Abstract: Date production in North Africa is facing a worrying slowdown and a decline because of Fusarium wilt or bayoud date palm (Phoenix dactylifera L., caused by Fusarium oxysporum f. sp. albedinis (F. o. a). The objective of this work is to study the in vitro effect of flavonoid aglycones extracted from the roots of two cultivars of date palm (one sensitive to bayoud (Deglet Nour) and the other resistant (Takerboucht)) on the growth and production fusaric acid of the pathogen. Results show that during the first week of development of F. o. a on potato dextrose liquid medium, the flavonoid aglycones extracts of the susceptible cultivar roots stimulates mycelial growth as well as conidiogenesis of F.o.a, nevertheless it has no effect on the synthesis of fusaric acid. However, the flavonoid aglycones extract of resistant cultivar roots stimulates mycelial growth and decreases both the number of conidia production and fusaric acid. It therefore appears possible that the resistant cultivar aglycones have two types of action: they either inhibit the synthesis of fusaric acid, or they metabolize this toxin into hydrosoluble product, this is called detoxification.
Abstract: Cyanobacteria play a vital role in the production of phycobiliproteins that includes phycocyanin and phycoerythrin pigments. Phycocyanin and related phycobiliproteins have wide variety of application that is used in the food, biotechnology and cosmetic industry because of their color, fluorescent and antioxidant properties. The present study is focused to understand the pigment at molecular level in the Cyanobacteria Oscillatoria terebriformis NTRI05 and Oscillatoria foreaui NTRI06. After extraction of genomic DNA, the amplification of C-Phycocyanin gene was done with the suitable primer PCβF and PCαR and the sequencing was performed. Structural and Phylogenetic analysis was attained using the sequence to develop a molecular model.
Abstract: Knowledge is increasingly recognised in this, the
knowledge era, as a strategic resource, by public sector organisations,
in view of the public sector reform initiatives. People and knowledge
play a vital role in attaining improved organisational performance
and high service quality. Many government departments in the public
sector have started to realise the importance of knowledge
management in streamlining their operations and processes. This
study focused on knowledge management in the public healthcare
service organisations, where the concept of service provider
competitiveness pales to insignificance, considering the huge
challenges emanating from the healthcare and public sector reforms.
Many government departments are faced with challenges of
improving organisational performance and service delivery,
improving accountability, making informed decisions, capturing the
knowledge of the aging workforce, and enhancing partnerships with
stakeholders.
The purpose of this paper is to examine the knowledge
management practices of the Gauteng Department of Health in South
Africa, in order to understand how knowledge management practices
influence improvement in organisational performance and healthcare
service delivery. This issue is explored through a review of literature
on dominant views on knowledge management and healthcare service
delivery, as well as results of interviews with, and questionnaire
responses from, the general staff of the Gauteng Department of
Health. Web-based questionnaires, face-to-face interviews and
organisational documents were used to collect data. The data were
analysed using both the quantitative and qualitative methods. The
central question investigated was: To what extent can the conditions
required for successful knowledge management be observed, in order
to improve organisational performance and healthcare service
delivery in the Gauteng Department of Health.
The findings showed that the elements of knowledge management
capabilities investigated in this study, namely knowledge creation,
knowledge sharing and knowledge application, have a positive,
significant relationship with all measures of organisational
performance and healthcare service delivery. These findings thus
indicate that by employing knowledge management principles, the
Gauteng Department of Health could improve its ability to achieve its
operational goals and objectives, and solve organisational and
healthcare challenges, thereby improving organisational performance
and enhancing healthcare service delivery in Gauteng.
Abstract: In this study, statistical optimization design was used to study the optimum disinfection parameters using defatted crude Moringa oleifera seed extracts against Escherichia coli (E. coli) bacterial cells. The classical one-factor-at-a-time (OFAT) and response surface methodology (RSM) was used. The possible optimum range of dosage, contact time and mixing rate from the OFAT study were 25mg/l to 200mg/l, 30minutes to 240 minutes and 100rpm to 160rpm respectively. Analysis of variance (ANOVA) of the statistical optimization using faced centered central composite design showed that dosage, contact time and mixing rate were highly significant. The optimum disinfection range was 125mg/l, at contact time of 30 minutes with mixing rate of 120 rpm.
