Izrada i optička svojstva tankih slojeva MnCdS2 taloženih u kemijskoj kupki

Thin films of MnCdS2 were deposited on glass slide from aqueous solutions of MnCl2·4H2O, CdCl2·2frac12H2O and thiourea. Ammonium solutions and EDTA (or TEA) were employed as complexing agents. The optical characterization yielded band gap values in the range between 2.58 and 2.82 eV. Some of the films were found to have an average transmittance of greater than 60% in the UV-VIS regions while exhibiting high reflectance of greater than 12% in the same regions. Some of the films exhibit poor transmittance in the UV regions while exhibiting high transmittance of greater than 75% in the VIS-NIR regions. Hence, while some of the films could be effective as thermal coatings for cold climates, some could be effective as coatings against intensive sunlight as well good material for fabrication of solar cell.Proizveli smo tanke slojeve MnCdS2 na staklenim pločicama taloženjem iz vodenih otopina MnCl2·4H2O, CdCl2 · 2 1 2H2O i tiouree. Primijenili smo otopine amonijaka i EDTA (ili TEA) za kompleksiranje. Optička mjerenja dala su za procijepe vrpci vrijednosti između 2.58 i 2.82 eV. Za neke smo slojeve našli prosječnu propusnost veću od 60% u UV-VIS području, dok im je u tom području odraznost veća od 12%. Drugi slojevi pokazuju malu propusnost u UV području, a veliku propusnost u VIS-NIR području. Stoga se neki slojevi mogu rabiti kao toplinska izolacija u hladnim područjima, a drugi za zaštitu of UV zračenja i u proizvodnji solarnih ćelija

Study of the Effects of Thermal Annealing on the Optical Band Gap of Nanocrystalline CoO Thin Films Prepared by Chemical Bath Deposition.

Nanocrystalline films of cobalt oxide have been prepared on glass slides by chemical bath deposition process. For deposition of CoO thin films, cobaltous chloride [CoCl2.6H2O] was used as cationic and ammonia [NH3] as anionic precursor in aqueous medium. In this process NaOH was used as complexing agent. X-ray diffraction, scanning electron microscopic [SEM] analysis have been used to study the films’ crystal structures, optical and solid state properties. We hereby present the effects of thermal annealing on the optical band gap of CoO thin films. The optical transition in the films is direct one. For the as- deposited film, the band gap is 2.1eV. This later decreased to 2.08eV, so that increased thermal annealing reduces the optical band gap of CoO. However,the energy gap cannot be said to be dependent on the annealing temperatures. These films could be used as  photovoltaic cells, sensors light emitting diodes and also in biomedical imaging. Key Words: Nanocrystalline CoO, Chemical Bath Deposition, Band Gap and                               Thermal Annealing

SUPPORT SYSTEMS, ENTREPRENEURSHIP EDUCATION AND THE CHALLENGES OF START-UPS IN DEVELOPING ECONOMIES

Entrepreneurship has been recognised as an essential strategy for economic growth. It is also known for solving unemployment problems and reducing the poverty level. Entrepreneurship education is aimed at providing knowledge, skills, competencies, and motivation to create and innovate important business ideas that can lead to start-ups or businesses in various settings. Economic development, as witnessed by developed countries, can be traced to entrepreneurial activities. There are various motivating factors for starting a business. One of such motivating factors is the availability of support systems. Such supports include entrepreneurship education, enabling environmental/policies, infrastructure, media/market information, and finance. The effects of these support systems in developing economies such as Nigeria need to be properly examined to understand why many startups fail to develop into thriving and prosperous businesses. This paper intends to identify and discuss the challenges of start-ups and why support systems are important in developing economies. The methodology adopted for the study is a literature review. The study found that the absence or inadequate entrepreneurial support systems play a vital role in the attrition rate of start-ups within the study context

Synthesis, characterization and ab initio study of WO3 nanocubes with peculiar electrochemical properties

