Optical timing receiver for the NASA laser ranging system. Part 2: High precision time interval digitizer

The development of a high precision time interval digitizer is described. The time digitizer is a 10 psec resolution stop watch covering a range of up to 340 msec. The measured time interval is determined as a separation between leading edges of a pair of pulses applied externally to the start input and the stop input of the digitizer. Employing an interpolation techniques and a 50 MHz high precision master oscillator, the equivalent of a 100 GHz clock frequency standard is achieved. Absolute accuracy and stability of the digitizer are determined by the external 50 MHz master oscillator, which serves as a standard time marker. The start and stop pulses are fast 1 nsec rise time signals, according to the Nuclear Instrument means of tunnel diode discriminators. Firing level of the discriminator define start and stop points between which the time interval is digitized

Influence of Ag, Cu dopants on the second and third harmonic response of ZnO films

Silver- and copper-doped ZnO films were prepared by radio-frequency (RF)-magnetron sputtering on glass and quartz substrates. The influence of dopants content on the microstructural evolution and optical as well as nonlinear optical (NLO) properties were investigated. It has been found that the grain sizes were enlarged with increasing of Ag, Cu dopants amount in ZnO films. The Ag or Cu doping leads to the optical band gap narrowing. Besides, the second-order NLO response of Ag- and Cu-doped ZnO films is lower than that of undoped ZnO film. The second harmonic generation (SHG) efficiency of the ZnO:Ag film was found to be higher than that of the ZnO:Cu film at the similar concentration of dopant. In addition, the decrease of the third harmonic generation (THG) response is observed in ZnO films with increasing of Ag or Cu dopant amount

Використання полігексаметиленгуанідину в якості сучасного дезінфектанта

To increase the productivity of animals and reduce the cost of production, it is necessary to provide animals with a sufficient and high-quality level of feeding, to keep animals in appropriate conditions, to carry out high-quality and timely disinfection, which will lead to a decrease in pathogenic micro flora in the premises where animals are kept, there will be a break in the epizootic chain of disease spread. In modern animal husbandry, which is characterized by a significant accumulation of animals on a limited area, increased requirements for the quality and ecological products, and the prevention of infectious, invasive and especially anthropozoonous diseases, the leading place is occupied by disinfection. It is one of the most important directions in the complex of measures to combat infectious diseases, which prevents significant economic losses as a result of infection. Disinfection is also the cheapest, most availiable and highly effective method of disease prevention. The disinfectant market of Ukraine has a wide range of simple and complex preparations that can be used for disinfection. However, most of them do not meet modern requirements regarding solubility, activity against a wide range of microorganisms, the influence on biofilms of microorganisms, formation of resistance, anti-corrosion activity, the influence on the organism, environmental safety, universality. Among the new biocidal preparations used in human and veterinary medicine and which most fully meet the modern requirements for disinfecting properties, the leading place is occupied by polymeric compounds of guanidine, in particular polyhexamethyleneguanidine (PHMG). This preparation is an effective solution to the problem of combating infectious diseases that cause significant economic losses not only in animal husbandry, but also at the medical and ecological level. PHMG does not have a cumulative, sensitizing, irritating or skin-resorptive action. Disinfectants with polyhexamethyleneguanidine have a prolonged action and show the activity under conditions of changing pH, have long-term storage and are stable during transportation, can be used in various ways (spraying, watering, wiping, dipping, soaking, pouring, etc.), after use they form films with a long-lasting bactericidal effect, they can be disinfected in the presence of animals and people.Для підвищення продуктивності тварин та зниження рівня собівартості продукції потрібно забезпечити тварин достатнім та якісним рівнем годівлі, утримувати тварин в належних умовах, проводити якісну та своєчасну дезінфекцію, що призведе до зниження патогенної мікрофлори в приміщеннях, де утримуються тварини, відбудеться розрив епізоотичного ланцюга поширення хвороб. У сучасному тваринництві, яке характеризується значним скупчення тварин на обмеженій площі, посиленням вимог до якості та екологічності продукції та недопущенняя інфекційних, інвазійних і особливо антропозоонозних хвороб, провідне місце займає дезінфекція. Вона є одним із найважливіших напрямів у комплексі заходів з боротьби із заразними хворобами, яка попереджує значні економічні збитки в результаті інфекції. Також дезінфекція є найбільш дешевим, доступним високоефективним методом профілактики хвороб. Ринок деззасобів України має широкий спектр простих та складних препаратів, якими можна провести дезінфекцію. Проте більшість з них не відповідають сучасним вимогам щодо розчинності, активності до широкого спектру мікроорганізмів, впливу на біоплівки мікроорганізмів, формування резистентності, антикорозійної активності, впливу на організм, екологічної безпеки, універсальності. Серед нових біоцидних препаратів, що застосовують у гуманній і ветеринарній медицині і які найбільш повно відповідають сучасним вимогам щодо дезінфікуючих властивостей, провідне місце займають полімерні сполуки гуанідину, зокрема полігексаметиленгуанідин (ПГМГ). Даний препарат є ефективним вирішенням проблеми з боротьби із інфекційними хворобами, що завдають значних економічних збитків не тільки у тваринництві, а і на медико-екологічному рівні. ПГМГ не володіє кумулятивною, сенсибілізуючою, подразнюючою чи шкірно-резорбтивною дією. Деззасоби з полігексаметиленгуанідином володіють пролонгованою дією та проявляють активність за умови зміни рН, мають тривале зберігання і стабільні при транспортуванні, підлягають застосуванню різними способами (обприскування, зрошення, протирання, занурення, замочування, заливання тощо), після використання утворюють плівки з тривалим бактерицидним ефектом, їх можна викрористовувати в присутності тварин та людей

