Preliminary Tests Research Articles

Influence of two paraffin wax chewing gums with different con-sistencies on the stimulated salivary flow rate.

This study investigated and compared the consistency and compressive strength of two commercially available paraffin wax chewing gums (Aurosan (AU) and GC Europe (GC)), as well as their impact on stimulated salivary flow rate. Instrumental texture analysis was uti-lized to assess the consistency and compressive strength of AU and GC during a 7-min chewing period. Subsequently, stimulated salivary flow rate (sSFR) was evaluated in healthy subjects using AU and GC over a 7-minute period. The compressive strengths from the pre-liminary test were compared over time with the sialometry data. Eighty-one test subjects, comprising 33 men and 48 women, participated. Over the 7-min measurement period, dif-ferences were observed in the total amount of saliva accumulated per minute. Direct com-parison of AU and GC revealed that regardless of age and gender, the amount of saliva formed after 1 min was 0.63 times less with AU than with GC (95% CI: 0.56 - 0.70; P < 0.001). The accumulated saliva volume with AU was also significantly lower than that with GC in the first 4 min (P = 0.016). However, from minute 5 onwards, the two products no longer showed statistical differences in the total amount of saliva. Comparison of the com-pressive strength of AU and GC showed that the values after 1 and 2 min were significantly higher for AU than for GC (P < 0.05); for all other time points, the compressive strength was higher for GC. In the mixed-effects model after log-transformation of compressive strength and saliva volume, GC exhibited decreasing saliva volumes with increasing compressive strength (P <0.001). Conversely, the opposite was observed for AU (P = 0.019). The study suggests that the consistency or compressive strength of paraffin wax chewing gums from different manufacturers could impact sSFR.

Design and Preliminary Tests of a 20-T REBCO Insert Coil for a 35-T All Superconducting Magnet

Design and Preliminary Tests of a 20-T REBCO Insert Coil for a 35-T All Superconducting Magnet

태블릿PC와 노트필기 사용 집단 간 학습효과 분석

Objectives This study analyzes the learning effects between groups using Tablet PCs and handwritten notes methods among early childhood education freshmen. The focus is on examining learning engagement, enthusiasm, satisfaction with university life, and academic achievement.&#x0D; Methods The study participants consisted of 45 freshmen majoring in early childhood education at A university in Chungcheong province, all of whom had completed courses in early childhood music education. I conducted frequency(%) distributions and performed trend, normality, and reliability coefficient analyses of the research variables using SPSS 25.0. Since the normality assumptions were not met, I utilized the Mann-Whitney U test to assess the differences between the group using tablet PCs and the group employing handwritten notes. The statistical significance of the mean difference in pre-post scores between two groups was analyzed at the p&lt;.001, p&lt;.01, and p&lt;.05 levels.&#x0D; Results The main results are as follows: First, the preliminary homogeneity test between the groups using tablet PCs and handwritten notes revealed no statistically significant differences, indicatingthat homogeneity was established between the two groups. Second, the tablet PC group scored higher than the handwritten notes group on variables related to learning engagement and its sub-domains(cognitive, behavioral, and emotional engagement), academic enthusiasm and its sub-domains(energetic, committed, and engaged), and university life satisfaction and its sub-domain(administrative and welfare services), and these differences were statistically significant. On the other hand, there were no statistically significant differences in the variables related to overall university life satisfaction and the quality of university education, which are sub-domains of university life satisfaction. Academic achievement was higher in the tablet PC user group compared to the handwritten note user group, and this difference was statistically significant.&#x0D; Conclusions The research results suggest the need for contemplation on teaching and learning methods in response to the changes in the digital educational environment in higher education. I aim to propose a way to operate courses by applying AI-based innovative teaching methods, focusing on both theoretical and practical courses inthe field of early childhood education.&#x0D;

A Web-Based Tool to Assess Social Inclusion and Support Care Planning in Mental Health Supported Accommodation: Development and Preliminary Test Study.

