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This study aims to systematically evaluate the effect of Exhaust Gas Recirculation (EGR) variation on engine performance and exhaust emissions in dual-fuel diesel–CNG compression ignition engines, in response to increasing emission regulations and the need for cleaner yet practical combustion technologies. The research employs a comparative review approach, synthesizing experimental findings from selected peer-reviewed studies to analyze the influence of different EGR rates on key performance indicators, including Brake Thermal Efficiency (BTE) and Brake Specific Fuel Consumption (BSFC), as well as major emission components such as NOx, HC, CO, and smoke. The findings indicate that increasing EGR rates effectively reduce NOx and smoke emissions due to lower combustion temperatures and oxygen dilution; however, excessive EGR leads to deteriorated combustion efficiency, reflected in reduced BTE and increased HC and CO emissions. An intermediate EGR level, particularly around 10%, is consistently identified as providing the most favorable balance between emission reduction and performance retention in dual-fuel diesel–CNG operation. These results imply that optimized EGR control is a critical parameter for improving the environmental performance of dual-fuel engines without significant efficiency penalties, supporting its application as a transitional technology toward cleaner transportation systems. The originality of this study lies in its integrated comparative synthesis of performance–emission trade-offs across multiple EGR levels and fuel substitution ratios, offering a clearer operational insight that is not explicitly addressed in individual experimental studies.

COPD is a condition characterized by airflow obstruction that cannot be completely corrected. This limitation generally worsens over time and is associated with abnormal permeability to noxious particles or gases, resulting in narrowing of the airways, increased mucus secretion, and changes in the vascular system. The increase in chest expansion capacity is caused by the activity of respiratory muscle contraction. The activity of the respiratory muscles plays a role in chest expansion, which also affects lung growth. It is stated that the strength of the respiratory muscles decreases with age. Loss of intercostal muscle mass and strength are factors that reduce the ability of chest wall presence or development. This study used a case report design research method. Physiotherapy management for COPD is increasingly focused on exercise-based rehabilitation, both in outpatient and inpatient settings. Some therapies such as breathing exercises, thoracic expansion exercises and muscle release.

Background: The global energy transition requires low-carbon solutions that can be integrated into existing thermal systems without drastic infrastructure changes. Hydrogen blending in conventional combustion systems has emerged as a promising pathway to reduce carbon emissions while maintaining operational flexibility. Objective: This study aims to experimentally evaluate the effect of hydrogen blending ratios (0–100% by volume) on thermal efficiency, CO₂ emissions, and NOx emissions, and to determine the optimal blending range based on technical and economic feasibility. Methods: An experimental thermal system prototype was developed and tested under controlled conditions with three repetitions per operating point. Performance parameters included combustion temperature, fuel consumption rate, and thermal efficiency, while emissions of CO₂ and NOx were measured using a calibrated gas analyzer. Data were analyzed using descriptive statistics, one-way ANOVA at a 0.05 significance level, confidence interval estimation, and linear regression to examine the relationship between hydrogen fraction and emission reduction. Results: The findings indicate that increasing hydrogen fraction significantly improves thermal efficiency, reaching 87.5% at 100% hydrogen, while CO₂ emissions decrease linearly to zero. However, NOx emissions increase with higher hydrogen content due to elevated combustion temperatures. Statistical analysis confirms that hydrogen ratio has a significant effect on efficiency and emissions, with a strong linear correlation between hydrogen fraction and CO₂ reduction. A blending range of 40–60% hydrogen provides the most balanced performance in terms of efficiency improvement, emission reduction, and cost feasibility.

Aging is a dominant risk factor for most forms of cardiovascular disease. Sedentary lifestyle in elderly with obesity can decrease the function of cardiovascular system. Previous study determined that moderate intensity aerobic exercise was highly recommended in elderly because the type of exercise can improve body fitness and oxidative damage due to aging. The aims of this study was to investigate the effect of moderate intensity aerobic exercise on NOx plasma level, systolic blood pressure (SBP) and diastolic blood pressure (DBP) in sedentary elderly women with overweight. The research method is quasi experimental with pre test and post test design. The sample included 33 volunteer sedentary elderly women overweight with age 65,11±4,85 years old that divided on two group that is the experimental group (EG/ n=17) and control group (CG/ n=16). EG performed moderate intensity aerobic exercise (walking) during 30 min per session, intensity 50–80% heart rate maximum,  three times per week for 12 week. The examination of NOx plasma level by ELISA method and resting blood pressure by auscultation method. Data was processed by unpaired t-test. Experimental group had significantly lower level of SBP (-10,294 p 0,001) than CG. NOx plasma level showed significantly decreases in both group (p < 0,05), but the decreasing trend was found to be higher in the CG. DBP and body mass index (BMI) did not change (p >0,05). Moderate intensity aerobic exercise can delay the reduction of NO due to aging proceses.