Abstract: Takerbucht is the only cultivar of date palm known as being resistant to the bayoud disease, caused by Fusarium oxysporum f. sp. albedinis (F.o.a.). In the aim to understand more about the defense mechanisms implied, we realized phytochemical analyses of this cultivar leaflets and roots and this, for the first time, using gas chromatography-mass spectrometry (GC-MS).The examination of our results shows that fifty-four molecules have been detected, fourteen of which are common to leaflets and roots. This study revealed also the organs' richness in derivatives fatty acids: both saturated and unsaturated are represented mainly by methyl esters of Hexadecanoic and 9,12,15-Octadecatrienoic acids. 1-Dodecanethiol, derivative Dodecanoic acid is only present in roots. It’s of great interest to note that the screening revealed the steroidal saponins abundance, among which Yamogenin acetate and Diosgenin, exclusively detected in Takerbucht. They may play an essential role, in the date palm resistance to the bayoud disease.
Abstract: Equivalent fields are frequently used for central axis depth-dose calculations of rectangular and irregular shaped photon beam. Since most of the proposed models to calculate the equivalent square field, are dosimetry-based, a simple physical-based method to calculate the equivalent square field size was used as the basis of this study. The table of the sides of the equivalent square for rectangular fields was constructed and then compared with the well-known tables of BJR and Venselaar with the average relative error percentage of 2.5±2.5 % and 1.5±1.5 % respectively. To evaluate the accuracy of this method, the PDDs were measured for some special irregular symmetric and asymmetric treatment fields and their equivalent squares for Siemens Primus Plus linear accelerator for both energies 6 and 18MV. The mean relative differences of PDDs measurement for these fields and their equivalent square was approximately 1% or less. As a result, this method can be employed to calculate equivalent field not only for rectangular fields but also for any irregular symmetric or asymmetric field.
Abstract: The purpose of this paper is to simulate the production process of a metal stamping industry and to evaluate the utilization of the production line by using ARENA simulation software. The process time and the standard time for each process of the production line is obtained from data given by the company management. Other data are collected through direct observation of the line. There are three work stations performing ten different types of processes in order to produce a single product type. Arena simulation model is then developed based on the collected data. Verification and validation are done to the Arena model, and finally the result of Arena simulation can be analyzed. It is found that utilization at each workstation will increase if batch size is increased although throughput rate remains/is kept constant. This study is very useful for the company because the company needs to improve the efficiency and utilization of its production lines.
Abstract: The mixing of two or more liquids is very common in many industrial applications from automotive to food processing. CFD simulations of these processes require comparison with test results. In many cases it is practically impossible. Therefore, comparison provides with scalable tests. So, parameterization of the problem is sufficient to capture the performance of the mixer.
However, the influence of geometrical and thermo-physical parameters on the mixing is not well understood.
In this work influence of geometrical and thermal parameters was studied. It was shown that for full developed turbulent flows (Re > 104), Pet»const and concentration of secondary fluid ~ F(r/l).
In other words, the mixing is practically independent of total flow rate and scale for a given geometry and ratio of flow rates of mixing flows. This statement was proved in present work for different geometries and mixtures such as EGR and water-urea mixture.
Present study has been shown that the best way to improve the mixing is to establish geometry with the lowest Pet number possible by intensifying the turbulence in the domain. This is achievable by using step geometry, impinging flow EGR on a wall, or EGR jets, with a strong change in the flow direction, or using swirler like flow in the domain or combination all of these factors. All of these results are applicable to any mixtures of no compressible fluids.
Abstract: An experimental investigation was conducted to study the effect of surface roughness on friction factor and heat transfer characteristics in single-phase fluid flow in a stainless steel micro-tube having diameter of 0.85 mm and average internal surface roughness of 1.7 μm with relative surface roughness of 0.002. Distilled water and R134a liquids were used as the working fluids and testing was conducted with Reynolds numbers ranging from 100 to 10,000 covering laminar, transition and turbulent flow conditions. The experiments were conducted with the micro-tube oriented horizontally with uniform heat fluxes applied at the test section. The results indicated that the friction factor of both water and R134a can be predicted by the Hagen-Poiseuille equation for laminar flow and the modified Miller correlation for turbulent flow and early transition from laminar to turbulent flows. The heat transfer results of water and R134a were in good agreement with the conventional theory in the laminar flow region and lower than the Adam’s correlation for turbulent flow region which deviates from conventional theory.
