Identification and Analysis of Residual Stresses in the Axisymmetric Workpiece Existing before and after Machining

2016 ◽  
Vol 686 ◽  
pp. 33-38 ◽  
Author(s):  
Tadeusz Otko ◽  
Wojciech Zębala
Keyword(s):  
Point Of View ◽  
Internal Stresses ◽  
Entire Volume ◽  
Shape Accuracy ◽  
Workpiece Surface ◽  
Plastic Processing ◽  
Machining Allowance ◽  
Before And After ◽  
The Impact

Semi-manufactured parts dedicated for precise machining often have internal stresses which have remained after previous cutting and plastic processing. These stresses reside in a fixed state of balance over the entire volume of the workpiece. Removal of the machining allowance is associated with a change in the state of balance and deformation of the workpiece, which affect its dimensional and shape accuracy. The study, involving non-stress removal of precisely defined volume of the machining allowance and determination of the impact of this treatment on the deformation of the workpiece surface is presented. It is important from the point of view of dimensional tolerance of the axially symmetrical workpiece, finally processed by turning.

scholarly journals Developing a Dashboard Software for the ICUs and Studying its Impact on Reducing the Ventilator-Associated Pneumonia

2018 ◽  
Vol 12 (1) ◽  
pp. 42-50
Author(s):  
Mohammad Fathi ◽  
Hamid Moghaddasi ◽  
Azamossadat Hosseini ◽  
Monir Ebrahimi Aghdam
Keyword(s):  
User Satisfaction ◽  
Pilot Project ◽  
Point Of View ◽  
P Value ◽  
Ventilator Associated Pneumonia ◽  
Healthcare Organizations ◽  
Survey Tool ◽  
Usability Assessment ◽  
Before And After ◽  
The Impact

Objective: Ventilator-Associated Pneumonia (VAP), a lung infection developing in patients on a ventilator in Intensive Care Units (ICU), is the second most common nosocomial infection and a leading cause of morbidity and mortality in ICUs. To reduce the incidence rate of VAP complication, many healthcare organizations have already developed certain strategies and guidelines. However, there are still high rates of VAP infections mainly due to: conflicting guidelines from different sources, implementing the guidelines at different times and conditions, different ICU caregivers at different shifts, and of course the human mistakes. Methods: The present study aimed to develop a dashboard to help reducing VAP incidences in ICUs. To achieve the objective of the research, first, the VAP prevention guidelines were compiled. The object-oriented analysis approach was adopted for designing of the dashboard software. To assess the impact of the developed dashboard on the reduction of VAP events, a pilot hospital was selected and a pilot project was prepared. For the dashboard usability assessment based on user satisfaction, a questionnaire was developed as the survey tool. Conclusion: The dashboard was developed and put into operation in a pilot ICU. The results from the t-test (with a probable error of 0.05 percent) indicated a meaningful difference between the number of VAP patients before and after the dashboard implementation with p-value ˂ 0.02. Also, the developed software was evaluated from a usability point of view based on user satisfaction, with health professionals and caregivers of the pilot ICU as the users of the software. The total score was equivalent to 95 percent, falling within the acceptable range of 75-100 percent.

Atorvastatin: A Review of Analytical Methods for Pharmaceutical Quality Control and Monitoring

2019 ◽  
Vol 102 (3) ◽  
pp. 801-809
Author(s):  
Ana Carolina Kogawa ◽  
Ana Elisa Della Torre Pires ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
Analytical Chemistry ◽  
Quality Control ◽  
Analytical Methods ◽  
Pharmaceutical Products ◽  
Point Of View ◽  
Human Consciousness ◽  
Pharmaceutical Samples ◽  
Pharmaceutical Quality ◽  
The Impact

Abstract Background: Atorvastatin, a lipid-regulating drug, was the best-selling drug in the world in the early 2000s. Thus, monitoring of this drug is important because it is accessible to a large portion of the population. In addition, its quality control is fundamental to provide quality medicines. Method of analysis can be the first step in the rational use of pharmaceuticals. Objective/Methods: In this context, a critical review of analytical methods present in the literature and official compendia for the pharmaceutical quality control of atorvastatin was made. Results: Among the analytical methods most used in the evaluation of atorvastatin, HPLC is highlighted, followed by HPLC coupled to MS, and spectrophotometry in UV. Tablets are the most studied pharmaceutical samples, and plasma is the most studied biological matrix. In the literature, studies with atorvastatin-based pharmaceutical products are more common than biological materials. Acetonitrile is the organic solvent most commonly used in the methods surveyed to evaluate atorvastatin. Conclusions: Currently, awareness of the impact that the analytical choice has on the health of the operator and the environment is growing. Therefore, the suitability of existing methods for the determination of atorvastatin can be made to adhere to the current analytical chemistry. In this way, the analytical, environmental, and human consciousness will remain united. Highlights: Although the literature shows interesting methods from an economic and environmental point of view, such as UV, Vis miniaturized, and TLC, they can still be improved to meet the requirements of the current sustainable analytical chemistry.