Individuals with severe mental illness living in supported accommodation are often socially excluded. Social inclusion is an important aspect of recovery-based practice and quality of life. The Social Inclusion Questionnaire User Experience (SInQUE) is a measure of social inclusion that has been validated for use with people with mental health problems. Previous research has suggested that the SInQUE could also help support care planning focused on enabling social inclusion in routine mental health practice. This study aims to develop a web-based version of the SInQUE for use in mental health supported accommodation services, examine its acceptability and perceived usefulness as a tool to support care planning with service users, determine the extent of uptake of the tool in supported accommodation settings, and develop a program theory and logic model for the online SInQUE. This study involved a laboratory-testing stage to assess the acceptability of the SInQUE tool through "think-aloud" testing with 6 supported accommodation staff members and a field-testing stage to assess the acceptability, utility, and use of the SInQUE tool over a 5-month period. An implementation strategy was used in 1 London borough to encourage the use of the SInQUE. Qualitative interviews with 12 service users and 12 staff members who used the tool were conducted and analyzed using thematic analysis. The use of the SInQUE was compared with that in 2 other local authority areas, 1 urban and 1 rural, where the tool was made available for use but no implementation strategy was used. Overall, 17 staff members used the SInQUE with 28 different service users during the implementation period (approximately 10% of all service users living in supported accommodation in the study area). The staff and service users interviewed felt that the SInQUE was collaborative, comprehensive, user-friendly, and relevant. Although some staff were concerned that particular questions might be too personal, service users did not echo this view. Participants generally felt that the SInQUE could help identify individuals' priorities regarding different aspects of social inclusion by prompting in-depth conversations and tailoring specific support to address service users' inclusion goals. Some interviewees also suggested that the tool could highlight areas of unmet or unmeetable needs across the borough that could feed into service planning. The SInQUE was not used in the comparison areas that had no implementation strategy. The online SInQUE is an acceptable and potentially useful tool that can be recommended to assess and support care planning to enable social inclusion of people living in mental health supported accommodation services. Despite this, uptake rates were modest during the study period. A concerted implementation strategy is key to embedding its use in usual care, including proactive endorsement by senior leaders and service managers.

Measurement of Aerosol Transmission Through a Stress Corrosion Crack–Like Geometry

The formation of a stress corrosion crack (SCC) in the canister wall of a dry cask storage system (DCSS) has been identified as a potential issue for the long-term storage of spent nuclear fuel. The presence of a SCC in a storage system could represent a through-wall flow path from the canister interior to the environment. Modern, vertical DCSSs are of particular interest due to the commercial practice of using relatively high helium backfill pressures (up to approximately 800 kPa) in the canister to enhance internal natural convection. This pressure differential offers a comparatively high driving potential for blowdown of any particulates that might be present in the canister in the event of a through-wall SCC. In this study, the rates of gas flow and aerosol transmission of a spent fuel surrogate through an engineered microchannel with dimensions representative of a SCC were evaluated experimentally using coupled mass flow and aerosol analyzers. The microchannel was formed by mating two gauge blocks with a linearly tapering slot orifice nominally 13 μm (0.0005 in.) tall on the upstream side and 25 μm (0.001 in.) tall on the downstream side. The orifice is 12.7 mm (0.500 in.) wide by 8.89 mm (0.350 in.) long (flow length). Surrogate aerosols of cerium oxide (CeO2) were seeded and mixed with either helium or air inside a pressurized tank. The aerosol characteristics were measured immediately upstream and downstream of the simulated SCC at elevated and ambient pressures, respectively. The next iteration of testing involves replacing the engineered microchannel with lab-grown SCCs. Preliminary clean flow testing has been conducted on SCC samples provided by the Electric Power Research Institute. These data sets demonstrate a new capability to characterize SCCs under well-controlled boundary conditions. Preliminary testing efforts are focused on understanding the evolution in both the size and quantity of a hypothetical release of aerosolized spent fuel particles from failed fuel cladding into the canister interior, and ultimately, through a SCC.

Software and Architecture Orchestration for Process Control in Industry 4.0 Enabled by Cyber-Physical Systems Technologies

