bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties Investigation of Steel-TiC Composite Material Formed during Selective Laser Melting Process
Authors: Kolchanova Anna Vladimirovna , Kolchanov Dmitry Sergeevich , Grigoryants Alexander Grigoryevich
Published: March 2023

This paper is devoted to the parts formation from composite materials in the process of selective laser melting. Composite materials are of great interest, as they allow to combine properties of the composite constituent elements and expand parts manufacturing possibilities. Parts manufacturing from composites by selective laser melting (SLM) is interesting because the composite material is formed during the build process. There is a wide opportunity to combine the composition of the raw material for powder. Special attention is paid to composites with TiC-reinforced steel matrix. The results of manufacturing samples with different contents of carbide reinforcing elements are presented in this paper. The region of selective laser melting build parameters is highlighted, in which an almost continuous structure with a minimum number of defects is formed. Mechanical tests of the built samples were carried out. The influence of the TiC concentration on the mechanical properties, as well as on the change in the mass of the samples, was revealed.
Microstructure and Fatigue Behavior of High-Performance Aluminum Alloy Al2024 Produced by Laser Powder Bed Fusion
Authors: Konečná Radomila , Varmus Tibor , Nicoletto Gianni , Uriati Federico
Published: March 2023

Aluminum-based alloys are widely used in high-performance structural applications. Therefore, the opportunity to fabricate aluminum components using Laser Powder Bed Fusion (L-PBF) is a matter of great interest. In particular, the Al2024 alloy is extensively used for conventional part production but its processability by L-PBF remains a challenge because of its hot cracking sensitivity upon solidification. The new Reactive Additive Manufacturing (RAM) technology by Elementum 3D enables the production of innovative powders characterized by metal matrix and nanoceramic particles that can be processed using L-PBF. The ceramic nanoparticles of 2 % by weight improves properties and prevents Al2024-RAM2 alloy cracking during solidification. The present study investigates the fatigue performance of Al2024-RAM2 alloy manufactured by L-PBF using an SLM 280 HL equipment with a nominal layer thickness of 60 µm. A set of miniature vertical fatigue specimens were manufactured then underwent to a heat treatment T6. The specimens were tested in the as-built state (i.e., without any surface post-processing) under cyclic plane bending at a load ratio R = 0 at a frequency of 25 Hz. The fatigue performance was determined and compared to that of another Al-alloy produced by L-PBF. Specimens were examined by using optical microscopy and SEM analysis to determine the microstructure. The fracture surfaces of vertical specimens were investigated in the SEM to determine the mechanisms of crack initiation.
Study the Effect of Deposition Time on Optical Properties of CdZnS Nanofilms
Authors: Mohammed Kahtan A. , Hessan Reyam Sabah , Musa Sarab J. , Alkhafaji Mohammed Ayad , Zabibah Rahman S.
Published: March 2023

The optical properties of CdZnS nanofilms are studied in this paper in relation to the deposition time. Deposition times ranged from 15 to 60 minutes for the CdZnS thin films, which had been developed on surface of glassy substrates. The other factors, such as reactant concentration, solution pH, and bath temperature, were held constant throughout the deposition process. The films were annealed at 200 °C for 120 minutes in a thermal furnace after the deposition process. Measurements of absorbance, transmission spectrum, and direct and indirect energy gaps were made using UV-VIS spectrophotometers. Transmittance in the 400-1000 nm range was 70-90 percent for all of the prepared films. With a wavelength of 600 nm and higher, transmittance was around 90%. CdZnS films have bandgap energies ranging from 2.4–2.15 eV for direct transitions and from 2.1–1.97 eV for indirect band gaps.
Suitability of Conventional Ballast Mixed with Concrete Debris and Bottom Ash Waste
Authors: Duraisamy Youventharan , Jeevithan K.M. , Othman Rokiah , Sulaiman Mohd Arif
Published: March 2023

The use of waste materials as a substitute for natural aggregate has been widely tested in all areas of the construction industry. Yet, there is a lack of study on the suitability of the physical properties of waste material when used as one of the components in track ballast. This study evaluates the suitability of conventional ballast (CB) incorporated with concrete debris (CD) and bottom ash (BA) as track ballast material. To achieve the objective, sieve analysis, shape analysis, specific gravity test, water absorption test, and permeability test were carried out. Furthermore, microscopic analysis was used to validate the presence of voids. The result shows that the waste mixed ballast has a coefficient of uniformity (Cu) in the range of 1.92 to 12, a coefficient of curvature (Cc) in the range of 0.8 to 1.18, fines less than 14 mm account for 0.1 % to 28 %, and the mean size is in the range of 22.5 mm to 27.5 mm. Furthermore, the flakiness ranged from 7.56% to 22.5%, the void ratio was 0.43 to 0.55, and water absorption was 2.86% to 4%. The specific gravity was found to range from 2.30 to 2.77 when the permeability measurement was in between 30 cm/sec to 61 cm/sec. All these promising values of engineering properties exhibit the confidence of a suitable alternative to track ballast materials. Hence, CD and BA waste materials incorporated into conventional ballast have a high potential to exhibit better performance and reduce the dependency on natural aggregate.
Tannic Acid/Polyvinyl Alcohol as a Wellbore Strengthener for Water-Based Drilling Fluid in Natural Gas Hydrate Reservoir
Authors: Wang Xing Xing , Jiang Guan Cheng , Wang Guo Shuai , Yang Li Li , He Yin Bo , Wu Xiao Ya
Published: March 2023

