Minimum Level Research Articles

Stress and Learning Achievements in University Students in Juliaca-Puno, Peru

The main objective of the development of the article was to determine the relationship between stress and learning achievements in university students from Juliaca, Puno, Peru. The methodology was developed based on a basic study, a correlational level of non-experimental design, with a longitudinal section in which a sample of 320 university students was used. Descriptive statistics and a Pearson chi-square correlation test were used. Based on the results, it was obtained that the average age of the students is 29 years, mostly female, single marital status, family economic level of the vital minimum, most have an average of 78.9 learning achievements, while the average learning achievements were 14.3. It was found that the dimensions of physical reactions (p=0.021), psychological reactions (p=0.03) and behavioral reactions (p=-0.035) were significantly related to learning achievements. As a conclusion, it was found that the physical, psychological and behavioral aspects of stress significantly affect the learning achievement of university students in the city of Juliaca.

Lake Baikal Microseisms Based on Regional Seismic Network Data

Seismic ambient noise in the regional seismic network in the central part of the Baikal rift is studied. The probabilistic approach is used to thoroughly investigate the pattern of diurnal variations in microseisms and to analyze amplitude level and frequency content of spatial anomalies and temporal changes (seasonal and annual). Based on the 2020–2021 data, a regional probabilistic model of the microseismic noise is built in a wide range of periods. The study of microseisms in the frequency band of about 1 Hz revealed a seasonal anomaly against the level of the global minimum in the microseismic noise power spectrum. The anomaly is observed from May to December at seismic stations surrounding Lake Baikal except for the northern part of the lake. The direction of the back azimuth in the frequency range of about 1 Hz indicates the location of the lake, suggesting that these signals can be identified as lake microseisms. The high coherence values suggest a linear relationship between the wind speed and the occurrence of lake microseisms. The detailed analysis of the spectral and polarization parameters of seismic ambient noise revealed two types of lake microseisms with frequencies of 0.4–0.7 and 0.7–1.5 Hz. The first frequency interval is likely to correspond to single-frequency lake microseisms, while the second interval contains the frequency ranges of dual-frequency microseisms.

A Critical Analysis of the Corporate Alternative Minimum Tax

ABSTRACT The corporate alternative minimum tax, enacted as part of the 2022 Inflation Reduction Act, intends to impose a minimum level of taxation on profitable large corporations using financial statement income as a tax base. Although both alternative tax bases and the usage of financial statement income in taxes have a long history in the United States, the tax represents a substantial change in the current corporate tax law. Although the corporate alternative minimum tax is predicted to raise billions of dollars from a small subset of the largest corporations, its design raises concerns about long-term efficacy. In this article, we summarize the development of the corporate alternative minimum tax in light of its historical predecessors and compare its design against accepted standards of good tax policy, ultimately identifying multiple inadequacies in its construction and implementation. We conclude by making policy recommendations. JEL Classifications: H21; H25; K34.

The Lifestyles of Space Standards: Concepts and Design Problems

Space standards are envisioned as a powerful means to regulate dwelling design, ensuring the quality, functionality, and safety of homes. Their ultimate objective is to guarantee a minimum level of design quality that can accommodate a wide range of domestic activities. While space standards primarily focus on isolated quantitative aspects such as overall size, room dimensions, and occupancy limits, they also make assumptions about activities to be performed by ideal “users” and specific lifestyles to be accommodated within a home. However, these assumptions are being challenged by the increasing demands and diverse activities taking place in the dwelling realm, which call into question the validity of existing space standards. In response to these challenges, this article conducts a critical review of the theoretical basis and various interpretations of space standards, particularly in the context of England. It explores their fundamental concepts and historical approaches, as well as examines specific examples of their application and their correlation with design strategies. By delving into the concepts of “the normal” and “the minimum dwelling,” the article discusses the three main dimensions of space standards: program, user, and size. Consequently, it argues for a more comprehensive understanding of the general application of space standards, which requires incorporating architectural design problems, particularly from the perspective of flexibility. This approach takes into account the evolving needs and diversity of households, as well as the creation of inclusive and adaptable living spaces.