In the context of Industry 4.0, this paper explores the vital role of advanced technologies, including Cyber–Physical Systems (CPS), Big Data, Internet of Things (IoT), digital twins, and Artificial Intelligence (AI), in enhancing data valorization and management within industries. These technologies are integral to addressing the challenges of producing highly customized products in mass, necessitating the complete digitization and integration of information technology (IT) and operational technology (OT) for flexible and automated manufacturing processes. The paper emphasizes the importance of interoperability through Service-Oriented Architectures (SOA), Manufacturing-as-a-Service (MaaS), and Resource-as-a-Service (RaaS) to achieve seamless integration across systems, which is critical for the Industry 4.0 vision of a fully interconnected, autonomous industry. Furthermore, it discusses the evolution towards Supply Chain 4.0, highlighting the need for Transportation Management Systems (TMS) enhanced by GPS and real-time data for efficient logistics. A guideline for implementing CPS within Industry 4.0 environments is provided, focusing on a case study of real-time data acquisition from logistics vehicles using CPS devices. The study proposes a CPS architecture and a generic platform for asset tracking to address integration challenges efficiently and facilitate the easy incorporation of new components and applications. Preliminary tests indicate the platform’s real-time performance is satisfactory, with negligible delay under test conditions, showcasing its potential for logistics applications and beyond.

To Study the Prevalence of Urinary Tract Infection Its Bacteriological Profiling and the Drug Resistance Pattern of the Patients at a Tertiary Care Centre in Muzaffarpur, Bihar, India

Introduction: Urinary tract infections account for the majority of hospital visits worldwide and are a leading cause of morbidity and comorbidity in patients with underlying illnesses. Urinary tract infections (UTIs) and the spread of antibiotic resistance among uropathogenic bacteria remained major public health concerns. A targeted empirical antibiotic therapy necessitates routine evaluation of the microbiological organisms causing UTIs and their antimicrobial resistance. Aim and objective: To Study the Prevalence of Urinary Tract Infection its Bacteriological Profiling and the Drug Resistance Pattern of the patients at a Tertiary Care Centre Material and Methods: This was a Cross sectional study carried out in the Department of Microbiology, at New reliable path lab and Path Diagnostic Laboratory, Muzaffarpur, Bihar for a period of 24 months i.e, between April 2021 to April 2023. A total of 1000 urine freshly voided mid- stream urine sample were collected in a sterile wide mouth container from the individuals preliminary routine urine tests positive for pus cells and albumin. All the urine samples were processed within one hour after the collection for aerobic bacterial culture. If delayed, samples were refrigerated and processed within 4 - 6 hrs. The identification , biochemicals and the AST pattern was done according to the CLSI guidelines 2021. Results: In the present study total of 1000 urine samples were received in which 450 (45%%) urine samples were showing significant growth for UTI. The ratio of females were 284 (63.1%) more as compared to that of the males 166 (36.8%) with the maximum age of 31-40 (44.8%) years of age followed by 21-30 (26.2%) was affected the most. In the age group of 0-10 years and above 71 years was the least affected with the infection. It was observed that the maximum number of isolates were from the E.coli 180 (40%) followed by Klebsiella pneumonia 120 (26.6%), Pseudomonas aeruginosa 55 (12.2%), Acinetobacter baumanii 26 (5.6%) , and Staphylococcus aureus 30 (6.6%) for gram positive followed by Proteus 23 (5.1%) least for Enterococcus with 3.5%. The days of catheterization were observed to be the maximum in 4-7 followed by 8-12 days. It was clear that out of the total samples the comorbidity with diabetes was found to be low (16.4%). It was also observed that patients with hypertension and the kidney disease were observed to be low as compared to the healthy individuals. The maximum number of days with fever was observed to be maximum in 4-7 days, least for 1-3 days and 8-12 days In the present study the resistant rate for Ampicillin was observed to be 88.8% followed by Co-trimoxazole and cefotaxime with 89.1%. Imipenem and Nitrofurantoin were sensitive with (89.5%). Conclusion: The cost of UTI prevention can be reduced by doing the routine checks and the strict implementation of the antibiotic stewardship programs. The cost of UTI prevention can be reduced by doing these routine checks.

Lead Extraction in a Functionalized and Permeable Silica-Based Porous Liquid.

Silica-based porous liquids (PLs) are innovative and versatile liquid materials with a high potential, although their application is often restricted to gas sorption. In this work, we propose to evaluate their potential to extract metals. For this goal, we have adapted their synthesis to provide PLs functionalized with thiols that are expected to chelate metallic contaminants, such as lead. As the accessibility of liquids and metals to the PL's porous network is one of the key points for their application, we developed an original small-angle neutron scattering experiment to verify that the PL is permeable to polar liquids. Then, preliminary extraction tests have successfully been carried out, with an extraction of lead cations by complexation on one-third of accessible thiol groups. This work demonstrates that the extraction of metal species by a PL is possible and opens many perspectives for optimization.

