ДОСВІД БОРОТЬБИ З ЕРОЗІЄЮ ҐРУНТІВ У ЗЕМЛЕРОБСТВІ ЗАХІДНОГО РЕГІОНУ УКРАЇНИ (друга половина ХХ ст.)

Розглянуто зміст і основні результати досліджень з ґрунтоохоронної тематики в науково-дослідних установах західного регіону України в другій половині ХХ ст. Виявлено науково-методичні підходи до мінімізації ризику ерозії. Узагальнено досвід розробки та впровадження протиерозійних заходів. Особлива увага приділялася розвитку агротехнічних прийомів боротьби з ерозією ґрунтів. Встановлено вагомий внесок у розвиток ґрунтозахисного землеробства науково-дослідних інститутів і станцій

Prolongation of the residual recourse of welded joints of steels СТ3СP and 09G2С by high-frequency mechanical forging

Наведено результати досліджень ефективності застосування високочастотного механічного проковування (ВМП) для обробки зразків з тавровими зварними з’єднаннями, виготовленими з низьковуглецевих і низьколегованих сталей. Зразки з накопиченими втомними пошкодженнями на рівні 50% загальної довговічності піддавались ВМП, а потім – втомним іспитам шляхом регулярного і блокового навантаження. Встановлено, що застосування технології ВМП дозволяє подовжити циклічну втомну довговічність таких з’єднань не менш, ніж у 12 разів.The paper gives the results of investigation of the effectiveness of application high-frequency mechanical forging (HFMF) with regular and block loading to improve residual fatigue life of T-shaped welded joins of low-carbon and low-alloyed steels with 50% level of accumulated fatigue damages. It is established that application of HFMF technology allows 12 times improvement of cyclic fatigue life of such joints

Navigation of Distinct Euclidean Particles via Hierarchical Clustering

We present a centralized online (completely reactive) hybrid navigation algorithm for bringing a swarm of n perfectly sensed and actuated point particles in Euclidean d space (for arbitrary n and d) to an arbitrary goal configuration with the guarantee of no collisions along the way. Our construction entails a discrete abstraction of configurations using cluster hierarchies, and relies upon two prior recent constructions: (i) a family of hierarchy-preserving control policies and (ii) an abstract discrete dynamical system for navigating through the space of cluster hierarchies. Here, we relate the (combinatorial) topology of hierarchical clusters to the (continuous) topology of configurations by constructing “portals” — open sets of configurations supporting two adjacent hierarchies. The resulting online sequential composition of hierarchy-invariant swarming followed by discrete selection of a hierarchy “closer” to that of the destination along with its continuous instantiation via an appropriate portal configuration yields a computationally effective construction for the desired navigation policy

Dielectric breakdown model for conductor-loaded and insulator-loaded composite materials

In the present work we generalize the dielectric breakdown model to describe dielectric breakdown patterns in both conductor-loaded and insulator-loaded composites. The present model is an extension of a previous one [F. Peruani et al., Phys. Rev. E 67, 066121 (2003)] presented by the authors to describe dielectric breakdown patterns in conductor-loaded composites. Particles are distributed at random in a matrix with a variable concentration p. The generalized model assigns different probabilities P(i,k!i8,k8) to breakdown channel formation according to particle characteristics. Dielectric breakdown patterns are characterized by their fractal dimension D and the parameters of the Weibull distribution. Studies are carried out as a function of the fraction of inhomogeneities, p.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasUniversidad de Buenos Aire

The creation and characterization of the bread wheat line with a centric translocation T2DL.2RL

The development of bread wheat introgressions with alien genetic material from cultural and wild Triticeae species is an effective method for expanding the wheat gene pool necessary for breeding. To date, numerous collections of introgressions as substitutions and chromosome modifications have been obtained; however, the creation and study of wheat with new valuable traits still remain an important line of research. Rye Secale cereale L., whose chromosomes carry genes that control valuable economic and biological characteristics and properties, is widely used to produce new wheat forms. In this study, a wheat-rye translocation obtained by backcrossing the wheat-rye disomic-substitution line 2R(2D)1 with the variety Novosibirskaya 67 was characterized. The chromosomal composition of karyotypes was studied using fluorescent in situ hybridization and C-banding. Two centric translocations, derived from two long arms of chromosomes 2D and 2R, T2DL.2RL, were identified, the remaining 40 wheat chromosomes did not undergo modifications. Meiosis in the lines was stable. Chromosomes T2DL.2RL formed bivalents in all meiocytes, which confirmed their homology. The morphological characteristics of the spike in the T2DL.2RL line and Novosibirskaya 67 did not differ. A comparative analysis of productivity between the T2DL.2RL translocation line and the parental forms, Novosibirskaya 67 and the 2R(2D)1 line, was carried out. The T2DL.2RL line is inferior to Novosibirskaya 67 in all characters with different confidence levels. The productivity characters of the 2R(2D)1 line exceeded or did not differ from those of T2DL.2RL, however, the mass of 1000 grains was significantly lower. The results showed the effect of the T2DL.2RL translocation on the trait “plant height”. This character was significantly lower than that of Novosibirskaya 67 in two vegetation periods. Consequently, the T2DL.2RL translocation reduces plant height and productivity

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns