The accuracy and reliability of comparative efficiency assessment of portable fire extinguishers used in the process of fire extinguishing of structural components of motor vehicles and automotive finishing

2021 ◽  
Vol 30 (2) ◽  
pp. 88-97
Author(s):  
D. S. Kuprin ◽  
A. S. Polyakov
Keyword(s):  
Measurement Accuracy ◽  
Statistical Significance ◽  
T Test ◽  
Motor Vehicles ◽  
Test Bed ◽  
Fire Extinguishing ◽  
Student’S T ◽  
Iso 5725 ◽  
Student’S T Test ◽  
Fire Extinguishers

Introduction. The relevance of this work resides in the need to perform an unbiased comparative assessment of fire extinguishers. The focus must be placed on the efficiency of a fire-fighting agent, as it has a major impact on the process of fire extinguishing. The purpose of this work is to confirm the applicability of a dimensionless efficiency indicator of portable fire extinguishers, assess the measurement accuracy (correctness and precision) and their statistical values.Materials and methods. The co-authors used the methodology specified in GOST R 51057–2001 applicable to the fire extinguishing of class A model fire seats. The model fire seat had samples of materials attached to its upper edge at the angles whose values were obtained using a specialized test bed. A specialized test bed was used to perform the testing and identify the sample’s inclination angles that prevented the fire extinguishing agent, applied to their surface, from streaming down or crumbling. The accuracy (correctness and precision) was assessed pursuant to the methodologies specified in GOST R ISO 5725-1–2002, GOST R ISO 5725-6–2002. The statistical significance of measurements was assessed using Student’s t-test.Results and discussion. The co-authors offer the results of the experiments aimed at the identification of an inclination angle of the fire seat surface that prevents the fire extinguishing agent from streaming down or crumbling. The results of comparative fire testing of fire extinguishers that contain quick setting foam and powder are provided. The formula of a dimensionless efficiency indicator, applicable to portable fire extinguishers, is provided, and its applicability is proven.Conclusions. The measurement accuracy assessment, performed pursuant to the methodologies, specified in the regulations, has shown the effectiveness of mean arithmetic values of all indicators applied to calculate Peo efficiency indicator. The assessment of the statistical significance of experimentally obtained values of all indicators, performed with the help of Student’s t-test, has demonstrated that the discrepancy of their mean arithmetic values is reliable and it doesn’t have a random nature. The superiority of the quick setting foam extinguisher over the powder one was proven in an experiment. The value of its Peo efficiency indicator exceeds the one of a powder extinguisher 50-fold due to the comprehensive impact made by the extinguishing agent and the construction of a fire extinguisher.

scholarly journals THE NEED FOR COMPREHENSIVE PREVENTION OF HYPERESTHESIA AFTER THE TEETH WHITENING PROCEDURE

2021 ◽  
Vol 17 (3) ◽  
pp. 35-39
Author(s):  
Aleksandr Shumsky ◽  
Ol'ga Titova
Keyword(s):  
Scientific Literature ◽  
Statistical Significance ◽  
T Test ◽  
Lower Jaw ◽  
Frontal Part ◽  
Group A ◽  
Increased Sensitivity ◽  
Comparison And Analysis ◽  
Student’S T ◽  
Student’S T Test

Relevance: people's need for teeth whitening is growing every year. At the same time, during various bleaching procedures, changes in the structure of the surface of the teeth may occur and as a result, there is an increased sensitivity (hyperesthesia) of the teeth, which in some cases leads to the rejection of bleaching. At the same time, there is little data in the scientific literature today about the features of hyperesthesia after teeth whitening, in particular about the ratio of hypersensitivity to various factors (chemical, thermal, mechanical). Also, the predominance of dental hyperesthesia, depending on their localization, has not been studied. Purpose: to analyze the features of hyperesthesia after teeth whitening. Methodology. In this study, using the index of the intensity and prevalence of hyperesthesia, the features of hyperesthesia after teeth whitening were analyzed in 100 patients. For the study, patients with the enamel color of the red-brown group A (Vita Classic), namely to the colors A2 and A3, were selected.All patients underwent chemical teeth whitening using the Opalescence Boost PF whitening system. Comparison and analysis of the results of the conducted study were performed in the IBM SPSS Statistics 23 program. The Student's t-test was used to assess the statistical significance of the differences between the samples. The differences were considered statistically significant at p < 0.05. Result. As a result, it was revealed that hyperesthesia after bleaching prevailed in the frontal part of the lower jaw teeth. Hyperesthesia of teeth after bleaching was characterized by a generalized form and tended to decrease in intensity after 2 weeks. At the same time, the reaction to stimuli was preserved. Conclusions. The above dictates the need for comprehensive prevention of hyperesthesia after the teeth whitening procedure.