Recent Upgrade of the Magnetic Diagnostic System in the Alvand-U Tokamak

The main acting parameters in tokamak plasma experiments, such as currents and electric and magnetic fields, are present inside and outside the plasma volume. To analyze the changes in the shape of tokamak plasma, it is necessary to use experimental data obtained from magnetic measurements. Until recently, a four-digit magnetic probe (MP) was used for qualitative analysis of the magnetic field, but its accuracy was low, and it could not be practically used as a diagnostic system. Following the Magnetic Confinement Group, Tokamak Laboratories’ approach to optimize and improve the measurement of plasma parameters, the use of a richer array of MPs to accurately measure changes in the magnetic field and identify plasma parameters in the Alvand tokamak was considered. In order to upgrade the magnetic diagnostic system, two MP arrays were designed and manufactured. Each array contains 12 poloidal and radial probes. The MPs of each array were attached to Mylar belts and mounted on the vacuum vessel of the tokamak. In addition, an integrator unit was designed and installed as a magnetic diagnostic subsystem. The conducted research involved the MP and calibration setup followed by preliminary tests of the array probe.

Design, Synthesis, and Anti-tuberculosis Activity of Streptomycin Derivatives

Background: The treatment of tuberculosis has been a serious medical and health problem that needs to be solved urgently. Streptomycin has been one of the important anti-tuberculosis drugs for decades; however, no systematic structural modification of streptomycin has been done, which means that the anti-tuberculosis ability of streptomycin derivatives deserves further exploration. Objective: In this study, we investigated the effect of systematic structural modification of the aldehyde groups in streptomycin on its anti-tuberculosis activity. Methods: Streptomycin was selected as the lead compound, and its aldehyde group was modified to obtain hydrazone, amino hydrazide, and sulfonyl hydrazide derivatives, respectively. In addition, siderophore fragments were introduced into streptomycin. The anti-tuberculosis activities of the new compounds against H37Rv were evaluated. Results: A total of 21 novel streptomycin derivatives have been designed and synthesized. All compounds were characterized with 1H NMR, 13C NMR, and HRMS. The preliminary bioactivity test showed that most analogues bearing hydrazine, acylhydrazine, or sulfonyl hydrazine, such as 12a, 13a-d, and 15a-f, possessed potent anti-tuberculosis activity with MIC value of 2 μg/mL, which was comparable to streptomycin, while secondary amine or siderophore derivatives caused a dramatic reduction in activity. Conclusion: The structural modification and structure-activity relationship of the aldehyde group of streptomycin were systematically studied for the first time. The results showed that the aldehyde group was not necessary for exhibiting its activity. It was well tolerated when the aldehyde group was converted into hydrazine, acylhydrazine, or sulfonyl hydrazine. These novel analogues provide potential lead structures for further modification in the future.

Formulation of Lipid Nanoparticles based Nanogel of Sertaconazole Nitrate and its Evaluation

Background: Sertaconazole nitrate is a topical antifungal drug used to treat interdigital tinea pedis in patients with immunocompetent conditions. The class of imidazole includes the antifungal medication sertaconazole nitrate. It is available in topical formulations for treating skin infections, including athlete's foot. Solid lipid nanoparticles (SLN) are at the cutting edge of nanotechnology, with several potential uses in drug delivery and research. Because of their unique size-dependent features, lipid nanoparticles hold the promise of novel therapies. Objective: Drug incorporation into nanocarriers creates a new drug delivery prototype that could be employed for drug targeting. The research aims to study the formulation and evaluation of Sertaconazole nitrate solid lipid nanoparticles. The goal behind formulating SLN gel is to provide and maintain therapeutic concentrations of the drug at the target biological site to maximise therapeutic efficacy and minimise side effects. Methods: Sertaconazole Nitrate Solid Lipid Nanoparticles are prepared by using High Pressure Homogenizer to get nanogel formulation as the final formulation and In-vitro drug release using a diffusion apparatus. The prepared SLNs were evaluated in their FTIR studies to determine compatibility between the drug and the excipients; zeta potential indicates the solid lipid nanoparticle was stable, and polydispersity index was used to determine particle size. Result: The results demonstrate that optimised SLN-based Sertaconazole nitrate gel exhibited the best physicochemical properties, including FTIR studies of the drug, excipients, and optimised formulation demonstrate that all are compatible with each other, particle size is less than 200 nm, zeta potential ranging from 12 to -20 mV, and highest entrapment efficiency is 71.48%. Optimised solid lipid nanoparticles showed good in vitro release and antimicrobial results. The main application of SLN large scale-up is possible, and the drug can be effective with less dose incor-poration. Conclusion: In this research work, the proposed plan of work SLN of Sertaconazole Nitrate was formulated successfully. The preliminary identification tests were performed, such as melting point determination, estimation of λmax by UV-visible spectrophotometry and plot of its calibration curve in solvent and buffer system, and FT-IR investigation to confirm the purity and confirmation of medication. High physical stability and drug loading are advantageous to SLN.

Preliminary experimental tests of a novel friction damper for seismic retrofit of RC precast structures

Precast RC structures have been widely adopted for industrial and commercial buildings since the ’60 s in the most developed countries. For this structural typology, connections between structural elements set a crucial point in the presence of lateral loads, such as earthquakes, since the deficiency, or lacking, of connection elements is the main responsible for their structural collapse. This paper shows the preliminary mechanical testing of an innovative damping device conceived to be installed in beam-to-column joints of precast RC structures, with a bidirectional dissipative potential due to its geometry. This new Bidirectional Rotation Friction Damper (BRFD) has been designed and optimised after a tribological campaign, which led to the selection of the two different friction interfaces investigated in this work. The mechanical tests have been performed considering the guidelines of EN15129 and the previous tribological investigation findings, showing the influence of sliding frequency and bolt torque increment on the steadiness of the BRFD hysteresis cycle.

An Automatic Method for Detection and Naive Classification of the Martian Ionospheric Irregularities

AbstractThe abundant observations and research established a detailed category of the terrestrial ionospheric irregularities, which significantly advanced our understanding of how the Earth system's complicated physical and chemical process generates the intermediate‐scale structures of the charged particles. Motivated by a future attempt at categorizing the Martian ionospheric irregularity, this study designs a method for naive classification of the plasma density depletion, enhancement, and oscillation based on the in situ measurements of the Martian ionosphere. The technique consists of several procedures: trend estimation, detrending and candidate extraction, and parameterization. The classification is achieved through a machine‐learning‐like process using some testing artificial density profiles. A preliminary credence test shows a good performance in separating the terrestrial low‐latitude Equatorial Plasma bubble (depletion) and mid‐latitude Median‐scale Traveling Ionospheric Disturbance (oscillation). Another detection experiment of the Martian plasma depletion events (collected by Basuvaraj et al. (2022a, https://doi.org/10.1029/2022je007302)) showed a recall rate (i.e., true positive) of 38% but with a high precision of 67.8%. Therefore, we believe the proposed method could convincingly extract different Martian ionospheric irregularities and help uncover the climatological characteristics in the future.

STUDY OF LUBRICANT ADDITIVES FOR EXPANSION PIPE EXPANSION IN MONODIAMETER WELLS

There is a need to improve well design and completion in order to reduce material intensity while maintaining sufficient casing cross-sections. One of the possible solutions for this is the construction of mono-diameter wells using expandable casing technology. The technology of drilling wells with the same fixed bore diameter from the wellhead to the productive formation could solve many problems and limitations in the construction of wells, opening up opportunities for the development of large oil and gas reserves that are currently classified as difficult to recover or inaccessible. The technology of drilling monodiameter wells also reduces drilling volumes, reduces the adverse impact on the environment and, ultimately, leads to minimization of construction costs.For purposeful choice of flushing fluid components, especially reagents of complex action and lubricating additives necessary for drilling of mono-diameter wells, their preliminary laboratory tests on experimental installations providing physical similarity of interaction processes (wear) of friction pairs in relation to drilling technology are required. The task of this article is to study lubricating additives for reaming of reaming pipe in mono-diameter wells for subsequent selection of the most optimal of them. The experiments were carried out on the wellknown universal machine II 5018, designed for testing friction and wear of metals and alloys, hard engineering plastics and composites. The loading system and the II 5018 work unit were upgraded to simulate the processes being studied. During the experiments, the friction coefficient and wear rate of the sample were measured. To carry out the research, various lubricating and cooling media used in drilling technology were selected.

