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International Journal of Scientific & Technology Research

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IJSTR Volume 10 - Issue 11, November 2021 Edition - ISSN 2277-8616

All listed papers are published after full consent of respective author or co-author(s).
For any discussion on research subject or research matter, the reader should directly contact to undersigned authors.

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M. H. Kassar, S. Z. El-Abden, M. N. El-Sheikh

Thin-walled cup is considered as main parts in the development of aeronautic, aerospace, rocket capsule components, military industry, and other manufacturing process for daily use parts. These parts can be produced by conventional spinning with rollers or by ball spinning process. Recent development of ball spinning of tubes and thin wall thickness cup face challenge of large, consumed load due to material built up formation in front of the forming balls, this problem have been addressed separately in the literature without a unified approach to simultaneously overcome it. The current study introduces a new ball set design that is claimed to be able to overcome the pile-up problem simultaneously using a new forming tool based on ball spinning process or it can be called Ballizing technique. The new proposed design is built and verified. The proposed design consists of 4 balls distributed in four planes, having one ball in each plane. The first plane is set to suppress the pile-up formation, the second, third and fourth plane are set for the main forming process. Each two consecutive planes are shifted by 90 deg. from each other to suppress the folding creation. The results show that the new design has shown the potential to significantly overcome the pile-up formation in front of the forming balls beside its ability to complete the process with less forming force. The optimum rotational speed of the mandrel with the optimum feed rate of tool regarding the process load were determined.

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Maria J. Poblaciones, Concepcion Marin, Teodoro Garcia-White

As a way to control the spread of the COVID-19 virus, the global education system —including higher education— switched to digital education. Most of face-to-face educational strategies can be used in a virtual teaching, with slight adaptations. In the case of flipped classroom, the students are provided with learning resources before the class and online classroom time is used to deepen understanding through discussion with faculty and peers’ different problems. In this study, an optional experience of using flipped classroom, with first year students of Agricultural Engineering Grade in the subject Mathematics I, during online teaching period due to COVID-19 pandemic is described. Thirty-two of 76 students took part in this experience. More than 50% of them attended to 8 out of 10 seminars. Both the percentage of students who took the final exam and the qualifications, especially those above 6, were better for students involved in flipped classrooms. However, there was not a clear relationship between the marks obtained and the number of seminars received. Therefore, all the results show that this methodology is highly effective and has a great deal of take up among students.

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Kiki Franselaa, Edi Syahputra, Humuntal Banjarnahor

This research aims to: (1) To determine the validity, effectiveness, and practicality of learning media assisted by Macromedia flash; (2) To find out whether macromedia flash-based learning media through the jigsaw type cooperative learning model can improve the mathematical spatial ability of 11th grade student of RPL at PAB 2 Helvetia Vocational High School Students. This research uses the Thiagarajan 4-D development model and the product in this research is Macromedia flash-assisted learning media on three-dimensional material. This research was conducted at PAB 2 Helvetia Vocational High School Student which is one of the vocational high schools in Deli Serdang Regency in the even semester of the 2019/2020 academic year on three-dimensional material. The subjects in this study were students of 11th grade student of RPL at PAB 2 Helvetia Vocational High School Students. The results of this study indicate that: (1) the developed learning media has met the valid, practical, and effective criteria; (2) mathematical spatial ability has increased after using Macromedia flash-based learning media.

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Mostafa A. Hussien, Abeer A. Sharfalddin, Mariusz Jaremko

Molecular docking is a highly sophisticated method that has been utilized in drug design in various biological fields. We are currently suffering from the global pandemic caused by the new coronavirus (SARS-CoV-2), which advanced rapidly and needs immediate action. Therefore, to find an effective anti-viral drug for SARS-CoV-2, thirteen natural products with high bioactivities against another series of viruses were screened for their interactions with the SARS-CoV-2 at different stages of viral development using molecular docking. Among the investigated herbal medicines, Saikosaponin C exhibited the highest docking scores and strong and stable binding interactions with all chosen proteins. The practical binding energy score of Saikosaponin C was -11.79 KJ/mol with 1O86 protease, which represents ACE2, the first infection stage target protein. Moreover, it also showed strong binding (-11.4 KJ/mol) to proteases PLpro (Papain-like protease) PDB = 4OW0, which represents the last stage of virus replication in the host cell. Therefore, we suggest that, after further validation and investigation, this extracted molecule can be used as a potential inhibitor against SARS-CoV-2.