Bio-safe drinking water with or without chlorine: a review

Abstract Drinking water biosafety has become an increasing concern for public health. Chlorination is widely used as the main disinfection strategy worldwide but has clear and well-known byproduct issues. The Netherlands has successfully demonstrated unchlorinated approach for almost 20 years but has not been widely adopted by other countries. To chlorine or not chlorine is becoming a critical question in front of all the water utilities. This review aims to provide a good overview of current biosafety management strategies, their disadvantages, as well as the latest developments and future trends. Firstly, the advantages and deficiencies of conventional disinfection and non-disinfection were discussed. Secondly, the commonly used and promising methods for biostability assessment are described. Finally, critical views on the strategy selection for ensuring drinking water biosafety were discussed. It is recommended to achieve both biological and chemical balance by removing pathogens while minimizing the organic matter and dosing a minimum level of disinfectants, which would represent the compromise choice between the current chlorine-based disinfection and chlorine-free strategy. It's worth noting that the complexity of ensuring biosafety lies in the variations among different regions, the selection of suitable methods should be tailored to specific situations on a case-by-case basis.

Levels of naturally occurring radioisotopes in local and imported bottled drinking water available in Québec City, Canada

Consumption of local and imported bottled water in Canada has greatly increased during the past three decades. While the presence of natural radioactivity is often overlooked when dealing with the water quality of these bottled products, it could contribute substantially to the uptake of radionuclides especially when sourced from regions with higher radioactivity levels compared to where it is consumed. In this study, the activity of several naturally occurring radionuclides (i.e., 210Po, 226,228Ra, 230,232Th, 234,235,238U) were measured in bottled water available in Québec, Canada after sample pretreatment and analysis by either radiometric or mass spectrometry approaches. 230,232Th and 228Ra concentrations were below minimum detectable activity levels in all samples tested. Analytical results for 234U, 235U, 238U, and 226Ra showed concentrations that ranged from 0.38 to 115 mBq/L, (2.2–313) x 10−2 mBq/L, 0.48–58.4 mBq/L, and 1.1–550 mBq/L, respectively. 210Po was detected in only 5 samples and its activity ranged from 2 to 26 mBq/L. To determine variability in activity within brands, the same brands of bottled water were purchased during two consecutive years and analyzed. The possible radiological impact of the consumption of these types of water was assessed based on different drinking habit scenarios. Some of the imported water brands showed higher activity concentrations than local sources or tap water, suggesting that individuals drinking predominantly imported bottled water would receive a higher radiation dose than those who drink mainly local water.

Exploring the relationship between seed weight and seed coat characteristics in the adlay (Coix lacryma-jobi L.) cultivar WATANI-2 through N, P and K treatment compositions

Adlay plant (Coix lacryma-jobi) grown in many Asian countries, as a source of carbohydrates. The cultivation of adlay faces challenges such as long growth periods, low yields, and hard seeds. Efforts to enhance productivity are crucial, specifically by applying Nitrogen, Phosphorus, and Potassium fertilizers at the appropriate and balanced doses that have not yet been established. Therefore, this study aimed to investigate the relationship between seed weight and seed coat characteristics under optimal N, P, and K fertilizer doses. The exploration process was conducted at the Research Station and Plant Production Technology Laboratory, Faculty of Agriculture, Padjadjaran University, from April 2019 to November 2020. Features of the location included an altitude of 750 – 800 m above sea level, a climate type C3 (Oldeman), an average temperature of 23.8oC, and a soil classified as Inceptisols with a pH of 5.83. The experimental design incorporated several treatments at minimum, optimum, and maximum dosage levels, namely N (90kg/ha, 180 kg/ha, and 270 kg/ha), P (37.5kg/ha, 75 kg/ha, and 150 kg/ha), and K (60 kg/ha, 120 kg/ha and 240 kg/ha) fertilizers, each was repeated twice. Fertilizer application was administered at the beginning of growth and the late vegetative phase, while P was given during the late vegetative phase and before seed formation. Subsequently, a regression analysis was performed to determine the relationship of the weight of 100 seeds with thickness and hardness, generating the equation: Y = 13.755 + 0.061 X1 + 0.012 X2, where X1 = seed hardness and X2 = seed coat thickness. Observations were carried out on the weight, thickness, and hardness of adlay seeds, both macroscopically by measuring length and width or diameter and microscopically through the evaluation of coat and silica layer thickness). The results showed a significant relationship between seed weight, thickness, and hardness, yielding 5.56 t/ha with an 80% land efficiency.