Agarose as a tunable platform for oral drug delivery: Controlled release of a highly soluble drug, theophylline, within a sequentially-changing-pH medium

The purpose of this study was to expand the use of freeze-dried agarose-based systems for the oral controlled release of highly water-soluble drugs. Three additives (Eudragit S-100 and RL-PO and Labrafac) were included within these systems together with Theophylline. The release of this drug from the rehydrated systems was evaluated in deionized water and in a sequentially-changing-pH medium that simulated the conditions under oral administration. Considering the results obtained in the preliminary release test in water, only the Eudragit-containing compositions were further characterized. The theophylline release in a sequentially-changing-pH medium showed two different patterns that mainly depend on the additive nature: those systems containing Eudragit S-100 showed a similar behaviour to that observed in the absence of additives while the presence of Eudragit RL-PO yields a progressive and pH-independent release. Agarose-based systems were capable of accommodating additives that allows tailoring a controlled release of theophylline, a highly soluble drug.

ANALISIS VALIDITAS PENGEMBANGAN MODUL PEMBELAJARAN PENGELASAN SMAW BERBASIS PROYEK (PROJECT BASED LEARNING)

A teaching module is a set of tools, media, methods, instructions and learning guidelines that are prepared and planned to suit the student's development phase. The following research aims to examine the feasibility of a product from developing a project-based SMAW Welding Module (PjBl) for Mechanical Engineering Vocational Education students, Faculty of Teacher Training and Education, Sultan Ageng Tirtayasa University. This research was carried out using a quantitative approach. The following research is part of research and development using the Borg and Gall method, namely Develop Preliminary Form of Product Testing using the Expert Judgment validity test. The research results were analyzed descriptively quantitatively. The research results showed that the feasibility of the module content reached 87% in the very good and very feasible category, the feasibility of the learning presentation reached 92% in the very good and very appropriate category, the appropriateness of the language reached 89% and was in the very good and very feasible category and finally based on feasibility. Graphics reached 93% so it is included in the very good and very worthy category. Overall, the conclusion is drawn that the validity of the Project-based SMAW Welding Module (PjBl) is in the very good and very feasible category and can be continued to the Preliminary Field Testing stage.

Synthesis and catalytic activity of silver N-heterocyclic carbene complexes based on bis(3,5-dimethylpyrazol-1-yl)methyl-substituted pyridylimidazole

A series of N-heterocyclic carbene (NHC) silver complexes derived from 6-[bis(3,5-dimethylpyrazol-1-yl)methyl]-2-pyridylimidazole have been synthesized and characterized by physico-chemical and spectroscopic methods, and the structures of four complexes have been confirmed by X-ray structural analyses. The functionalized NHC is a monodentate ligand in (NHC)AgCl through the carbene carbon atom, and a bridging [C,N,N] tridentate ligand in (NHC)2Ag2(BF4)2 and (NHC)2Ag2(PF6)2 through two pyrazolyl nitrogens and the carbene carbon to form a metallomacrocycle, in which a head (carbene)– to tail (nitrogen) coordination mode to two silver atoms is observed. Preliminary catalytic tests show that these newly synthesized Ag–NHC complexes exhibit excellent catalytic activity at a low catalyst loading (0.1–1 mol%) in the aldehyde–amine–alkyne coupling reaction.

Synthesis, characterization, and photocatalytic activity for water remediation and hydrogen evolution of Zn(II) and Ni(II) bis(thiosemicarbazone) complexes

The extensive industrial use of organic dyes causes large amounts of these substances to arrive at water sources, so nowadays, organic compound removal from fresh water is a major concern. The use of photocatalysts is an interesting approach to solving this problem, with coordination compounds playing an outstanding role. We report the selective synthesis and characterization of three new dissymmetric bis(thiosemicarbazone) ligands and their nickel(II) and zinc(II) complexes, which have been fully characterized by several techniques. The photocatalytic activity of the six complexes for methyl orange degradation was also evaluated. All the complexes can degrade this organic dye, although the photoefficiency of the nickel compounds is, in general, higher than for the zinc ones, as the degradation is faster and they do not reach a plateau. Density functional theory calculations show a clear dependence of the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap, as well as with the relative energies of these orbitals. On the other hand, the need for green fuels that do not produce the greenhouse effect is one of the major goals of modern life, and molecular hydrogen is one of the most promising ones. Considering the proven potential of bis(thiosemicarbazone) complexes to electrocatalyze H2 evolution recently reported in the literature, we also made some preliminary tests to investigate the potential of the nickel complexes to act as photocatalysts for water splitting. The results indicate that two of the complexes produce H2 in the conditions tested, so they could be used in the development of efficient photocatalytic systems for hydrogen evolution.

