Application of FTIR Spectroscopy for Quantitative Analysis of Blood Serum: A Preliminary Study

The aim of this study was to analyze the possibility of simultaneous determination of the concentration of components from the characteristics of FTIR spectra using the example of a model blood serum. To prepare model solutions, a set of freeze-dried control sera based on bovine blood serum was used, certified for approximately 38 parameters. Based on the values of the absorbance and areas of absorption bands in the FTIR spectra of model solutions, a regression equation was constructed by solving a nonlinear problem using the generalized reduced gradient method. By using the absorbance of the absorption bands at 1717 and 3903 cm−1 and the areas of the absorption bands at 616, 3750, and 3903 cm−1, it is possible to simultaneously determine the concentrations of 38 components with an error of less than 0.1%. The results obtained confirm the potential clinical use of FTIR spectroscopy as a reagent-free express method for the analysis of blood serum. However, its practical implementation requires additional research, in particular, analysis of real blood serum samples and validation of the method.

The Real-time Water Discharge Computation in the Conditions of Unsteady Flow (the Yana River in the Verkhoyansk Gaging Section as a Study Case)

The real-time water discharge computation involves practical real-time computation of water discharge values to ensure forecasting and preventing dangerous hydrological phenomena, as well as daily monitoring of river water content and information support for the functioning of water management facilities in river basins. Nowadays the task of the real-time discharge accounting is very relevant. The article presents the outcomes of the study of two methods of computation of the real-time water discharges in the conditions of the unsteady flow that enable to pass to automatic operative accounting of the river flow. The first method is based on using of optimal extrapolation of the relative deviations of the measured water discharges from the reference rating curve obtained from the data of water discharge measurements for previous years. The second method is a new approach based on the Jones formula. The parameters of the Jones formula were obtained from measurements of water discharge over the past years using an optimization tool based on the generalized reduced gradient method. The daily real-time water discharges calculated in two ways were compared with the daily water discharges published in the reference books of the water cadaster «Daily data on the regime and resources of land surface waters». As a result, it was found that both methods can be used for automated real-time water discharge computation in conditions of unsteady flow.

Characterizing the hyper-viscoelastic behavior of adhesive films

In this study, the hyper-viscoelastic behavior of adhesive films was characterized. A constitutive model was developed by combining the Mooney–Rivlin hyperelastic model and a viscoelastic model expressed in terms of the Prony series to describe the constitutive behavior of the adhesive films. The material parameters of the developed constitutive model were determined through single-step stress relaxation tests conducted for 30 min at four strain levels: 100%, 200%, 300% and 400%. Based on the reduced gradient method, the optimized material parameters were then evaluated by curve fitting the experimental data. To validate the proposed constitutive model, we performed the tensile tests at different strain rates from 5 × 10−4 to 5 × 10−1 s−1 and the multistep stress relaxation tests on the adhesive films. The model predictions and experimental data were in good agreement. Thus, the proposed hyper-viscoelastic constitutive model with parameters determined through single-step stress relaxation tests is effective in characterizing the mechanical behavior of adhesive films.

RATIONAL VALUES OF THE PARAMETERS OF THE END PRESSING PROCESS OF TENON JOINT ELEMENTS

Glue tenon joints are widely used in wood products. The face pressing method of the tenon joint elements is an economical alternative to traditional milling. The industrial implementation of the new method requires a reasonable choice of process operating parameters that ensure high quality processing with minimal resource costs. This multicriteria problem belongs to the field of operations research and is solved by mathematical modeling methods. The goal of the work is to determine the rational values of the parameters of the end face pressing process of rectangular eyes in blanks from wood of typical species: coniferous (pine), broad-leaved diffuse-porous (birch), leaf ring-porous (oak). The development of the objective function for the optimization procedure was carried out on the basis of the principle of fair compromise with the reduction of particular criteria to dimensionless form. To construct the objective function, we used regression models that describe the output parameters of the process: the pressing force, the hardness of eye bottoms, and the depth of the deformed zone. The search for solutions to optimization problems was performed using the generalized reduced gradient method in the Microsoft Excel software package. The rational values of the input parameters (moisture content, depth and width of the eyes) and the expected values of the output parameters for each of the studied species have been determined. Recommended moisture values for blanks from pine wood are 8%, birch - 9.5%, oak - 7%; the depth of the pressed eyes is 11, 8 and 9 mm, respectively, the width of the eyes is 4 mm. The objective function has the potential in the direction of reducing the width of the eyes, which can be used to improve the strength characteristics of adhesive joints on multiple extruded spikes.

Optimization of technological parameters of heat treatment of minced fish products in combi steamer

The article considers the process of baking minced fish products in the convection mode in a combi steamer as an alternative to roasting them. There has been developed an optimization technique to determine the optimal technological parameters of heat treatment in a combi steamer. Optimization of technological parameters of heat treatment was carried out on the basis of mathematical modeling. To do this, there were used the methods of correlation-regression and variance analysis. An optimization mathematical model consisting of a target function and a system of constraints was constructed. The target function is a two-factor regression model that functionally relates the output of finished products (optimization parameter), temperature, and duration of the baking process. The target function was subject to conditional maximization. The system of constraints consists of one equation and four inequalities. These restrictions take into account the culinary readiness and organoleptic properties of products, energy costs, as well as the range of temperature changes in the working chamber of the combi steamer. The maximum value of the target function, subject to all restrictions, was found in MS Excel software by using the generalized reduced gradient method. In the result, the optimal technological parameters of heat treatment process in the combi steamer were the following: temperature = 231°C, process duration = 11 minutes. At the same time, the yield of finished fish minced products made 86.7%, and energy costs did not exceed 1 kWh. The results obtained have been confirmed experimentally. The finished products have high organoleptic qualities: the total score = 19.5. The nutritional and energy value of tilapia meatballs was determined. In 100 g of product the amount of protein = 12.8 g, fats =3.8 g, carbohydrates = 11.4 g, energy value = 128 kcal.

MULTI-METHOD OPTIMIZATION OF CONTROL FUNCTIONS AND PARAMETERS

An optimal control problem withphase constraints is considered, which contains control parameters both in the right-hand sides of the controlled system and in the initial conditions. To solve this complex problem, it is proposed first to reduce to a mathematical programming problem, and then to find the optimal parameter values and control functions, we use a multi-method algorithm consisting of linearization methods, the reduced gradient method, and the designed Lagrangian method

Optimization and comparison of different standards for compressed welded box columns

Stability is one of the most critical problems in the design of welded metal structures, since in many cases instability causes failure or collapse of the structures. The present study aims to show the minimum mass design procedure for welded steel box columns loaded by a compression force. The normal stresses and overall stability are calculated for pinned columns. The dimensions of the box columns are optimized by using constraints on global stability, local buckling of webs and flanges. Different design rules and standards are compared: Eurocode 3, Japan Railroad Association, American Petroleum Institute, and American Institute of Steel Construction. The calculations are made for different loadings, column length and steel grades. The yield stress varies between 235 and 690 MPa. Optimization is carried out using the generalized reduced gradient method in Excel solver. Cost calculations and comparisons show the most economical structure.

Integrated vendor–buyer strategies for imperfect production systems with maintenance and warranty policy

Collaboration has evolved as a key component of many modern supply chains, supporting the competitive advantages of companies in a range of operations from manufacturing to sales. With this viewpoint, the present paper develops an integrated inventory model in which manufacturing is carried out at the vendor’s end so as to fulfill demand at the buyer’s doorway. As the production process is presumed to be imperfect it shifts from an “in-control” state to “out-of-control” state at any random time and yields non-conforming items. The vendor uses regular preventive maintenance actions for the efficient operation of the production system and offers free minimal repair warranty on the products sold to the buyer. Along with preventive maintenance actions the vendor also uses the rework process and restoration process as effective steps towards minimizing the imperfections of the production system. The proposed model solves the non-linear cost minimization problem through a generalized reduced gradient method by using Lingo 15.0. The aim is to jointly optimize the order size, backorder size and the number of shipments in order to minimize the integrated cost of the vendor and the buyer. Numerical analysis and sensitivity analysis is performed on key parameters that render some important supervisory insights.