Residual life modeling and maintenance planning for repairable systems

Abstract Accepted by: Phil Scarf This paper formulates a state-dependent mean residual lifetime model for a repairable system operating in a dynamic environment. The problem is addressed by means of a two-state damage process reflecting the effect of operating environment on the system and a repair process associated with the damage process. As the damage process shifts to a higher state, to maintain a minimum level of performance, the decision maker repairs the system at times that arise according to a point process with a constant intensity. We demonstrate the generality of the proposed model and show how existing models emerge as specific cases. Our approach stimulates further research on the determination of two types of maintenance policies: maintenance policy based on the number of imperfect repairs (Model I) and time-based maintenance policy (Model II). In both cases, using the renewal reward theorem argument, we aim at minimizing the long-run average maintenance cost per unit time by determining optimal replacement policies and the optimal level of imperfect repairs. We illustrate the proposed models and carry out a comparative analysis of maintenance policies through numerical examples. The main conclusions drawn are that repair and maintenance policies depend on the failure mechanism, repair frequency and the level of costs involved. Also, numerical comparison shows that the maintenance modelling based on the number of imperfect repairs (model I) outperforms the time-based replacement model (model II) and two baseline models ignoring the effect of operating environment or whose attention is restricted to perfect repair.

Power sector carbon reduction review for South Korea in 2030

This study investigates the cost-effectiveness and decarbonization of four essential carbon reduction strategies to achieve Korea’s recent 2030 NDC (Nationally Determined Contribution) goal in the power sector. Examining overseas experiences and identifying potentials and challenges in implementing these strategies in Korea, this study explores the performance of future Korean power systems under fifty-four configurations combining these strategies. The evaluation results indicate that: 1) Thirty-one of the fifty-four tested configurations can achieve the emission target (149.9 MtCO2e) with carbon abatement costs (COA) ranging from -$89 to $105/tCO2e. The optimal configuration with the lowest COA is a combination of nuclear restoration and renewable expansion strategies. 2) Renewable expansion significantly reduces the COA and levelized cost of electricity (LCOE). A pure renewable expansion strategy with photovoltaics of 68 GW and wind turbines of 35 GW attains the emission goal at a COA of -$54/tCO2e, in which the generation share of renewables reaches 42%. 3) A carbon tax of $104/tCO2e achieves the target if complemented by nuclear restoration. Otherwise, $120/tCO2e is needed. The COA and LCOE are increases by switching from cheap coal to expensive natural gas in both cases. 4) Twenty percent coal–ammonia co-firing combined with a carbon tax of $32/tCO2e and nuclear restoration can achieve the goal with relatively high costs compared with the optimal strategies. However, a co-firing strategy is limited because the generation shrinks at a minimum level when 40%∼ mixing ratios are applied, or when the fuel price gap between ammonia and natural gas becomes large.

A Comprehensive Narrative Review on the Hazards of Bee Honey Adulteration and Contamination

Honey bees are renowned for producing a remarkable substance known as bee honey, which stands as a functional food celebrated for its numerous health benefits. This natural wonder possesses a spectrum of advantageous properties, including anti-inflammatory, antioxidant, analgesic, antibacterial, and wound-healing qualities. However, in our modern era of heightened utilization of bee products, a new and pressing global health concern has emerged—the contamination of honey with pesticides, antibiotics, microorganisms, and heavy metals. The consumption of beekeeping products containing pesticide residues has been linked to a range of health issues, including genetic malformations, cellular degradation, allergic reactions, and even potential carcinogenic effects. Troublingly, documented cases exist of botulism in newborns resulting from the ingestion of contaminated honey. Additionally, the use of antibiotics in beekeeping practices has been associated with the concerning emergence of antibiotic resistance. This comprehensive review sheds light on the substantial consequences of honey contamination for human health. It underscores the urgent need for the establishment of a rigorous monitoring system, the validation of minimum acceptable pollutant levels, and, at the very least, the regulation of maximum residue limits for bee products, with a particular emphasis on bee honey.

