28 research outputs found
Terenska metoda za dokazivanje organofosfornih spojeva u vodama
An enzyme test has been worked out for detecting organophosphorus compounds in water. The lest is based on the inhibition of cholinesterase. The detection limits for the Ā»nerve gasesĀ« are (Āµg/L): Soman 0.12, VX 5.9, Sarin 9.9 and Tabun 26. The detection limit for the organophosphorus pesticide dichlorvos is 50 Āµg/L.RazraÄena je terenska metoda za dokazivanje organofosfornih spojeva u vodama, koja se osniva na kinetici inhibicije kolinesteraza. U metodi se rade sljedeÄe reagencije: lifolizirani serum Äovjeka kao izvor enzima, butiriltiokolin kao stupstrat i DTNB kao tiolni reagents. Garnitura test-reagencija sadržava i pufer i destiliranu vodu. Enzim i potencijalno kontaminirana voda inhibiraju SP 15 min prije dodatka supstrata, a zatim se tijekom 5-10 min prati nastajanje žute boje. Ako je voda kontaminirana organofosfornim spojevima, onda Äe otopina biti bezbojna ili svijetložuta u odnosu na kontrolni uzorak, koji Äe imati intenzivno žutu boju. U kontrolnom uzorku enzim se inkubira s destiliranom vodom. Granice detekcije za nervne bojne otrove su (Āµg/L): Soman 0,12, VX 5,9, Sarin 9,9 i Tabun 26. Granica detekcije za organofosforni pesticid diklorvos: 50 Āµg/L
Managing Relationship Decay Network, Gender, and Contextual Effects
Relationships are central to human life strategies and have crucial fitness consequences. Yet, at the same time, they incur significant maintenance costs that are rarely considered in either social psychological or evolutionary studies. Although many social psychological studies have explored their dynamics, these studies have typically focused on a small number of emotionally intense ties, whereas social networks in fact consist of a large number of ties that serve a variety of different functions. In this study, we examined how entire active personal networks changed over 18 months across a major life transition. Family relationships and friendships differed strikingly in this respect. The decline in friendship quality was mitigated by increased effort invested in the relationship, but with a striking gender difference: relationship decline was prevented most by increased contact frequency (talking together) for females but by doing more activities together in the case of males
Yeasts associated with the production of distilled alcoholic beverages
Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine
On second-order slidingmode control of fractional-order dynamics
Abstract-A second-order sliding mode control scheme is developed to stabilize a class of linear uncertain fractionalorder dynamics. After making a suitable transformation that simplifies the sliding manifold design, a chattering-free second order sliding mode approach that accomplishes the control task by means of a continuous control action is developed. Simple controller tuning formulas are constructively developed along the paper by Lyapunov analysis. The simulation results confirm the expected performance
Continuous finite-time stabilization for some classes of fractional order dynamics
This paper analyzes some basic issues involving the application of discontinuous control techniques for controlling fractional order systems (FOS). With reference to a simple class of SISO perturbed processes, we compare the performance of two distinct approaches, namely the āfractional sliding manifoldā (FSM) approach, and the āfractional dynamic input extensionā (FDIE) approach. The latter, which is the main new contribution of this paper, is shown to provide for the finite time convergence property of the systems' state. Remarkably, this approach also attenuates the chattering phenomenon by leading to a continuous, although obviously non-smooth, control action. The performance of the two methodologies under investigation are determined by means of Lyapunov approach. Additionally, we derive two new results involving the application of second-order sliding mode control techniques in the context of SISO FOS, and the application of the unit-vector methodology for controlling uncertain multivariable FOS. The presented analysis is supported by simulation results
Discrete Particle Swarm Optimization Algorithm for Solving Optimal Sensor Deployment Problem
Abstract ā This paper addresses the Optimal Sensor Deployment Problem (OSDP). The goal is to maximize the probability of target detection, with simultaneous cost minimization. The problem is solved by the Discrete PSO (DPSO) algorithm, a novel modification of the PSO algorithm, originally presented in the current paper. DPSO is generalpurpose optimizer well suited for conducting search within a discrete search space. Its applicability is not limited to OSDP, it can be used to solve any combinatorial and integer programming problem. The effectiveness of the DPSO in solving OSDP was demonstrated on several examples
Nonlinear fractional PI control of a class of fractional-order systems
This paper deals with the design of nonlinear PI control techniques for regulating a class of fractional-order dynamics governed by a commensurate-order model, possibly nonlinear, perturbed by an external disturbance. The suggested control algorithm is the combination between a fractional-order PI controller and a nonlinear robust version of it, namely a second-order sliding mode control algorithm called "super-twisting" controller in the literature. A key feature of the approach is the use of ad-hoc sliding manifolds whose construction involves fractional order derivatives. A constructive Lyapunov based synthesis is illustrated, which leads to simple tuning rules for the controller parameters guaranteeing the asymptotic rejection of the external disturbance under appropriate smoothness restrictions. Computer simulations illustrate the effectiveness of the proposed technique
Complex-Order Models: A System Identification Point of View
The present paper proposes a framework for the systematic and fruitful application of complex-order operators for modeling and control applications. We emphasize that special care must be taken when using complex-order elements to ensure that their responses to real-valued stimuli are real-valued themselves. The proposed complex-order real-valued elements enable the seamless generalization of their conventional real and integer-order counterparts. We further demonstrate how any linear operator can be extended in much the same way as the differintegral, by āraisingā it to a power of a complex order, while ensuring that its kernel remains real-valued. The applicability of our considerations is demonstrated by a model of a compressed natural gas injection system
Complex-Order Models: A System Identification Point of View
The present paper proposes a framework for the systematic and fruitful application of complex-order operators for modeling and control applications. We emphasize that special care must be taken when using complex-order elements to ensure that their responses to real-valued stimuli are real-valued themselves. The proposed complex-order real-valued elements enable the seamless generalization of their conventional real and integer-order counterparts. We further demonstrate how any linear operator can be extended in much the same way as the differintegral, by “raising” it to a power of a complex order, while ensuring that its kernel remains real-valued. The applicability of our considerations is demonstrated by a model of a compressed natural gas injection system
Factors that predict walking ability with a prosthesis in lower limb amputees
Introduction. Identification of predictive factors for walking ability with a
prosthesis, after lower limb amputation, is very important in order to define
patientās potentials and realistic rehabilitation goals, however challenging
they are. Objective. The objective of this study was to investigate whether
variables determined at the beginning of rehabilitation process are able to
predict walking ability at the end of the treatment using support vector
machines (SVMs). Methods. This research was designed as a retrospective
clinical case series. The outcome was defined as three-leveled ambulation
ability. SVMs were used for predicting model forming. Results. The study
included 263 patients, average age 60.82 Š} 9.27 years. In creating SVM
models, eleven variables were included: age, gender, cause of amputation,
amputation level, period from amputation to prosthetic rehabilitation,
Functional Comorbidity Index (FCI), presence of diabetes, presence of a
partner, restriction concerning hip or knee extension, residual limb hip
extensor strength, and mobility at admission. Six SVM models were created
with four, five, six, eight, 10, and 11 variables, respectively. Genetic
algorithm was used as an optimization procedure in order to select the best
variables for predicting the level of walking ability. The accuracy of these
models ranged from 72.5% to 82.5%. Conclusion. By using SVM model with four
variables (age, FCI, level of amputation, and mobility at admission) we are
able to predict the level of ambulation with a prosthesis in lower limb
amputees with high accuracy