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Temperatures of worker- and drone-brood rearing in various hive locations were compared in both colonies kept on small-cell combs (4.90 mm) (SMC) and standard-cell combs (5.50 mm) (STC) in two seasons. Temperatures close to the worker-brood comb placed near the rightmost storage-comb were lower than those near the worker brood in the nest centre but equal to those near the outskirt drone-brood comb (34.37-35.24°C) regardless of the month and the comb-cell size. Temperatures of the brood rearing in the SMC did not differ from those in the STC, independently on the location (center-periphery) and the brood type (drone-worker). Occasionally, they were even higher in the STC near the peripheral drone-brood comb and in the nest centre. We concluded that the drones which are involved in colony reproduction could affect its thermoregulation. The peripheral drone brood can be heated just as well as the worker brood, if the colony is strong enough and has the proper drone-worker ratio. Therefore, it is doubtful whether a higher temperature near the worker brood in the SMC limit the development of the V. destructor population. A lower temperature may not be a factor in encouraging V. destructor females to prefer trap-drone-combs for reproduction in the SMC. Strong field colonies may be especially prone to such behaviour. Therefore, temperature cannot be considered a mechanism of effective Varroa control in SMC.

The paper describes a new method for forming a crankshaft preform. The method is based on the skew rolling technique. With this method the part is formed by three tapered rolls rotated with the same velocity and in the same direction. Simultaneously, the rolls either converge or diverge depending on the desired cross section of the product. The numerical modeling enabled determination of the distributions of effective strains, temperatures, and damage function according to the Cockroft - Latham criterion, aswell as variations in the loads and torques during rolling. The results confirm that a crankshaft preform can be formed by the proposed skew rolling method.

This paper presents results of plastometric tests for plasticine, used as material for physical modelling of metal forming processes. The test was conducted by means of compressing by flat dies of cylindrical billets at various temperatures. The aim of the conducted research was comparison of yield stresses and course of material flow curves. Tests were made for plasticine in black and white colour. On the basis of the obtained experimental results, the influence of forming parameters change on flow curves course was determined. Sensitivity of yield stresses change in function of material deformation, caused by forging temperature change within the scope of 0&C ÷ 20&C and differentiation of strain rate for ˙ɛ = 0.563; ˙ɛ = 0.0563; ˙ɛ = 0.0056s−1,was evaluated. Experimental curves obtained in compression test were described by constitutive equations. On the basis of the obtained results the function which most favourably describes flow curves was chosen.

Purpose: People living with HIV are twice as likely to develop cardiovascular diseases (CVDs) and myocardial infarction related to atherosclerosis than the uninfected population. This study aimed to evaluate the prevalence of subclinical atherosclerosis in a young, mid-eastern European population of PLWH receiving ART for undetectable viremia. Patients and Methods: This was a single-centre study. We included 34 patients below 50 years old, treated in Szczecin, Poland, with confirmed HIV-1 infection, treated with antiretroviral therapy (ART), and undetectable viremia. All patients underwent coronary artery computed tomography (CACT), carotid artery intima-media thickness (IMT) evaluation, and echocardiography. Results: In the primary assessment, only two (5.8%) patients had an increased CVD risk calculated using the Framingham Risk Score (FRS), but we identified coronary or carotid plaques in 26.5% of the patients. Neither traditional risk factors nor those associated with HIV significantly influenced the presence of the plaque. IMT was significantly positively correlated with age and the FRS (R=0.38, p=0.04). Relative wall thickness assessed in echocardiography was higher in those with plaque (0.49 vs 0.44, p=0.04) and significantly correlated with IMT (R=0.38, p=0.04). Conclusion: In our population, more than a quarter of PLWH with undetectable viremia had subclinical atherosclerosis in either the coronary or carotid arteries. The FRS underpredicted atherosclerosis in this population. The role of RWT as a possible early marker of atherosclerosis needs further studies. [ABSTRACT FROM AUTHOR]

Remanufacturing processes are one of the key pillars of the so-called closed-cycle economy. Unfortunately, the design and organization of such processes pose a significant problem, due to, among other things, the high variability of the process as a consequence of both the degree of wear and tear and the quality of the remanufactured components. This article presents a method for optimizing the flow of the brake caliper remanufacturing process in the MTO (make-to-order) model. For the optimization process, the system dynamics (SD) method, which belongs to a group of simulation methods, was used. The developed model allows, in particular, the prediction of the number of components at the input to the regeneration process and the method of defining the size of the transport batch and evaluating its impact on the length of the production cycle of the batch of regenerated products. The issues of staffing management at individual positions and the organization of transport operations with variable production batch sizes were also discussed. The provided experiments have shown that reducing the size of the transport batch contributes to shortening the production order execution time, both with standard and increased staffing. [ABSTRACT FROM AUTHOR]

The purpose of this review was to present clay–cement suspensions that are mainly used in the construction and renovation of hydrotechnical facilities and flood protection. We present the characteristics of clay–cement slurries that are used in waterproofing barriers. One of their significant components are clays of different types and origins. Examples of kaolin-type and smectite-type clays, which are associated minerals, as balanced components of suspensions are presented. As mentioned, before the hydration process, barriers are suspended, and the main test methods are rheometric measurements. Their rheological parameters, extremely important from the point of view of injection mechanics, are shown. The higher the flow limit and faster the reconstruction of thixotropic structures, the higher the energy input of the injection processes. After the hydration process, it is important to form agglomerates and seal the barrier; therefore, we present a summary of the strength results, filtration coefficients and microscopic images of the resulting structures. Additional properties of such barriers in terms of limiting contaminant migration are indicated. One of the aspects affecting the use of liquid slurries is their application methods; thus, a summary of low-energy slurry injection methods is also presented. [ABSTRACT FROM AUTHOR]