Perception and Representation of Drug Consumption by Finalist Students of the Kele-Kele Educational Institute in Kananga, Central Kasai Province

Abstract

Introduction: The spread of drug use in schools is growing from year to year, requiring the intervention and involvement of all stakeholders in order to stem this scourge. This study sought to understand the perception and representation of students at the Kele Kele Educational Institute on drug consumption. Methods: This is a study that is part of the field of mental health, school health component. It is of the qualitative phenomenological type. 38 students from the Kele Kele Educational Institute were interviewed. Data analysis was carried out using the phenomenological reduction method. Results: The results showed that students perceive drug consumption in 2 ways: drugs are like food and also like an intellectual stimulant. So drugs as a physical tonic capable of changing mood. In this, they represent drugs as a stimulant in different moods of the organism. For young people, drugs provide a feeling of self-control and well-being; On the other hand, unfavorably, drugs produce a feeling of headache or weakness. And in most cases the finalist students of the Kele Kele Pedagogical Institute consume two types of drugs: hemp and alcohol. Conclusion: Faced with the scale of drug consumption in schools and the negative consequences it has on social and academic development, health, and youth, it seemed imperative for parents of students to take the problem seriously. Arm the body. But to fight against the consumption and marketing of drugs in schools, the Congolese youth ministry should make a plea for a definitive cessation.

Share and Cite:

Mulamba, P.N., Bukasa, A.K., Kabamusu, C.K., Muyaya, T.T., Tshibasu, G.T., Mikobi, S.K., Kamba, M.N., Kabanga, C.K., Augustin, T.B., Tshiamanga, S.K., Maka, G.M., Wabuza, R.S. and Makangu, A.T. (2023) Perception and Representation of Drug Consumption by Finalist Students of the Kele-Kele Educational Institute in Kananga, Central Kasai Province. Open Access Library Journal, 10, 1-12. doi: 10.4236/oalib.1110718.

1. Introduction

The misuse of psychoactive substances is undoubtedly a global problem that is given special attention in almost all countries of the African continent. Globally, cannabis remains by far the drug most widely used by young people with an annual prevalence of use between 2.6% and 5% in 2010 [1] .

According to the UN (2015), 5% of the world’s population has used illegal drugs, the figure of users has increased by 80% in one year mainly due to the growing population as cannabis, consumed by more than 160 million people in 2003 [2] . Laure Com-Ruelle, Nelly Le Guen (2013) show that tobacco and alcohol are the substances most frequently experimented with between the ages of 12 and 18 [3] .

The consumption of licit and illicit drugs is responsible for the annual loss of 130,000 human lives in France and a considerable health and social cost. Direct expenditure of public finances amounts to 22.1 billion euros or almost 1% of GDP. The high level of use of these substances in adulthood is explained by a very early start in their consumption, then by regular progressions, as shown by the three series of prevalence surveys carried out between 2010 and 2017 among adolescents. from 11 to 17 years old. These consumptions therefore constitute a major public health problem to which it seems important to provide priority responses. Among 35 countries, in terms of consumption by young people aged 16 over the last 30 days, France ranks 1st for cannabis, 3rd for other illicit drugs, 11th for tobacco and 15th for alcohol. Adolescence constitutes a period of particular vulnerability to addictions due to the absence of neuropsychological maturity. Many factors can facilitate the transition to addiction, whether genetic, environmental, or linked to psychiatric vulnerability or personality traits. Generally speaking, drug use during adolescence is likely to cause numerous disorders [4] .

Drug use among young people is a concern for families and public authorities. At the end of adolescence, nine out of ten young people have already drunk alcohol at least once during their life (91%), almost seven out of ten have already smoked a cigarette (68%) and a few more than four in ten use cannabis (41%) although a majority of these initiations remain limited, both in time and in the quantities consumed, a significant proportion of adolescents indulge in excessive consumption likely to affect their schooling, their development, and even, in the longer term, their health and cognitive abilities [5] .

A survey carried out in Canada on tobacco, alcohol and other drugs showed that 20.6% of young people aged 15 to 19 said they had used drugs in the last 5 years, therefore in 2017 [6] .

The increase in alcohol consumption among younger generations rightly raises awareness and concerns public opinion. Its consequences are numerous and are a subject of major concern not only for political leaders, health, justice and education professionals but also for parents [7] .