In South China Sea, the natural gas hydrates are usually reserved in argillaceous siltstones. These argillaceous siltstones are weakly cemented and incorporated with the solid hydrates. During the drilling process, the natural gas hydrates may decompose unexpectedly, resulting in the wellbore collapse. To improve the stability of the wellbore, this study develops a wellbore strengthener for water-based drilling fluids used in argillaceous siltstones. Tannic acid/polyvinyl (TA/PVA) alcohol has been adopted for preparing the wellbore stabilizer. A series of experiments have been conducted to investigate the effects of newly developed wellbore strengthener on the mechanical properties of the argillaceous siltstones as well as its mechanisms on the wellbore stability. The experimental results show that the wellbore strengthener developed in this study can significantly improve the compressive strengths of the argillaceous siltstone cores. The AFM characterizations indicate that the adhesion force between the silica (the major compound in argillaceous siltstones) microspheres and the wellbore strengthener can reach up to 2138 nN. Moreover, the SEM images visually show good cementation of the argillaceous siltstones after being treated by the wellbore strengthener. In addition, the wellbore strengthener can also assist in reducing the fluid losses of water-based drilling fluids. It is hopeful that the wellbore strengthener provided in this study help the development of underwater natural gas hydrates.
Dose-dependant preventive effect of a herbal compound on crystal formation in rat model
Authors: Güzel Rasim , Erïhan İsmet Bilger , Özaydin İsa , Aydin Uğur , Bağcioğlu Murat , Kocaaslan Ramazan , Yildirim Ümit , Sarica Kemal
Published: March 2023

Introduction: To analyze the dose-dependent preventive effect of a plant-based herbal product on the new crystal formation in a rat model.
Materials and methods: A total of 42 rats were divided into 7 groups and zinc discs were placed into the bladder of rats to provide a nidus for the development of new crystal formation: Group 1: control, Group 2: 0.75 percent ethylene glycol (EG); Group 3: 0.75 percent EG plus 0.051 ml of the compound; Group 4: 0.75 percent EG plus 0.179 ml of the compound; Group 5: 0.75 percent EG plus 0.217 ml of the compound; Group 6: 0.75 percent EG plus 0.255 ml of the compound; Group 7 0.75 percent EG plus 0.332 of the compound).
The analysis and comparison focused on the disc weights, changes in urinary oxalate and calcium levels, urinary pH, and the histopathologic evaluation of the inflammatory changes in the bladder after 14 days.
Results: According to the evaluation of discs placed in the bladders of the animals, animals receiving the herbal compound on a dose-dependent basis showed a limited increase in the disc weights values after 14 days, despite a considerable increase in animals receiving EG alone (p = 0.001). Further evaluation of the increase in disc weights on a dose-dependent basis in different subgroups (from Groups 3 to 7) demonstrated that the limitation of crystal deposition began to be more prominent as the dose of herbal compound increased. This effect was more evident particularly in comparisons between group 7 and others, according to LSD multiple comparison tests (p = 0.001).
As anticipated, there has been no discernible change in the weight of the discs in the control group. Although urinary calcium levels in animals of Groups 2, 6, and 7 were significantly higher than the other groups, we were not able to demonstrate a close correlation between urinary oxalate levels and the increasing dose levels. Even though mean urine pH levels were statistically considerably higher in Group 3, there was no statistically significant correlation between the oxalate and calcium levels between all groups, and no association was seen with the administration of herbal agents. The transitional epithelium between the three groups of animals' bladder samples did not exhibit any appreciable difference according to pathological analysis.

Conclusions: In this animal model, the treatment of the compound was successful in lowering the amount of crystal deposition surrounding the zinc discs, most noticeably at a dosage of 0.332 ml, three times per day.
Stillbirths’ microbiology: a favorable time for post-mortem microbiology
Authors: Bonanno Roberta , Iacopino Olga Stefania , Cucinotta Mario , D'Aleo Francesco
Published: March 2023

Post-Mortem Microbiology (PMM) aims to detect infections that could be a cause of stillbirth. A newborn having no sign of life after delivery is defined as stillbirth. Different infections could cause a chain of events leading to stillbirth but the relationships between maternal infection and stillbirth are often not very clear; as a matter of fact, the positive serologic tests do not prove causality. Screening, prevention, and treatment of maternal infections are important to reduce the stillbirth risk. The identification of an infectious agent that causes stillbirth through PMM is a shared aim by microbiologists, pathologists and surgeons, and it is also the common goal in clinical and forensic autopsies. The aim of this paper is a review the major infections that lead to stillbirths.
Shaping, and disinfecting abilities of ProTaper Universal, ProTaper Gold, and Twisted Files: A correlative microcomputed tomographic and bacteriologic analysis
Authors: Sivakumar Malavika , Nawal Ruchika Roongta , Talwar Sangeeta , Baveja CP , Kumar Rega , Yadav Sudha , Kumar S Santosh
Published: March 2023

Aim:

The purpose of this study was to assess the canal shaping ability and reduction of Enterococcus faecalis (E. faecalis) by ProTaper Universal (PTU), ProTaper Gold (PTG), and Twisted File (TF) systems, using microcomputed tomography (µCT).

Methods:

Distobuccal canals of 36 extracted human maxillary molars were inoculated with E. faecalis American Type Culture Collection 29212 for 28 days. Thirty-three specimens (three excluded due to contamination) were randomly divided into three groups with 11 specimens in each group, according to the instrumentation system that was utilized: PTU, PTG, and TF. Sterile distilled water was used as the irrigant during preparation. Paper points had been used to collect samples from the root canals both pre- and postpreparation, and bacterial quantification was done to examine the bacterial reduction. Pre- and postinstrumentation µCT scanning of roots were done to analyze the shaping ability.

Results:

After preparation, all three techniques significantly lowered the amount of E. faecalis while also significantly increasing the canal volume (P < 0.001). Intergroup comparison of the % of bacterial reduction and uninstrumented area disclosed no significant differences (P > 0.05), whereas the increase in canal volume of the PTU was significantly higher than PTG and TF, and that of the PTG was significantly higher than TF.

