SHIP MOTIONS DURING REPLENISHMENT AT SEA OPERATIONS IN HEAD SEAS

During replenishment at sea operations the interaction between the two vessels travelling side by side can cause significant motions in the smaller vessel and affect the relative separation between their replenishment points. A study into these motions has been conducted including theoretical predictions and model experiments. The model tests investigated the influence of supply ship displacement and longitudinal separation on the ships’ motions. The data obtained from the experimental study has been used to validate a theoretical ship motion prediction method based on a 3-D zero-speed Green function with a forward speed correction in the frequency domain. The results were also used to estimate the expected extreme roll angle of the receiving vessel, and the relative motion between the vessels, during replenishment at sea operations in a typical irregular seaway. A significant increase in the frigate’s roll response was found to occur with an increase of the supply ship displacement, whilst a reduction in motion for the receiving vessel resulted from an increase in longitudinal separation between the vessels. It is proposed that to determine the optimal vessel separation it is vital that the motions of the vessels are not considered in isolation and all motions need to be considered for both vessels simultaneously.

Genetic diversity assessment of ancient mulberry (Morus spp.) in Lebanon using morphological, chemical and molecular markers (SSR and ISSR)

Lebanon has ancient mulberry trees which are the remnants of the abundant orchards that dominated its lands during the nineteenth century. Lebanese mulberry germplasm has not been assessed yet. This study aims to collect local old rainfed mulberry accessions from different geographical regions and assess their diversity by using morphological and molecular markers (SSR and ISSR). Genetic diversity of 70 accessions of mulberry were evaluated by using 27 morphological traits. The dendrogram based on the morphological attributes showed a relative separation of the different accessions based on fruits color and taste. Molecular analysis was performed for the accessions by using selected SSR and ISSR primers. The primers marked a high discriminating power (0.7 to 0.89). The dendrogram constructed on the base of UPGMA method showed 13 different groups. The clustering patterns indicated no location nor local name specificity among mulberry accessions. The combination of SSR and ISSR primers was informative for estimating the extent of mulberry genetic diversity. It can be concluded that there is a high level of genetic diversity within mulberry trees in Lebanon. These results will be useful for mulberry germplasm management in terms of biodiversity protection and as a valuable source of gene pool for crop improvement.

Roaming pathways and survival probability in real-time collisional dynamics of cold and controlled bialkali molecules

Perfectly controlled molecules are at the forefront of the quest to explore chemical reactivity at ultra low temperatures. Here, we investigate for the first time the formation of the long-lived intermediates in the time-dependent scattering of cold bialkali $$^{23}\hbox {Na}^{87}$$ 23 Na 87 Rb molecules with and without the presence of infrared trapping light. During the nearly 50 nanoseconds mean collision time of the intermediate complex, we observe unconventional roaming when for a few tens of picoseconds either NaRb or $$\hbox {Na}_2$$ Na 2 and $$\hbox {Rb}_2$$ Rb 2 molecules with large relative separation are formed before returning to the four-atom complex. We also determine the likelihood of molecular loss when the trapping laser is present during the collision. We find that at a wavelength of 1064 nm the $$\hbox {Na}_2\hbox {Rb}_2$$ Na 2 Rb 2 complex is quickly destroyed and thus that the $$^{23}\hbox {Na}^{87}$$ 23 Na 87 Rb molecules are rapidly lost.

Astrometric accuracy of snapshot fast radio burst localisations with ASKAP

The recent increase in well-localised fast radio bursts (FRBs) has facilitated in-depth studies of global FRB host properties, the source circumburst medium, and the potential impacts of these environments on the burst properties. The Australian Square Kilometre Array Pathfinder (ASKAP) has localised 11 FRBs with sub-arcsecond to arcsecond precision, leading to sub-galaxy localisation regions in some cases and those covering much of the host galaxy in others. The method used to astrometrically register the FRB image frame for ASKAP, in order to align it with images taken at other wavelengths, is currently limited by the brightness of continuum sources detected in the short-duration (‘snapshot’) voltage data captured by the Commensal Real-Time ASKAP Fast Transients (CRAFT) software correlator, which are used to correct for any frame offsets due to imperfect calibration solutions and estimate the accuracy of any required correction. In this paper, we use dedicated observations of bright, compact radio sources in the low- and mid-frequency bands observable by ASKAP to investigate the typical astrometric accuracy of the positions obtained using this so-called ‘snapshot’ technique. Having captured these data with both the CRAFT software and ASKAP hardware correlators, we also compare the offset distributions obtained from both data products to estimate a typical offset between the image frames resulting from the differing processing paths, laying the groundwork for future use of the longer duration, higher signal-to-noise ratio (S/N) data recorded by the hardware correlator. We find typical offsets between the two frames of ${\sim}0.6$ and ${\sim}0.3$ arcsec in the low- and mid-band data, respectively, for both RA and Dec. We also find reasonable agreement between our offset distributions and those of the published FRBs. We detect only a weak dependence in positional offset on the relative separation in time and elevation between target and calibrator scans, with the trends being more pronounced in the low-band data and in Dec. Conversely, the offsets show a clear dependence on frequency in the low band, which we compare to the frequency-dependent Dec. offsets found in FRB 200430. In addition, we present a refined methodology for estimating the overall astrometric accuracy of CRAFT FRBs.

