bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Sand Plug at the Gas Well Bottom-hole on its Productive Characteristics
Authors: Kondrat R. М. , Dremliukh N. S. 
Published: March 2020

The reasons that lead to the destruction of the bottomhole zone during the operation of wells with unstable reservoirs are considered. The negative effects of the sand carry-over from the formation into the wellbore are shown. The review of scientific and technical literature on the effect of the sand plug on well productivity is presented. It indicates that the studies have mainly considered oil wells, but the effect of the sand plug on well productivity has not been studied sufficiently. For most gas wells, Darcy's law is primarily violated while filtering gas to the bottom-hole of the well, especially at high gas flow rates. The authors have studied theoretically the effect of a sand plug at the bottom of a gas well with permeability variations on the productive characteristics. According to the results of theoretical studies, the authors construct and analyze graphical dependencies in the form of the ratio of gas flow with and without a sand plug to the ratio of the reservoir permeability and the plug, on condition that the plug blocks the reservoir completely and the plug height exceeds the reservoir thickness. The scientists work a formula for indicating the flow rate of a gas well with a sand plug at the well bottom, on condition that the plug blocks the reservoir completely and the plug height exceeds the reservoir thickness while filtering gas in the reservoir according to the binominal law. On the basis of the research, it is established that on condition of the identical height of the sand plug and the identical ratio of reservoir permeability and the plug, the productivity of the gas well with the sand plug increases with the increase of the reservoir permeability. If the height of the plug exceeds the reservoir thickness, the flow rate of the gas well will be the smaller, the greater is the height of the sand plug compared to the reservoir thickness.
INVESTIGATION OF THE AMPLITUDE STABILITY RELATION OF A MATHEMATICAL MODEL OF A CENTRIFUGAL PUMP OF A PUMPING UNIT AS AN OBJECT OF CONTROL WITH A DEGREE OF GAS PRESSURE
Authors: Lahoida A. I. , Lahoida L. I. 
Published: March 2020

Using the experimental data obtained intheprocesso fchange inthetime of the degree of increase in gas pressure, as well as the performance of the centrifugal supercharger of the gas pumping unit, . Digitization of graphs of change of degree of increase of pressure of gas, and also productivity of the centrifugal supercharger of gas-pumping unitis made with the help of software Graph2Digit. The digitization wasper formed with a sampling period of 0.3 s. The number of values forth edegree of increase of gaspressure, as well as the performance of the centrifugal pump gas pumping unitis 581 each.
The experimental data are divide dinto ranges (1 - 811 sec - 818 sec; 2 - 818 sec - 825 sec; 3 - 811 sec - 831 sec; 4 - 825 sec - 831 sec; 5 - 827 pp. - 832 pp .; 6 - 829 pp. - 831 pp.). In the course of the study, the mathematical expectation for each of the intervals, as well as the spectral density equation for the degree of gas pressure increase and the spectral density equation for the performance of the centrifugal supercharger of the gaspumping unit, were determined at appropriate intervals.
Using there lation between the spectral densitiesand the fact function of the Matlab software product, which factorizes fractional-rational expression, the gear function saredetermine date achinter valand the stability stocks are determine dusing the Nyquist criterion.
The plot of the stability reserve of the centrifugal supercharger of the gas pumping unit as an object of control from the mathematical expectation, which is obtained on the basis of the spectral density ratios, is made. This dependency is approximated by the CurveExpert Professional software to select the optimalma them at icalmodel.
From the set of results, the one with the high estcorrelation coefficient and the small eststandard error isselected.
IMPROVING EFFICIENCY OF ELECTRICAL EQUIPMENT FOR ROAD TRANSPORT
Authors: Shevchuk M. Ya. , Hlad I. V. , Batsala Ya. V. , Kiianiuk O. I. 
Published: March 2020

This paper presents the reasons for the increased level of automobile accumulators are given, the design of the start-charging device of increased reliability is considered. The most damaged nodes of the system of electrical equipment of motor vehicles are listed, the differentiation of elements from the standpoint of their structural reliability is shown, ways of increasing the reliability of the elements of the electrical equipment system are determined. It is shown that the main reasons for finding optimal modes of operation of vehicles electrical equipment are the economic factor, the impact on the environment, the need to reduce the dependence on the constant rise in price of petroleum products. Car lead acid batteries are starter batteries, that is, they do not involve deep discharge. As a result of the deep discharge of the battery on its plates, the phenomenon of sulfitation and shedding of the active mass. The longer the battery is discharged, the more active it becomes and the starter current decreases. Therefore, the issue of regular recharging of the battery and guaranteed starting of the internal combustion engine with a discharged battery is urgent. It is established that the causes of rapid discharge of the battery or reduction of its capacity may be the deviation of the electrolyte density from the recommended value, the sulfation of the plates and the shedding of their active mass, malfunction of the vehicle electrical equipment. Most serial chargers are not designed for starting a car engine, and specially designed models have a high price. The complexity and considerable volume of work on researching and predicting the reliability of the car electrical system requires the efforts of specialists, as well as the coordination and coordination of their activities by developing methodological recommendations first to address partial and then general issues of the problem. It is shown that quantitative indicators of the reliability of each element included in the system are of great importance when addressing issues related to the organization of maintenance, the establishment of overhaul terms and repair volumes of the car electrical system. The developed charger will reduce the time spent on starting the car engine during the cold period, as well as significantly increase the battery life due to its full charge.
ANALYSIS OF METHODS AND MEASURES OF MEASUREMENT OF HEAT OF COMBUSTION OF NATURAL GAS IN UKRAINE AND ABROAD
Authors: Shynkaruk K. M. 
Published: March 2020

In connection with the increase in prices for natural gas, the urgent issue is to calculate not only the amount of gas consumed, but also its quality precisely with the consumer. The quality of gas is the compliance of its physicochemical parameters with established regulatory documents. With the current gas accounting and payment system in Ukraine, consumers using the same number of cubic meters receive different heat of combustion.
The paper analyzes the regulatory framework for assessing the energy performance of natural gas. The necessity of the transition to accounting for natural gas in energy units is substantiated. Existing methods and means for determining the calorific value of natural gas that are used in Ukraine and abroad are considered. Currently, direct and indirect methods are used to determine the calorific value of natural value of natural gas. The most common is the calculation method based on chromatographic analysis, the implementation of which requires expensive equipment. Other methods for determining the calorific value of natural gas is correlation. The essence of which is to establish the relationship between a certain physicochemical property of natural gas and calorific value, which can be established by experimental observations and based on theoretical analysis, which makes it possible to draw a conclusion about the calorific value of natural gas. Based on the analysis, it was found that currently there are no simple in design and not expensive means of controlling the qualitative characteristics of natural gas commercially available. Therefore, it is relevant to solve the problem of operational control of the quality of natural gas, through scientific justification, development and improvement of tools that enable the indirect accounting of the energy value of natural gas in accordance with global trends in energy accounting.
A correlation analysis was carried out to establish the relationship between the thermal conductivity and the calorific value of natural gas. The use of the thermocatalytic method for determining the calorific value of gas is proposed, which will allow designing a relatively cheap and easy-to-use device for monitoring the quality of natural gas specifically for the consumer.
"One Great Epic Unfolding": H.G. Wells and the Interwar Debate on the Teaching of History
Authors: Osborne Ken 
Published: March 2020

AbstractThis essay explores H.G. Wells’s attempts to reform the teaching of history between the two World Wars. Holding history teachers largely responsible for creating the mood of bellicose nationalism that made the First World War possible, Wells concluded that only a fundamentally reformed history education would ensure the survival of the human species. He pressed for a global history, to be taught in all the world’s schools, that began with the origins of the universe and ended with the present and a glimpse into the future that transcended national borders, and would be taught appropriately. Wells was widely read and often quoted by teachers but was unable to change the priorities of educational policy-makers. This essay examines his objections to conventional history; explores his alternative model of history education; and explains his eventual failure. Wells made an important contribution to the debate about history teaching in the inter-war years and his educational ideas have been unduly neglected. Résumé Cet article expose les tentatives de l’écrivain H. G. Wells en vue de réformer l’enseignement de l’histoire entre les deux guerres mondiales. Il tenait les professeurs d’histoire responsables du climat de nationalisme belliqueux qui avait rendu possible la guerre de 1914-1918. Wells était arrivé à la conclusion que seule une réforme en profondeur de l’enseignement de l’histoire pouvait assurer la survivance de l’espèce humaine. Il préconisait une histoire universelle, enseignée dans toutes les écoles du monde, qui commencerait avec les origines de l’univers et qui se terminerait avec le présent et un aperçu du futur qui transcenderait les frontières nationales. Cette histoire se devait d’être enseignée adéquatement. Beaucoup lu et souvent cité par des enseignants, néanmoins Wells n’a pas réussi à influencer les orientations des programmes. Cet article examine sa critique de l’enseignement conventionnel de l’histoire, explore son modèle alternatif et explique son échec éventuel. La contribution importante de Wells au débat sur l’enseignement en histoire durant l’entre-deux-guerres et ses idées éducationnelles ont été par trop négligées.
Difficulties in breastfeeding: Easy solution by Oketani breast massage
Authors: Roy S. K. , Tasnim Saria , Jahan Ms. Khurshid , Nazmeen Summyia , Debnath Sumon Chandra , Islam A.B.M Muzharul 
Published: March 2020

Background: Breastfeeding is universally recommended feeding method for promoting child survival. Many mothers in developing countries do not practice optimum breastfeeding due to difficulties in the breast that may lead to temporary or permanent cessation of breastfeeding. Oketani breast massage approach is one such technique to overcome those difficulties for successful lactation to promote child growth. The aim of this study was to assess the difficulties in breastfeeding and mother’s expression on benefits of Oketani breast massage.
Methods: A cross sectional study was conducted at lactational management center (LMC) in the Institute of Child Mother Health (ICMH), Dhaka, Bangladesh during March to August 2015. A total of 98 mothers (having 0-12 month’s old children) who had breast problems or difficulty in breastfeeding were included in the study. The mothers agreed to undertake Oketani massage. This is a breast massage that promotes breast milk production and helps the lactating mothers to overcome certain difficulties in the breast. Mothers who received Oketani massage were interviewed using a semi-structured questionnaire.
Results: Ninety-eight mothers were interviewed for this study. About two-thirds (66.3%) of babies were girls of which 57.1% were less than 2 months. More than two-thirds (78.6%) mother ages were more than 25 years. Half of the mothers completed secondary school certificate (SSC) in which non-working (63.3%) mothers were more than working mother (36.7%). The proportion of exclusive breastfeeding practice was 50.0%. Most common difficulties included breast engorgement (22.4%), followed by sore nipple (17.3%) and insufficient milk (14.3%). After receiving Oketani massage mother’s perception of getting confidence improved to 80.6%. About 69% said that the baby can be fed well, 61.2% felt that there was increase in breast milk production and 56.1% mothers expressed feeling good after the massage. Study findings revealed that Breast feeding significantly improved with the Oketani breast massage (p=0.001).
Conclusion: Oketani massage is considered as a useful technique to build confidence and improved milk secretion among mothers facing difficulty during lactation. A multicentre study with detailed assessment of quality, the quantity of breastmilk as well as baby’s growth and nutritional assessment is recommended.
Early and mid-term outcome of CABG surgery in diabetic and non-diabetic patients in a tertiary care hospital in Bangladesh
Authors: Rahman Md. Mazibur , Karim Md. Rezaul , Rahman Md. Hamidur , Siraj Masoom , Uddin Jamal , Amin Md. Nurul , Rashid M. A 
Published: March 2020

Background: Previous trials showed that diabetic patients had worse in-hospital and long term outcome after coronary artery bypass grafting (CABG) than non diabetic ones. However, the majority of such studies was carried out in western countries and limited information is available for the Asian population.
Objective: The present study was intended to determine the impact of diabetes on early and mid-term outcome among patients undergoing CABG surgery in a tertiary care hospital in Bangladesh.
Methods: This study was performed at Ibrahim Cardiac Hospital & Research Institute, Dhaka, Bangladesh, from January to June 2014. Based on enrollment criteria, 202 patients (115 diabeticsand 87 non-diabetics) were enrolled and evaluated for their early outcome (within 30 days of operation) and midterm (after 30 days post-operatively). Patients with known diabetes or preoperative fasting blood sugar ≥6.4 mmol/L or random blood sugar ≥11.1 mmol/L were considered as diabetics. The outcome measures were ICU stay, reopening for bleeding, atrial fibrilation, cardiac arrest, total hospital stay, left ventricular ejection fraction and mortality.
Results: Diabetic patients in this study had higher prevalence of hypertension, hyperlipidaemia, and renal failure. The diabetic and the non diabetic groups received a mean number of grafts of 3.2±1.06 and 2.81±1.21, respectively, Postoperative mortality in diabetic and non-diabetic patients at early and mid-term were not significantly different in univariate analysis (4.3% vs. 2.3%, p= 0.352) and (2.6 % vs. 2.3%,p = 0.630) respectively. The mean intensive care unit (ICU) stay in diabetic and non-diabetic were same (3.5days) but total hospital stay was significantly higher in the former group (one day or more). Re-opening for bleeding, atrial fibrilation and cardiac arrest in ICU were found higher in DM than those in non-DM group (28.7%vs.20.7%,10.4% vs. 8% and 4.2% vs.1.1% respectively).
Conclusion: Although the mortality rate of diabetic patients following CABG surgery was in significantly higher than their non-diabetic counterparts. Morbidity was also a bit higher. Strict perioperative glyacemic control could reduce morbidity and mortality in diabetic patients undergoing CABG.
Sympathetic cardiovascular function status of chronic obstructive pulmonary disease (COPD)
Authors: Baksh Sohel , Akhter Shahin , Ali Obaidullah Ibne , Munna Momena Khatun , Rownak Nihad , Khan Sakhawat Mahmud 
Published: March 2020

Background: Chronic obstructive pulmonary disease (COPD) is a chronic progressive obstructive airway disease which is often associated with cardiovascular diseases. Sympathetic dysfunction may complicate the cardiovascular diseases which may in turn increase the morbidity and mortality in COPD patients.
Objective: Aim of this study was to evaluate sympathetic cardiovascular function status of COPD patients to reduce the cardiovascular complication in those patients.
Methods: This comparative cross-sectional study was carried out at the department of Physiology and department of Medicine, Rajshahi Medical College, Rajshahi from July 2013 to June 2014.
Results: A total number of 80 subjects aged 40-55 years were selected, among which 40 were clinically diagnosed COPD patients (case) and 40 were age, sex and BMI matched apparently healthy persons for comparison (control group). To observe sympathetic cardiovascular function status resting pulse rate, resting systolic BP, resting diastolic BP, decline of systolic BP in response to standing from lying position (orthostatic test) and rise of diastolic BP in response to sustained hand grip for 5 minutes (isometric exercise test) were measured. For statistical analysis Independent sample t-test, and Pearson’s correlation coefficient test were performed. In this study resting pulse rate, systolic BP, diastolic BP and rise of diastolic blood pressure in isometric exercise test were significantly increased in COPD than in healthy control group. On the other hand, decline of systolic blood pressure in orthostatic test was significantly decreased in COPD than in control group.
Conclusion: This study concludes that sympathetic cardiovascular function is overactive in COPD and sympathetic over activity correlates with severity of the disease.
Status of self-medication among the patients attending outpatient department in selected private hospitals in Dhaka city
Authors: Hasan Md. Riyadh , Yasmin Nawzia , Seoty Nuhad Raisa , Hasan Md. Maniul , Shahjahan Maj. Gen. (Retd) Dr. M 
Published: March 2020