Abstract: Gait disturbance, particularly freezing of gait (FOG), is a phenomenon that is common in Parkinson’s patients and significantly contributes to a loss of function and independence. Walking performance and number of freezing episodes have been known to respond favorably to sensory cues of different modalities. However, a topic that has so far barely been touched is how to resolve freezing episodes via sensory cues once they have appeared. In this study, we analyze the effect of five different sensory cues on the duration of freezing episodes: (1) vibratory alert, (2) auditory alert, (3) vibratory rhythm, (4) auditory rhythm, (5) visual cue in form of parallel lines projected to the floor. The motivation for this study is to investigate the possibility of the design of a gait assistive device for Parkinson’s patients. Test subjects were 7 Parkinson’s patients regularly suffering from FOG. The patients had to repeatedly walk a pre-defined course and cues were triggered always 2 s after freezing onset. The effect was analyzed via experimental measurements and patient interviews. The measurements showed that all 5 sensory cues led to a decrease of the average duration of freezing: baseline (7.9s), vibratory alert (7.1s), auditory alert (6.7s), auditory rhythm (6.4s), vibratory rhythm (6.3s), and visual cue (5.3s). Nevertheless, interestingly, patients subjectively evaluated the audio alert and vibratory signals to have a significantly better effect for reducing their freezing duration than the visual cue.
Abstract: In the present study, the problem of geometrically nonlinear free vibrations of functionally graded circular plates (FGCP) resting on Pasternak elastic foundation with immovable ends was studied. The material properties of the functionally graded composites examined were assumed to be graded in the thickness direction and estimated through the rule of mixture. The theoretical model is based on the classical Plate theory and the Von Kármán geometrical nonlinearity assumptions. Hamilton’s principle is applied and a multimode approach is derived to calculate the fundamental nonlinear frequency parameters, which are found to be in a good agreement with the published results dealing with the problem of functionally graded plates. On the other hand, the influence of the foundation parameters on the nonlinear frequency to the linear frequency ratio of the FGCP has been studied. The effect of the linear and shearing foundations is to decrease the frequency ratio, where it increases with the effect of the nonlinear foundation stiffness.
Abstract: The aim of the study is evaluation of absorbed doses for thyroids by using neck phantoms. For this purpose, it was arranged the irradiation set with different phantoms. Three different materials were used for phantom materials as, water, parafine and wood. The phantoms were three different dimensions for simulation of different ages and human race for each material. Co-60 gammao source was used for irradiation and the experimental procedure applied rigorously with narrow beam geometry. As the results of the experiments the relative radiation doses are evaluated for therapic applications for thyroids and backscattering factors were calculated and shown that water, parafine and wood can appropriate for phantom material with the converge values of backscattering factors.
Abstract: E-governance is an emerging and challenging initiative in developing countries. It is not only concerning the provision of services through the use ICT but rather entails building external interactions with citizen and businesses, enhancing democracy and trust of the political institutions of government. It embraces among other principles, openness, accountability and citizen engagement in public policy process. This study aims at finding users’ satisfaction with three chosen dimensions of e-governance, namely: openness, collaborative governance, and participation. These dimensions of e-governance are neither studied before in the context of Arab countries and nor explored earlier in relation to some demographics variables. A study of 900 users of e-government in United Arab Emirates (UAE) was undertaken to examine how gender, age, education, nationality, and employment affect their satisfaction with e-governance. Generally, satisfaction ratings vary significantly with these variables. However, the overall level of satisfaction with the three attributes was less favorable. Knowing the differences of citizen’s perceptions towards e-governance services would help policymakers in the design of effective e-governance strategy.
Abstract: The adoption and diffusion of Information Technology (IT) is one of the fastest growing trends in organizations operating within Nigeria’s economy. Public and private organizations make huge capital investments in an attempt acquire and adopt the state-of-the-art IT for improving operational efficiency. In this study the level of IT adoption is considered the primary driver of efficiency witnessed by organizations. The research gathered data on the intensity of IT usage, and resultant efficiency increase in the organizations’ operations. The data was analyzed using multiple regression analysis and reveals that high level of IT usage has enhance efficiency of private and public organizations in Northern part of Nigeria with organizations having strategic intent on IT adoption indicating higher efficiency gains.
Abstract: The tribological outcomes of micro dent are found to be outstanding in many engineering and natural surfaces. Ceramic (Al2O3) is considered one of the most potential material to bearing surfaces particularly, artificial hip or knee implant. A well-defined micro dent on alumina oxide interface could further decrease friction and wear rate, thus increase their stability and durability. In this study we fabricated circular micro dent surface profiles (Dia: 400µm, Depth 20µm, P: 1.5mm; Dia: 400µm, Depth 20µm, P: 2mm) on pure Al2O3 (99.6%) substrate by using a micro tool machines. A preliminary tribological experiment was carried out to compare friction coefficient of these fabricated dent surfaces with that of non-textured surfaces. The experiment was carried on well know pin-on-disk specimens while other experimental parameters such as hertz pressure, speed, lubrication, and temperature were maintained to standard of simulated hip joints condition. The experiment results revealed that micro dent surface texture reduced 15%, 8% and 4% friction coefficient under 0.132,0.162, 0.187 GPa contact pressure respectively. Since this is a preliminary tribological study, we will pursue further experiments considering higher ranges of dent profiles and longer run experiments. However, the preliminary results confirmed the suitability of fabricating dent profile to ceramic surfaces by using micro tooling, and also their improved tribological performance in simulated hip joints.