Statistical student's t-test in carbon nanospheres synthesis from cis-1,4-polyisoprene

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3371-3377
Author(s):  
Jaime A. Guzmán-Fuentes ◽  
José J. Contreras-Navarrete ◽  
Erasmo Cadenas-Calderón ◽  
Jael M. Ambriz-Torres ◽  
Diana L. García-Ruíz ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Chemical Vapor ◽  
T Test ◽  
Quartz Tube ◽  
Chemical Vapor Deposition Method ◽  
Tube Surface ◽  
Carbon Nanospheres ◽  
Steel Bar ◽  
Student’S T ◽  
Student’S T Test

AbstractA student's t-test was applied in carbon nanospheres synthesis from cis-1,4-polyisoprene considering the green chemical principles. The synthesis was carried out by Chemical Vapor Deposition method with a quartz tube reactor using an AISI 304 steel bar as catalyst. It was possible to obtain two types of different samples, one from the surface of the steel bar (catalyst) and another from the quartz tube surface (without catalyst) in the same experiment. Carbon spheres were observed in both samples by micrographs obtained by FESEM. The Raman and FTIR spectroscopies shown characteristic bands of this carbon structures (G and D). The results obtained by student's t-test proved a statistical significance between spheres means of samples collected from steel bar and quartz tube surface.

scholarly journals Comparison between the Techniques of Radiocephalic Arteriovenous Fistulas for Haemodialysis: A Retrospective Analytical Study

2021 ◽  
Author(s):  
R Anil ◽  
Prabhu Avinash ◽  
Kumar Niranjan ◽  
Naik Nagraj
Keyword(s):  
Analytical Study ◽  
Statistical Significance ◽  
T Test ◽  
Efficacy Rate ◽  
Exact Test ◽  
Arteriovenous Fistulas ◽  
Student’S T ◽  
Venous Fistula ◽  
Lost To Follow Up ◽  
Student’S T Test

Introduction: Chronic Kidney Disease (CKD) has become a major health issue worldwide. CKD patients require Renal Replacement Therapy (RRT) throughout their life. Haemodialysis is one of the options for RRT. Arterio-Venous Fistula (AVF) creation is required for haemodialysis. The radiocephalic fistula is the initial option for creating vascular access. Fistula can be created by anastomosing cephalic vein to radial artery either by End-To-Side (ETS) or Side-To-Side (STS) techniques. Aim: To compare the efficacy rate of radiocephalic AVF using ETS or STS anastomotic methods. Materials and Methods: This was a retrospective analytical study conducted at SDM college of medical sciences and hospital, Dharwad from March 2017 to February 2020. A total of 43 CKD patients were enlisted for the above duration from the hospital records. These patients were included in the study since they underwent radiocephalic AVF creation. AVF creation at other anatomical sites for rest of the CKD patients was excluded. Out of 43 patients, 24 of them underwent ETS technique and 19 STS technique; 15 patients from the former group and 17 from the latter were followed-up for a period of three months. Eleven patients were lost to follow-up. Demographic variables were analysed with frequency, mean and standard deviation. Its association with two different operative techniques was analysed using Fisher’s-exact test. Outcome of the two operative procedures was analysed using Student’s t-test. Results: Effectively 15 patients from ETS group and 17 from STS group were compared. Three (20%) in ETS group and 5 (29.41%) in STS group had primary failure. Mean of maturation time in weeks in ETS group was 4.73±2.73 weeks and in STS group was 5.29±3.75 weeks. Three months patency rate in ETS group was 12 (80%) and in STS group was 12 (70.58%). Student’s t-test was performed comparing the above parameters and no statistical significance was noted. Conclusion: Comparison of two techniques of radiocephalic AVF creation proves that both the techniques are beneficial with no superiority of one over other.

scholarly journals Nurses' leadership styles in the icu: association with personal and professional profile and workload

2009 ◽  
Vol 17 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Alexandre Pazetto Balsanelli ◽  
Isabel Cristina Kowal Olm Cunha ◽  
Iveth Yamaguchi Whitaker
Keyword(s):  
Leadership Styles ◽  
Leadership Style ◽  
T Test ◽  
Descriptive Statistics ◽  
Nursing Workload ◽  
Comparison Test ◽  
Multiple Comparison Test ◽  
Professional Profile ◽  
Student’S T ◽  
Student’S T Test

This study aims to explore the association between nurses' leadership styles and personal and professional nursing profile and workload. The sample consisted of seven nurses and seven nursing technicians who were grouped into pairs. At the end of three months, nurses were queried regarding what leadership style would be adopted when the nursing technician under their evaluation delivered care to patients admitted to the ICU. Relevant data was analyzed by applying descriptive statistics, Tukey's multiple comparison test and Student's t-test (p< 0.05). Nursing workload reached 80.1% on average. The personal and professional profile variables did not show any relation with the leadership styles chosen by nurses (p>0.05). The determine, persuade, and share leadership styles prevailed. However, whenever the nursing workload peaked, the determine and persuade styles were used (p<0.05).