Simple sol–gel method has been exploited to deposit Sn-doped TiO2 thin flms on glass substrates. The resultant coatings were characterized by X-ray difraction (XRD), UV–visible techniques (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and photoluminescence analysis (PL). The XRD pattern reveals an increase in crystallite size of the prepared samples with the increasing doping concentration. A decrease in doping concentrating resulted in the decrease in bandgap values. The diferent chemical bonds on these flms were identifed from their FTIR spectra. The photoluminescence analysis shows an increase in the emission peak intensity with increasing dopant concentration, and this can be attributed to the efect created due to surface states. The prepared samples were tested as antibacterial agent toward both Gram-positive and Gram-negative bacteria like S.aureus (Staphylococcus aureus) and E.coli (Escherichia coli), respectively. The size of the inhibition zones indicates that the sample shows maximum inhibitory property toward E.coli when compared to S.aureus

EDUCATIONAL QUALIFICATIONS, ENTREPRENEURIAL STIMULATION AND START-UPS IN NIGERIA

Continuous increase in unemployment has negatively impacted the lives of Nigerians. The effect of COVID-19 pandemic has made it worse- as many companies/employers keep laying off their staff continuously. If the increasingly high unemployment rate is not urgently reversed, the consequences will be the prevalence of crimes and criminality. Therefore motivating or stimulating people to be entrepreneurial and to set up new businesses is vital for their emancipation and global economic sustainability. Meanwhile, many faith-based organisations (FBOs) in Lagos have been engaging their members with entrepreneurial training programmes to support government moves and in response to their members' economic challenges. The FBOs are driven to partake in members' economic emancipation by promulgating trainings that are impactful to start businesses. However, some factors have been underscored as the motivating influence for the trainees starting businesses. Little is known about the influence of educational qualification in participation of entrepreneurial training and entrepreneurial activities. Hence this study investigates the education qualifications of participants in the entrepreneurial training programmes of selected FBOs towards business start-ups. Out of 643 copies of the questionnaire distributed, 620 copies were retrieved, accounting for 96.4% response rate, which is considered adequate and appropriate for analysis. This study's data were subjected to relevant statistical analysis, including descriptive statistics using SPSS version 25. Frequency distribution and percentage analysis were used to present the educational background of the respondents. Respondents with HND/BSc/BA qualification have the highest participation of 296 which accounts for about 47.6% in the entrepreneurial training programme. This is followed by respondents with OND/NCE qualification with 163 and about 26.4%. Respondents with MSc/MA/MBA qualifications have 88, which is about 14.2%. Respondents with SSCE qualifications' participation was 52 (8.4%). Trainees/graduates should not be discouraged to continue with their higher educations because it gives room for better entrepreneurial awareness that can lead to start-ups

Peculiar Size Effects in Nanoscaled Systems

In this minireview, we intend to shed light on relatively recent examples related to the size and shape effects on materials at the nanoscale and their usage to test a set of quantum mechanics governed phenomena

Challenges of Students’ Industrial Work Experience Scheme (SIWES) in Library and Information Science in the ICT Environment

The ICT revolution has permeated every profession and all areas of human endeavour. Professions such as law, medicine , engineering, and library and information science are adjusting to the ICT environment through re-tooling, retraining, and curriculum revision. The purpose of this study is to explore the impact of ICT on the student industrial work experience scheme (SIWES) of library and information science students. It traces the historical development of the scheme, the ICT development trends in LIS, and the challenges this development brings to SIWES. Strategies to absorb this shock created by ICT are offered

EFFECT OF CONCENTRATION OF Mn DOPANT IONS ON THE STRUCTURAL AND OPTICAL PROPERTIES OF ZINC OXIDE CRYSTALS

Manganese (Mn) doped ZnO crystals have been successfully grown via the gel route. Identification of the chemical species of the crystals grown was done using Fourier Transform Infrared Spectroscopy (FTIR), structural analysis was done using X-Ray Diffraction technique while the optical properties were studied using UV-VIS technique. Results from the FTIR and XRD analysis show that high concentrations of manganese dopant ions results in the formation of synthetic MnO 2 (pyrolusite), degrading the quality of the ZnO crystals