Resistance of a mixed bacterial culture isolated from bee dysbiosis to disinfectant in laboratory conditions

Disinfection is one of the components of preventive actions to prevent disease in animals by infectious agents. Through the elimination of agents of infectious diseases in the environment, it is able to interrupt the mechanisms of the epizootic process. For the development of beekeeping and obtaining quality and products, it is necessary to carry out activities in apiaries, which include disinfection. The introduction of new disinfectants in the field is possible after preliminary laboratory tests. The aim of our research objective to investigate the resistance of a mixed bacterial culture isolated from bees with the symptoms of dysbiosis to disinfectant under laboratory conditions. Bacteriological investigations carried out in Petri dishes using meat-peptone agar and Mueller-Hinton agar. The disinfectant diluted with distilled water at concentrations of 0.25 %, 0.5 %, 1,25 % and 2,5 %. On the Mueller Hinton agar, the bacterial elimination zones recorded at 1.25 % (11,6 ± 0,45 mm) and 2.5 % (12,4 ± 0,27 mm) concentration of disinfectant at 1 day of investigation, and 7,4 ± 0,27 mm (1,25 %), 11,2 ± 0,42 mm (2.5 %) at 72 hours of the experiment, respectively. In addition, the bacterial growth inhibition effect increased with experimental time and ranged from 24.0 ± 0.35 mm (0.5 %) to 28.2 ± 0.22 mm (2.5 %) on day 3 of the study. Bacteriostatic and bactericidal effects appeared to be less pronounced on meat-peptone agar. The highest diameters of inhibition of the processes of reproduction and development of microorganisms from mixed microbial association on this medium were recorded at 1.25 % and 2.5 % concentrations of the disinfectant at the 3rd day of the investigation with diameters of the zones of inhibition of growth 15.6 ± 0.45 mm and 26.4 ± 0.27 mm, respectively. The specificity of diffusion of the investigated active substance from the discs into the agar medium thickness was also noted. This effect has a varying effect on infectious agents in in vitro experiments. Thus bacteriological laboratory experiments should be performed on several culture media in purpose of obtaining accurate results. The analysis of the obtained results indicates the demonstration of antimicrobial effect of the investigated disinfectant against mixed bacterial culture in the form of bactericidal and bacteriostatic actions. Therefore, a promising direction of research for veterinary doctors and apiary business owners is the search for effective and efficient disinfectants. Laboratory investigation of the activity of a remedy are the first step before it is approbation.

MnOx-Coffea arabica Husk and Catha edulis Leftover Biochar Nanocomposites for Removal of Methylene Blue from Wastewater.

In this study, we investigated the use of manganese oxide-biochar nanocomposites (MnOx-BNC), synthesized from coffee husk (CH) and khat leftover (KL) for the removal of methylene blue (MB) from wastewater. Pristine biochars of each biomass (CH and KL) as well as their corresponding biochar-based nanocomposites were synthesized by pyrolyzing at 300°C for 1 h. The biochar-based nanocomposites were synthesized by pretreating 25 g of each biomass with 12.5 mmol of KMnO4. To assess the MB removal efficiency, we conducted preliminary tests using 0.2 g of each adsorbent, 20 mL of 20 mg·L-1 MB, pH 7.5, and shaking the mixture at 200 rpm and for 2 h at 25°C. The results showed that the pristine biochar of CH and KL removed 39.08% and 75.26% of MB from aqueous solutions, respectively. However, the MnOx-BNCs removed 99.27% with manganese oxide-coffee husk biochar nanocomposite (MnOx-CHBNC) and 98.20% with manganese oxide-khat leftover biochar nanocomposite (MnOx-KLBNC) of the MB, which are significantly higher than their corresponding pristine biochars. The adsorption process followed the Langmuir isotherm and a pseudo-second-order model, indicating favorable monolayer adsorption. The MnOx-CHBNC and MnOx-KLBNC demonstrated satisfactory removal efficiencies even after three and six cycles of reuse, respectively, indicating their potential effectiveness for alternative use in removing MB from wastewater.