Second and third order nonlinear optical properties of nanostructured ZnO thin films deposited on α-BBO and LiNbO3

The nanocrystalline ZnO films were deposited on α-BaB2O4 (0 0 1 2) and LiNbO3 (0 0 0 1) single crystals by RF-magnetron sputtering technique. Their structure was studied using X-ray diffractometry, scanning electron microscopy and atomic force microscopy. Besides, the optical absorption spectra were investigated. The second and third harmonic generation measurements were performed by means of the rotational Maker fringe technique using Nd:YAG laser at 1064 nm in picoseconds regime. Finally, the second and third order nonlinear susceptibilities were determined and their values have been found and compared

New possibilities arise for studies of hybridization: SNP-based markers for the multi-species Daphnia longispina complex derived from transcriptome data

In order to trace community dynamics and reticulate evolution in hybrid species complexes, long-term comparative studies of natural populations are necessary. Such studies require the development of tools for fine-scale genetic analyses. In the present study, we developed species-diagnostic SNP-based markers for hybridizing freshwater crustaceans: the multispecies Daphnia longispina complex. Specifically, we took advantage of transcriptome data from a key species of this hybrid complex, the annotated genome of a related Daphnia species and well-defined reference genotypes from three parental species. Altogether eleven nuclear loci with several species-specific SNP sites were identified in sequence alignments of these reference genotypes from three parental species and their interspecific hybrids. A PCR-RFLP assay was developed for cost-efficient large population screening by SNP-based genotyping. Taxon assignment by RFLP patterns was nearly perfectly concordant with microsatellite genotyping across several screened populations from Europe. Finally, we were able to amplify two short regions of these loci in formaldehyde-preserved samples dating back to the year 1960. The species-specific SNP-based markers developed here provide valuable tools to study hybridization over time, including the long-term impact of various environmental factors on hybridization and biodiversity changes. SNP-based genotyping will finally allow eco-evolutionary dynamics to be revealed at different time scale

Hard-core Radius of Nucleons within the Induced Surface Tension Approach

In this work we discuss a novel approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons. Therefore, we perform a detailed analysis of its value which follows from hadronic and nuclear matter properties and find the most trustworthy range of its values: the hard-core radius of nucleons is 0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent.Comment: 12 pages, 4 figures, references added, typos correcte

Isospin Fluctuations from a Thermally Equilibrated Hadron Gas

Partition functions, multiplicity distributions, and isospin fluctuations are calculated for canonical ensembles in which additive quantum numbers as well as total isospin are strictly conserved. When properly accounting for Bose-Einstein symmetrization, the multiplicity distributions of neutral pions in a pion gas are significantly broader as compared to the non-degenerate case. Inclusion of resonances compensates for this broadening effect. Recursion relations are derived which allow calculation of exact results with modest computer time.Comment: 10 pages, 5 figure

The canonical partition function for relativistic hadron gases

Particle production in high-energy collisions is often addressed within the framework of the thermal (statistical) model. We present a method to calculate the canonical partition function for the hadron resonance gas with exact conservation of the baryon number, strangeness, electric charge, charmness and bottomness. We derive an analytical expression for the partition function which is represented as series of Bessel functions. Our results can be used directly to analyze particle production yields in elementary and in heavy ion collisions. We also quantify the importance of quantum statistics in the calculations of the light particle multiplicities in the canonical thermal model of the hadron resonance gas.Comment: 10 pages, 2 figures; submitted for publication in EPJ

Partition Functions in Statistical Mechanics, Symmetric Functions, and Group Representations

Partition functions for non-interacting particles are known to be symmetric functions. It is shown that powerful group-theoretical techniques can be used not only to derive these relationships, but also to significantly simplify calculation of the partition functions for particles that carry internal quantum numbers. The partition function is shown to be a sum of one or more group characters. The utility of character expansions in calculating the partition functions is explored. Several examples are given to illustrate these techniques.Comment: 16 pages of RevTe