On the Role of Primary and Secondary Assets in Adaptive Security: An Application in Smart Grids

peer-reviewedAdaptive security aims to protect valuable assets managed by a system, by applying a varying set of security controls. Engineering adaptive security is not an easy task. A set of effective security countermeasures should be identified. These countermeasures should not only be applied to (primary) assets that customers desire to protect, but also to other (secondary) assets that can be exploited by attackers to harm the primary assets. Another challenge arises when assets vary dynamically at runtime. To accommodate these variabilities, it is necessary to monitor changes in assets, and apply the most appropriate countermeasures at runtime. The paper provides three main contributions for engineering adaptive security. First, it proposes a modeling notation to represent primary and secondary assets, along with their variability. Second, it describes how to use the extended models in engineering security requirements and designing required monitoring functions. Third, the paper illustrates our approach through a set of adaptive security scenarios in the customer domain of a smart grid. We suggest that modeling secondary assets aids the deployment of countermeasures, and, in combination with a representation of assets variability, facilitates the design of monitoring function

An Assessment of Image Quality of Radiographs in a Nigerian Teaching Hospital by Film Densitometry

3000 radiographs covering chest, upper limb, lower limb,lumbar spine (AP) and skull (PA) from the University ofCalabar teaching hospital (UCTH) were retrospectivelystudied by densitometry to assess the degree of variationin radiographic contrast over a ten year period (1999 –2008). The results show that variation in meanradiographic contrast from year to year was statisticallyinsignificant (p < 0.05) for the respective projectionsstudied. This result implies a relatively basicstandardisation in image quality arising from consistencyin technique acquired over time. The results would serveas a baseline for developing a more robust qualityassurance programme in the hospital

Thermoeconomic and exergo environmental sustainability of a power-cooling organic Rankine cycle with ejector system

The study presents a power-cooling organic Rankine cycle with an ejector system (ORCPCES). The objective is to determine the thermodynamic, economic and sustainability of the ORCPCES from the manufacturing, commissioning and decommissioning phases. Component-wise modelling was first performed based on the exergy concept. The system simulation was carried out using a developed source code in Engineering Equation Solver (EES). The refrigerant leakages and the material component impact on the environment were evaluated at all phases of the plant life cycle. The results indicate that the evaporator cooling rate (ECR) and the power-cooling efficiency (PCE) varied from 120.8 to 153 kW and 28.87 to 34.43 % across the refrigerants with the highest PCE and exergy efficiency obtained using R1234ze. The maximum power output was obtained using R1234ze. The overall environmental impact due to the components occurred at, and for R245fa, R1234yf, and R1234ze, respectively, while and was due to the working fluids in that order. The unit cost of electricity (UCOE) across the refrigerants varies from 0.181$/kWh to 0.2291$/kWh with the least UCOE, 0.181$/kWh obtained using R1234ze. The highest exergetic sustainability index of 0.56 was achieved using R1234ze

Thermoeconomic and exergoenvironmental sustainability of a power-cooling organic Rankine cycle with ejector system

The study presents a power-cooling organic Rankine cycle with an ejector system (ORCPCES). The objective is to determine the thermodynamic, economic and sustainability of the ORCPCES from the manufacturing, commissioning and decommissioning phases. Component-wise modelling was first performed based on the exergy concept. The system simulation was carried out using a developed source code in Engineering Equation Solver (EES). The refrigerant leakages and the material component impact on the environment were evaluated at all phases of the plant life cycle. The results indicate that the evaporator cooling rate (ECR) and the power-cooling efficiency (PCE) varied from 120.8 to 153 kW and 28.87 to 34.43 % across the refrigerants with the highest PCE and exergy efficiency obtained using R1234ze. The maximum power output was obtained using R1234ze. The overall environmental impact due to the components occurred at, and for R245fa, R1234yf, and R1234ze, respectively, while and was due to the working fluids in that order. The unit cost of electricity (UCOE) across the refrigerants varies from 0.181$/kWh to 0.2291$/kWh with the least UCOE, 0.181$/kWh obtained using R1234ze. The highest exergetic sustainability index of 0.56 was achieved using R1234ze

Distribution and diversity of flora and fauna in International Institute Of Tropical Agriculture (IITA) forest and nature reserve, Ibadan, Oyo state, Nigeria