Currently in Vietnam, according to a recent survey by the Central Institute for Mental Health Studies, the consumption of synthetic drugs has unfortunate consequences on mental and physical health as well as on behavior, especially among young people. Around 68% of consumers are affected by phases of delirium, 72% of hallucinations and 23% of depression. However, unfortunately, there is still no drug for detoxification [8] . Furthermore, heavy and regular use during adolescence can harm mental health, lead to the onset of psychotic symptoms and double the chance of being diagnosed with schizophrenia [9] .

The consumption of psychoactive substances is widespread despite the ban, the problems of managing these substances must be solved by other means. Models of regulation are constructive means to consider any chain of production, transformation, trade until consumption, in such a way as to make possible both the desire of individuals for better recreation and the demand for safety and the protection of minors and adolescents in Congolese society.

The studies carried out so far by the National Program for the Fight Against Drug Addiction and Toxic Substances (PNLT) with the support of its partners, 3% of Congolese children aged 10 to 19 are poly-drug addicts and 11% with violent behavior. According to the Ministry of Gender, Family and Child (year), 15,654 cases of sexual violence due to alcohol and drug abuse were recorded in 2012, an increase of 52% compared to 2011, of which 98% were against women. The average age varies between 12 and 17 years [10] .

Thus, in Kasai Central, drug use remains a main cause of serious crime and death. In most of our schools, many students, due to the influence of the environment, consume drugs and the most frequent are tobacco and alcohol, which are sold even in the vicinity of the schools.

Our study, like others, shows how important it is today to take an interest, more than has been done until now, in alcohol consumption behavior among children and young adolescents. Only the understanding of the perception and representation that adolescents have of drug consumption can allow the development and implementation of effective strategies for the fight against this scourge. The present study aims to understand the perception and the representation of the pupils of the Pedagogical Institute of Kele Kele on the consumption of drugs.

2. Material and Method

2.1. Type and Framework of the Study

We conducted a descriptive qualitative study of the phenomenological type in order to explore the perception and representation of finalist students on drug use. The study is conducted at the Kele Kele Pedagogical Institute, in the city of Kananga, Kasai Central Province, in the Democratic Republic of Congo.

2.2. Target Population and Sampling

As part of our research, the target population is made up of all finalist students at the Kele Kele Pedagogical Institute. We used non-probability purposive sampling, that is to say, we selected the participants according to the needs of the study. These units were selected on the basis of this characteristic of drug users, which could provide the possibility of having precise information on the phenomenon. Amuli Jiwe and Ngoma Mandevo (2012), consider the purposive sample as one which is made up of units that are within the reach of the researcher [11] . Our sample size was built up gradually during field data collection. A total of 38 finalist students including 26 boys and 12 girls were selected for this study.

2.3. Data Collection Technique and Instruments

The face-to-face semi-structured interview technique is the one we used to collect the data, using an individual guide composed of open-ended questions allowing respondents to express their perception and representation in their own terms. While respecting the principle of informed consent, the information delivered during the interview was recorded on our telephone and memory card followed by the transcription on paper with a view to analyzing the content. During data collection, we reached data saturation with 38 finalist students.

2.4. Data Collection Process and Survey Conduct

Data collection took place exclusively from a free face-to-face interview scheme because we wanted to have the respondents’ perceptions and try as little as possible for their answers, we used open-ended questions and let them tell their story. It was thus possible for us to study in depth the individual’s life trajectory and to highlight the common characteristics of each participant.

This collection was carried out thanks to an interview guide, this instrument was developed by us according to the memory stimulus research questions and before moving from one question to another, we made the restitutions to the interlocutor about what had been said. Data collection took place from 11/20 to 12/10/2022, i.e. 21 days.

2.5. Data Analysis Plan

Data analysis was carried out using the phenomenological reduction method. This aims to emerge the hidden meanings inherent in the descriptions made by the subjects of the phenomenon studied. This step consisted of finding meaning or significance in the data collected in the verbatim form and demonstrating how they answered our research questions.

The steps followed in this analysis are: Transcribing the materials several times; the choice of units of meaning or meaning units; identification of general themes; categorization and classification.

