scholarly journals Effect of Needle Heating on the Sewing of Medical Textiles

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4405
Author(s):  
Adnan Mazari
Keyword(s):  
Experimental Work ◽  
Theoretical Explanation ◽  
Antibacterial Performance ◽  
High Speeds ◽  
Medical Textiles ◽  
High Production

Medical textiles, such as gowns, scrubs, and even disposable uniforms, are all stitched by sewing machines. These garments are mostly made from polypropylene (PP) and polyester due to their durability, antibacterial performance, and functionality. Demand for these garments has significantly risen in the last few years, and sewing machines are able to stitch at extremely high speeds. However, higher sewing speeds can cause burnt spots on the fabric, lower seam strength, and a decrease in production due to thread breakage. In this paper, I have deeply discussed how medical textiles lose their strength and functionality due to higher sewing speeds; this problem is often neglected due to high production demands. This research is based on PP medical gowns, stitched with polyester (PET) threads, sewn at different speeds. The experimental work is also followed by a theoretical explanation of needle heating during the stitching of medical textiles.

Paper 1: The Dynamics of Railway Vehicles on Straight Track: Fundamental Considerations of Lateral Stability

1965 ◽  
Vol 180 (6) ◽  
pp. 29-44 ◽  
Author(s):  
A. H. Wickens
Keyword(s):  
Experimental Work ◽  
Lateral Motion ◽  
Lateral Stability ◽  
Railway Vehicles ◽  
Realistic Theory ◽  
High Speeds ◽  
Lateral Plane ◽  
Excited Oscillation ◽  
Yield Values ◽  
Combined Action

The dynamics of existing railway vehicles on straight track is dominated by motions in the lateral plane commonly referred to as hunting. Hunting is a self-excited oscillation caused by the combined action of the conicity of the wheels and the creep forces acting in the contact plane between wheel and rail. In this paper existing and recently developed theories of the lateral motion of railway vehicles are discussed in relation to experimental work on both models and full-scale vehicles. It is shown that a realistic theory taking into account flexibility between the wheelsets and the frame in the longitudinal, lateral, and vertical directions, and the influence of wheel and rail profiles, yield values for the critical speeds which are consistent with experimental results. The influence of various parameters on stability is discussed and it is explained how railway vehicles can be designed for stable running at high speeds. Examples of suitable choices of suspension and other parameters will be given and experiments carried out in order to verify these concepts will be described.

Iron status in diabetes mellitus

2019 ◽  
pp. 7-12
Keyword(s):  
Diabetes Mellitus ◽  
Beta Cells ◽  
Defense Mechanism ◽  
Acute Stress ◽  
Islet Cells ◽  
Iron Status ◽  
Acute Phase Reactant ◽  
Iron Deposition ◽  
Muscle Tissues ◽  
High Production

Diabetes mellitus can be defined as chronic metabolic disease which results from either relative or complete absence of insulin by the pancreatic beta islet cells. This in-turn may lead to hyperglycemia due to disturbances in the metabolism of glucose. In the human body, iron is con- sidered to be an effective pro-oxidant and participates in the generation of reactive oxygen species (ROS) such as hydroxyl radical. Because of the poor antioxidant defense mechanism of beta cells (low production of antioxidant enzymes such as catalase, glutathione peroxidase and dismutase), so they are highly prone to iron-induced oxidative stress and iron deposition in it and this will lead to apoptosis, and subsequently insulin deficiency. This iron deposition in beta cells will also lead to insulin resistance by reducing insulin extracting ability of the liver and inhibiting glucose uptake in muscle tissues and fats, this in turn will result in high production of hepatic glucose. Ferritin which is an acute phase reactant protein, that responds to acute stress like trauma, infections, tissue necrosis and surgery, it can produce diabetes mellitus either through inflammation or by increasing iron stores.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

Research into the Effect of Photometric Flicker Event on the Perception of Office Workers

2019 ◽  
pp. 22-27
Author(s):  
Cenk Yavuz ◽  
Ceyda Aksoy Tırmıkç ◽  
Burcu Çarklı Yavuz
Keyword(s):  
Experimental Work ◽  
Psychological Problems ◽  
Office Workers ◽  
Questionnaire Study ◽  
Fast Growing ◽  
Lighting Conditions ◽  
Lighting Systems ◽  
Enormous Number

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.

