Production of biodiesel from microalgae

Biodiesel production from microalgae is a promising technique, with advantages of high biomass yield with high lipid content. Challenges include effective techniques to harvest the grown microalgae, extraction of the algal oil and its transesterification to biodiesel. A microalgae strain was selected from 8 different species screened for growth rate and lipid content. A Tubular Photobioreactor was designed and constructed to study microalgae growth. Productivity of 1 g of dry algal biomass per liter of medium within 12 days was achieved, with lipid content up to 20 %. The observed 10 fold increase in biomass is higher than those reported for open ponds and helical photobioreactors In situ transesterification of dry algae to fatty acids methyl esters (FAMEs) was achieved using ultrasonication. A Gas Chromatograph was used to analyze the FAMEs. Biodiesel produced through 20 minutes of in situ transesterification yields up to 3.679 mg of FAMEs per g of dry algal

Navigating the complex nexus: cybersecurity in political landscapes

Cybersecurity in politics has emerged as a critical and intricate realm intersecting technology, governance, and international relations. In this interconnected digital context, political entities confront unparalleled challenges in securing sensitive data, upholding democratic procedures, and countering cyber threats. This study delves into the multifaceted landscape of political cybersecurity, examining the evolving landscape of cyberattacks, their impact on political stability, and strategies for bolstering digital resilience. The intricate interplay between state-sponsored hacking, disinformation campaigns, and eroding public trust underscores the imperative for robust cybersecurity measures to safeguard political system integrity. Through an extensive exploration of real-world case studies, policy frameworks, and collaborative initiatives, this research illuminates the intricate network of technological vulnerabilities, geopolitical dynamics, and ethical concerns that shape the dynamic evolution of cybersecurity in politics. Amidst evolving digital landscapes, the imperative for agile and preemptive cybersecurity strategies is paramount for upholding the stability and credibility of political institutions

Fuzzification-based Feature Selection for Enhanced Website Content Encryption

We propose a novel approach that utilizes fuzzification theory to perform feature selection on website content for encryption purposes. Our objective is to identify and select the most relevant features from the website by harnessing the principles of fuzzy logic. Fuzzification allows us to transform the crisp website content into fuzzy representations, enabling a more nuanced analysis of their characteristics. By considering the degree of membership of each feature in different fuzzy categories, we can evaluate their importance and relevance for encryption. This approach enables us to prioritize and focus on the features that exhibit higher membership degrees, indicating their significance in the encryption process. By employing fuzzification-based feature selection, we aim to enhance the effectiveness and efficiency of website content encryption, ultimately improving the overall internet security

Environmental Scanning in Globally Oriented Small Businesses: Practices Suggested by Managers

This paper identifies information sources and practices of environmental scanning preferred by managers of globally oriented small and medium-sized enterprises (GOSMEs). Data were collected using a Delphi technique and were analysed by NUD*IST software and the Homogeneity Analysis technique. Major findings indicate that although managers of GOSMEs generally prefer external and personal sources in their environment scanning process, contingent conditions related to the industry, the organization and the owner-manager guide the choice of appropriate information source and the need to scan systematically each sector of the environment. Statistical relationships were identified, and these relationships allowed the formulation of general propositions that could be helpful for practice and research in GOSMEs. The paper concludes that the manager's need to scan systematically a specific sector of the environment and the information source the firm might use are dependent on the level of uncertainty aroused by this sector, the amount of pertinent information the source has, and its accessibility by the firm

SMEs and Sustainable Competitiveness in the Worldwide Market: How to Overcome the Learning Challenge?

This study identifies organizational learning practices that globally oriented small and medium-sized firms could carry out. Suggestions from managers were analyzed using Nud*ist and HOMALS programs. The results indicate that formal as well as informal learning practices could be used following a pollination model in order to obtain explicit and tacit knowledge. However, the content and the learning practices to be adopted are dependent, among other things, on the position, tasks, and career needs of the beneficiary

Passive treatment of acid mine drainage using South African coal fly ash in a column reactor