2.6. Ethical Consideration

Respondents were informed that they could withdraw from the study at any time if they did not subscribe and finally, we guaranteed them the anonymity and confidentiality of the information collected after data analysis. In addition, we obtained the consent of the minors’ guardians to facilitate our understanding of the phenomenon in this age group.

3. Results

Our results are presented in two parts, those linked to the socio-demographic characteristics of the respondents, as well as those linked to the themes retained from the central theme.

3.1. Sociodemographic Variables of Respondents

Table 1 shows that male students are in the majority compared to female students (i.e. 68.4%), marital status all are single (i.e. 100%). The age group that comes first is that of 17 to 20 years (i.e. 73.7%). Christians are in the majority (i.e. 50%), in the rank of the fraternity, intermediaries occupy 1st place (i.e. 50%) and most live in the commune of Katoka (i.e. 50%).

3.2. Results Related to Thematic Analysis

After reading our transcriptions of the interviews recorded with 38 participants who used the syntactic analysis unit in a closed encoding of the interviews, the central theme retained is: “drug use by the finalist students of the Pedagogical Institute of Kele Kele”.

From this central theme retained, four sub-themes arise:

- Perception of finalist students on drug use;

- Representation of student finalists in drug use;

- Feelings of finalist students in drug use;

- types of drugs chosen by the finalist students.

1) Perception of finalist students on drug consumption

Students perceive drug use in two ways: drugs are like food and also like an intellectual stimulant. So drugs as a physical tonic capable of changing mood.

They are expressed in the statements below.

… Well, for me, consuming alcohol is good because I don’t know why people are used to seeing us badly. It’s a product made with corn and cassava and it encourages you to eat a lot (laughing)… Student 1.

Table 1. Sociodemographic variables of respondents.

People think that when we consume drugs, we become crazy, delinquent, no, they are natural things created by God for example, hemp is the leaves that God created. “Student 12”.

Dad!!! you know that for me, drugs are more than fufu, bread and even tea. Me, before going to school, I can take hemp or diazepan to strengthen my abilities… “Student 33”.

… There is no harm in me taking liquor, only if I consume that, I take mastery… “Student 13”.

Usually, at our place we sell alcohol and Filtered, that’s why every morning, I take it soothes the stomach and it makes you sleep, that’s why I take a little morning and evening… “Student 25”.

When I consume, I become strong and able to understand the material, once finished, I understand nothing… “Student 16”.

I want us to accept hemp that we are allowed to smoke, even if we are students because it’s like thirst, you see white people smoke everywhere, and that’s why they become more intelligent than us. “Student 17”.

At home, my dad takes drugs and he’s good with us, what’s the problem even if I also take a little, we often say like father, like son, I look like my dad in every way. “Rep 8”.

2) Representation of finalist students on drug consumption

The participants have a positive view of drugs, they say that it is a remedy and a sexual stimulant, a stress-relieving substance that gives courage.

This is what they approve in the quotes below:

… I have the habit of consuming especially at night, if I don’t smoke or drink liquor, I don’t sleep. “R3”.

Good!!! (laughing), when I do drugs, I gain courage and then I’m not ashamed even if the teacher scolds me, it doesn’t make me feel cold or hot. “Student 4”.

Drugs are cough medicine. It cures a lot of things, we sell it at the market, in the shops and there are vermin, at the liquor store it’s the consumers. “Student 5”.

I am Musala Mpasu, with us it is above all hemp that dominates. When I take it, I feel that there is a difference in my body and then, having smoked, I gain nothing except that the thoughts fly away. “Student 6”.

What pushed me to take drugs were worries. A girl from our neighborhood refused me and I had too many worries, I started drinking alcohol in order to take away the worries and the images of this girl whom I had loved very much. “Student 11”.

I am an orphan. However, when I think of my mother’s death, I cry, but to get rid of my worries, I take strong liquors. “Student 7”.

My old man, you yourselves are going to see our teachers smoking, Ah! Forget it, they are real professionals in alcohol and Filtered, I can tell you others but, … you see a teacher teaching without shame so, he took it. “Student 28”.

3) Feelings of finalist students while consuming drugs

Young people experience favorable and unfavorable feelings: drugs provide a feeling of self-control and well-being; On the other hand, unfavorably, drugs produce a feeling of headache or weakness. They endorse this in the receipts collected below.

… If I haven’t taken some drugs, in any case, I feel bad, and angry all the time, I can even fight with 5 people. “Student 18”.

