The effect of the initial size on the height of the crank press die

The expansion of the technical and technological capabilities of forging and stamping machines and equipment can be carried out through the introduction of new designs of actuators with wide functionality. These developments require solving the problems of kinematic synthesis and analysis of mechanisms. In this work a comparative analysis of the endurance indicators of a crank press with the mechanism for transforming the motion of Stephenson II depending on the elastic compliance of the connecting rods and the deformation of the forging was shown. In this regard, the features of the kinematics of a crank press driven by an asynchronous motor taking into account the flexibility of the connecting rods and the workpiece was investigated.

Development of a complex anti-radiation protective drug

The article reports results of development of a drug for the prevention and treatment of radiation lesions in animals based on radio modified microorganisms E. coli PL-6 and B. bifidum 1. Aimed at target changing of metabolism, bacteria were exposed to gamma irradiation at doses from 1 to 20 kGy, studying the interaction of microorganisms in the consortium, as well as the safety of produced drugs. Irradiation of E. coli at a dose of 2 kGy led to the appearance of individual cells with polymorphism and having a length exceeding the initial size by 3-7 times. The irradiation of B. bifidum 1 at a dose of 4 kGy contributed to the formation for atypical, polychromic cells, multiple darkening of pigment granules and cell fragments as a result of destruction of microorganisms. The original E. coli PL-6 did not produce the enzymes superoxide dismutaseand catalase, but the metabolites of radiomodified strains of E. coli PL-6 (R10) contained 0.97±0.09 m.c.M/g SOD and 27.38±0.59 mcat/g/ml of catalase activity. In the metabolites of radio-resistant bifidobacteria, as compared with the initial ones, a 1.45-fold excess of peroxidase was recorded.

Results of a pilot experiment on monitoring the condition of buildings and structures using unmanned aerial vehicles

The purpose of the experimental study presented in the paper is to generate new knowledge about the possibility of using unmanned aerial vehicles to survey buildings and structures for subsequent extraction of information about their condition in hard-to-reach or remote places. As objects for the pilot experiment, the following were selected: a residential building in an urban environment that has been destroyed during operation; an object of unfinished construction; a roadway on the carriageway. An unmanned aerial vehicle of the model: DJI Mavic Air was used to survey the objects. The results of the study of objects are recorded in the form of photo and video streams for each object. Comparison of the results of the inspection of objects by experts and unmanned aerial vehicles showed the possibility and necessity of using new means to collect information about the condition of buildings and structures. The primary processing of the obtained images revealed their features: the effect of illumination on the color characteristics of the object of study; the presence of a textural component that complicates the process of separating the defect from the background; the presence of objects in the image that are not related to the elements of surface destruction; the change in the initial size of the object over time. The detected features of the images allow the use of standard algorithms and processing and require the synthesis of unique trajectories of their application.

Evaluation of the Response of Odontogenic Keratocysts to Tube Decompression: A Clinical and Radiographic Study

Background and Objectives: Keratocyst is the most aggressive entity of odontogenic cysts with a high tendency to recure after enucleation. This study was conducted to assess the effect of decompression in inducing cyst shrinkage before enucleation. Materials and Methods: A prospective non-randomized study was conducted on 11 patients with odontogenic keratocyst the department of maxillofacial surgery, university-affiliated teaching hospital, between February 2016 to March 2021. There were 8 males and 3 females, with a mean age of 57 years. Tube decompression was conducted as a preliminary treatment, before enucleation. The size of the cyst was measured on orthopantomograph, before, during, and after decompression. The percentage of reduction was calculated, as well as, the correlation of cyst regression with the initial size of the lesion and age of the patient. Results: The mean duration time of decompression was 208 days (152-316). The pre- and post-decompression size of the cysts was 14.51 cm2 (5.63 cm2 -32.37 cm2) and 6.69 cm2 (1.76 cm2-14.81 cm2), respectively. The total and monthly percentage of reduction in the size of the cysts was 54.39% (37.29%-76.37%) and 7.84% (4.45%-11.27%), respectively. The initial size of the lesion has no significant correlation with the percentage of reduction, whereas the age of the patients showed a significant negative correlation with the percentage of reduction. Conclusion: Decompression is a well-tolerated conservative treatment, which leads to marked reduction in cyst dimensions. It induces shrinkage of the cyst away from anatomical structures, to reduce the morbidity associated with subsequent surgical treatment.

Effect of Particle Sizes on the Efficiency of Fluorinated Nanodiamond Neutron Reflectors

Over a decade ago, it was confirmed that detonation nanodiamond (DND) powders reflect very cold neutrons (VCNs) diffusively at any incidence angle and that they reflect cold neutrons quasi-specularly at small incidence angles. In the present publication, we report the results of a study on the effect of particle sizes on the overall efficiency of neutron reflectors made of DNDs. To perform this study, we separated, by centrifugation, the fraction of finer DND nanoparticles (which are referred to as S-DNDs here) from a broad initial size distribution and experimentally and theoretically compared the performance of such a neutron reflector with that from deagglomerated fluorinated DNDs (DF-DNDs). Typical commercially available DNDs with the size of ~4.3 nm are close to the optimum for VCNs with a typical velocity of ~50 m/s, while smaller and larger DNDs are more efficient for faster and slower VCN velocities, respectively. Simulations show that, for a realistic reflector geometry, the replacement of DF-DNDs (a reflector with the best achieved performance) by S-DNDs (with smaller size DNDs) increases the neutron albedo in the velocity range above ~60 m/s. This increase in the albedo results in an increase in the density of faster VCNs in such a reflector cavity of up to ~25% as well as an increase in the upper boundary of the velocities of efficient VCN reflection.