Thesis (MEng (Chemical Engineering))--Cape Peninsula University of Technology, 2020Fly ash (FA) and acid mine drainage (AMD) are two undesirable materials generated from combustion of pulverized coal for energy and mining activity respectively. Both waste materials have serious, negative impacts on the environment. Fly ash storage leaches a variety of contaminants into surface and groundwater and AMD contains high amounts of toxic metals besides the already dominant !"# concentrations. Many studies had investigated AMD treatment using FA and successfully removed significant amounts of sulphate, as well as minor and trace elements. Hence AMD can be treated using coal fly ash in an active or passive system without addition of any other chemicals. This study had as of objectives the evaluation of the neutralization capacity of FA from two South African’s power stations located in Mpumalanga which are Lethabo and Kendal with mine drainage water from the Mpumalanga coal fields using passive treatment. The research program simulated ex-situ neutralization of AMD in a fly ash slurry followed by continued AMD contact, representing the potential for using spent material as mine annulus fill to reduce air and water content and further AMD generation. Both the fly ash and AMD were obtained from the Mpumalanga province in Eastern South Africa. A 3:1 slurry ratio of AMD to fly ash was mixed until pH stabilized. After mixing, the slurry was packed in columns and left for a duration of 24 hours for a good settling time before the hydraulic treatment. Thereafter the AMD was continuously passed through the columns using gravity flow. Samples of effluent were collected at set time intervals during the hydraulic treatment. These samples were used to determine the flow rate, pH of the leachates and some sent for analysis by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Ion Chromatography (IC) to determine the composition of the effluent water recovered. The X-ray diffraction done on both coal fly ash sources shown a dominance of quartz and mullites,on the other hand the X-ray fluorescence demonstrate that Kendal and Lethabo coal fly ash belong to class F ash due to fact that the total composition of SiO2, Al2O3 and Fe2O3 was exceeding 70% of the entire composition. Moreover, trace elements such as As, V, Ni, Mn, S, Sr, Cu, Y and Pb are found in the CFA used as well. The ICP-OES analysis showed that Eyethu AMD is very acidic with a pH of 2.23, with sulphate concentration of 2680 mg/L, displaying the existence of some metals some of which are Ca, Al and Fe. The neutralization process of Eyethu acid mine drainage using Kendal and Lethabo CFA was highlighted by the variation of pH from the time mine water was in contact with CFA, for the treatment with Lethabo CFA the treated water had its pH raised from 2.23 to 12.65 and from 2.23 to 8.37 using Lethabo and Kendal CFA respectively and this phenomena was explained by the dissolution and hydrolysis of the oxide components such as CaO. This neutralization process was characterized by a strong buffer zone around the pH of 12.83 to 8.37 from the Lethabo leachate and between 8.37 to 7.28 for the leachate from Kendal column. This buffer zone is explained by the hydrolysis of Al3+ which forms a hydroxide phase until all the aluminum ion was totally hydrolyzed. Electrical conductivity was also observed to vary. An amount of 1440 g of Kendal fly ash was used in the columns and treated 15 bed volumes of Eyethu AMD before the CFA was exhausted and lost its neutralizing power in the case of Lethabo CFA, 13 bed volumes of AMD were treated with 1280g CFA before breakthrough was observed. During treatment of Eyethu AMD with Lethabo and Kendal CFA the flow rate of the effluents water first increased during the first minutes of contact of AMD with CFA then started decreasing with time. The concentration of sulphate was reduced to up to 88% in the effluent from Lethabo CFA and 56% in the effluent from Kendal CFA. Some other metals such Fe, Mg, Mn, Al have been significantly removed from the AMD in the Lethabo and Kendal leachate. Furthermore, mass balance calculation were done around the columns in order to determine the moisture content and the % water recovery. From the calculation done it was shown that the column made of Kendal CFA can treat the AMD with a water recovery of 91.9% while Lethabo column could only recover 83.33% of the inlet water. In addition, Acid Base accounting tests were done in order to determine whether either Kendal or Lethabo CFA are from an acid generating or neutralizing rock. Test results have shown that both Kendal and Lethabo CFA are from an alkaline producing rock as their Net Neutralizing Potential and Neutralizing Potential Ratio were above 20 Kg/t CaCO3

Zero-day vulnerability prevention with recursive feature elimination and ensemble learning

This study focuses on spotting and stopping new types of online threats by improving the UGRansome dataset to detect unusual activity in real-time. By blending different machine learning methods, like naïve tree-based ensemble learning and recursive feature elimination (RFE), the research achieves a high accuracy rate of 97%. Naïve Bayes (NB) stands out as the most effective classifier. The suggested setup, combining gradient boosting (GB) and random forest (RF) with NB, effectively identifies and prevents unknown vulnerabilities in computer systems. UGRansome successfully blocks over 100 kilobits per second (kbps) of harmful online traffic by using details pinpointed by the RFE method, specifically uniform resource locators (URLs). This outperforms existing Intrusion Detection System (IDS) datasets. It\u27s particularly good at stopping secure shell attacks, proving the dataset\u27s usefulness in making networks safer. This research marks significant progress in detecting intrusions. The NB model excels in accuracy, precision, and remembering patterns, especially in identifying new threats. Moreover, the suggested naïve tree-based ensemble model shows outstanding accuracy, standing out as the best-performing technique among all models studied. Applying the UGRansome properties-based rule noticeably changes how traffic is sorted, decreasing unknown traffic while increasing unclassified traffic, which requires more investigation

Inter-firm Networking Propensity in Small and Medium-sized Enterprises (SMEs)

In the past decade, market globalization has not only been a threat for small and medium-sized enterprises (SMEs), but also an opportunity to expand their activities in many countries (Murphy and al., 1991). In fact, some of SMEs are worldwide leaders in their sectors (Simon, 1990; Entreprise, 1995). Moreover, few of these worldwide SME leaders started businesses directly on an international level (Christensen, 1991; Brush, 1992; McDougall and al., 1994). This suggests that these SMEs use many processes to overcome resource and competency constraints, which would otherwise impede the success of a transnational business in the new global environment (Barlett and Ghoshal, 1987; Fombrun and Wally, 1992). Some studies have identified co-operation as one of the most powerful means an SME operating across borders can use to overcome its constraints (Olleros and Macdonald, 1988; McDougall and al., 1994; Scully and Fawcett, 1994). To face the complexity, diversity, dynamism and change characterizing the global market, SMEs need to form strong and sustainable ties with other organizations (Forrest, 1990; Harry, 1990). These ties can be made with big, medium-sized or other small enterprises (Shutt and Whittington, 1987; Lorenzoni and Ornati, 1988; Stevens, 1992; Darréon and Faiçal, 1993; Fernandez and Noël, 1994). The balance of power between partners is very important in this kind of inter-firm relationship. SMEs have fewer resources than their partners, and yet their owner-managers prefer autonomy. Then, how do SMEs reconcile the apparent contradictory necessity to cooperate due to resource constraints with their desire for autonomy? What is the ideal quantity of activities that can be devoted to the partnership without threatening the organization itself? The purpose of this paper is to examine propensity of transnational SMEs to subcontract, to outsource (prime contract) or to collaborate on an equivalent basis with other businesses. It is important therefore, to first review the literature related to small business networking. Second, a summary of the methodology and results will follow. Third, propositions will be stated followed by conclusions