I tell you it gives you control, calm and appetite. You yourself look at how bad our country is, but if you drink alcohol, Oh! you even have the idea of joining our FARDC. “Student 35”.

When I’m angry and I take this, it allows me to calm my anger, I feel at ease without any problem, there I am in the land of agents. “R1 and R3”.

Every day, given the difficulties of paying my study fees, I have a little alcohol and it makes me feel good. “Student 36”.

When I drink alcohol my mood changes, sometimes if I have had a lot my head hurts and I regret drinking. “R2”.

Oh my there there! When I take it afterwards, I get too tired, sometimes I vomit and I have no appetite. “Students 37 and 34”.

4) Types of drugs chosen by the finalist students

By analyzing the statements, we note that the finalist students of the Kele Kele Pedagogical Institute consume two types of drugs: hemp and alcohol.

Ndemba’s alcohol here (Angene), to remove my high “Student 21”.

At home we sell filtered alcohol, all kinds of alcohol, every morning, before going to school, I take a measure of 88. “Student 24”.

We, as we don’t want anyone to find out, we bring the hemp in our bags, during recess, the others eat the peanuts, we have hemp or next to our school, we have our client from Tshitshiampa (alcohol), it even gives us debt and Filtered. “Student 25 and 27”.

I only take cigarettes because my father also takes that, an adage says: like father, like son. “Student 38”.

Me, especially beer and hemp, I become calm and many girls envy me. “Student 36”.

For us, it is first of all ndemba (alcohol), especially mixed with maternal plants, it is not felt at that time. “Student 23”.

I mainly drink liquor and hemp.

4. Discussion

The profile of our respondents indicates that male students are in the majority compared to female students (i.e. 68.4%). Our results found here are comparable to those found by Lushiku Tshisungu (2017) [12] . Marital status: all are single (i.e. 100%). The age group that comes first is 17 to 20 years old (i.e. 73.7%). Christians are in the majority (i.e. 50%), in the rank of the fraternity, intermediaries occupy 1st place (i.e. 50%) and most live in the commune of Katoka (i.e. 50%). The results in relation to the age group are compared to those of Lushikyu Tshisungu (2017), according to which the age range is 17 to 26 years (66%) [12] . Furthermore, Laure Com-Ruelle & Nelly Le Guen. (2013) show that tobacco and alcohol are the substances most frequently experimented between ages 12 and 18, but their progression between these ages differs [3] . Another study conducted by Bailly et al. demonstrated that 73.4% reported having already experimented with alcohol and 3.7% having already been drunk at least once; 5.4% (8.5% among boys and 2.4% among girls) reported consuming alcohol at least once a month and can, as such, already be considered “regular” consumers. There was a close correlation between “regular” alcohol consumption, the experience of intoxication, tobacco use and cannabis experimentation. Compared to other students, these “regular” consumers had significantly more emotional, relational and social adaptation difficulties, and they had already integrated a rather “positive” image of alcohol [7] .

Regarding the results of the thematic analysis, students perceive drug consumption in 2 ways: drugs are like food and also like an intellectual stimulant. So drugs as a physical tonic capable of changing mood. It is appropriate to note the results in line with the general trend which shows that drug consumption is observed in all human societies. These substances have multiple functions: pleasure, care, conviviality, etc. and statuses that evolve over time since they can be legal or illegal, available with free access or under certain conditions. They are often associated with the notion of danger [13] . Furthermore, Nikiéma et al. highlight some factors associated with drug consumption: spending evenings away from home without parental authorization (OR-CI 3.82 [2.50 - 5.83]), the fact of “skipping classes” (2.14 [1.52 - 3.02]), consumption in the entourage both among parents (1.50 [1.05 - 2.15]) and by friends (5.66 [4.02 - 7.96]). For alcohol, the factors most significantly associated with consumption by students are consumption within the family circle (5.52 [3.83 - 7.96]) or by friends (3.55 [2.56 - 4.91]) and cannabis use by students is mainly associated with having a friend who uses it (16.29 [5.89 - 45.03]) [14] .