THE ROLE OF LITERACY METHODS IN MASTERING OF WRITTEN LANGUAGE BY STUDENTS WITH DEVELOPMENTAL DYSLEXIA

2019 ◽  
Vol 7 (1) ◽  
pp. 10-18
Author(s):  
Tsvetanka Tsenova
Keyword(s):  
Experimental Work ◽  
Developmental Dyslexia ◽  
Reading Skills ◽  
Writing Skills ◽  
Written Language ◽  
Reading And Writing ◽  
Empirical Verification ◽  
Literacy Methods ◽  
The Relationship

This article focuses on the relationship between literacy methods applied at school and the emergence of serious difficulties in mastering reading and writing skills that shape the developmental dyslexia. The problem was analyzed theoretically and subjected to empirical verification. Experimental work was presented which aims to study the phonological and global reading skills of 4- th grade students with and without dyslexia. Better global reading skills have been demonstrated in all tested children, and this is much more pronounced in those with dyslexia than their peers without disorders. Hence, the need to develop a special, corrective methodology for literacy of students with developmental dyslexia consistent with their psychopathological characteristics.

Simulation Model of the Dynamic Behavior of a Tire Running Over an Obstacle

1988 ◽  
Vol 16 (2) ◽  
pp. 62-77 ◽  
Author(s):  
P. Bandel ◽  
C. Monguzzi
Keyword(s):  
Simulation Model ◽  
Dynamic Behavior ◽  
Black Box ◽  
Box Model ◽  
Vehicle Suspension ◽  
Empirical Relationships ◽  
Static Tests ◽  
High Speeds ◽  
Dynamic Forces ◽  
Vehicle Suspension System

Abstract A “black box” model is described for simulating the dynamic forces transmitted to the vehicle hub by a tire running over an obstacle at high speeds. The tire is reduced to a damped one-degree-of-freedom oscillating system. The five parameters required can be obtained from a test at a given speed. The model input is composed of a series of empirical relationships between the obstacle dimensions and the displacement of the oscillating system. These relationships can be derived from a small number of static tests or by means of static models of the tire itself. The model can constitute the first part of a broader model for description of the tire and vehicle suspension system, as well as indicating the influence of tire parameters on dynamic behavior at low and medium frequencies (0–150 Hz).

Efficient Steganography Algorithm Based On DCT And Entropy Thresholding Technique

2018 ◽  
Vol 8 (1) ◽  
pp. 45
Author(s):  
Satvir Singh
Keyword(s):  
Relative Entropy ◽  
Experimental Work ◽  
Random Function ◽  
Signal To Noise Ratio ◽  
Binary Sequence ◽  
Threshold Value ◽  
Absolute Difference ◽  
Secret Message ◽  
Signal To Noise ◽  
Confidential Information

Steganography is the special art of hidding important and confidential information in appropriate multimedia carrier. It also restrict the detection of  hidden messages. In this paper we proposes steganographic method based on dct and entropy thresholding technique. The steganographic algorithm uses random function in order to select block of the image where the elements of the binary sequence of a secret message will be inserted. Insertion takes place at the lower frequency  AC coefficients of the  block. Before we insert the secret  message. Image under goes dc transformations after insertion of the secret message we apply inverse dc transformations. Secret message will only be inserted into a particular block if  entropy value of that particular block is greater then threshold value of the entropy and if block is selected by the random function. In  Experimental work we calculated the peak signal to noise ratio(PSNR), Absolute difference , Relative entropy. Proposed algorithm give high value of PSNR  and low value of Absolute difference which clearly indicate level of distortion in image due to insertion of secret message is reduced. Also value of  relative entropy is close to zero which clearly indicate proposed algorithm is sufficiently secure. 

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