Abstract: The planning in manufacturing system is becoming complicated day by day due to the expanding networks and shortage of skilled people to manage change. Consequently, faster lead time and rising demands for eco-efficient evaluation of manufacturing products and processes need exploitation of new and intelligent knowledge management concepts for manufacturing planning. This paper highlights motivation for incorporation of new features in the manufacturing planning system. Furthermore, it elaborates requirements for the development of intelligent knowledge management concept to support planning related decisions. Afterwards, the derived concept is presented in this paper considering two case studies. The first case study is concerned with the automotive ramp-up planning. The second case study specifies requirements for knowledge management system to support decisions in eco-efficient evaluation of manufacturing products and processes
Abstract: The understanding on the contribution of root respiration to total soil respiration is still very limited, especially for sugarcane. In this study, trenching experiments in sugarcane plantations were conducted to separate and investigate soil respiration for this crop. The measurements were performed for the whole growing period of 344 days to quantify root respiration. The obtained monitoring data showed that the respiration rate is increasing with the age of the plant, accounting for up to 29% of the total soil respiration before harvesting. The root to soil respiration ratio increased rapidly during the young seedling stage, i.e. first five months, then declined and finally got stabilized during yield formation and ripening stages, respectively. In addition, the results from the measurements confirmed that soil respiration was positively correlated with soil moisture content.
Abstract: This paper presents a study of Ni-silicides as the bottom electrode of HfO2-based RRAM. Various silicidation conditions were used to obtain different Ni concentrations within the Ni-silicide bottom electrode, namely Ni2Si, NiSi, and NiSi2. A 10nm HfO2 switching material and 50nm TiN top electrode was then deposited and etched into 500nm by 500nm square RRAM cells. Cell performance of the Ni2Si and NiSi cells were good, while the NiSi2 cell could not switch reliably, indicating that the presence of Ni in the bottom electrode is important for good switching.
Abstract: Structural interpretation of aeromagnetic data and Landsat imagery over the Middle Benue Trough was carried out to determine the depth to basement, delineate the basement morphology and relief, and the structural features within the basin. The aeromagnetic and Landsat data were subjected to various image and data enhancement and transformation routines. Results of the study revealed lineaments with trend directions in the N-S, NE-SW, NWSE and E-W directions, with the NE-SW trends been dominant. The depths to basement within the trough were established to be at 1.8, 0.3 and 0.8km, as shown from the spectral analysis plot. The Source Parameter Imaging (SPI) plot generated showed the centralsouth/ eastern portion of the study area as being deeper in contrast to the western-south-west portion. The basement morphology of the trough was interpreted as having parallel sets of micro-basins which could be considered as grabens and horsts in agreement with the general features interpreted by early workers.
Abstract: This study focused on the estimation of carbon released to the atmosphere from dry dipterocarp forest (DDF) fires in Thailand. Laboratory experiments were conducted using a cone calorimeter to simulate the DDF fires. The leaf litter collected from DDF in western Thailand was used as biomass fuel. Three different masses of leaf litter were employed, 7g, 10g and 13g, to estimate the carbon released from this type of vegetation fire to the atmosphere. The chemical analysis of the leaf litter showed that the carbon content in the experimental biomass fuel was 46.0±0.1%. From the experiments, it was found that more than 95% of the carbon input was converted to carbon released to the atmosphere, while less than 5% were left in the form of residues, and returned to soil. From the study, the carbon released amounted 440.213±2.243 g/kgdry biomass, and the carbon retained in the residues was 19.786±2.243 g/kgdry biomass. The quantity of biomass fuel consumed to produce 1 g of carbon released was 2.27±0.01gkgdry biomass. Using these experimental data of carbon produced by the DDF fires, it was estimated that this type of fires in 2009 contributed to 4.659 tonnes of carbon released to the atmosphere, and 0.229 tonnes of carbon in the residues to be returned to soil in Thailand.