Modeling of Operation Processes of a Motor Grader Engine During Work Under Unsteady Load

We proposed a model of operation processes of a motor grader engine under unsteady load during technological processes of road construction works. Theoretic dependences of operation processes of a diesel motor grader engine, described by third order differential equations, were determined. The developed mathematical model of operation processes of a motor grader engine under unsteady mode makes it possible to employ known theoretical provisions to improve the system of air regulation in the commercially available motor grader engines. The model is a description of patterns of influence of differential equations coefficients and the load character on a change in the rotation rate of crankshaft of engine, cyclic fuel supply and hourly fuel consumption. Numerical modeling was carried out of load throw off and load gain of a motor grader engine using third-order differential equations in relative magnitudes. It was established that at a decrease in the values of coefficients of differential equation the transition process proceeds more intensively. In this case, time of delay in the response to disturbance and the duration of damping the oscillation process decrease. The proposed model would ultimately optimize engine performance under unsteady modes

A Method of Evaluating Vehicle Controllability According to the Dynamic Factor

The study has explored one of the most important performance properties of the vehicle, which determines road traffic safety, – control in a steady mode. A method has been suggested for evaluating the stability of a vehicle against yaw with regard to the dynamic factor. We have found a dependence of the dynamic factor on the design and operational parameters of the vehicle. The dynamic factor can be reduced through achieving a neutral steering of the vehicle by controlling the ratio of the total lateral rigidity of the tires of the front and rear wheels. It has been determined that a change in the tire air pressure, measured by the developed algorithm, improves vehicle stability against yawing and thus contributes to traffic safety. In the example of the truck Ural-4320, the suggested method was used to determine the total lateral stiffness of the wheels under the condition of ensuring the vehicle's neutral steering. The study has revealed that in the case of an equipped vehicle it is necessary to reduce the tire pressure in the wheels on the equalizer trolley in correlation to the air pressure in the tires of the front wheels. The research results can be used both in operating the existing vehicles and for designing new ones

Development of A Method of Protection of Concrete Floors of Animal Buildings From Corrosion at the Expense of Using Dry Disinfectants

Concrete floors are most commonly used in animal housing. However, the specific environment of livestock buildings (moisture, urine, disinfectants) has a negative effect on concrete and leads to its corrosion. The influence of chemical and physical factors on concrete is reinforced by the development of microorganisms, which quickly adapt and use concrete as a living environment. To reduce the influence of an aggressive environment on the concrete floor, an experimental mixture of dry disinfectants was proposed. The components of the disinfection mixture have been selected taking into account the safety for animals and humans. The TPD-MS method was used to determine the change in the chemical composition of concrete. To study the microstructure of concrete, the method of scanning electron microscopy was used. Microbiological studies revealed bacteria A. Thiooxidans, S. aureus, E. coli, S. enteritidis, S. Сholeraesuis, C. Perfringen and micromycetes of the genus Cladosporium, Fusariums, Aspergillus, which contribute to the development of biological corrosion of concrete in livestock buildings. The fact of the negative impact of concentrated disinfectants on the structure of concrete was also established. As a result of the studies carried out, it was proved that a mixture of dry components for disinfection exhibits antimicrobial properties to varying degrees to the strains of field isolates of bacteria and fungi isolated in a pig-breeding farm. It was found that when using the proposed mixture of dry disinfectants in the research room of the pigsty, the relative humidity decreases by 38.5 %; ammonia content – by 46.2 %; hydrogen sulfide – by 57.8 %; microbial bodies – by 74.7 %, compared with the control room. It has been experimentally proven that the proposed mixture of dry disinfecting components has hygroscopic and antimicrobial properties and is promising for use in livestock farms

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (>59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P <.001). Overall motor and cognitive performance (P <.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P <.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P <.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P <.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients