Worm Gear Drives with Improved Kinematic Accuracy

This paper presents the fundamentals of the design and applications of new worm gear drive solutions, which enable the minimisation of backlash and are characterised by higher kinematic accuracy. Different types of worm surfaces are briefly outlined. Technological problems concerning the principles of achieving a high degree of precision in machining are also described. Special attention is paid to the shaping of conical helical surfaces. Increasing the manufacturing precision of drive components allows one to achieve both lower backlash values and lower levels of its dispersion. However, this does not ensure that backlash can be eliminated, with its value being kept low during longer periods of operation. This is important in positioning systems and during recurrent operations. Various design solutions for drives in which it is possible to reduce backlash are presented. Results of experiments of a worm gear drive with a worm axially adaptive only locally, in its central section, are presented. In this solution, it is possible to reduce backlash by introducing adjustment settings without disassembling the drive. An important scientific problem concerned defining the principles of achieving a compromise between the effectiveness of reducing backlash and the required load capacity of the drive. In this paper it has been shown that in worm gear drives with a locally axially adaptive worm, as well as with a worm wheel with a deformable rim, it is possible to achieve significant reduction of backlash. In high precision drives—for example, those with an average backlash value of <15 micrometers—this can enable more than a two-fold reduction of the average backlash value and more than a three-fold decrease of the standard deviation of local backlash values.

Civilizational Aspects of Japanese History: Continuities and Discontinuities

This paper discusses the merits and problems of civilizational perspectives on Japanese history, with particular reference to the task of combining a comparative approach with valid points made by those who see Japan as a highly self-contained cultural world. After a brief consideration of Claude Lévi-Strauss’s reflections on Japan, the central section of the paper deals with Shmuel Eisenstadt’s work. His conception of Japan as a distinctive civilization characterized by pre-axial patterns is rejected on the grounds that the native mode of thought which he proposes to describe is more plausibly interpreted as an offshoot of Chinese traditions, although a notably autonomous and historically changing one. The transmission of Daoism to Japan, although much less explicit than the reception of Confucianism and Buddhism, was of crucial importance. That said, Eisenstadt’s concrete analyses of Japanese ways to transform foreign inputs are often detailed and insightful, and his comments on the relationship between culture and institutions raise important questions, although they must in many cases be reformulated in more historical terms. The paper discusses the genesis, dynamics and collapse of the Tokugawa regime (1600–1868), and concludes with reflections on Japanese modernity, up to and including its present crisis.

dogs of Roman Vindolanda, Part IV: Large sighthounds and guard and utility dogs

In this report we investigate the origin and nature of morphological diversity in domestic dogs utilizing a database of over 1,000 recent and ancient canid skulls and skeletons. Integrated skull–skeleton analysis reveals eight functional groups, giving a clear picture of the extent and kind of morphological diversity produced by dog breeders in Europe, North Africa, and western Asia beginning in the Neolithic and intensifying about 2,100 years ago during the late Iron Age and Roman Era. We report nearly complete associated remains of a large sighthound from Vindolanda, a Roman-era fort–village site in northern England. With this we compare skulls of other sighthounds, and contrast them with remains of guard dogs from Vindolanda and other archaeological sites. The shape of jaw rami, relative size of teeth and state of dental wear, and the size and proportions of postcranial elements are the best differentiators of large dog morphotypes, while most skull parameters are less useful. The central section of the basicranium in ancient sighthounds (parameter Px which measures juvenilization) is little different from wolves, whereas in some modern breeds it is noticeably longer. By contrast, many ancient guard dogs have Px shorter than in wolves and show moderate juvenilization. Gracile sighthounds appear in the archaeological record in the Neolithic, while the earliest robust guard dogs appear later, in Iron Age sites. Building on results of previous work (Bennett & Timm, 2018) we continue to find intriguing similarities between west Asian dog

General Hydrography of the Beagle Channel, a Subantarctic Interoceanic Passage at the Southern Tip of South America