Regarding the representation of finalist students on drug consumption, the participants in our study have a positive view of drugs, they say that it is a remedy and a sexual stimulant, a de-stressing substance that gives courage. It has been shown that in the contemporary social context, the consumption of illicit recreational drugs occupies an increasingly significant place, particularly among the population of young adults aged 18 to 24. They thus have access to numerous substances with varied psychoactive effects and which affect sexual behavior and functions in multiple ways. Among these drugs, the consumption of ecstasy is becoming more and more widespread and several studies, especially of a quantitative type, have been devoted to the study of its effects on sexual response [15] .

Young people experience favorable and unfavorable feelings: drugs provide a feeling of self-control and well-being; On the other hand, unfavorably, drugs produce a feeling of headache or weakness. These results meet the statement of a respondent in the study by Enoka et al. (2022) who explains that Regarding the causes of the consumption of psychotropic drugs, the collection and analysis of the data in this study show that, in descending order Of importance, the reasons for consuming tobacco, alcohol, cannabis and other psychotropic drugs lie in the fact that friends use it, we want to do it out of curiosity or just to get drunk and get “high” [16] . Even more, other respondents say that it is because it is “cool”, to relax and forget about your problems. These reasons are however not the only causes because for Dubé et al. (2007) young people who use psychotropic drugs are popular and do so to break the ban or challenge school authority, and parents and to pass the time [17] .

By analyzing the statements, we note that the finalist students of the Kele Kele Pedagogical Institute consume two types of drugs: hemp and alcohol. Obradovic (2015) explains that, like its common use in the adult population (8.8 million regular users), alcohol plays a major role in adolescent drug use. they drink their first glass of alcohol before experimenting with any other psychoactive substance and experience their first intoxication on average one year later (around fifteen years). At seventeen, one in ten adolescents drinks alcohol regularly (at least ten times in the last month) and one in two reports occasional heavy drinking in the last month (at least five drinks on the same occasion) [18] . In the study by Goullé and Morel, they report that the ESCAPAD 2017 survey shows that at 17 years old, the diffusion of alcohol remains massive, even if it is in decline during the period 2014-2017: experimentation, minus 3.6%; regular use (more than 10 times per month), minus 3.8%; API, minus 5.4%. As for occasional heavy drinking (API, i.e. 5 or more glasses of alcohol on a single occasion during the past month), the ESPAD 2015 survey indicates that it is more common among boys than girls (35% vs. 28%). The frequency of APIs among young French people at 16 is lower than the European average (31% vs. 35%), which ranks the country in 23rd position out of 35. The decline in APIs is a general phenomenon in Europe, and France is a country showing one of the largest declines in this area between 2011 and 2015 [4] .

Search Limits

This study is geographically restricted to the Kele Kele educational institute in the commune of Katoka in Kananga. we cannot extrapolate it to other neighborhoods or municipalities.

The study is also limited by its sampling, students who could represent particular characteristics in terms of their education. These students may or may not be representative of all students, but it is their statements (verbalisation) that matter, hence the need to complete this study for quantitative research.

This study made it possible to understand and have an image of what young learners (humanities finalist students) have about drug consumption.

In addition, this study will serve as a support for all partners who are involved in the education of adolescents in order to take as a starting point the perceptions and representations of the latter in order to see to what extent and how to constitute educational messages to support these young people.

5. Conclusions

The spread of drug use in schools is growing from year to year, requiring the intervention and involvement of all stakeholders in order to stem this scourge. This study sought to understand the perception and representation of students at the Kele Kele Educational Institute on drug consumption.

Approached using a qualitative approach, the results showed that students perceive drug consumption in two ways: drugs are like food and also like an intellectual stimulant. So drugs as a physical tonic capable of changing mood. In this, they represent drugs as a stimulant in different moods of the organism. Faced with the scale of drug consumption in schools and the negative consequences it has on social and academic development, health, and youth, it seemed imperative for parents of students to take the problem seriously. arm the body. But to fight against the consumption and marketing of drugs in schools, the Congolese youth ministry should make a plea for a definitive cessation.