The study examined the distribution and diversity of plant and animal  species at the International Institute of Tropical Agriculture forest and nature reserve, it was aimed at assessing the numbers of plant and  animal species and the areas where they occur in the study sites. Plant and animal species were enumerated through direct on-site field  observation for fifteen months to provide data that could enhance the management and sustainable utilization of the forest. Eighty-seven plant species from 39 families were found in the area; 55 species were trees while shrubs and grasses were 32 species. The common tree species found in the area were Elaeis guineensis (32.4%) Funtumia elastica (11.4%) Newbouldia laevis (7.6%) and Lecaniodiscus cupanioides (4.5%). Two particularly interesting climber species found, were Pararistolochia  goldieana and Caesalpinia bonduc. Also, there are several wild relatives of cultivated yams which grow naturally these are Dioscorea bulbifera, Dioscorea dumentorum, Dioscorea hirtiflora, Dioscorea togoensis,  Dioscorea praehensilis and Dioscorea Prevssii. These form potential gene pool/resources for improvement of the cultivated yam. Ninety-two species of wild animals from 45 families were also found in the study area. There were 66 species of birds from 28 families, 3 species of reptiles from 3 families and 23  species of mammals from 16 families. A total of 11,632 sightings were recorded. The most abundant animal species found in the area were  Corvus albus (7.8%), Viverra civetta (7.4%), Cephalophus rufilatus (7.2%) and Dendrocygna viduata (5.4%). The endemic Ibadan malimbe  (Malimbus ibadanensis) was also sighted in the study site and several other birds which normally winter around the lake.Key words: Ecology, Distribution, Diversity, Forest, Nature Reserve, IITA

Compliance of Radiation Dose and Image Quality in a Nigerian Teaching Hospital with the European Guidelines for Pediatric Screen-Film Chest Radiography

Introduction Blue light is a part of the spectrum with the highest energy content, which can reach the retina. The damage that it can cause to the retina is called photochemical or blue-light retinal injury. For the retinal injury assessment of the photochemical and aphakic retinal hazards in the wavelength range of 300-700 nm, use of effective spectral radiance limits (W.m-2.sr-1) seems to be slightly perplexing for ophthalmologists. However, in this study, the temperature (OC) that can emit the same effective spectral radiance limit was detected using a computer code; this method could help prevent blue-light retinal injury. Materials and Methods The limits proposed by International Commission on Non-Ionizing Radiation Protection for blue-light induced photochemical and aphakic eye hazards were expressed in terms of temperature by a computer code for 13 Planckian sources that produce the same radiance. The calculated temperature by the computer code, here known as threshold temperature, is the maximum source temperature that for a specified viewing distance and source diameter does not cause the exposure at the receptor position to exceed the exposure limit. Results In terms of threshold temperature, the exposure limits for aphakia or infant retinal injury are much lower than retinal photochemical damage. For light sources with more effective radiances, these differences reach 800 K. Conclusion This method allows evaluation of photochemical and aphakic retinal hazard only by comparing the calculated threshold temperature by a computer code with the temperature of the radiant source, which may be beneficial for hygienist and ophthalmic clinicians

THE CONSEQUENCES OF RAPID POPULATION GROWTH ON HOUSING IN CALABAR METROPOLIS

The rapid growth of population has constituted serious problems especially in urban cities with great housing demand. This paper seeks to examine the consequences of rapid population growth on housing in Calabar. Findings show a high negative value of-0.67 at 95 % confidence level which also shows a calculated value of 2.57 greater than the tabulated value of 2.31. This indication reveals that there is a significant relationship between housing supply and population increase in the area. However, it was observed that the area weakest series of urban problems such as squalor settlements and high occupancy rates which were attributed to high population growth. Despite these problems, there was a significant improvement in housing development and quality in the area. Therefore, the various agencies in housing development must ensure that housing regulations are properly flowered by those in the industry

Studies on thiophene-thiazole-carbohydrazides as methicillin-resistant staphylococcus aureus (MRSA) agents: Insight from DFT and Molecular docking simulation

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly common bacterial infection that poses a serious threat to human health. MRSA is resistant to many common antibiotics, making it particularly difficult to treat. To address this issue, the density functional theory (DFT) approach was employed in this study to examine thiophene- and thiazole-containing carbohydrazides for their biological activities. Quantitative experimental and spectroscopic results were obtained and compared to the theoretical. The FMO reactivity parameters revealed superior biological activity and reactivity of compound 6 G in gas phase, polar and non-polar solvents according to the data. Additionally, molecular electrostatic potential (MESP) analysis and non-covalent interaction (NCI) indicated that compound 6F contained more weak and steric repulsion interactions, while compound 6 G featured minimal van der Waals forces of attraction. Also, compound 6 G had the highest stabilization energy in the NBO analysis which show a better donor - acceptor charge transfer and electron delocalization. Molecular docking analyses with standard drugs showed higher binding affinities for compound 6 G with 3VSL than with CIPRO. The in-silico analysis suggests that 6F and 6 G have great bioactivity for tackling MRSA

X-ray absorption by sodium chloride

In vitro Sodium Chloride absorption of X-rays was studied with concentrations of 46 mg/mol to 460 mg/mol, which include the range of sodium and chloride ion concentrations in the human body. Irradiation was done with an incident x-radiation dose equivalent of 0.0309 m Sv, with Lithium Fluoride as detector. Absorbed doses read off the thermoluminiscent detectors (TLD) with a TLD reader showed a non uniform variation, but linear relationship between concentration and absorbed dose, with a strong positive correlation of 0.8140. The radiobiological implications of these results are discussed. Keywords: Sodium Chloride, X-ray, Absorption, concentration, phosphors, selection, patients (Global Journal of Pure and Applied Sciences: 2002 9(1): 133-138