Behavior of functionally graded carbon nanotube reinforced composite sandwich beams with pultruded GFRP core under bending effect

A novel generation of composite sandwich beams with laminated carbon fiber-reinforced polymer skins and pultruded glass fiber-reinforced polymer core materials was examined for their flexural behavior. The strength and failure mechanisms of the composite sandwich beams in flatwise and edgewise configurations were investigated using three-point static bending tests. These sophisticated composite structures must be designed and used in a variety of sectors, and our research provides vital insights into their performance and failure patterns. In comparison to the reference specimens (FGM-1), the carbon nanotube-reinforced specimens’ bending capacity was affected and ranged from −2.5% to 7.75%. The amount of the carbon nanotube addition had a substantial impact on the beams’ application level and load-carrying capacity. Particularly, the application of 0.5 wt% additive in the outermost fiber region of the beams, such as in FGM-4, led to an increase in the bending capacity. However, the stiffness values at the maximum load were decreased by 0.3%–18.6% compared to FGM-1, with the minimum level of the decrease in FGM-4. The experimental results were compared with the theoretical calculations based on the high-order shear deformation theory, which yielded an approximation between 11.99% and 12.98% by applying the Navier’s solution.

Comparative Analysis of Morphological and Biochemical Traits in Fragaria × ananassa (Cv. Chandler) under Varied Cultivation Systems

The present research was carried out at Khalsa college Amritsar during 2018-19 to investigate the effect of different cultivation systems on the morphological and biochemical attributes of strawberry cv. Chandler under subtropical conditions of Punjab. The experiment was laid out in Randomized Block design by using eight treatments, each comprising three replications. The different planting systems including flat beds, raised beds, ridges, soilless media, polythene bags, cement pots, plastic crates and low poly tunnels were employed during this research. The runners of strawberry collected from Dr Y S Parmar University of Horticulture and Forestry, were utilized for the experiment. The morphological parameters such as fruit size, weight, number of achenes and biochemical parameters like Total soluble solids, acidity, sugars and ascorbic acid content were analyzed. The results of this present study revealed that maximum fruit length, breath, number of achenes were observed underlow poly tunnels. Similarly, the maximum TSS, total sugar content, ascorbic acid and minimum acidity level was recorded under low under poly tunnels. These outcomes strongly suggest the superiority of utilizing low poly tunnels for strawberry cultivation, emphasizing their potential to enhance both morphological traits and biochemical compositions compared to the other employed planting systems.

Voltage stability improvement and power losses reduction through multiple grid contingency supports

A stable power system is a desirable state for the optimal performance and delivery of electricity to the end-users. This study evaluates the effectiveness of grid contingency support devices in power system stability enhancement. The new voltage stability pointer (NVSP) was employed to optimally infer the flexible alternating current transmission systems devices through N − 1 contingency ranking. In this research, the static synchronous compensator (STATCOM) was considered as a grid support device. The effectiveness of this technique was validated in R2018a MATLAB with the IEEE 30-bus system using different combinable contingency cases to ascertain the critical lines and vulnerable buses to outages. Based on the results obtained through the NVSP, buses 30, 26, and 29 were cited as STATCOM candidate buses for overall optimal grid performance. The results obtained from the simulation revealed that the total real power loss was reduced by 90.21%. Similarly, the voltage magnitude of the buses was significantly improved to a minimum of 1.00 p.u. after placement of STATCOMs. Further investigation on single STATCOM placement in the IEEE 30-bus system revealed that the highest level of voltage improvement, minimum level of voltage deviation and maximum active power loss reduction was achieved when the STATCOM was placed at bus 30. The overall assessment of the proposed technique yielded better results compared with other methods on the same test system.

Validity and Reliability of Finger-Strength Testing in 6 Common Grip Techniques for the Assessment of Bouldering Ability in Men.

To determine the criterion validity and test-retest reliability of isometric finger-strength testing in 6 differentiated grip techniques for the assessment of bouldering ability among male climbers. We recruited participants at climbing gyms in Sweden and through online advertisements. We included climbers over 15 years of age with a minimum bouldering performance level of 17 International Rock Climbing and Research Association (IRCRA) for men and 15 IRCRA for women. We tested unilateral, maximal isometric peak finger strength in the front 3 drag, half crimp, closed crimp, 35 sloper, 45 × 90-mm, and 90 × 90-mm pinch through maximal force deloaded of a force plate. We analyzed criterion validity, test-retest reliability, and capacity to determine bouldering performance ability using a stepwise multivariable regression model. Women were excluded from the analysis due to insufficient sample size (n=16). Thirty-two male participants were included in the primary analysis. The median (interquartile range) age in the advanced and elite group was 27 (25; 35) and 23 (22; 32) years, respectively. The half crimp for the participants' weak and strong hand displayed the highest ability to determine bouldering grade performance, explaining 48% to 58% of the variance. In the stepwise regression, maximal strength in the half crimp and the front 3 drag collectively explained 66% of the variance for performance. Strength in the half crimp proved the most important performance indicator. The results of this study provide a reliable and valid framework for maximal isometric peak finger-strength testing in advanced and elite male boulderers.

Consistency Verification of Frequency Maintenance Criteria Based on Minimum Level of Inertia in South Korea

Consistency Verification of Frequency Maintenance Criteria Based on Minimum Level of Inertia in South Korea

Can redistribution of vaccine improve global welfare? Lessons from COVID-19.

The disparity in the distribution of COVID-19 vaccine has been recorded with more than 70% vaccination rate for high-income countries as compared to less than 40% for low-income countries. The low affordability of vaccines for the majority of low-income group invites the need for redistribution of vaccines. The disproportionate donation of vaccines across the globe motivates us to explore the incentive for the high-income group to redistribute. An exploratory analysis of cross-country COVID-19 vaccination distribution data shows that the countries which have received vaccines as donation has also contributed to vaccine wastage. This paper intends to provide a theoretical background for this counterintuitive observation using welfare analysis. We find that the market mechanism leads to a negative impact on global welfare due to redistribution. Only an invention with a defined redistribution mechanism may ensure an increase in global welfare. It is found that a critical value of redistribution mechanism reinforced by a minimum threshold level of income is essential to enhance welfare. The reduced form from the theoretical predictions is empirically validated with cross-country data on COVID-19 vaccination for all countries. As identified in theory, the internal support variables like political stability, government effectiveness, and health expenditure at the country level will impact global welfare. Therefore, when global cooperation is essential during a health crisis like COVID-19, improved internal coordination and intentions cannot be ignored.

Investment Portfolio Optimization Using Black-Litterman Model in Smart Carbon Economy Transition

An optimal investment portfolio needs to be formed before an investor invests because it can help investors determine which financial instruments are suitable to choose in order to get the maximum return or profit and the minimum level of risk. In the current situation, where there is an economic transition to a smart carbon economy or low carbon economy, it is necessary to form the optimal portfolio of stocks to facilitate investors in making investments. The purpose of this study is to form the optimal investment portfolio using the Black-Litterman model in a smart carbon economy. The data used is stock data from 24 companies listed on the LQ45 Low Carbon Leaders index for the period 2022-2023. Based on the research results, the Black-Litterman model generates the optimal portfolio with a 0.1% expected return. Thus, the optimal portfolio results with the Black-Litterman model are estimated to generate a profit of 0.1% for smart carbon stock data listed on the LQ45 Low Carbon Leaders index for the 2022-2023 period.