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Ahmed A. H. A. Al-Farhan, MAHMOUD A. A. HAMMOUDA

The bill for the cost of electricity production in most countries is very high, and therefore these countries tend to develop ways to save electricity consumption. Refrigeration and air-conditioning devices are among the highest devices that consume electricity, so the general trend is how to reduce the consumption of these devices. The main component of electricity consumption is the compressor. This paper deals with the types of fixed-speed and inverter-operated compressors, as well as the types of electric motors that operate on DC and those that work on variable current, and the traditional control methods in air conditioning systems and those that use modern methods to save energy.

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Peter Iacobelli

The causal mechanism from which Alzheimer’s Disease (AD) originates has yet to be illuminated in full, although significant progress has been made in that very direction. Ideas have been put forth since the disease’s founding by Dr. Alois Alzheimer over 100 years ago that have implicated the beta amyloid (Aβ) peptide in the onset and progression of the disease in its exclusively elderly population of patients, as aggregations of this antimicrobial protein formed plaques in the autopsied brain of the earliest studied AD brain and in all of those that have come after her. Because increased availability of improved technology has allowed for greater observational tracing of the disease, it has come to be known that the quantity of Aβ deposition is directly proportional to the severity of the behavioral symptoms observed of the patient in question. This left little doubt as to whether or not Aβ played an important role in the exacerbation of AD, and it is on these grounds that ideas such as the common amyloid cascade hypothesis have been put forth. While incomplete, these long standing frameworks for thinking about the intricacies and causal mechanisms of AD have given way to more complete theories on the matter such as the cyclical immunoreactive theory of AD. Nonetheless, all plausible frameworks surrounding the onset and progression of AD afford the majority of their focus to Aβ, while ignoring some of the more peripheral, though important elements of AD. Perhaps the only rival to Aβ in terms of prevalence, consistent presence, and potential causal involvement is the tau protein. Having also been observed very early on in the autopsied brains of AD patients by Dr. Alzheimer the microtubule associated protein (MAP) tau has been shown to aggregate in a manner similar to that of Aβ in the AD brain. These accumulations of the pathological protein are called neurofibrillary tangles (NFTs), and no doubt play a role similar to Aβ plaques in the slow yet consistent progression of the neurodegenerative disease. This text will assess the role of the tau protein in the brain of AD patients, and review relevant studies on the subject all with the aim of defining its role within the context of what is thus far the most complete framework for diagnosing and describing the intricacies of AD.

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Francis Makombe, Manoj Lall

The pressure to improve on success rates is greater on private HEIs than on public funded HEIs, as their main source of funding is from fees collected from students. Poor success rates will undoubtedly affect private HEIs’ reputation and funding. To minimise the impact of a poor success rate amongst students, it is important to be able to identify students at risk of failing at an early stage, so that a more targeted remedial action could be taken. Private institutions apply various strategies such as making provision for extra tuition, extended laboratory access and establishing learning communities. From the discussion presented here, it is apparent that the timely identification of students at risk of failing a particular programme is of significant importance to both the students and the institutions they are registered with. In this article, artificial neural networks, extreme gradient boost, logistic regression, support vector machine, naive Bayes, and random forest are used for the classification of students. A dataset of 3 000 students were collected from a private higher education provider. It was observed that artificial neural networks produced the best performing model with an accuracy of 88.07%.

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Ardi Friyatna, Syarif Hidayatullah, Yusaq Tomo Ardianto

Good governance is one of the main reform that aim to realize good governance in providing services to the user that are carried out consistently. Service activities provided by the Office of Communication, Informatics and Statistics of Blitar City are periodically assessed for their performance based on their performance level user satisfaction. The problem that some people still complain about is the service time to the user which is considered too long for the user. This study is to analyze the effect of management information systems, public service performance, on the user satisfaction index through service quality at the Office of Communication and Information Technology of Blitar City. The sample used in this study is 149 employees. The method used is linear regression analysis. The results showed that partially there was a significant effect of management information system variables, public service performance and service quality on the user satisfaction index. The management information system indirectly has no significant effect on the user satisfaction index through service quality. Public service performance has no significant effect on the user satisfaction index through service quality at the Blitar City Communications and Information Office.