The Beagle Channel (BC) is a long and narrow interoceanic passage (∼270 km long and 1–12 km wide) with west-east orientation and complex bathymetry connecting the Pacific and Atlantic oceans at latitude 55°S. This study is the first integrated assessment of the main oceanographic features of the BC, using recent oceanographic observations from cruises, moored instruments and historical observations. The waters transported into the BC are supplied mainly by the Cape Horn Current, which carries Subantarctic Water (SAAW) at depth (100 m below surface) along the Pacific Patagonian continental shelf break. SAAW enters the continental shelf via a submarine canyon at the western entrance of the BC. The SAAW is diluted by fresh, nutrient depleted (nitrate, phosphate and silicic acid) Estuarine Water (EW) from Cordillera Darwin Ice Field (CDIF) forming modified SAAW (mSAAW). Freshwater inputs from the CDIF generate a two-layer system with a sharp pycnocline which delimits the vertical distribution of phytoplankton fluorescence (PF). Two shallow sills (&lt;70 m) along the BC contribute to EW and mSAAW mixing and the homogenization of the entire water column east of the sills, coherent with Bernoulli aspiration. The central section of the BC, extending ∼100 km toward the east, is filled by a salty (31–32) variety of EW. In winter, this central section is nearly vertically homogeneous with low nutrient concentrations (0.9–1.1 μM PO4 and 7.5–10 μM NO3) and PF. The temporal variability of seawater temperature from 50 to 195 m in the central section of the BC was found to be mostly dominated by the annual and semiannual cycles and influenced by tidal forcing. The middle section of the BC was less influenced by oceanic inputs and its basin-like structure most likely favors retention, which was observed from the weakly stratified water column at the mooring site. Toward the east, the central section bathymetry is disrupted at Mackinlay Strait where another shallow sill separates the middle channel from the shallow eastern entrance that connects to the Atlantic Ocean. In this section, a weakly stratified two-layer system is formed when the eastward surface outflow (salty-EW) flows over a deeper, denser tongue of oceanic mSAAW.

Principles of Resistance in Gharbi Mustafa’s What Comes with the Dust, Goes with the Wind

This paper examines the principles of resistance in Gharbi M. Mustafa’s novel titled What Comes with the Dust, Goes with the Wind (2017). It is mainly an attempt to focus on the inner and outer enegertic power to a person in the hard times and shows the major principles of resistance along with its significance for survival This study primarily provides an introduction to the research statement and problem of the study. Concerning the methodology, close reaidng is used as an approach to conduct the study, besides, it further deals with an introduction to the origins of the Yazidi people and religion. The second section of the paper introduces the critical overview, which summarizes the findings of a number of studies related to the sufferings of the Yazidis’ females during their captivity by several researchers. The central section provides the various forms of violence used against the Yazidis’ females and the impact of their wills and power, and their resistance to survive. In addition, the conclusion of the study concludes the findings of the research.

ЗНИЖЕННЯ МЕТАЛОМІСТКОСТІ РОТАЦІЙНО-ПРОФІЛЬОВАНИХ КОЛІСНИХ ОБОДІВ РІЗНИХ ТИПІВ І ТОВЩИНИ

The research carried out made it possible to develop a new scheme for the process of rotary profiling of wheel rims, which allows to reduce the specific quantity of metal for parts. The essence of the solution lies in the fact that at the second step the jet central section is additionally made more powerful. This allows to change the nature of the deformation after the second step and to eliminate unnecessary thickening of the jet base. With an increase in the jet depth the edge sections are subjected to insignificant tensile stresses, while the stress-strain state of the part remains symmetric and constant at each point. The worked out sequence of calculating a new technological process allows calculating all technological parameters: width and length of a flat workpiece; maximum permissible stress in the workpiece material; a profiling route; as well as to identify deformations and stresses for edge elements and in hazardous areas. Further, taking into account the elastic deformations of the workpiece, the profile of the rollers was built, and then optimal deformation force along the transitions was calculated, then feed and the number of revolutions of the rollers were assigned. The new scheme made it possible to reduce metal consumption for parts and obtain a significant economic effect. Ovality of the part and multiple repeated deformation of the same sections of the workpiece are eliminated, and the degree of strengthening of the material is also reduced.

How Jesus Taught His Disciples to Walk With Head Held High

In spring 2010, a student of the Orthodox Theological Faculty of Belgrade invited me to visit the well-known monasteries of his region of Valjevo: Celije, Pustinja and Lelich. I had heard of Nicholai Velimirovich before. I knew about his outstanding role in the Serbian Orthodox Church and the 20th century history of the Serbian people. But when I saw his birth place and breathed the air and the spiritual atmosphere of this amazing scenery, he became for me a much more living person. The following text is not a research paper on his homilies, but an exegetical essay. However, I am grateful to the Nicholai Studies for publishing it, since it shares the endeavour which was Nicholai’s: to read and patiently reread the Gospel and to communicate the teaching of Jesus Christ as faithfully as possible so that it may illuminate both our personal lives and the destinies of our nations. The Serbian Chrysostom insisted that we need Christ to open our eyes in order to understand who He is. This is precisely what the central section of Saint Mark’s Gospel, analysed in the present study, is about. It also contains this aspect of Jesus’ teaching which was central for Bishop Nicholai: we will see God’s Kingdom and walk with head held high when we follow in the steps of Jesus, when we, instead of sacrificing the others to our interests, become their servants.

Luxury Supply Chain Management

This chapter focuses on supply chain management in the luxury sector. The concepts of supply chain and supply chain management are introduced first, with an overview of the most prominent scientific research works as well as industrial frameworks and methodologies; a discussion of luxury supply chain management in scientific literature follows. The central section of the chapter is dedicated to dissecting the anatomy of the typical luxury supply chain: first of all, it argues that there is simply no such a thing as ‘the typical luxury supply chain’, as the luxury industry is characterised by opposing trends; the section continues by illustrating how these opposing trends are moving companies into clusters which are internally homogeneous but significantly differing from one another. The chapter then illustrates some market trends that are increasing the complexity of supply chain management in luxury, followed by a brief discussion on how brands are reacting.

Creep on the Sargent Fault over the Past 50 Yr from Alignment Arrays with Implications for Slip Transfer between the Calaveras and San Andreas Faults, California

ABSTRACT The 55-km-long Sargent fault connects the creeping Calaveras fault with the locked San Andreas fault through the Santa Cruz Mountains west of Gilroy, California. The position of the Sargent fault between these two faults may have implications for slip transfer and strain accumulation between a creeping and locked fault. The detection and measurement of creep on the Sargent fault would indicate where interseismic strain is accumulating adjacent to these neighboring faults. In 1969, two alignment arrays separated by 3.7 km were installed across the central section of the Sargent fault to investigate potential creep. These arrays were measured in 1970 and 1975, and comparison of these measurements yielded a creep rate of 3.4 ± 0.6 mm/yr across two fault strands in the northern array; results from the southern array were never published. In 2019 and 2020, we resurveyed both arrays using a total station and analyzed the results to determine accumulated fault creep. Our results show that between 1970 and 2020, a period of 49.3 yr, the northern array was dextrally offset 164 ± 25 mm across the same two fault strands that were active in the 1970s, yielding an average creep rate of 3.3 ± 1.3 mm/yr. Thus, it appears that the 5 and 50 yr creep rates at this site are similar. The southern array, which may not span the entire fault zone, was dextrally offset 84 ± 13 mm across two fault strands between 1970 and 2019, yielding an average creep rate of 1.7 ± 0.8 mm/yr over 48.9 yr. These recent surveys document continued creep on the Sargent fault, which may reduce seismic strain accumulation and therefore seismic hazard. However, continued aseismic slip on this fault may result in the redistribution of stress and strain to adjacent faults and should be an area of continued study.