scholarly journals ENVIRONMENTAL INDICATORS OF THE EFFICIENT FUNCTIONING OF AGROINDUSTRIAL TERRITORIES OF ADVANCED DEVELOPMENT

2020 ◽  
Author(s):  
L. A. Voyevodina ◽  
Keyword(s):  
Water Resources ◽  
Raw Materials ◽  
Environmental Indicators ◽  
Point Of View ◽  
Transport Efficiency ◽  
Economic Entity ◽  
Before And After ◽  
Four Blocks ◽  
The Impact ◽  
Advanced Development

Purpose: substantiation of environmental indicators of the efficiency of functioning of agro-industrial territory of advanced development (APTOR). Materials and methods. The methods of systematic, complex study, comparison, analysis and generalization of data were used. Results. As a result of the study, indicators that characterize the efficiency of APTOR functioning from an environmental point of view have been identified. The proposed indicators are harmonized with previously developed, widespread and recognized domestic and international methods. The main focus of the proposed indicators is aimed at assessing the effectiveness of management and operative activity. To characterize the efficiency of the APTOR activity based on the use of reclamation technologies, including reclamation parks, it is recommended to use, first of all, indicators indicating the efficiency of water resources use, among which the definition in dynamics (before and after the APTOR operation) “water consumption in the calculation per unit (in physical or value terms) of products (agricultural raw materials and products from them) produced at APTOR”. Due to the fact that the APTOR activities, which is planned to include many technological processes, can have a significant impact on other components of the environment, except for water resources, it is proposed to calculate indicators demonstrating the impact of APTOR activities on the state of air and soil in terms of energy efficiency, transport efficiency, pollution and waste management. On the basis of the indicators for the above recognized equal four blocks, an integrated indicator can be calculated. Conclusions. The use of the proposed indicators will make it possible to assess the effectiveness of the ecological activity of a new economic entity: an agro-industrial territory of advanced development.

Geochemistry of Geological Hydrogen Storage in Sandstone Reservoirs

2021 ◽  
Author(s):  
Aliakbar Hassanpouryouzband ◽  
Katriona Edlmann ◽  
Mark Wilkinson
Keyword(s):  
Hydrogen Storage ◽  
Clean Energy ◽  
Pressure Change ◽  
Point Of View ◽  
Mineral Dissolution ◽  
Geological Storage ◽  
Before And After ◽  
Geochemical Reactions ◽  
Sandstone Reservoirs ◽  
The Impact

<p>To enable a fast transition of the global energy sector towards operation with 100% renewable and clean energy technology, the geological storage of hydrogen in depleted gas fields or salt caverns has been considered as a strong candidate for the future energy storage required for limiting global warming to well below 2 °C, as agreed under the Paris Agreement. As such, understanding the impact of injected hydrogen on the geochemical equilibrium in these storage reservoirs is critical. Here, using our bespoke high pressure/temperature batch reaction vessels we investigate the potential effects of hydrogen injection into 3 different sandstones reservoirs.  These experiments were conducted at reservoir temperature and at different injection pressures from 1 to 20 MPa with salinities from 0 to 10 weight% over different time periods from 1 to 8 weeks.  Our experiments reveal that there is no hydrogen-associated geochemical reaction for the selected sandstones. Although changing reservoir pressure slightly affected the mineral dissolution equilibria at ppm level for hydrogen injection scenarios, the fluctuations of mineral dissolution in water associated with pressure change have a negligible influence on the efficiency of geological hydrogen storage.  Therefore, based on the analysis of water chemistry before and after the mentioned experiments, we demonstrate that from geochemical point of view geological storage of hydrogen in these sandstone reservoirs is safe and we don’t expect any hydrogen loss due to geochemical reactions. </p>