Performance of a novel cobalt phthalocyanine sulfonamide‐based catalyst for oxidative desulphurization of gas condensate

AbstractSulphur compounds and mercaptans in gas condensate cause corrosion problems, poison catalysts in catalytic processes, and have adverse environmental impact through SOx emission upon combustion. Therefore, it is essential to remove sulphur and mercaptan from gas condensate to standard levels. In this study, the oxidative desulphurization (ODS) process in the presence of a cobalt phthalocyanine sulfonamide‐based catalyst was investigated. The homogeneous catalyst containing 23 wt.% active material was used and optimum operating conditions of temperature, volume ratio of caustic to gas condensate, caustic concentration, and solvent amount were determined to decrease sulphur content to less than 500 ppm and mercaptan to less than 200 ppm. The catalyst consumption in all experiments was kept constant at a minimum level (0.01 g/400 mL gas condensate). Results showed that this catalyst improved the reaction rate in the lower temperature and lower caustic to feed ratio and lower caustic concentration. The maximum sulphur removal was obtained at 5°C and 4 vol.% of caustic to gas condensate ratio at 16.7 wt.% of caustic concentration. Moreover, this catalyst improved sulphur removal from the gas condensate to about 5% compared to caustic sweeting without catalyst. Sulphur compounds had higher solubility in acetone rather than methanol, and sulphur removal by acetone was 96% while it was 91% for methanol. Finally, the economical and acceptable solvent for sulfoxides removal was methanol with 5% volume fraction.

Assessment of knowledge, attitude, perception towards pharmacy practice regulations 2015 among community pharmacists in Mangalore

The Pharmacy Practice Regulations of 2015 were formulated to standardize and enhance pharmacy practices in India. Community pharmacy professionals globally are taking on expanded roles in patient care and health promotion. However, some lack awareness of recommended pharmaceutical care services in new regulations. This knowledge gap poses risks of medication errors and serious consequences, even patient fatalities. To address this, it's crucial to provide ongoing education, enhance communication, integrate technology, ensure regulatory compliance, and establish effective feedback mechanisms within pharmacies. These measures aim to improve knowledge, compliance, and, ultimately, patient safety. This study, conducted in Mangalore over a period of approximately 2.5 months, is a community-based cross-sectional study with a sample size of 100 participants. It included community pharmacists working in Mangalore. Knowledge of community pharmacists were analysed and it was found that out of 100 participants only 18% were aware, 60% were not aware and 22% were not sure about the PPR,2015. In this study, 42% of participants were not aware of the duties outlined in PPR,2015. Among the surveyed pharmacists, 55% believed that adhering to Pharmacy Practice Regulations was essential for improving patient healthcare. In contrast, 20% held the opinion that following these regulations was unnecessary, while 28% expressed uncertainty on the matter. Mandating minimum education level for working in community pharmacies should be implemented. Practicing pharmacists should be encouraged to update their knowledge by attending continuous education programmes. The morals and responsibilities of community pharmacists should be continuously reminded to the pharmacists.

Information technology, gender economic inclusion and environment sustainability in sub-Sahara Africa

PurposeThis study examines the relevance of information and communication technologies in the effect of gender economic inclusion on environmental sustainability.Design/methodology/approachThe focus is on a panel of 42 sub-Saharan African countries over the period 2005–2020. The empirical evidence is based on generalized method of moments. The environmental sustainability indicator used is CO2 emissions per capita. Three indicators of women’s economic inclusion are considered: female labour force participation, female employment and female unemployment. The chosen ICT indicators are mobile phone penetration, Internet penetration and fixed broadband subscriptions.FindingsThe results show that: (1) fixed broadband subscriptions represent the most relevant ICT moderator of gender economic inclusion for an effect on CO2 emissions; (2) negative net effects are apparent for the most part with fixed broadband subscriptions (3) both positive ICT thresholds (i.e., critical levels for complementary policies) and negative ICT thresholds (i.e., minimum ICT levels for negative net effects) are provided; (4) ICT synergy effects are apparent for female unemployment, but not for female employment. In general, the joint effect of ICTs or their synergies and economic inclusion should be a concern for policymakers in order to better ensure sustainable development. Moreover, the relevant ICT policy thresholds and mobile phone threshold for complementary policy are essential in promoting a green economy.Originality/valueThe study complements the extant literature by assessing linkages between information technology, gender economic inclusion and environmental sustainability.