scholarly journals Intravesical prostaglandin e2 effectiveness in the prevention of urinary retention after transvaginal reconstruction of the pubo-cervical fascia and short arm sling according to Lahodny: a prospective randomized clinical trial

2010 ◽  
Vol 14 (1) ◽  
pp. 15 ◽  
Author(s):  
G. QUADRI ◽  
N. NATALE ◽  
C. SPREAFICO ◽  
C. BELLONI ◽  
D. BARISANI ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Urinary Retention ◽  
Study Groups ◽  
T Test ◽  
Control Group ◽  
Fisher Exact Test ◽  
Test Results ◽  
Exact Test ◽  
Student’S T ◽  
Student’S T Test

Intravesical prostaglandin E2 is effective in the recovery of spontaneous voiding after transvaginal reconstruction of the pubocervical fascia and short arm sling according to Lahodny. The aim of the study was to compare the effects of intravesical prostaglandin E2 in the prevention of urinary retention after transvaginal reconstruction of the pubocervical fascia and short arm sling according to Lahodny. STUDY DESIGN: From November 1996 to June 1999 fifty women underwent the Lahodny procedure for moderate/severe cystocele and stress urinary incontinence. Women were randomly assigned to 1 of the 2 study groups: intravesical prostaglandin E2 versus controls. Data obtained were analyzed with the Student t test and the Fisher exact test. RESULTS: Two patients of the treatment group had to be excluded from the study, one because of the wrong measurement of the post-voidal residual volume and another due to a fastidious burning sensation which appeared immediately after prostaglandin instillation and required the suspension of the treatment. No other side effects such as nausea, vomiting, diarrhea or hyperthermia were observed. Patients who underwent the prostaglandin E2 treatment showed a recovery of spontaneous voiding after 7.9&plusmn;6.7 days, whereas this interval was significantly longer in the control group, being 12.9&plusmn;9.7 days (p=0.04, Two tailed Unpaired Student's T test). CONCLUSION: The effectiveness and the low associated morbidity mark the treatment with intravesical prostaglandin E2 useful in the recovery of normal voiding after transvaginal pubocervical fascia reconstruction and short arm sling with the procedure according to Lahodny.

scholarly journals Study of Relationship of Anemia among Edentulous Patients

2018 ◽  
Vol 5 (2) ◽  
pp. 105-108
Author(s):  
Lijo Isaac ◽  
A. P. Nirmal Raj ◽  
Reshma Karkera ◽  
R Naveen Reddy
Keyword(s):  
Nutritional Status ◽  
T Test ◽  
Dental Status ◽  
Adult Patients ◽  
Control Group ◽  
Age Group ◽  
Edentulous Patients ◽  
Student’S T ◽  
Relationship Of ◽  
Student’S T Test

Very little studies were done on relationship of the dental status and the nutritional status. The present study was done to study relation between edentulism and the presence of anemia. The study was included of 46 adult patients with edentulism and same numbers of patients were taken as controls. The results were tabulated and analyzed with the help of IBM SPSS statistics 20 using student’s t test. The hemoglobin levels were lower in the edentulous patients that that of the control group. The present study had shown that the nutritional status were poor resulting in anemia in case of edentulous patients as compared to control group with the same age group.  

scholarly journals The influence of proteinuria on tubular transport of Na+, K+, CL

2002 ◽  
Vol 130 (3-4) ◽  
pp. 64-67
Author(s):  
Dejan Petrovic ◽  
Radmila Obrenovic ◽  
Mileta Poskurica ◽  
Biljana Stojimirovic
Keyword(s):  
Statistical Analysis ◽  
Creatinine Clearance ◽  
Significant Influence ◽  
Fractional Excretion ◽  
T Test ◽  
The Third ◽  
Tubular Transport ◽  
Student’S T ◽  
Student’S T Test

Functional and structural damages of tubulointerstitium are caused by proteinuria. The aim of this study was to assess the influence of different proteinuria levels on Na+, K+, Cl tubular transport. We examined 50 patients (24 males, 26 females), mean age 46.50 ? 13.08 years, with mean creati-nine clearence of 87.29 ? 31.17 mL/min. They were separated in three groups depending on proteinuria value. The first group with proteinuria less than 0.3 g/24h included 19 persons (7 males, 12 females), mean age 45.12 ? 13.28 years, with mean creatinine clearance of 94.27 ? 34.70 mL/min. The second group of 18 patients (8 males, 10 females), mean age 45.39 ? 12.64 years had proteinuria of 0.3-3,0 g/24h and mean creatinine clearance of 90.07 ? 31.89 mL/min. The third group had proteinuria level higher than 3.0g/24h and mean creatinine clearance of 73.25 ? 20.44 mL/min. It included 13 patients (9 males, 4 females), mean age 50.08 ? 13.73 years. As a parameter of proteinuria influence on tubular transport of Na+, K+ and Cl-, fractional excretion of these electrolytes, was studied. Student's T test, Mann Whitney U test and c2 test were used for statistical analysis. No statistically significant influence of proteinuria was found on Na+, K+ and Cl tubular transport.

