Prediction of crack depth and fatigue life of an acrylonitrile butadiene styrene cantilever beam using dynamic response

n this article, a methodology is proposed that can be used to predict the crack growth and fatigue life of a cantilever beam made of Acrylonitrile Butadiene Styrene (ABS) manufactured with fused deposition modeling. Three beam configurations based on length (L = 110, 130, and 150 mm) are considered. Empirical relationships are formulated between the natural frequency and the crack growth. The analytical and experimental results are found to be in good agreement for all configurations. Using the experimental data, a global relation is formulated for the crack depth prediction. This global relation is useful for an in situ crack depth prediction with an error of less than 10 %. Later, a residual fatigue life of these specimens is compared with a metallic structure (Aluminum 1050) of similar configuration available in the literature. It is found that the ABS material has more residual fatigue life compared with the metallic structure at the same frequency drop. Based on the remaining fatigue life, ABS material can be a potential material to manufacture machine components under cyclic loads

Role of proline, K/Na ratio and chlorophyll content in salt tolerance of wheat (Triticum aestivum

Abstract Studies to determine the role of proline, K/Na ratio and chlorophyll contents in salt tolerance of wheat genotypes were conducted in lysimeters using hydroponics technique. Seeds were allowed to germinate under normal condition (1.5 dS m -1 ) and salinity treatment of 12 dS m -1 was imposed after one week of germination. Crop was irrigated at the interval of two weeks or whenever required with 1/4 th Hoagland nutrient solution of respective concentrations. Results clearly indicated that wheat genotypes with higher proline, K/Na ratio and chlorophyll contents had higher grain yield. On the basis of yield reduction, three genotypes viz. Lu-26s, Sarsabz and KTDH were found tolerant. These genotypes also maintained the higher concentration of proline, K/Na ratio and chlorophyll contents under saline conditions

Experimental investigation on compression ignition engine powered with pentanol and thevetia peruviana methyl ester under reactivity controlled compression ignition mode of operation

In the current study, an effort is carried out to study the influence of pentanol as low reactive fuel (LRF) along with diesel and Thevetia peruviana methyl ester (TPME) as high reactive fuels (HRF) in reactivity controlled compression ignition (RCCI) engine. The experiments are conducted on dual fuel engine at 50% load for RCCI mode of operation by varying pentanol percentage in injected fuels. The results revealed that RCCI mode of operation at 10% of pentanol in injected fuels exhibited higher brake thermal efficiency (BTE) of 22.15% for diesel and pentanol fuel combination, which is about 9.1% and 27.3% higher than other B20 and pentanol, B100 and pentanol fuel combinations respectively. As the percentage of pentanol increased in injected fuels, hydrocarbon (HC) and carbon monoxide (CO) emissions are increased while nitrogen oxide (NOx) and smoke emissions are decreased. Among various fuel combinations tested diesel and pentanol fuel combination gives lower HC, CO and smoke emissions and higher NOx emissions. At 10% pentanol in injected fuels, the highest heat release rate (HRR) and in-cylinder pressure are found for diesel and pentanol fuel combinations compared with other fuels

Effect of primary and secondary alcohols as oxygenated additives on the performance and emission characteristics of diesel engine

The demand for renewable energy sources is gradually escalating due to the spontaneously growing population and global economic development. The access to fossil fuels is gradually declining due to the limited available reserves. Hence, renewable energy resources, technology choice, and energy policy are always being revised due to the modernization of society. Meanwhile, the liquid energy sources such as methyl ester from locally produced vegetable oils are readily accepted by many countries globally, although it is currently being blended (up to 20%) with diesel. Oxides of nitrogen are the most substantial emissions from diesel engines produced due to high combustion temperature. The addition of alcohol in the fuel reduces the NOx formation since alcohols have high latent heat of evaporation. The present study's primary purpose is to investigate the effect of different alcohol types on engine performance and emission characteristics. For this purpose, seven test fuels and neat diesel were used. The test fuels P20 (20% palm biodiesel with 70% neat diesel and 10% alcohol on a volume basis), D70P20E10, D70P20Pr10, D70P20B10, D70P20Pe10, D70P20H10 were prepared and tested on a single-cylinder, 4-stroke, DI-diesel engine at different speeds at 100 % load. The P20E10 ternary fuel blend illustrated the most practical combination of all the bioethanol-based blends, which considerably improves the BTE, BSFC and reduces NOxformation at high speed compared to other types of alcoholic fuel blends. Also, the P20E10 fuel blend improved the cloud point of neat diesel

Sustainable adsorption method for the remediation of malachite green dye using nutraceutical industrial fenugreek seed spent

Nutraceutical industrial fenugreek seed spent (NIFGS), a relatively low-cost material abundantly available with nearly negligible toxicity for the bioremediation of malachite green (MG) dye from aqueous media, is reported. Studies on the various parameters affecting the adsorption capacity of NIFGS were carried out to evaluate the kinetics and the equilibrium thermodynamics. All the experiments were designed at about pH 7. The adsorption isotherm model proposed by Langmuir fits better than the Freundlich isotherm model. Kinetic study data confirms the viability of pseudo-second-order model. Calculated thermodynamic factors suggest that the adsorption phenomenon is endothermic, almost instantaneous, and physical in nature

Hydrogen injection in a dual fuel engine fueled with low-pressure injection of methyl ester of peruvenia thevetia [MEPT] for diesel engine maintenance application

The present work is mapped to scrutinize the consequence of biodiesel and gaseous fuel properties, and their impact on compression-ignition (CI) engine combustion and emission characteristics in single and dual fuel operation. Biodiesel prepared from non-edible oil source derived from Thevetia peruviana belonging to the plant family of Apocynaceaeis. The fuel has been referred as methyl ester of Thevetia peruviana (METP) and adopted as pilot fuel for the effective combustion of compressed gaseous fuel of hydrogen. This investigation is an effort to augment the engine performance of a biodiesel-gaseous fueled diesel engine operated under varied engine parameters. Subsequently, consequences of gas flow rate, injection timing, gas entry type, and manifold gas injection on the modified dual-fuel engine using conventional mechanical fuel injections (CMFIS) for optimum engine performance were investigated. Fuel consumption, CO, UHC, and smoke formations are spotted to be less besides higher NOx emissions compared to CMFIS operation. The fuel burning features such as ignition delay, burning interval, and variation of pressure and heat release rates with crank angle are scrutinized and compared with base fuel. Sustained research in this direction can convey practical engine technology, concerning fuel combinations in the dual fuel mode, paving the way to alternatives which counter the continued fossil fuel utilization that has detrimental impacts on the climate

Effect of palm-sesame biodiesel fuels with alcoholic and nanoparticle additives on tribological characteristics of lubricating oil by four ball tribo-tester

Dilution of engine oil with unburned fuels alters its lubricity and tribological properties. In this research paper, SAE-40 lubricating oil samples were contaminated with known percentages (5%) of fuels (diesel, palm-sesame biodiesel blend (B30), B30 + ethanol, B30 + dimethyl carbonate, B30 + carbon nanotubes and, B30 + titanium oxide). The effect of all these fuels on wear and frictional characteristics of lubricating oil was determined by using a 4-ball tribo tester and wear types on worn surfaces were analyzed by using SEM. Lubricating oil diluted with B10 (commercial diesel) showed highest COF (42.95%) with severe abrasive and adhesive wear than mineral lubricant among other fuels. Lubricating oil diluted with palm-sesame biodiesel (B30 blend) with alcoholic additives showed comparatively less COF, less wear scar diameter and polishing wear due to presence of ester molecules. Lub + B30 + Eth exhibited increment in COF value (35.81%) compared to SAE-40 mineral lubricant. While lubricating oil contaminated with B30 with nanoparticles showed least frictional characteristics with abrasive wear. Lub + B30 + TiO2 showed least increment in COF value (13.78%) among all other contaminated fuels compared to SAE-40 mineral lubricant. It is concluded that nanoparticles in biodiesel blends (B30) helps in reducing degradation of lubricants than alcoholic fuel additives and commercial diesel. (C) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University

Pulmonary Tuberculosis and Drug Resistance in Dhaka Central Jail, the Largest Prison in Bangladesh

There are limited data on TB among prison inmates in Bangladesh. The aim of the study was to determine the prevalence of pulmonary tuberculosis (TB), its drug resistance and risk factors in Dhaka Central Jail, the largest prison in Bangladesh.Cross sectional survey with, active screening of a total number of 11,001 inmates over a period of 2 years. Sputum samples from TB suspects were taken for acid- fast bacilli (AFB) microscopy, culture and drug susceptibility testing. (5.37, 4.02–7.16).The study results revealed a very high prevalence of TB in the prison population in Dhaka Central Jail. Entry examinations and active symptom screening among inmates are important to control TB transmission inside the prison. Identifying undiagnosed smear-negative TB cases remains a challenge to combat this deadly disease in this difficult setting

Вплив компетенцій проектного менеджеру, його емоційного інтелекту та трансформаційного лідерства на успіх проекту в галузі інформаційних технологій

The study aims to examine the impact of project managers’ competencies (PMC), emotional intelligence (EQ) and transformational leadership (TL) on project success (PS). Data were collected from 250 respondents including project managers, project leaders, project directors, functional managers, and project sponsor board members working in the information technology (IT) sector. The results of the analysis revealed that the project manager’s prominent characteristics influence the success of the project positively. The study proposes the hiring of project managers, project leaders, and project directors who have competencies like communication, teamwork, attentiveness and conflict management along with expertise in managerial skills in the IT sector. Moreover, resources must be made available to train the existing workforce and enhance their competencies, emotional intelligence and transformational leadership styles through professional courses, workshops and seminars. This study supports the theoretical argument that a project manager with a transformational leadership style has a positive impact on the project’s success. IT project managers ranked transformational leadership as an important aspect for project success. Transformational leaders are inspiring and encouraging, stick to their teams, motivate employees, show them a correct path, and boost employees’ confidence. As a result, a responsive and pleasant environment will be created in which the whole team works together under a trustworthy project manager and attain the project goals. The research provides a unique set of lessons that organizations can use to design or re-design their activities in order to improve the efficiency of their employees.Метою дослідження є вивчення впливу компетенцій проектного менеджеру (PMC), його емоційного інтелекту (EQ) та трансформаційного лідерства (TL) на успіх проекту у секторі інформаційних технологій (PS). У ході дослідження було опитано 250 респондентів, до складу яких входили: проектні менеджери, керівники та директори проектів, функціональні менеджери та ініціатори проекту, у тому числі, які працюють у секторі інформаційних технологій (ІТ). Результати аналізу показали, що основні характеристики проектного менеджеру позитивно впливають на успіх проекту. Автори дослідження пропонують під час прийняття рішень щодо прийняття на роботу працівника (проектного менеджеру, керівників та директорів проектів) брати до уваги їх комунікативні здібності, готовність до роботи в команді, ефективність управління конфліктами, а також досвід роботи на управлінських посадах у сфері ІТ. Крім того, автори наголошують на необхідності інвестування в розвиток наявного персоналу та удосконалення їх компетенцій, емоційного інтелекту та трансформаційного лідерства через професійні курси, тренінги та семінари. Результати дослідження свідчать про позитивний взаємозв’язок між успіхом проекту та наявністю навичок трансформаційного лідерства у проектного менеджеру. Так, менеджери ІТ-проектів визначили трансформаційне лідерство як ключовий фактор їх успішності. Автори стверджують, що основне завдання трансформаційних лідерів стимулювати, надихати, мотивувати працівників та підвищувати їх впевненість в успішності реалізації проекту та досягненні поставлених цілей. В результаті зазначених дій формується позитивний психологічний клімат команди, що реалізує ІТ-проект. З метою підвищення ефективності роботи команди ІТ-спеціалістів авторами було запропоновано ряд заходів щодо формування та реінжерінгу бізнес-процесів

Exploring and Measuring Organizational Learning Capability and Competitive Advantage of Petroleum Industry Firms

Organizational learning is important in today’s dynamic and discontinuous environment of change.This study attempts to test the theoretical underpinning that organizational learning is related to competitive advantage. Through personal interviews and mailed surveys, 94 responses from employees of the petroleum industry were used in the regression analysis. Empirical findings show that theoretically assumed dimensions of the learning organization and organizational learning contribute significantly towards the achievement of competitive advantage. Multiple regression analysis showed the existence of significant relationships between seven independent variables and the dependent variable of competitive advantage. Strategic thinking and team learning explained 59.2% and 22.3% of variance respectively in achieving a competitive advantage. A discussion of the results along with implications and recommendations are provided