A Determination of Contact-Loss at a Bearing of a Linkage Mechanism

1977 ◽  
Vol 99 (2) ◽  
pp. 375-379 ◽  
Author(s):  
C. L. S. Wu ◽  
S. W. E. Earles
Keyword(s):  
Experimental Investigation ◽  
Dynamic Response ◽  
Point Of View ◽  
Linkage Mechanism ◽  
Design Point ◽  
The Impact

A method is described for analyzing the kinematic and dynamic response of a linkage mechanism in which one bearing has a known clearance. Assuming the clearance to be represented by a massless link, the analysis predicts the occurrence of contact-loss. Part of an extensive experimental investigation is presented in which the impact accelerations resulting from contact-loss are measured. A good correlation is shown to exist between the predicted and measured times of contact-loss. Although the analysis may predict no contact-loss, it does not readily indicate, from a design point of view, how this condition could be produced.

scholarly journals The changes of the workpiece surfaces by hard machining by milling and burnishing

Mechanik ◽  
2018 ◽  
Vol 91 (8-9) ◽  
pp. 727-729
Author(s):  
Daniel Grochała ◽  
Emilia Bachtiak-Radka ◽  
Sara Dudzińska
Keyword(s):  
Time Use ◽  
Automotive Industry ◽  
High Hardness ◽  
The State ◽  
Functional Requirements ◽  
Technological Parameters ◽  
Shape Accuracy ◽  
Part Surface ◽  
The Impact

Today’s machines have to be characterized by increasingly better functional and operational properties. The devices should work faster, more efficiently with higher accelerations and at the same time use less energy than it was a few years ago. These requirements apply to the products from the automotive industry, aviation machine tools or machines serving people in everyday life to play or learn. At the same time, a guarantee of long and trouble-free operation is required. In connection with the above, it is increasingly difficult for the technologist to prepare parts that meet the very strict requirements of dimensional and shape accuracy and the state of the geometric structure of the surface (SGP). Also, more and more emphasis is placed on meeting the additional functional requirements of the part surface (hydrophobic or hydrophilic properties, the degree of isotropy or the ability to maintain coatings and lubricants). The paper presents the results of the work aimed at determining the effect of technological parameters of milling and burnishing when treating the surface of parts in the state improved by heat to high hardness. The work focused in particular on the determination of the impact of the strategy of the implemented treatment on changes in the value of SGP indices describing the load-bearing capacity of the surface.

scholarly journals Exchange Rate Pass-Through in Turkey before and after the Adoption of Inflation Targeting Regime

2017 ◽  
Vol 8 (2) ◽  
pp. 37-48 ◽  
Author(s):  
Özcan Karahan
Keyword(s):  
Exchange Rate ◽  
Inflation Targeting ◽  
Single Equation ◽  
Point Of View ◽  
Turkish Economy ◽  
Before And After ◽  
The Exchange Rate ◽  
Pass Through ◽  
Exchange Rate Pass Through ◽  
The Impact

The impact of exchange rate change on the domestic price level which is called as exchange rate pass through has long been of interest in international economics literature. Along with the application of inflation targeting regime widely, the focus of this interest has also evolved to examine the changes in degree and speed of exchange rate pass through under inflation targeting regime. Turkey, adopted Inflation Targeting (IT) as a monetary regime between 2001 and 2006 implicitly and then explicitly, exhibits which was a genuine experience to be analyzed in this respect. From this point of view, the goal of the study is to provide a time-series analysis of exchange rate pass-through for Turkish economy based on single equation Error Correction Model estimation using the monthly data under pre-IT period 1995-2000 and post-IT period 2006-2014. Thus, we try to clarify the effectiveness of inflation targeting regime as monetary policy on the exchange rate pass-through. The findings of the study indicate that the exchange rate pass-through decreased in the post-IT period compared to pre- IT period. Accordingly, it can be argued that the implication of inflation targeting regime reduced exchange rate pass through in Turkey.

scholarly journals Characterization of Polyethylene Carrying Bags Before and After Isothermal Oxidative Aging in an Oven

2001 ◽  
Vol 71 (3) ◽  
pp. 534-548
Author(s):  
Malik Jehanzeb Khurram ◽  
Musa Kaleem Baloch ◽  
Leonardo C. Simon ◽  
Wajid Rehman ◽  
Cun-Yueguo Cun-Yueguo
Keyword(s):  
Degradation Process ◽  
Point Of View ◽  
The Other ◽  
Research Report ◽  
Sem Images ◽  
Oxidative Aging ◽  
Before And After ◽  
Ft Ir ◽  
Index Value ◽  
The Impact