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Al-shaymaa K. Dyab, Mohamed A. EL Aghoury, Sherif M. Ibrahim, Amr B. Saddek

This paper presents experimental and numerical investigations to assess the feasibility and efficiency of using carbon fiber reinforced polymer (CFRP) strips as a strengthening technique in improvement the shear capacity of corrugated web steel beams (CWSBs). Experimental investigation is conducted on five CWSBs, with one control un-strengthened specimen and four strengthened specimens. The study takes into consideration different CFRP strips schemes (bonded on horizontal folds only or both horizontal and inclined folds), arrangement (bonded on one-fold side or both-fold sides). A numerical investigation is conducted using a finite element (FE) model developed in ANSYS software. The FE model results are validated against the experimental ones. The proposed FE model proved to accurately reflects the real overall behavior and the ultimate loads of both un-strengthened and strengthened CWSBs. The results demonstrated the efficiency of using CFRP strengthening technique in enhancement the shear capacity of CWSBs up to 68.61% depending on CFRP configuration.

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Dr. Mostafa shendy, Mohammed Balbola, Emila Paul, Dr. Ebthal Hassan

Introduction: Bladder herniation is a relatively uncommon condition, most of the cases are diagnosed intraoperatively as the patient is often asymptomatic, however; few patients could develop dysuria, frequency, incomplete emptying, and even acute kidney injury. Surgical repair is considered the standard treatment of bladder herniation. Presenting case: A case of a 69-year-old male presented after noticing a right groin lump while he was gardening, computerized tomography detected complete herniation of the bladder into the right scrotum associated with bilateral hydroureteronephrosis. Afterward, the patient developed acute kidney injury which required urethral catheterization and two-stage voiding. Bladder reduction and mesh surgical repair were performed, and the patient recovered without any complication. Discussion: Bladder hernia represents 1-4% of the inguinal hernia. It is related to multiple factors like obese men, weak pelvic floor muscles, decrease muscle tone, in addition to benign prostatic hyperplasia. It could involve herniation of part of the bladder or complete herniation of the bladder into the inguinal canal. The herniated bladder is a relatively uncommon condition so it should be suspected if the hernia is accompanied by significant urinary symptoms. Our case is considered the perfect presentation for bladder hernia. The patient presented with the common complication as he had acute kidney injury, incomplete bladder emptying, which required two-stage voiding, and discovered the right testicle blood supply is compromised during the repair. In addition to that, he was diagnosed preoperatively properly. Moreover, he was managed by surgical repair as recommended. Conclusion: Scrotal-inguinal cystocele is an uncommon condition that could lead to acute kidney injury and need to be managed urgently with surgical repair.

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Hanan Hussien Eltobgy, Anwar Badawy Abu-Sena, Omer Nazmi Abdelnabi

Carbon Fibers Reinforced Polymers (CFRP) are widely utilized to strengthening various structural elements in order to sustain higher loads or to restore the strength of the deteriorated elements. This paper aims to investigate the behavior of hollow steel beams reinforced by unidirectional carbon fibers composite laminates applied in longitudinal and transversal directions. Experimental and numerical investigations were conducted in this study. Six specimens of rectangular hollow sectional (RHS) were subjected to a four-point loading test and divided into two groups. Each group of three specimens was tested in different positions “Mx and My”. Each group included one reference beam and two, specimens strengthened with CFRP laminates in longitudinal and transversal directions. Ultimate loads and deflection were determined through the tests. Numerical analysis was performed using a finite element program in order to determine the failure load of beams. Results of finite element model were verified with their experimental counterparts, it is found in a good agreement. As per experimental results, using the CFRP strengthening system effectively improved the strength and the ductility of strengthened beams. Also, strengthened beams with longitudinal laminates achieved a higher improvement compared to strengthened beams with transversal laminates.

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Anwar Badawy Abu-Sena, Hanan Hussien Eltobgy, Omer Nazmi Abdelnabi

This paper aims to study the impact of hollow steel beams reinforced by carbon fibers reinforced polymers (CFRP) applied in transversal directions. Experimental and numerical investigations were carried out in this study. This study has focused on the impact of increase the number of wrapping layers. Six specimens of rectangular hollow sectional (RHS) were included in the experimental study. Specimens were subjected to a four-point bending test and divided into two groups according to the case of applied bending moment; the First group was subjected to bending moment about the major axis while the second group was subjected to bending moments about the minor axis. The behavior and strength of specimens were determined through the experimental tests. The numerical model was developed using a finite element program in order to predict the failure load of tested beams. Results of the numerical model were verified with the corresponding results of the experimental test, and a good agreement was observed. As per experimental results, transversal wrapping systems of CFRP can delay the buckling occurrence of strengthened steel beams. Hence, it is capable of improving the strength and the deflection of strengthened beams. Also, increasing the number of CFRP wrapping layers in the strengthening system, increase the improvements compared to strengthened beams with a single layer of CFRP.