scholarly journals Πρόγνωση ασθενών με κακοήθεια που εισάγονται στη μονάδα εντατικής θεραπείας

2013 ◽  
Author(s):  
Σουσάνα Ανίσογλου
Keyword(s):  
Standard Deviation ◽  
Performance Status ◽  
T Test ◽  
Apache Ii ◽  
Saps Ii ◽  
Student’S T ◽  
Student’S T Test

ΣΚΟΠΟΣ: Η συλλογή, ανάλυση και επεξεργασία στοιχείων ογκολογικών ασθενών που νοσηλεύθηκαν στη Μονάδα Εντατικής Θεραπείας (Μ.Ε.Θ.) και η συσχέτισή τους με συγκεκριμένους πιθανούς παράγοντες κινδύνου .ΥΛΙΚΟ: Πρόκειται για μία προοπτική μελέτη παρατήρησης (prospective observational) σε δείγμα 125 ογκολογικών ασθενών που νοσηλεύθηκαν στη Μ.Ε.Θ. κατά την τελευταία διετία.ΜΕΘΟΔΟΣ: Αξιολογήθηκαν επιδημιολογικοί, κλινικοί και λειτουργικοί παράγοντες. Ειδικότερα ελέγχθηκαν η πρωτοπαθής νεοπλασματική νόσος, η ηλικία, η παρουσία στεφανιαίας νόσου, χρόνιας αποφρακτικής πνευμονοπάθειας, σακχαρώδους διαβήτη, νεφρικής ανεπάρκειας, ο δείκτης μάζας σώματος, η εφαρμογή χημειοθεραπείας ή και ακτινοθεραπείας, η διάρκεια νοσηλείας, τα score βαρύτητας (APACHE II, SAPS II, SOFA) και η έκβαση (εξιτήριο ή θάνατος) και έγιναν συσχετίσεις με τα προηγούμενα στοιχεία. Χρησιμοποιήθηκε το στατιστικό λογισμικό πακέτο SPSS 17.0 (SPSS, Chicago, IL, USA) για Windows. Οι συνεχείς μεταβλητές παρουσιάζονται ως μέσοι όροι + τυπική απόκλιση (mean + standard deviation). Για τη σύγκριση των μέσων όρων μεταξύ δύο ομάδων έγινε χρήση του student’s t-test, εφόσον οι μεταβλητές ακολουθούσαν την κανονική κατανομή και του Mann-Whitney U test στην αντίθετη περίπτωση. Για την ανάδειξη συσχετίσεων μεταξύ ποιοτικών μεταβλητών έγινε χρήση του x2 test.ΑΠΟΤΕΛΕΣΜΑΤΑ: Η θνητότητα ανήλθε στο 48.8%. Στατιστικά σημαντικοί παράγοντες κακής έκβασης κατά την εισαγωγή του ασθενούς στη ΜΕΘ ήταν τα score βαρύτητας (APACHE II, SAPS II, SOFA), το πτωχό performance status και τα συνυπάρχοντα σοβαρά νοσήματα. Στατιστικά σημαντικοί παράγοντες κακής έκβασης κατά τη διάρκεια νοσηλείας του ασθενούς στη Μ.Ε.Θ. ήταν η διάρκεια του μηχανικού αερισμού, η χρήση αγγειοσυσπαστικών, η πολυοργανική ανεπάρκεια και η σηπτική κατάσταση. Από τις εργαστηριακές εξετάσεις στατιστικά σημαντικές ήταν ο χαμηλός αριθμός αιμοπεταλίων και η θετική αιμοκαλλιέργεια. Ο στατιστικός έλεγχος αξιολόγησης κατά Hosmer Lemeshow παρά τον σχετικά μικρό αριθμό του δείγματος επιβεβαίωσε τη χρησιμότητα των APACHE II, SAPS II, SOFA ως προγνωστικών μοντέλων.ΣΥΜΠΕΡΑΣΜΑΤΑ: Η πρόγνωση ογκολογικών ασθενών που εισάγονται στη ΜΕΘ είναι μέτρια. Υπάρχουν σαφείς προγνωστικοί παράγοντες κινδύνου που μπορούν να συνθέσουν ένα είδος προγνωστικού μοντέλου, ωστόσο απαιτούνται περαιτέρω πολυκεντρικές μελέτες με προοπτικό χαρακτήρα σε μεγαλύτερο αριθμό ασθενών.

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