Conclusion:

It may be concluded, within the constraints of this in vitro study, that PTG and TF had better shaping ability than PTU, whereas no difference was found in their ability to reduce bacterial load.
Comparative evaluation of fracture resistance of simulated immature teeth restored with apical plugs of mineral trioxide aggregate, Biodentine, and bone cement: An in vitro study
Authors: Gudapati Swapnika , Satish R Kalyan , Sajjan Girija S , Varma K Madhu , Kumar V Santosh , Kumar M Sitaram
Published: March 2023

Aim:

This in vitro study aimed to compare the fracture resistance of simulated immature permanent teeth restored with apical plugs of mineral trioxide aggregate (MTA), Biodentine, and bone cement.

Methods:

Forty-eight single-rooted human maxillary central incisors were selected and decoronated 6 mm above and 9 mm below the cementoenamel junction to simulate the immature teeth. Based on weight and homogeneity, the samples were distributed into three experimental groups (n = 12) and one control group (n = 12). In all the experimental group samples, a peeso reamer size 5 was stepped out 1 mm beyond the apex to enlarge the apices to a diameter of 1.5 mm. Apical plugs of MTA Plus (Prevest DenPro Limited, India), Biodentine (Septodont, France), and Bone cement (Surgical Simplex P, Stryker, Australia) were placed to 4 mm, and obturation was done using gutta-percha and AH Plus® sealer (Dentsply DeTrey, Konstanz, Germany). The force was applied at 45° angulation until fracture, using the universal testing machine. The results were analyzed using a one-way analysis of variance followed by Tukey’s post hoc test at a 95% confidence level.

Results:

The Biodentine group showed a statistically higher fracture resistance value than the MTA Plus and bone cement group (P = 0.014 and P = 0.016, respectively). No statistically significant difference was reported between MTA Plus and the bone cement group.

Conclusion:

Within the limitations of this study, using Biodentine as an apical plug increases the fracture resistance of immature teeth. Bone cement can be used as a viable alternative to MTA.
Estimating the Burden of Tuberculosis in India: A Modelling Study
Authors: Mandal Sandip , Rao Raghuram , Joshi Rajendra
Published: March 2023

Background:

Measurements TB incidence and mortality are crucial for monitoring progress towards SDG goals for TB. Until recently, WHO estimated TB burden in India with applied simple, transparent equilibrium models to data from Gujarat, an Indian state where the first state-level prevalence survey was conducted in 2011. However, since then there has been several interventions in India including national TB prevalence survey, infection survey, sub-national survey & certification which gives opportunity for national and sub-national estimates for TB incidence and mortality.

Methods:

We developed a model is a compartmental, deterministic framework, taking account of TB natural history, as well as India’s healthcare system including health care seeking from public and private sector. To address changes in TB burden owing to COVID disruptions, we followed same model that used by WHO in the global TB Report 2022 with additional impact of delta wave in 2021. Major sources of data included National TB Prevalence survey, trends in caseloads in public and private sector including their contribution and mortality information.

Results:

We estimated total TB incidence of 2.77 million in the year 2022 as against 2.97 in the year 2015 and corresponding TB mortality of 0.32 and 0.36 million respectively. In terms of rate per 1,00,000 TB incidence in 2022 was 196 as compared to 225 in the year 2015 and mortality was 23 and 27 respectively. TB incidence estimates are similar to what was estimated by WHO, while mortality estimates appear different in our estimates due to different calibration targets depending on in-country published data.

Conclusion:

Even if TB burden is infeasible to measure directly, a range of data can nonetheless offer indirect evidence for its estimation: mathematical modelling can be a helpful tool for bringing together these diverse sources of evidence, and deriving estimates that are consistent with them all. While the RGI reported mortality is an important source of information, its quality and coverage for medically certified cause of deaths requires improvement in India.
Primary Tuberculosis of Maxillary Sinus – A Rare Case Report
Authors: Patil Seema , Shree A. Latha , Subhash B. V , Shriyanka R.
Published: March 2023

Tuberculosis of the maxillary sinus is uncommon. Primary tuberculosis involving the sinus is very rare, and it is generally secondary to pulmonary involvement. The clinical presentation of this condition is vague and not pathognomonic. This may result in an incorrect diagnosis leading to complications. An unusual presentation of primary tuberculosis affecting the maxillary sinus in a 54-year-old male is discussed in the present case report.
The Economic Freedom Fighters of South Africa:What do they Stand for, and who Votes for them?
Authors: Mtimka Ongama , Prevost Gary
Published: March 2023

The Economic Freedom Fighters (EFF) have emerged as a significant force in South African politics during the past eight years. Still, only a few scholarly  studies have been published analysing its ideology, strategy, and tactics, who is voting for the party, and why. The authors argue that the EFF had  emerged as a challenger to the African National Congress (ANC) by positioning itself to the left of the ruling party with a set of ideas and policy proposals  that emerged from the ANC Youth League when current EFF leader Julius Malema led it. Survey and exit polling data analysed by the authors indicate that  the EFF is gaining traction election by election with younger black voters in the townships on issues of land and jobs and, in the process, threatens  the single-party dominance of the ANC in future South African elections. However, despite a good start, the party appears to have lost some momentum  after the fall of former President Jacob Zuma and made some tactical mistakes.
Comparative impact of Covid-19 and common diseases on poverty in Cameroon and sustainable response strategies
Authors: Defo Charles Michel Chomssem
Published: March 2023

In the context of a developing country like Cameroon characterized by the scarcity of financial resources and the appearance of Covid-19, this article  shows that this pandemic was not more important than the pre-existing health problems to the point of giving it more importance in funding compared  to strengthening the health system. The theoretical elasticity model of the poverty rate to growth is used to estimate the impact of Covid-19 and the  incidence of impoverishing health expenditure is used for the impact of common diseases. It is estimated through direct health payments that common  diseases push about 340,865 people into extreme poverty annually. The Covid-19, through the loss of growth generated between 4.8 and 6.6 points  according to the optimistic or pessimistic scenarios, would impoverish between 224,193 and 398,565 people: impact on the number of poor ranging from  0.7 to 1.2 times that of all common diseases, i.e., equivalent on average, but sensitive to the speed of spread of the virus and the duration of the  crisis while the impact of common diseases is structural and linked to the poorly performing health system. The solutions proposed are endogenous and  linked to the impact mechanisms.
Itikadi na ufundishaji wa nadharia za uhakiki wa fasihi
Authors: Wafula Richard Makhanu
Published: March 2023

Ufundishaji wa nadharia za uhakiki wa fasihi ulipoanza, ilifikiriwa kwamba hatimaye fasihi imefanikiwa kupata silaha za kiuhakiki na kiakademia za kutegemewa. Wahakiki na wananadharia wa Kimagharibi kama Wellek na Warren (1986) walifikiria kwamba nadharia ya uhakiki wa fasihi ilikuwa moja popote fasihi iliposomwa. Hivi sasa katika Karne ya 21, nadharia ni nyingi na zinaendelea kuundwa kuendana na mazingira anuwai ambamo wahakiki wanapatikana. Makala hii inanuia kuonesha kwamba wingi wa nadharia zilizopo unaashiria uchimuzi wa itikadi zinazoratibisha kuwapo kwa nadharia hizo. Japo Wellek na Warren walikuwa wakizungumzia kuhusu nadharia katika umoja wake, walikuwa wakiitikia masuala ya kiitikadi. Jambo hili linahusu fasihi ya Kiswahili vilevile.
Matumizi ya kanuni za utambuzi wa mofimu za Nida (1949) katika utambuzi wa mofimu za lugha ya Kiswahili
Authors: Ndumiwe Elishafati J. , Jasson Tasiana
Published: March 2023

Utambuzi wa mofimu katika lugha tofautitofauti huongozwa na kanuni za kimajumui zilizopendekezwa na Nida (1949). Kanuni hizo zimehakikiwa katika baadhi ya lugha za Afrikasia ambazo ni Kiyoruba, Kigala na Kihausa. Hata hivyo, kuna utofauti kati ya lugha za Afrikasia na lugha za Kibantu. Isitoshe, kanuni hizo haziko bayana katika lugha za Kibantu. Kwa hiyo, makala hii inahakiki matumizi ya kanuni za utambuzi wa mofimu katika kuchambua mofimu za lugha ya Kiswahili. Data ya makala hii imekusanywa kutoka Kamusi ya Kiswahili Sanifu (2013) kwa kutumia mbinu ya upitiaji wa nyaraka. Aidha, uchambuzi wa data umeongozwa na mkabala wa mofimu kama umbo na maana uliopendekezwa na Rastle na Davis (2008). Matokeo ya makala hii yanaonesha kwamba kanuni tano kati ya sita zinafaa katika kuchambua mofimu za lugha ya Kiswahili. Kanuni hizo ni ya kwanza, ya pili, ya nne, ya tano na ya sita. Kanuni ya tatu haitumiki katika kutambua mofimu za lugha ya Kiswahili kwa sababu maumbo yanayoelezwa na kanuni hii hayamo katika lugha ya Kiswahili kutokana na tofauti za kimuundo kati ya lugha moja na nyingine. Aidha, tumependekeza kuwa uundwaji wa kanuni uendane na maumbo ya lugha tofautitofauti kwa sababu ya umajumui wake.
Assessment Of Adenoid Nasopharyngeal Ratio In Children With Symptoms Suggestive Of Obstructive Adenoid Disease
Authors: Dahilo E.A. , Itanyi U.D. , Yikawe S.S. , Folorunsho D.F. , Ibekwe T.S.
Published: March 2023

Background: Adenoid hypertrophy (AH) is a common childhood illness that occurs due to obstruction of the nasopharynx by enlarged adenoids. Lateral  nasopharyngeal X-ray is used for diagnosis and assessment of patency of the nasopharyngeal air column by assessing the Adenoid Nasopharyngeal  Ratio (ANR). This study aims to assess the ANR of symptomatic patients with AH that presented to Ear, Nose and Throat/ Head and Neck Surgeon  (ENT/HNS) Department of the University of Abuja Teaching Hospital (UATH).

Methodology: This was a retrospective study conducted in the ENT/HNS Department of UATH, Gwagwalada from January 2019 to December 2021. The  case notes and lateral nasopharyngeal xrays of 112 children aged between 3 months to 15 years, diagnosed with Adenoid Hypertrophy, were retrieved.  Relevant information such as demographics, and Lateral Nasopharyngeal X-ray measurements were extracted.

Results: A total number of 112  participants were enrolled into this study. Out of these, 77 (68.8%) were males and 35 (31.2%) were females. The mean  age of participants was 3.86 0.27 years, and age range was 3 months to 15 years. Most participants were between 0 – 5 years. The mean ANR among  participants was 0.69 0.02. The minimum ANR was 0.03, and the maximum ANR was 1.00 Majority of participants had ANR 0.69. None of the participants  between 10 – 15 years had an ANR > 0.79. Regression analysis showed statistically significant correlation between ANR and Age (p = 0.05).

Conclusion: We  observed an Adenoidal Nasopharyngeal Ratio that was lower than the benchmark of ANR considered for AH, this may probably be due to  our inability to control the timing for obtaining the radiographs from clinic visit and some may have commenced treatment
Combination of SCCT and TPB in explaining the social entrepreneurial intention
Authors: Anh Bui Ngoc Tuan , Minh Pham
Published: March 2023

Social enterprises are an emerging field in the world. Social enterprises are expected to help solve social problems that the government and commercial enterprises do not want or do not plan to deal with in the near future. This article uses social cognitive career theory and theory of planned behavior to help explain the social entrepreneurial intention of Vietnamese students. The study was conducted from August 2020 to February 2021 with the participation of 587 students. The results after being analyzed by PLS-SEM have shown the important role of the two above theories in the desire to become a social entrepreneur, Specific factors such as perceived behavior control and self-efficacy have the strongest impact on social entrepreneurial intention. This finding will help policymakers have appropriate solutions to promote the formation of social entrepreneurs in Vietnam.
Coordinating supply and demand applied Bass diffusion modelling
Authors: Tram Nguyen Thi Bich
Published: March 2023