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Prive Widya Antika, Happy Nursyam, Arning Wilujeng Ekawati

Dunaliella sp. is one type of green microalgae that can be used as natural food because it is easy to digest. In mixotrophic culture, microalgae in their growth carry out the process of photosynthesis and use organic carbon nutrients to produce energy. Choice of organic carbon sources for growing Dunaliella sp. using waste cassava. The organic carbon content in waste cassava is still very complex, so that Dunaliella sp. for its growth, it can be done by breaking down carbohydrates into simple glucose using hydrolysis with the addition of a-amylase and glucoamylase enzymes. This research has 2 stages, stage 1 is the hydrolysis of waste cassava using a-amylase and glucoamylase enzymes. Phase 2 research on microalgae Dunaliella sp. mixotrophic cultured using organic carbon as a source of glucose from the hydrolysis of waste cassava. The results showed that the administration of the enzyme a-amylase 3.15 µl/g and glucoamylase 2.10 µl/g was able to break down carbohydrates into glucose in waste cassava by producing a glucose level of 34,285 mg/L. The administration of glucose organic carbon from different waste cassava under mixotrophic cultured significantly affected the growth of Dunaliella sp. The best glucose concentration was 0.30 g/l with the highest average density of 6.5 x 106 cells/ml, the specific growth rate was 1.04 days-1 with a doubling time of 0.66 days.

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Sudarlan, Omar Dhanny, Irmanita Yuliati

The aim of the research is to identify the most determinant elements affecting the quality of audit in East Kalimantan, Indonesia. The variables are used to influence the quality of audit in this paper such as independence, competence, integrity, objectivity and work experience. This study used questonaries to obtain the data from the auditors who live in Balikpapan dan Samarinda cities with five likert scales to express the respondent’s opinions. In processing it, used SPSS Package to check the validity and the reliabilty test and Eviews softwares to check the impact of the independence to dependence variables. The new interesting finding in this paper that only two variables have positive impact and statistically significant on the quality of the audits that are the integrity and objectivity variables. Otherwise the three other variables are not significant such as independence, competence and work experience. The value of the research is as a reference for the future related topic to a quality of the audit.

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Xiaopeng Zhou, Peng Cao, Mingfei Wang

Traditional control method of printing-oils for color offset press is usually based on a single computer system, which has many inconveniences in realizing remote control and centralized management. We designed a CMYK oil-supply control system based on cloud, edge and end-devices. The system is divided into clouds layers, the edge layer and the field equipment layer. The computer is used as the server of the cloud layer and the edge node of the edge layer, design a visual interface through LabVIEW software. STM32 is used as the core controller of the master station and the slave station of the field equipment layer. The STM32 of the master station is transplanted with μC/OS-Ⅲ operating system and LwIP protocol Stack. The master station is connected with the slave station by RS485 bus, and it is connected with the edge node by Ethernet, which realized multi-task scheduling and completed the protocol conversion. Experiments show that system has reduced the delay of transmission by 80% compared to the traditional technology, and the control precision of supply-oil-keys have increased some, at the same time, it also has better performance in real-time and reliability.

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Houda RHILANE, Insaf EL IDRISSI, Abdelhadi EL MOUDDEN

The aim of this paper is to study and analyze the ability of the MPPT control designed for a photovoltaic system to ensure the search and continuity of the maximum power point at the output of a photovoltaic generator, under standard test conditions as well as during climatic changes (Illumination and temperature). For comparison, we have dealt with two different methods, the incremental conductance and the perturbation and observe. Both methods allowed the system to maintain its maximum power point in each case of study but with some differences. For this, we chose MATLAB/Simulink as the platform used to perform simulations of all the study cases.The emphasis was put on obtaining a system that presents a better adaptation between its different components: photovoltaic generator (GPV) and load. The PV system used in this study consists of a photovoltaic array that - under standard test conditions (T=25°C and G=1000W/m²) - is characterized by a peak power of 59.5 W, an optimal voltage of 17.5V and a current of 3.4A.

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ISSN 2277-8616
IJSTR - January 2022 - Volume 11 Issue 1