Acknowledgements

We sincerely thank the authorities of the Pedagogical Institute of Kele Kele, for having facilitated us by allowing us to contact the population of the health area to collect data.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] World Health Organization (2016) The Health and Social Effects of Nonmedical Cannabis Use. https://apps.who.int/iris/handle/10665/251056
[2] ONU/SIDA (2015) Rapport Mondial sur les drogues 2015 de l’ONUDC: La consommation de drogues doit être traitée comme une question de santé publique prioritaire. https://www.unaids.org/fr/resources/presscentre/featurestories/2015/june/20150626_wdr
[3] Com-Ruelle, L. and Guen, N.L. (2013) Les jeunes et l’alcool: évolution des comportements, facteurs de risque et éléments protecteurs. Questions d’économie de la santé n°19. https://www.irdes.fr/recherche/questions-d-economie-de-la-sante/192-les-jeunes-et-l-alcool-evolution-des-comportements-facteurs-de-risque-et-elements-protecteurs.pdf
[4] Goullé, J.-P., and Morel, F. (2020) Rapport 19-09. Consommation de drogues licites et illicites chez l’adolescent: Une situation alarmante qui impose une prévention précoce. Bulletin de l’Académie Nationale de Médecine, 204, 4-15. https://doi.org/10.1016/j.banm.2019.11.007
[5] Spilka, S., et al. (2012) Les drogues à 17 ans: Premiers résultats de l’enquête ESCAPAD 2011. Tendances n° 79-Février 2012 I. http://www.ofdt.fr/BDD/publications/docs/eftxsps2.pdf
[6] Statistique Canada (2015) Enquête canadienne sur le tabac, l’alcool et les drogues (ECTAD): sommaire de 2015. https://www.canada.ca/fr/sante-canada/services/enquete-canadienne-alcool-drogues/sommaire-2015.html
[7] Bailly, D., Rouchaud, A., Garcia, C., Roehrig, C. and Ferley, J.-P. (2015) Consommation d’alcool chez les jeunes adolescents: Enquête en milieu scolaire. Archives de Pédiatrie, 22, 510-517. https://doi.org/10.1016/j.arcped.2015.02.016
[8] Magasine Le corrier du Vientman (2019) Drogues en milieu scolaire, un véritable fléau. https://lecourrier.vn/drogues-en-milieu-scolaire-un-veritable-fleau/636515.html
[9] OMS (2022) Alcool. Stratégie mondiale visant à réduire l’usage nocif de l’alcool. En ligne sur. https://www.who.int/fr/news-room/fact-sheets/detail/alcohol
[10] Programme National de lutte contre les Toxicomanies et les Substances Toxiques (2016) Plan quinquennal de couverture du programme national de lutte contre les toxicomanies et des substances toxiques 2016-2020. RDC. https://untobaccocontrol.org/impldb/wp-content/uploads/reports/drc_2016_annex2_five_year_plan_on_addictions_2016_2020.pdf
[11] Amuli Jiwe, J.P. and Ngoma Mandevo, O. (2012) Méthodologie de la recherche scientifique, De la conception à la publication. Edition Médiaspaul, Kinshasa, RDC, 302.
[12] Lushiku Tshisungu, S. (2017) Vécu quotidien des jeunes consommateurs des drogues dans la zone de santé de Kingabua. Mémoire de Licence en santé Communautaire. Institut Supérieur des Techniques Médicales de Kinshasa, République Démocratique du Congo.
[13] Nguyen, A. (2022) La consommation de drogues en France. Actualités Pharmaceutiques, 61, 18-24. https://doi.org/10.1016/j.actpha.2022.02.006
[14] Laetitia, N.,et al. (2011) Consommation des psychotropes en milieu scolaire, au Burkina Faso : Prévalences et facteurs de risque. Science et technique, Sciences de la santé, 34, 100-112.
[15] Garceau-Brodeur, M.-H. (2007) Ecstasy et sexualité: Une étude exploratoire au Québec. Drogues, santé et société, 5, 111-133. https://doi.org/10.7202/015696ar
[16] Patrice, E., et al. (2022) Consommation des psychotropes chez les élèves du Lycée Classique et Moderne de Bafia: Causes, conséquences et mesures de prévention. Cameroon Journal of Biological and Biochemical Sciences 2022, 30, 52-63.
[17] Dubé, G., Isabelle, M., Tremblay, R. and Issouf, T. (2007) Enquête québécoise sur le tabac, l’alcool, la drogue et le jeu chez les élèves du secondaire, 2006. Québec: Institut de la statistique du Québec.
[18] Obradovic, I. (2015) Usages de drogues et société addictogène. Adolescence, 33, 177-192. https://doi.org/10.3917/ado.091.0177

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.