Sediment size on talus slopes correlates with fracture spacing on bedrock cliffs: implications for predicting initial sediment size distributions on hillslopes

The detachment of rock fragments from fractured bedrock on hillslopes creates sediment with an initial size distribution that sets the upper limits on particle size for all subsequent stages in the evolution of sediment in landscapes. We hypothesize that the initial size distribution should depend on the size distribution of latent sediment (i.e., fracture-bound blocks in unweathered bedrock) and weathering of blocks both before and during detachment (e.g., disintegration along crystal grain boundaries). However, the initial size distribution is difficult to measure because the interface across which sediment is produced is often shielded from view by overlying soil. Here we overcome this limitation by comparing fracture spacings measured from exposed bedrock on cliff faces with particle size distributions in adjacent talus deposits at 15 talus–cliff pairs spanning a wide range of climates and lithologies in California. Median fracture spacing and particle size vary by more than 10-fold and correlate strongly with lithology. Fracture spacing and talus size distributions are also closely correlated in central tendency, spread, and shape, with b-axis diameters showing the closest correspondence with fracture spacing at most sites. This suggests that weathering has not modified latent sediment either before or during detachment from the cliff face. In addition, talus at our sites has not undergone much weathering after deposition and is slightly coarser than the latent sizes because it contains unexploited fractures inherited from bedrock. We introduce a new conceptual framework for understanding the relative importance of latent size and weathering in setting initial sediment size distributions in mountain landscapes. In this framework, hillslopes exist on a spectrum defined by the ratio of two characteristic timescales: the residence time in saprolite and weathered bedrock and the time required to detach a particle of a characteristic size. At one end of the spectrum, where weathering residence times are negligible, the latent size distribution can be used to predict the initial size distribution. At the other end of the spectrum, where weathering residence times are long, the latent size distribution can be erased by weathering in the critical zone.

High Sensitivity Multi-Axes Rotation Sensing Using Large Momentum Transfer Point Source Atom Interferometry

A point source interferometer (PSI) is a device where atoms are split and recombined by applying a temporal sequence of Raman pulses during the expansion of a cloud of cold atoms behaving approximately as a point source. The PSI can work as a sensitive multi-axes gyroscope that can automatically filter out the signal from accelerations. The phase shift arising from the rotations is proportional to the momentum transferred to each atom from the Raman pulses. Therefore, by increasing the momentum transfer, it should be possible to enhance the sensitivity of the PSI. Here, we investigate the degree of enhancement in sensitivity that could be achieved by augmenting the PSI with large momentum transfer (LMT) employing a sequence of many Raman pulses with alternating directions. We analyze how factors such as Doppler detuning, spontaneous emission, and the finite initial size of the atomic cloud compromise the advantage of LMT and how to find the optimal momentum transfer under these limitations, with both the semi-classical model and a model under which the motion of the center of mass of each atom is described quantum mechanically. We identify a set of realistic parameters for which LMT can improve the PSI by a factor of nearly 40.

Stresses affect inbreeding depression in complex ways: disentangling stress-specific genetic effects from effects of initial size in plants

The magnitude of inbreeding depression (ID) varies unpredictably among environments. ID often increases in stressful environments suggesting that these expose more deleterious alleles to selection or increase their effects. More simply, ID could increase under conditions that amplify phenotypic variation (CV²), e.g., by accentuating size hierarchies among plants. These mechanisms are difficult to distinguish when stress increases both ID and phenotypic variation. We grew in- and outbred progeny of Mimulus guttatus under six abiotic stress treatments (control, waterlogging, drought, nutrient deficiency, copper addition, and clipping) with and without competition by the grass Poa palustris. ID differed greatly among stress treatments with δ varying from 7% (control) to 61% (waterlogging) but did not consistently increase with stress intensity. Poa competition increased ID under nutrient deficiency but not other stresses. Analyzing effects of initial size on performance of outbred plants suggests that under some conditions (low N, clipping) competition increased ID by amplifying initial size differences. In other cases (e.g., high ID under waterlogging), particular environments amplified the deleterious genetic effects of inbreeding suggesting differential gene expression. Interestingly, conditions that increased the phenotypic variability of inbred progeny regularly increased ID whereas variability among outbred progeny showed no relationship to ID. Our study reconciles the stress- and phenotypic variability hypotheses by demonstrating how specific conditions (rather than stress per se) act to increase ID. Analyzing CV² separately in inbred and outbred progeny while including effects of initial plant size improve our ability to predict how ID and gene expression vary across environments.

Autologous Mesenchymal Stem Cells in The Treatment of Spinal Aneurysmal Bone Cyst

Purpose: We retrospectively analysed a cohort of patients treated at our Centre with bone marrow concentrated (BMC) injection for aneurysmal bone cyst (ABC) of the spine, in order to propose this treatment as a valid alternative for the management of ABCs.Methods: Fourteen patients (6 male, 8 female) were treated between June 2014 to December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12- 60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Results: Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up Conclusions: Results of this paper reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE treatment is contraindicated or ineffective.