Demand management concerns what customers need and want, while supply management focuses on producing products/services to fulfill demand. It is challenging in coordinating demand and supply from both sides. Multi-method modeling, which is an interesting combination between system dynamics and agent-based models, is adapted to address this issue through the Bass diffusion model to replicate a non-competitive supply chain, including a retailer, a wholesaler, and a factory in this study. The research findings show that there is a bullwhip effect on the supply chain due to sudden changes in demand impacted by marketing efforts, namely advertising, words of mouth, and electronic words of mouth. It is recommended that in the process of sales and operations planning, businesses should implement, measure, and estimate marketing effectiveness corresponding with supply capabilities. Additionally, through the study, the strengths and weaknesses of the multi-method simulation in facilitating business research reflect through multiple scenarios running with cost and time efficiency, as well as the validity of the study findings associated with modelers’ decisions on the model’s level of simplicity and elaboration.
Analysis of factors influencing blockchain implementation in finance sector in Sri Lanka
Authors: Abeysekera Manisha C. , Kumarawadu Priyantha
Published: March 2023

The global finance industry is highly impacted by fintech innovations and technology transformations due to rapidly evolving emerging technologies. Blockchain has become one of the key emerging technologies to bring promising results in the finance sector. These transformations and the use of decentralized ledger systems would contribute to significant changes in financial transaction processing and with the advent of distributed ledger technology and its ability to enforce better transparency, blockchain is becoming a disruptive force in the finance industry. This research investigated challenges in implementing blockchain solutions in the finance sector in Sri Lanka. The Interpretive Structural Modeling (ISM) based approach was used to investigate relationships between identified factors that influence blockchain solutions. According to the results of the study, the factors with higher driving power included lack of trust in new and immature technology, lack of regulations and governance, lack of standardization, cost of implementation, and interoperability issues with legacy systems. The results of the study emphasize the importance of regulatory bodies to develop new rules and regulations to support the technology transformation and blockchain vendors to provide better interoperability and standardization across platforms.
Các yếu tố ảnh hưởng đến khả năng tiếp cận chương trình tín dụng vi mô: Trường hợp chương trình cho vay phụ nữ ở Thới Lai, Cần Thơ
Authors: Phượng Đặng Thị Kim , Khôi Phan Đình
Published: March 2023

Bài viết phân tích các yếu tố ảnh hưởng đến khả năng tiếp cận chương trình tín dụng vi mô của phụ nữ tại huyện Thới Lai, Thành phố Cần Thơ. Thông qua dữ liệu thu thập từ 160 quan sát phụ nữ tại huyện và sử dụng mô hình Probit, kết quả nghiên cứu chỉ ra các yếu tố: giá trị tài sản, số lần tham dự cuộc họp, thu nhập, dân tộc và việc làm có ảnh hưởng đến khả năng tiếp cận chương trình tín dụng vi mô của phụ nữ. Dựa trên kết quả, bài viết đề xuất một số giải pháp giúp phụ nữ nâng cao khả năng tiếp cận chương trình tín dụng vi mô bao gồm phụ nữ tích cực tham gia vào hội phụ nữ ở địa phương để xây dựng thêm vốn xã hội, trong khi chính quyền địa phương tăng cường hỗ trợ phụ nữ tiếp cận chương trình.
Hàm Cobb-Douglas hay hàm Translog? Nghiên cứu thực nghiệm tại Việt Nam
Authors: Cảnh Trần Quang , Phức Vũ Trực
Published: March 2023

Trong kinh tế học và kinh tế lượng, hàm sản xuất Cobb-Douglas và hàm Translog thường được sử dụng rộng rãi để biểu thị mối quan hệ kỹ thuật giữa lượng của hai hoặc nhiều yếu tố đầu vào và lượng đầu ra. Tuy nhiên, theo khảo lược từ các nghiên cứu trước thì đa phần đều sử dụng hàm Cobb-Douglas, cũng có một số nghiên cứu sử dụng hàm Translog hoặc cả hai hàm trong một nghiên cứu. Tuy nhiên, việc so sánh kết quả phân tích của hai dạng hàm này hầu như chưa được đề cập đến.

Bài viết này sử dụng số liệu thống kê đầu vào là GDP Việt Nam từ 2009 - 2019, thực hiện phân tích bằng cả hai hàm Cobb-Douglas và Translog. Kết quả nghiên cứu cho thấy từ việc so sánh độ lệch chuẩn, so sánh đồ thị giá trị dự báo với đồ thị của giá trị thực tế và các chỉ số Mean Absolute Error (MAE), Mean Abs. Percent Error (MASE), Root Mean Squared Error (RMSE), Theil Inequality Coefficient (Theil) đều thể hiện kết quả dự báo bằng hàm Translog cho kết quả đáng tin cậy hơn so với dự báo bằng hàm Cobb-Douglass.
Các nhân tố ảnh hưởng đến ý định mua máy nước nóng năng lượng mặt trời của hộ gia đình tại Việt Nam
Authors: Thanh Trần Nam , Bé Bùi Thị Ngọc
Published: March 2023