Utility of polymeric material is a major contribution to the production of waste, particularly in Pakistan. An easy escape to it is the damping in the land which is not commendable for an environmental point of view. On the other hand, the aging of polymer is analogous to its burial conditions under the soil in the absence of light. Therefore, in this research report, two different brands of polyethylene carrying bags were investigated. One sample was obtained from Pakistan abbreviated as sample `Y` while the other from Canada abbreviated as `E`. In order to accelerate the degradation process and to observe the impact of aging in a shorter span of time, these samples were heated at an elevated temperature (80�C) in an oven for the period of 20 days. The samples were characterized before and after aging with an interval of 2 days by applying different techniques like FT-IR, SEM, DSC, and thermogravimetric analysis (TGA). Carbonyl peak at 1715 cm-1 was observed only in the case of sample `E` displaying carbonyl index value as 28.45 % after 20 days of aging. The SEM images before and after aging revealed that the degradation took place at preferential sites in case of sample `Y` and at numerous sites in case of sample `E`. The results of percent crystallinity obtained by DSC showed an increasing pattern with aging for both the samples and was high in case of sample `E.` The activation energy determined by using Flynn-Wall-Ozawa showed a decreasing pattern for both the samples with aging. It concluded that the thermal aging initiates the process of degradation which was then accelerated by heating in TGA oven. The order of reaction was slightly decreased after aging for both the samples and was found to be independent of the heating rate.

Study of essential and toxic elements content in medicinal herbs harvested in Ukraine

2021 ◽  
pp. 6055-6060
Author(s):  
Pawel Konieczynski ◽  
Roman Lysiuk ◽  
Marlena Kopistecka ◽  
Marek Wesolowski
Keyword(s):  
Medicinal Plants ◽  
Essential Elements ◽  
Medicinal Herbs ◽  
Point Of View ◽  
The European Union ◽  
Plant Samples ◽  
European Union Commission ◽  
Elemental Contents ◽  
The Impact

Purpose: Medicinal plants can origin both from their cultivation, and from collection in natural locations, therefore investigation of their chemical composition is indispensable for assuring the appropriate quality. Thus, the aim of the studies was evaluation of medicinal plants collected in natural locations in Ukraine in the light of their elemental contents, taking into consideration both essential elements - P, Cu, Zn, Fe, and toxic – Cr, Pb, Cd and Ni. Methods: The microwave-assisted digestion was applied for preparation of the samples prior to analysis of plant samples to quantitative determination of investigated elements by the flame technique of atomic absorption spectroscopy. Results: The results of studies show that there is a large differentiation of medicinal herbs originating from Ukraine from the point of view of their elemental contents. In many cases, e.g. birch leaves, the impact of botanical plant species on the level of elements was crucial. Hence, the loadings of principal components confirmed that the highest influence on the differentiation of studied plant samples had the concentrations of Cr, Zn, Cd and Fe. The impact of a place of growth on the level of selected elements such as Cd and Fe in St John’s wort was noticed, too. The analysis of toxic metals concentration in all studied plant samples has also shown that Pb and Cd level didn’t exceed the norms established by the European Union Commission in 2006. Conclusion: It is recommended to monitor heavy metals concentrations in medicinal herbs originating from Ukraine available in the European pharmaceutical market.

Internal stress in titanium G4 before and after metal forming in increased temperature and shot-peening determinated by sin2ψ method

2020 ◽  
Vol 25 (1-2) ◽  
pp. 31-37
Author(s):  
Jerzy Jeleńkowski ◽  
Joanna Zdunek ◽  
Piotr Nawrocki ◽  
Grzegorz Mońka
Keyword(s):  
Shot Peening ◽  
Metal Forming ◽  
Source Material ◽  
Internal Stresses ◽  
Ray Method ◽  
X Ray ◽  
Plastic Processing ◽  
Before And After ◽  
Titanium Grade ◽  
Structure Diversity

The article presents the assessment of the macroscopic residual stresses in titanium, grade G4, determined by the sin2ψ X-ray method. The values of stresses measured in the source material and in samples of sub/microstructure obtained after plastic processing in the Gleeble plastometer at the temperature 875 K, optimized strain ε and strain velocity έ were compared. After shot peening, regardless of the structure diversity, the roughness of the polished surfaces of the samples sometimes increased even about 10 times. Small differences occurred in hardness, higher in the more plastic sub/microstructure, which was also reflected in the magnitude of internal stresses.

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