Individual dynamical masses of DENIS J063001.4−184014AB reveal a likely young brown dwarf triple

ABSTRACT The binary nature of the M8.5 dwarf DENIS J063001.4−184014AB (DE0630−18) was discovered with astrometric monitoring from the ground, which determined the unresolved photocentric orbit and the trigonometric parallax of the system. Here we present radial velocity monitoring and resolved observations in the near-infrared with Keck aperture masking that allows us to measure the system’s relative separation and brightness. By combining all available information, we determine the individual dynamical masses of the binary components to be $M_1 = 0.052^{+0.009}_{-0.008}$MSun and $M_2 = 0.052^{+0.005}_{-0.004}$MSun, both firmly in the substellar regime. These masses are surprising, given the object’s M8.5 optical spectral type and equivalent absolute magnitude, and the significant difference in brightness between the components (ΔK = 1.74 ± 0.06 mag). Our results suggest that DE0630−18 is a relatively young system (∼200 Myr) with a secondary component that is itself a potentially unresolved binary.

PROSOPOGRAPHY OF THE KHARKIV MEDICAL INSTITUTE IN 1945–1991

PROSOPOGRAPHY OF KHARKIV MEDICAL INSTITUTE IN 1945–1991 Ilin V. The article aims to determine and consider the typical features of the key healthcare organizers in the post-war Soviet Kharkiv. The author created the collective portrait of 15 prominent physicians, scholars and administrators who got education or made a career at Kharkiv Medical Institute. In particular the origin, work path, professional achievements and civic activity were taken into account. As a result the author came to such conclusions: pre-war repressions and the WWII caused the gap of generations in the medical community despite preservation of the certain scientific schools; the relative separation of duties on public-administrative and scientific was noticeable among the healthcare organizers; engagement of women to the healthcare management became widespread; formation of the post-war generation of healthcare administrators was influenced by war outcomes, isolation of a medical science and education, ideological pressure, formal mandatory public activity and importance of informal party and professional ties for the career advancement. The preliminary set of personal qualities typical for the post-war generation of medical administrators was distinguished in comparison with qualities of their teachers – representatives of the last pre-Soviet generation. The prospects of the further studies were outlined such as study of informal vertical and horizontal relations at Kharkiv Medical Institute. Key words: Kharkiv Medical Institute, post-war era, prosopography, Soviet healthcare. Резюме. ПРОСОПОГРАФІЯ ХАРКІВСЬКОГО МЕДИЧНОГО ІНСТИТУТУ В 1945–1991 pp. Ільїн B. Метою статті є визначення та розгляд типових рис ключових організаторів охорони здоров’я в післявоєнному Харкові. Автор створив колективний портрет 15 видатних лікарів, науковців та керівників, які отримали освіту або зробили кар’єру в Харківському медичному інституті. Зокрема, було взято до уваги походження, трудовий шлях, професійні досягнення та громадська активність. У результаті автор дійшов таких висновків: довоєнні репресії та Друга світова війна зумовили розрив поколінь в медичній спільноті попри збереження окремих наукових шкіл; відносний поділ обов’язків на суспільно-адміністративні та наукові був помітним серед організаторів охорони здоров’я; поширеним стало залучення жінок до управління охороною здоров’я; на формування післявоєнного покоління адміністраторів охорони здоров’я вплинули наслідки війни, ізоляція медичних науки та освіти, ідеологічний тиск, формально обов’язкова громадська активність і важливість неформальних партійних й професійних зв’язків для кар’єрного просування. Було визначено попередній перелік особистих рис післявоєнного покоління медичних керівників порівняно з рисами їхніх вчителів – представників останнього дорадянського покоління медиків. Окреслено перспективи подальших досліджень, зокрема, вивчення неформальних вертикальних і горизонтальних відносин у Харківському медичному інституті. Ключові слова: післявоєнна доба, просопографія, радянська охорона здоров’я, Харківський медичний інститут. Резюме. ПРОСОПОГРАФИЯ ХАРЬКОВСКОГО МЕДИЦИНСКОГО ИНСТИТУТА В 1945–1991 ГГ Ильин B. Целью статьи является определение и рассмотрение типичных черт ключевых организаторов здравоохранения в послевоенном Харькове. Автор создал коллективный портрет 15 выдающихся врачей, ученых и руководителей, которые получили образование или сделали карьеру в Харьковском медицинском институте. В частности, во внимание было принято происхождение, трудовой путь, профессиональные достижения и общественная активность. В результате автор пришел к следующим выводам: довоенные репрессии и Вторая мировая война обусловили разрыв поколений в медицинском сообществе несмотря на сохранение отдельных научных школ; среди организаторов здравоохранения наблюдлось относительное разделение обязанностей на общественно-административные и научные; распространенным стало привлечение женщин к управлению здравоохранением; на формирование послевоенного поколения администраторов здравоохранения повлияли: последствия войны, изоляция медицинских науки и образования, идеологическое давление, формально обязательная общественная активность, важность неформальных партийных и профессиональных связей для карьерного продвижения. Был определен предварительный перечень личных качеств послевоенного поколения медицинских руководителей в сравнении с качествами их учителей – представителей последнего досоветского поколения медиков. Очерчены перспективы дальнейших исследований, в частности, изучение вертикальных и горизонтальных отношений в Харьковском медицинском институте. Ключевые слова: послевоенная эпоха, просопография, советское здравоохранение, Харьковский медицинский институт.

