergarments, sanitary napkin is not only hygienic but also inexpensive and comfortable with effective protection against leakage. Findings demonstrate the newly developed prototype's substantial design and cost-effectiveness. &nbsp

AN EXPLORATORY STUDY ON MODERN 3D COMPUTERISED BODY SCANNING SYSTEM AND VARIOUS TYPES OF PATTERN MAKING SOFTWARE’S WITH THEIR CONSTRUCTIVE IMPLEMENTATION IN APPAREL INDUSTRY

Nowadays Computer-aided design (CAD) techniques such as Lectra Modaris is becoming exceedingly popular in the apparel industries worldwide for pattern construction because of its accuracy, efficiency and time-saving solutions to much arduous operation (Sayem et al., 2010). The principle objective of this article is to draft a set of pattern pieces by applying Lectra Modaris design environment after selecting a convenient style of trouser by different retail websites or fashion manuals. This paper contains all the essential draft patterns for the selected trouser such as front, back, waistband, pocket bag, pocket facing and fly piece which are constructed in Lectra Modaris V6R1 design software. These patterns are prepared after incorporating measurements into the design extracted from the body-scan point cloud data and from manual tape measurement. This paper also discussed briefly about the pattern construction procedure, different types of body scanning system and various types of pattern making software

AN EXPLORATORY STUDY ON MODERN 3D COMPUTERISED BODY SCANNING SYSTEM AND VARIOUS TYPES OF PATTERN MAKING SOFTWARE’S WITH THEIR CONSTRUCTIVE IMPLEMENTATION IN APPAREL INDUSTRY

Nowadays Computer-aided design (CAD) techniques such as Lectra Modaris is becoming exceedingly popular in the apparel industries worldwide for pattern construction because of its accuracy, efficiency and time-saving solutions to much arduous operation (Sayem et al., 2010). The principle objective of this article is to draft a set of pattern pieces by applying Lectra Modaris design environment after selecting a convenient style of trouser by different retail websites or fashion manuals. This paper contains all the essential draft patterns for the selected trouser such as front, back, waistband, pocket bag, pocket facing and fly piece which are constructed in Lectra Modaris V6R1 design software. These patterns are prepared after incorporating measurements into the design extracted from the body-scan point cloud data and from manual tape measurement. This paper also discussed briefly about the pattern construction procedure, different types of body scanning system and various types of pattern making software

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

On-Line Terrain Parameter Estimation for Planetary Rovers

to traverse very rough terrain with limited human supervision. Wheel-terrain interaction plays a critical role in rough-terrain mobility. In this paper an on-line estimation method that identifies key terrain parameters using on-board rover sensors is presented. These parameters can be used for accurate traversability prediction or in a traction control algorithm. These parameters are also valuable indicators of planetary surface soil composition. Simulation and experimental results show that the terrain estimation algorithm can accurately and efficiently identify key terrain parameters for loose sand

Online terrain parameter estimation for wheeled mobile robots with application to planetary rovers

Future planetary exploration missions will require wheeled mobile robots ("rovers") to traverse very rough terrain with limited human supervision. Wheel-terrain interaction plays a critical role in rough-terrain mobility. In this paper, an online estimation method that identifies key terrain parameters using on-board robot sensors is presented. These parameters can be used for traversability prediction or in a traction control algorithm to improve robot mobility and to plan safe action plans for autonomous systems. Terrain parameters are also valuable indicators of planetary surface soil composition. The algorithm relies on a simplified form of classical terramechanics equations and uses a linear-least squares method to compute terrain parameters in real time. Simulation and experimental results show that the terrain estimation algorithm can accurately and efficiently identify key terrain parameters for various soil types.clos