Nghiên cứu này nhằm khám phá các nhân tố và xem xét tác động của các nhân tố này đến ý định mua máy nước nóng năng lượng mặt trời (Solar Water Head - SWH). Dữ liệu được thu thập từ 382 hộ gia đình đang sinh sống ở Việt Nam, cả ở thành phố và nông thôn. Kết quả từ phương pháp Bootstrap được thực hiện trong phần mềm Amos 20 đã xác định vai trò trung gian của nhân tố Thái độ. Kết quả từ mô hình cấu trúc tuyến tính (SEM) đã chỉ ra rằng: Nhân tố Sự hiểu biết về SWH và Nhận thức kiểm soát hành vi có tác động gián tiếp đến Ý định mua SWH thông qua nhân tố trung gian Thái độ; nhân tố Nhận thức hữu ích vừa có tác động gián tiếp vừa có tác động trực tiếp đến Ý định mua SWH. Ngoài ra, có 04 nhân tố nữa cũng ảnh hưởng trực tiếp đến Ý định mua SWH theo thứ tự giảm dần là: Ảnh hưởng xã hội, Nhận thức về giá, Trợ cấp và hỗ trợ về tài chính, và Thái độ. Các nhân tố này tác động lên Ý định mua SWH với mức tác động R2 = 0.61 (61%). Cuối cùng, nghiên cứu đã đề xuất một số hàm ý cho các doanh nghiệp sản xuất, kinh doanh SWH để phổ biến rộng rãi SWH đến các hộ gia đình và tăng ý định của họ đối với việc mua SWH.
Tác động của giảng dạy trực tuyến đến hiệu quả học tập của sinh viên trong giai đoạn dịch Covid-19
Authors: Lam Tống Hồng , Hằng Nguyễn Thị Mỹ , Trường Lê Văn , Vy Trần Nguyễn Ngọc
Published: March 2023

Để đánh giá tác động của hình thức giảng dạy trực tuyến trong giai đoạn dịch bệnh Covid-19, nghiên cứu đã khảo sát sinh viên một số trường đại học ở Thành phố Hồ Chí Minh. Cụ thể, nghiên cứu ứng dụng lý thuyết mô hình kết hợp C-TAM-TPB, được kết hợp từ hai mô hình TAM (thuyết chấp nhận công nghệ) và TPB (thuyết hành vi hoạch định), nhằm xác định các yếu tố tác động đến hiệu quả học trực tuyến của sinh viên. Nghiên cứu đã thực hiện phương pháp phân tích các nhân tố và phân tích hồi quy, kết quả cho thấy có những nhân tố tác động tích cực đến hiệu quả học tập của sinh viên như thái độ học tập, chuẩn chủ quan, nhận thức kiểm soát hành vi, niềm tin. Tuy nhiên, các nhân tố nhận thức về sự hữu ích, tính dễ sử dụng, sự rủi ro không ảnh hưởng đến hiệu quả học tập của sinh viên. Kết quả nghiên cứu cung cấp thông tin cho các nhà quản lý, giảng viên và sinh viên có những giải pháp nâng cao hiệu quả học tập của sinh viên trong quá trình dạy học trực tuyến.
Động lực nghiên cứu khoa học: Góc nhìn của học viên sau đại học tại Thành Phố Hồ Chí Minh
Authors: Hà Nguyễn Minh , Hoa Nguyễn Thị Mai , Khoa Bùi Thành , Cường Đỗ Bùi Xuân
Published: March 2023

Một trong những yêu cầu đối với “nền giáo dục xuất sắc” đã xác định các chuẩn mực của thời đại mới và khuôn mẫu của người học hiện đại là vun đắp mối quan hệ với các tổ chức khác trên toàn thế giới thông qua nghiên cứu khoa học. Nghiên cứu khoa học là một quá trình có hệ thống áp dụng các phương pháp khoa học để giải quyết các vấn đề quan trọng, thỏa mãn mong muốn của con người. Tuy nhiên, việc nghiên cứu khoa học ở đối tượng học viên sau đại học vẫn đang còn nhiều hạn chế, đa phần do thiếu động lực nghiên cứu. Do đó, thông qua nghiên cứu định tính, thảo luận nhóm 11 học viên sau đại học, nghiên cứu này sẽ khám phá các động lực nghiên cứu khoa học của học viên sau đại học tại Thành phố Hồ Chí Minh. Kết quả chỉ ra rằng có sáu yếu tố sẽ là động lực để thúc đẩy học viên sau đại học thực hiện nghiên cứu khoa học. Từ đó, nghiên cứu cũng đề xuất một số giải pháp cho nhà trường nhằm nâng cao sự nghiên cứu khoa học của học viên sau đại học.
Khảo sát hiệu quả xử lý nước sông Sa Đéc - Đồng Tháp bằng PAC kết hợp than hoạt tính
Authors: Tuyền Nguyễn Thị Thanh , Hà Trần Thái , Triệu Hồ Trâm Quốc , Dung Đặng Thị Đoan , Huy Văn Từ Nhật
Published: March 2023

Nghiên cứu được thực hiện nhằm so sánh đánh giá khả năng xử lý nước mặt thuộc tuyến sông Tiền tại Thành phố Sa Đéc - Đồng Tháp bằng 02 phương pháp xử lý là dùng PAC + Polymer và dùng PAC + Polymer + Than hoạt tính. Hiệu quả xử lý nước được đánh giá thông qua bốn chỉ tiêu chất lượng nước: Tổng rắn lơ lửng (TSS), nhu cầu oxi hóa học (COD), amoni (NH4+), độ đục. Kết quả nghiên cứu cho thấy hiệu quả của việc sử dụng PAC và Polymer xử lý độ đục, COD, TSS. Hiệu quả xử lý COD đạt đến 54.54%, hàm lượng amoni giảm đến 0.15mg/L, độ đục đã giảm còn 0.2NTU. Việc cho thêm than hoạt tính vào phản ứng càng làm tăng thêm hiệu quả xử lý COD, với hiệu quả lên đến 76.79%. Trong nghiên cứu này, với chỉ tiêu độ đục và TSS thì việc sử dụng keo tụ tạo bông kèm than luôn đạt được hiệu quả tốt, nước sau xử lý đạt QCVN 01 - 1:2018/BYT (Bộ Y tế, 2018). Tuy nhiên với chỉ tiêu COD và amoni thì vẫn chưa đảm bảo nước sau xử lý đạt giá trị cho phép quy định trong QCVN 01 - 1:2018/BYT (Bộ Y tế, 2018). Mặc dù vậy, kết quả nghiên cứu cho thấy việc sử dụng than hoạt tính giúp tăng cường hiệu quả xử lý, và có tiềm năng tiến tới giải pháp sử dụng hóa chất PAC ít hơn mà vẫn cho ra được hiệu quả xử lý tương đương.
Predicting Driving Behaviour Using Deep Learning
Authors: Shirkande S. T. , Bhosale Rutuja. B. , More Shweta. S. , Awate Suyash. S.
Published: March 2023

