Hydrodynamics of single-deadrise hulls and their catamaran configurations

AbstractAsymmetric planing hulls are often used on high-speed catamarans. In this study, a linearized potential-flow method is applied for modeling steady hydrodynamics of single asymmetric hulls and their catamaran setups. Numerical results are validated with available experimental data and empirical correlations. Parametric calculation results are presented for the lift coefficient and the center of pressure for variable hull geometry, spacings, and speed regimes. The lift coefficient is found to increase at smaller hull spacings and decrease at higher Froude numbers and higher deadrise angles

Real-time relative permeability prediction using deep learning.

A review of the existing two and three phase relative permeability correlations shows a lot of pitfalls and restrictions imposed by (a) their assumptions (b) generalization ability and (c) difficulty with updating in real time for different reservoirs systems. These increase the uncertainty in its prediction which is crucial owing to the fact that relative permeability is useful for predicting future reservoir performance, effective mobility, ultimate recovery, injectivity among others. Laboratory experiments can be time consuming, complex, expensive and done with core samples which in some circumstances may be difficult or impossible to obtain. Deep Neural Networks (DNNs) with their special capability to regularize, generalize and update easily with new data has been used to predict oil-water relative permeability. The details have been presented in this paper. In addition to common parameters influencing relative permeability, Baker and Wyllie parameter combinations were used as input to the network after comparing with other models such as Stones, Corey, Parker, Honapour using Corey and Leverett-Lewis experimental data. The DNN automatically used the best cross validation result (in a 5-fold cross validation) for its training until convergence by means of Nesterov accelerated gradient descent which also minimizes the cost function. Predictions of non-wetting and wetting phase relative permeability gave good match with field data obtained for both validation and test sets. This technique could be integrated into reservoir simulation studies, save cost, optimize the number of laboratory experiments and further demonstrates machine learning as a promising technique for real time reservoir parameters prediction

Experimental and theoretical studies on corrosion inhibitory action of Peganum harmala (L.) seeds extract on carbon steel in 1M HCl

The objective of this study is to test the inhibitory efficiency of the methanol extract of P. harmala against the corrosion of carbon steel C38 in 1M hydrochloric acid by gravimetric method and electrochemical measurements. The results indicated that the methanol extract of P. harmala is a good inhibitor of carbon steel. The inhibition efficiency increases with the increase of the concentration of the inhibitor. The nature of adsorption of the extract on carbon steel surface was in conformity with Langmuir isotherm. Both kinetic and thermodynamic parameter of adsorption allows us to suggest chemical adsorption of this inhibitor on the metal. Potentiodynamic polarization measurements show that P. harmala acts as mixed type inhibitor.   The result of EIS was correlating with the result of polarization measurement. A theoretical study was done in solution for major alkaloids isolated from P. harmala seeds, and was investigated using density functional theory (DFT) at the B3LYP/6-31G(d,p) basis set level through the relationship between their molecular and electronic structure. The quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), energy gap (ΔE), dipole moment (μ), absolute hardness (η), absolute softness (S), the absolute electronegativity (χ), the fractions of electrons transferred from the inhibitor molecule to the metallic atom (ΔN) and the electrophilicity index (ω) were calculated. The local selectivity and reactivity has been analyzed through the Fukui function indices in order to compare the possible sites for nucleophilic and electrophilic attacks

On incomplete exponential \;_{r}R_{s}(P,Q,z) matrix function

The recurrence matrix relations, differentiation formulas, and analytical and fractional integral properties of incomplete gamma matrix functions $\gamma(Q, x)$ and $\Gamma(Q, x)$ are all covered in this article. The generalized incomplete exponential matrix functions with their integral representations functions have been examined, along with some relevant characteristics of these functions such as integral representations functions . Additionally, the infinite summation relations and formulas for two sequences are shown, along with the generalized incomplete exponential matrix functions with the integral representation, addition formula for addition of two arguments, multiplication formula for multiplication of two arguments, and recurrence matrix relation

Integrating Information Technologies Into Business Functions: A Taxonomy of Integration Strategies