Background: Inguinal hernia is a common problem and its repair is one of the most commonly performed procedures in general surgical practice. Several methods have been developed including Lichtenstein’s repair. Among these Lichtenstein’s repair has been standard technique for last few decades. In recent time a new procedure “no mesh Desarda hernia repair” has emerged as a recognized operative method for inguinal hernia repair.
Objectives: This study was conducted to evaluate the outcome of Desarda technique in repairing inguinal hernia.
Methods: This was a single centered descriptive study to see the outcome of inguinal hernia repair by Desarda technique in both elective and emergency surgery carried out in the Dept. of Surgery, Sher-E-Bangla Medical College Hospital, Barisal from August, 2015 to July, 2016.
Results: A total of 100 patients underwent Desarda repair for inguinal hernia including primary/recurrent and elective/ emergency cases. Variables includes age, type of surgery, operating time, post-operative complications, post-operative pain, post-operative hospital stay, cost of the procedure, chronic groin pain and any early recurrence. Mean age of patient was 48.9±9.07 years. Mean operating time was 43.72±9.64mins. Majority (54%) of the patient experienced mild post-operative pain on first day, measured in VAS score. Ten percent of patients developed different post-operative complications like wound infection (2%), seroma formation (1%) and scrotaledema (7%).
Conclusion: In this study, it is revealed that no mesh Desarda repair for inguinal hernia was associated with less operating time, less post-operative pain, less post-operative complications, short hospital stay, zero recurrence rate, no chronic groin pain and performed in emergency cases also. So, it is safe and most reliable technique for all type of inguinal hernia surgery.
Accuracy of SpO2 measurements by placing probes on newborns' wrist and ankle
Authors: Tajkia Gule , Shirin Mahfuza , Hossain M Monir , Al Mamun Mohammad Abdullah 
Published: March 2020

Background: Pulse oximetry is a noninvasive technique of measuring oxygenation of the blood that is used worldwide to assess critically ill patients. The accuracy of pulse oximetry reading may be related to the site of pulse oximeter probe placement; but this may be difficult in sick neonates. In neonates, palm and sole are commonly used site for probe placement.
Objective: This study was conducted to assess the accuracy of pulse oximeter oxygen saturation (SpO2) from probe placement at wrist and ankle as an alternative to palm and sole in neonates.
Methods: This cross sectional study was carried out in SCABU of Dhaka Shishu (Children) Hospital from December 2012 to March 2013. A total of 169 neonates were enrolled in this study. Two pulse oximeters were used for simultaneous paired SpO2 measurements. The SpO2 was measured at 0 sec, then at 30 sec and at 1 min over the palm and ipsilateral wrist, both side and repeated the same procedure over the sole and ipsilateral ankle, both side and were recorded in the case record form. Two tailed, Student’s t-test was performed for analysis of continuous, normally distributed variables. Regression analysis was performed to determine the relationship between paired SpO2 measurements.
Results: A total of 169 patients (birth weight 2530.8±772.2 g, gestational age 36.7±3.9 weeks, mean age 7.7 days and age range 1-27 days) were enrolled. There was a good correlation between SpO2 measured at the palm versus the wrist (r= 0.92, p<0.0001 (right); r= 0.88, p< 0.0001 (left)) and between SpO2 measured at the sole versus the ankle (r=0.90, p<0.0001 (right); r= 0.98, p<0.0001 (left)). There was also a good agreement between paired SpO2 measurements from these sites. The bias and precision for SpO2 at the right palm and right wrist was 0.08 ± 0.65% and for the left palm and left wrist 0.05 ± 0.79%. Similarly, the bias and precision for SpO2 at the right sole and right ankle was -0.11 ± 0.63% and for the left sole and left ankle was 0.56 ± 0.32%.
Conclusion: The wrist and ankle can be used as alternative sites, to measure SpO2 in newborn infants in place of the routinely used palm or sole.