In recent years, the rise in automobiles and drowsiness has been a significant cause of accidents, leading to numerous injuries and even deaths. To combat this issue, computerization has been implemented in various areas, promoting uniformity and enhancing the quality of life for users. However, despite the creation of drowsiness-finding systems over the past decade, these systems still require improvement in terms of efficiency, cost, speed, and accuracy, among other factors. This paper proposes an integrated approach that incorporates various parameters, including the PERCLOS eye and mouth check status, the computation of a new vector called the Facial Aspect Ratio (FAR), as well as EAR and MAR, to detect drowsiness. The system detects uncontrolled eye movements, an open mouth, and other actions such as nodding and hand motions to control drowsiness. Additionally, the system includes styles and textural-based grade patterns to detect sunglasses on the driver's face and locate the driver's face in different directions. The proposed study demonstrated, improved precision and tested on datasets similar to NTHU-DDD, YawDD, and EMOCDS (Eye and Mouth Open Close Data Set). An android application utilizing the device's camera can detect drowsiness by observing the user's eyes and face, which can be helpful while driving, working, or studying. In conclusion, this integrated approach offers promising results for detecting drowsiness and enhancing user safety.
REMOVAL OF SIDE ILLUMINATION IN THE IMAGE PLANE IN TWO-MIRROR PANCRATYC SYSTEM FOR COLLIMATOR
Authors:   SPACE RESEARCH AND TECNNOLOGY INSTITUTE BULGARIAN ACADEMY OF SCIENCES, SOFIA 1113, ACAD. GEORGI BONCHEV ST., BL.1, Zhekov Zhivko
Published: March 2023

The specifics of certain tasks, which are solved by a collimator, as well as the large amounts of light losses in the optic materials which are used in the shortwave and longwave range of the optical specter require the development of mirror and mirror-lens systems. An advantage of these systems is the increased light transmission, small length and the possibility to correct the chromatic abberations. It should only be noted that in the two-component pancratyc systems with reflecting planes with constant optic characteristics there is a danger of illumination of the image plane by side rays – side illuminations. In two-mirror pancratyc system for a collimator it is necessary to exclude illumination of the image plane throughout the whole range of the components movement. In the development process formulas are derived and schemes are presented which help the vizualization when calculating the diaphragm in front of two-mirror pancratyc system and calculation of diaphragm which is located between the components of two-mirror pancratyc system. The results from the calculations of a diaphragm for two-mirror pancratyc system are presented in tables. The results from research of the diaphragms for two-mirror pancratyc sysmem make us conclude that the second method of preventing the image plane from side illuminations is the preferred one. It ensured smaller sized and less change in the diaphragm length.
A COMPARISON OF SEVERAL STOCHASTIC TECHNIQUES FOR COMPUTATION OF MULTIDIMENSIONAL INTEGRALS
Authors:   Bulgarian Academy of Sciences, Institute of Mathematics and Informatics and Institute of Inormation and Communication Technologies: Sofia, BG, Todorov Venelin , Dzhurov Valerij ,   ROUSSE UNIVERSITY ”ANGEL KANCHEV”, Tzvetkov Ilian ,   ROUSSE UNIVERSITY ”ANGEL KANCHEV”
Published: March 2023

A comprehensive experimental study based on Sobol sequence, Importance Sampling and Fibonacci based lattice rule has been done. This is the first time the Sobol sequence has been compared with the Importance sampling method for the problem under consideration. The numerical tests show that the stochastic algorithms under consideration are efficient tool for computing multidimensional integrals. In order to obtain a more accurate and reliable interpretation of the results this is very important.
ADVANCED STOCHASTIC METHODS FOR MULTIDIMENSIONAL INTEGRALS AND APPLICATIONS
Authors:   Bulgarian Academy of Sciences, Institute of Mathematics and Informatics and Institute of Inormation and Communication Technologies: Sofia, BG, Todorov Venelin
Published: March 2023

The problem for accurate evaluation of multidimensional integrals related to different areas has been presented. A comprehensive experimental study based on Faure and Hammersley low discrepancy sequences and Fibonacci based lattice rule has been done. Our tests show that the quasi-Monte Carlo algorithms under consideration are efficient tool for computing multidimensional integrals. This will be important in order to obtain more reliable results in some applications.
MODELLING OF GEOGRAPHICAL REALITY
Authors:   Konstantin Preslavsky University of Shumen, Faculty of Technical Sciences, Bulgaria, Ivanov Sabin
Published: March 2023

From a cartographic point of view, mapping modeling can be defined as a method of creating mathematical models that are similar copies of objects of reality. They are divided into descriptive (visual) and predictive. This is the general classification of cartographic models. Descriptive models show existing objects or phenomena, as well as the links between them, presenting the results in an appropriate form that allows the user to identify them immediately. This type of model is simple and easy to create, and this reason makes it the most commonly used. The second type of cartographic model shows the predictive possibilities of the descriptive model and is called a predictive cartographic model. Predictive models require the introduction of factors and parameters that are important for the functioning of phenomena appearing in a particular territory.
SPATIAL DATA MODELS
Authors:   Konstantin Preslavsky University of Shumen, Faculty of Technical Sciences, Bulgaria, Ivanov Sabin
Published: March 2023

Spatial data represents the shape, location, and spatial relationships of geographic features to other features. The form represents the geometry of the objects, the location is described by a list of x, y coordinates of discrete points of the objects, and the spatial connections (topological information) of the geographical objects determine the interaction between them. Spatial (coordinate) information can also include time-related data.
NEW APPLICATOIN OF LOGISTICS PROCESSING
Authors:   Konstantin Preslavsky University of Shumen, Faculty of Technical Sciences, Bulgaria, Bogdanov Andrey
Published: March 2023