Intrinsic and observed dual AGN fractions from major mergers

A suite of 432 collisionless simulations of bound pairs of spiral galaxies with mass ratios 1:1 and 3:1, and global properties consistent with the ΛCDM paradigm, is used to test the conjecture that major mergers fuel the dual AGN (DAGN) of the local volume. Our analysis was based on the premise that the essential aspects of this scenario can be captured by replacing the physics of the central black holes with restrictions on their relative separation in phase space. We introduce several estimates of the DAGN fraction and infer predictions for the activity levels and resolution limits usually involved in surveys of these systems, assessing their dependence on the parameters controlling the length of both mergers and nuclear activity. Given a set of constraints, we find that the values adopted for some of the latter factors often condition the outcomes from individual experiments. Still, the results do not, in general, reveal very tight correlations, the clearest effect being the tendency of the frequencies normalized to the merger time to anticorrelate with the orbital circularity. In agreement with other theoretical studies, our simulations predict intrinsic DAGN abundances that range from ∼ a few to 15% depending on the maximum level of nuclear activity achieved, the higher the bolometric luminosity, the lower the fraction. At the same time, we show that these probabilities are reduced by about an order of magnitude when they are filtered with the typical constraints applied by observational studies of the DAGN fraction at low redshift. Seen as a whole, our results prove that consideration of the most common limitations involved in the detection of close active pairs at optical wavelengths is sufficient alone to reconcile the intrinsic frequencies envisaged in a hierarchical universe with the small fractions of double-peaked narrow-line systems which are often reported at kpc-scales.

Comparison of various column packing materials efficiency for hydrocarbons and aqueous mixtures

The efficiency of industrial column packings is commonly tested by standard hydrocarbon mixtures. However, a reduced efficiency value is often observed, particularly during distillation of aqueous mixtures. In this paper, distillation experiments with various binary mixtures were carried out on different column packings to evaluate relative separation efficiencies of mixtures for each packing material. Each of the binary mixtures, which comprised heptane–methylcyclohexane, ethanol–water, morpholine–water, and acetic acid–water, was distilled under atmospheric pressure and total reflux ratio on column packings that were made of PTFE, ceramic, zirconium metal, and inox steel 316. According to the results, aqueous solutions of morpholine and acetic acid generally exhibited low relative separation efficiency (in comparison with standard mixture of heptane–methylcyclohexane), ranging between 40 % and 80 %. The highest relative efficiencies were observed with packings made of steel and ceramic. These observations will be useful for the future design of distillation columns, especially for aqueous solutions.

Chemocatalytic Production of Lactates from Biomass-Derived Sugars

In recent decades, a great deal of attention has been paid to the exploration of alternative and sustainable resources to produce biofuels and valuable chemicals, with aims of reducing the reliance on depleting confined fossil resources and alleviating serious economic and environmental issues. In line with this, lignocellulosic biomass-derived lactic acid (LA, 2-hydroxypropanoic acid), to be identified as an important biomass-derived commodity chemical, has found wide applications in food, pharmaceuticals, and cosmetics. In spite of the current fermentation of saccharides to produce lactic acid, sustainability issues such as environmental impact and high cost derived from the relative separation and purification process will be growing with the increasing demands of necessary orders. Alternatively, chemocatalytic approaches to manufacture LA from biomass (i.e., inedible cellulose) have attracted extensive attention, which may give rise to higher productivity and lower costs related to product work-up. This work presents a review of the state-of-the-art for the production of LA using homogeneous, heterogeneous acid, and base catalysts, from sugars and real biomass like rice straw, respectively. Furthermore, the corresponding bio-based esters lactate which could serve as green solvents, produced from biomass with chemocatalysis, is also discussed. Advantages of heterogeneous catalytic reaction systems are emphasized. Guidance is suggested to improve the catalytic performance of heterogeneous catalysts for the production of LA.