The objective of this paper is to establish a taxonomy of integration strategies that will assist information technology managers in integrating information technologies into business functions and strategies. Such integration is becoming even more of a reality now because of several factors: increased capabilities of inter-networking, availability of development tools that permit multi-platform interfaces, and the evolution of distributed databases. The paper provides a scheme for defining integration that identifies three dimensions: scope, object, and organization. Objectives of integration are classified into gaining competitive advantage, achieving more effective and efficient operations, and improving customer relations. The taxonomy of integration strategies is presented based on the following layers of platforms: information technologies, network, data base, application development, and organization strategies. An integration project may include one or more dimension, achieve one or more objectives, and span over one or more platforms. Without proper planning and implementation, integration projects may fail causing the loss of technology and financial resources

Conductive Ink Meets Spider Silk

Spider silk proteins can be created synthetically and are highly valued for their strength, durability, and flexibility. By altering the genome of goats, silk worms, and the bacteria E. coli we are able to manufacture spider silk products in lab. The production and manipulation of these ‘recombinant spider silk proteins’ along with the process of aqueous solubilization can yield many useful spider silk materials such as films, fibers, gels, coatings, and more. Conductive ink is a recent and popular scientific discovery that let’s you create flexible working circuits. This product has many applications including RFID tags, circuit boards, and printers. However, most conductive inks contain a highly toxic organic compound known as butanone along with a conductive salt. Our research is to prove that replacing butanone with spider silk proteins in conductive inks will still create a flexible and durable circuit without the toxicity. This non-toxic conductive ink could prove useful when applying the circuit directly into living systems. We also think that using spider silk proteins in our circuits will improve the durability and elasticity of the circuits created

Evolving robotic surgery training and improving patient safety, with the integration of novel technologies

INTRODUCTION: Robot-assisted surgery is becoming increasingly adopted by multiple surgical specialties. There is evidence of inherent risks of utilising new technologies that are unfamiliar early in the learning curve. The development of standardised and validated training programmes is crucial to deliver safe introduction. In this review, we aim to evaluate the current evidence and opportunities to integrate novel technologies into modern digitalised robotic training curricula. METHODS: A systematic literature review of the current evidence for novel technologies in surgical training was conducted online and relevant publications and information were identified. Evaluation was made on how these technologies could further enable digitalisation of training. RESULTS: Overall, the quality of available studies was found to be low with current available evidence consisting largely of expert opinion, consensus statements and small qualitative studies. The review identified that there are several novel technologies already being utilised in robotic surgery training. There is also a trend towards standardised validated robotic training curricula. Currently, the majority of the validated curricula do not incorporate novel technologies and training is delivered with more traditional methods that includes centralisation of training services with wet laboratories that have access to cadavers and dedicated training robots. CONCLUSIONS: Improvements to training standards and understanding performance data have good potential to significantly lower complications in patients. Digitalisation automates data collection and brings data together for analysis. Machine learning has potential to develop automated performance feedback for trainees. Digitalised training aims to build on the current gold standards and to further improve the 'continuum of training' by integrating PBP training, 3D-printed models, telementoring, telemetry and machine learning

PRELIMINARY DESIGN OF OSCILLATORY FLOW BIODIESEL REACTOR FOR CONTINUOUS BIODIESEL PRODUCTION FROM JATROPHA TRIGLYCERIDES

The concept of a continuous process in producing biodiesel from jatropha oil by using an Oscillatory Flow Biodiesel Reactor (OFBR) is discussed in this paper. It has been recognized that the batch stirred reactor is a primary mode used in the synthesis of biodiesel. However, pulsatile flow has been extensively researcehed and the fundamental principles have been successfully developed upon which its hydrodynamics are based. Oscillatory flow biodiesel reactor offers precise control of mixing by means of the baffle geometry and pulsation which facilitates to continuous operation, giving plug flow residence time distribution with high turbulence and enhanced mass and heat transfer. In conjunction with the concept of reactor design, parameters such as reactor dimensions, the hydrodynamic studies and physical properties of reactants must be considered prior to the design work initiated recently. The OFBR reactor design involves the use of simulation software, ASPEN PLUS and the reactor design fundamentals. Following this, the design parameters shall be applied in fabricating the OFBR for laboratory scale biodiesel production