The report analyzes the possibility of using analytic hierarchy process in logistics demand forecasting. It proposes a method to estimate parameters of the individual values of the analysis.
MAPK2 AND NRAMP6 EXPRESSION ANALYSIS UNDER CD STRESS IN DOMESTIC KALE VARIETIES FROM BiH
Authors:   International University of Sarajevo, Faculty of Engineeiring and Natural Sciences, Šutković Jasmin , Van Wieren Annissa ,   International University of Sarajevo, Faculty of Engineeiring and Natural Sciences, Yildirim Ahmet ,   International University of Sarajevo, Faculty of Engineeiring and Natural Sciences
Published: March 2023

Brassica oleracea var. acephala (kale) is a worldwide known vegetable plant, known for its heavy metal accumulation abilities. This study analyzed the phytoremediation potential of domestic BiH kale varieties, grown in a controlled environment and with different concentrations of Cadmium (Cd). Cd is a known pollutant found in small concentrations in soil under normal environmental conditions. Real-Time PCR was used to analyze the gene expression activity of Cd heavy metal correlated genes (MAPK2 and NRAMP6). The root analysis assay confirmed shorter root length after Cd treatment, confirming severe Cd impact on plant cell growth, implying shorter growth in roots in all treated kales. Gene expression results showed that Cd triggers the expression of MAPK2 and NRAMP6 suggesting their significant involvement in Cd metabolizing processes. Based on the combined results, kale from the Stolac region is found to be the most resistant variety, while the only hybrid kale, accumulates the most Cd suggesting its phytoremediation potential.
PROMOTING SMART AGRICULTURAL PRACTICES IN MAIZE PRODUCTION INBIH - H2020 SMARTWATER PROJECT
Authors:   University of Banja Luka, Faculty of Agriculture, Bosnia and Herzegovina, Marković Mihajlo , Čereković Nataša ,   University of Banja Luka, Faculty of Agriculture, Bosnia and Herzegovina, Hajder Đurađ ,   University of Banja Luka, Faculty of Agriculture, Bosnia and Herzegovina, Šipka Milan ,   University of Banja Luka, Faculty of Agriculture, Bosnia and Herzegovina, Zapata Nery ,   Agencia Estatal Consejo Superior de Investigaciones Cientificas, Madrid, Spain, Paço Teresa A. ,   Universidade de Lisboa, Instituto Superior de Agronomia, Portugal, Riezzo Erminio E. ,   University of Sarajevo, Faculty of Agriculture and Food Science, osnia and Herzegovina, Čadro Sabrija ,   Centro Internazionale di Altistudi Agronomici Mediterrranei, Italy, Todorović Mladen
Published: March 2023

Agricultural practices in Bosnia and Hercegovina demand different improvements, including smart management of land and water resources. A new H2020 project started in 2021 in this regard. The objective of this publication is to spread knowledge about SMARTWATER project by describing different achievements in two years of implementation (2021-2022), to invite target groups to participate in the action and to promote smart agricultural practices. Presented results indicate that the implementation is at a satisfactory level. Project consortium will continue with efforts, including twinning, networking, research, dissemination and increasing competency and fund rising skills.
INFLUENCE OF HEAVY METALS ON WHEAT STEM DEVELOPMENT
Authors:   Tamiš Research and Development Institute, Serbia, Mickovski Stefanović Violeta , Stanisavljević Dragana ,   Toplica Academy of Vocational Studies-Department of Agricultural and Food Studies, Serbia, Bačić Jasmina ,   Tamiš Research and Development Institute, Serbia, Brković Predrag ,   Tamiš Research and Development Institute, Serbia, Pavlović Miloš ,   Tamiš Research and Development Institute, Serbia, Matković- Stojšin Mirela ,   Tamiš Research and Development Institute, Serbia
Published: March 2023

Plants that grow in contaminated soil absorb and accumulate heavy metals in its above ground organs. Research was conducted in which content of heavy metals in wheat stem in phenophases of tillering and beginning of stemgrowth, and also stem hight of wheat from soil level to tip of appical leaf. The aim of research was to determine the influence of heavy metals on first stages of wheat varieties Pobeda and Ljiljana. Trial was conducted in pots with controled conditions of heat and moisture with adding different concentrations of heavy metals mixture. Higher concentrations of heavy metals had significant effect reducing the growht and wheat stem development of both wheat varieties. Significant concentration of heavy metals was detected throug analisis in stems of wheat.
THE INFLUENCE OF HEAVY METALS ON THE DEVELOPMENT OF THE SURFACE OF WHEAT LEAVES
Authors:   Tamiš Research and Development Institute, Serbia, Mickovski Stefanović Violeta , Brković Predrag ,   Tamiš Research and Development Institute, Serbia, Roljević Nikolić Svetlana ,   Tamiš Research and Development Institute, Serbia, Majstorović Helena ,   Tamiš Research and Development Institute, Serbia, Stanisavljević Dragana ,   Toplica Academy of Vocational Studies-Department of Agricultural and Food Studies, Serbia, Ilić Predrag ,   Univrsity of Niš, Faculty of Philosophy, Serbia
Published: March 2023

Heavy metals represent a very significant group of environmental pollutants because they are potential metabolic inhibitors. Therefore, a study was conducted where the height of the wheat stem, as well as the surface of the leaves in the budding and leafing stages, were examined when contaminated with a mixture of heavy metals in concentrations of 250 and 500 ppm. The aim of the research was to determine the influence of heavy metals on the initial phenophase of wheat varieties Pobeda and Ljiljana. An experiment was carried out in volumetric flasks where two different concentrations of a mixture of heavy metals 250 ppm and 500 ppm were added under controlled conditions.