Small Circle Research Articles

Prolegomena to a genealogy of “society”

The article reconstructs the evolution of the semantics of one of the social sciences’ most important concepts, that of society. It follows two main systematizations, those of the societas and the societas civilis, respectively, through a millennia-long history rooted in Graeco-Roman civilization. This history exhibits remarkable continuity across time. Its modern adaptations survive to the present day. But the social sciences appear to know only the latter which, in the form of the nation-state, they adopted as their default model under the intellectual leadership of Parsons. Recent developments in the social world have rendered that model obsolete. This leaves the social sciences in dire straits, as they have failed, with one exception, to develop a persuasive alternative. The exception is Niklas Luhmann's systems theory of world society, a theory barely known outside small niche circles. The article ends on a brief speculative note about what might account for the odd tenacity of a theoretically untenable concept.

Maleic anhydride esterified potato starch as the binder in silicon nanoparticles anode for lithium-ion batteries

Potato starch is a natural carbohydrate binder. Starch has hydroxyl groups that can promote interaction with silicon particles using multifaceted hydrogen bonds. Maleic anhydride esterified potato starch can produce a binder that maintains the cycle stability of lithium-ion batteries. Fourier-transform infrared spectroscopy spectra show wavelengths of 1776 cm−1 and 1855 cm−1. Thermal gravimetric analysis curves decreased in weight percent by 80 % at 286 °C. Carbon-13 nuclear magnetic resonance spectra show high peaks at 3.37 ppm, 3.65 ppm, 4.56 ppm, 5.09 ppm, and 6.22 ppm. Scanning electron microscope images show that the morphological change in esterified starch was due to the increased length of starch and the maleic anhydride grafted onto the starch granules. The cyclic voltammetry curve shows that the reduction peak is around 0.16 V, and the oxidation peak is around 0.38 V and 0.56 V. Nyquist plots show a small half circle, indicating that the electrode's solid-electrolyte interphase layer is low. The cycling performance shows a capacity of 1950 mAh/g.

Children’s Plight to Life of Poverty and Injustice Captured in F.H. Batacan’s Smaller and Smaller Circles

This research paper analyzes how children's experiences of poverty and injustice are imagined and articulated in F. H. Batacan's novel Smaller and Smaller Circles. By employing content analysis, passages and excerpts from the novel were identified and subjected to in-depth analysis using sociological and philosophical approaches to literary criticism. The study aims to explore the novel’s portrayal of the causes and effects of these experiences, and how it reflects the broader discourse on the morality of children's suffering. The findings reveal that the novel imagines children's experiences of poverty and injustice as resulting from a complex interplay of societal norms, such as generational responsibility, the culture of silence, and toxic masculinity. Institutional failures, including the church’s complicity, inefficient law enforcement, and barangay deficiencies, further exacerbate these conditions. Additionally, media and societal attitudes, particularly misplaced faith and victim blaming, contribute to the perpetuation of these harmful conditions. The novel portrays these imagined experiences as leading to psychosocial trauma, delayed or denied justice, delinquency, and even suicide. Through this portrayal, the novel positions itself within the discourse on the morality of children's suffering, raising questions about the ethical implications of these societal failures.

Comprehensive evaluation of right ventricular function in patients with acute pulmonary embolism

Objective. To study indices of right ventricular (RV) longitudinal deformation at transthoracic echocardiography (TTE) in patients with acute pulmonary embolism (APE), to determine their threshold values; to study indices of right ventricular-arterial coupling (RVAC) in patients with APE, to determine their threshold values.Methods. We examined 34 patients with acute massive and submassive pulmonary embolism. The diagnosis was made on the basis of computed-tomography pulmonary angiogram. The mean age was 61 ±13 years. Of these, 16 were women (47,1%) and 18 were men (52,9%). As a control group, 30 healthy individuals were examined: 14 males and 16 females. The mean age of the healthy individuals was 39±9,8 years. Echocardiography was performed on Vivid E95 (GE HealthCare, USA) with data postprocessing on EchoPak workstation. The indices of right ventricular (RV) systolic and diastolic function, the magnitude of global longitudinal deformation of the right ventricle (GLS RV) and longitudinal deformation of the right ventricular free wall (RVFWLS) were studied using two-dimensional speckle-tracking echocardiography. We studied indices of right ventricular-arterial coupling (RVAC). We determined the relationship of longitudinal deformation of RV and RVAC with other indices of its systolic function. Results. Mean values of traditional parameters of RV contractile function were within normal limits, whereas mean values of longitudinal strain in APE were significantly lower than normal. There was also a significant decrease ( P < 0,0001) of all measured parameters of right ventricular-arterial coupling in patients with APE in comparison with the control group.Conclusions. When longitudinal deformation parameters are included in the criteria of RV dysfunction in APE, its detectability increases from 26,47% to 61,77%. The revealed decrease of right ventricular-arterial coupling parameters in APE indicates a more frequent disturbance of the connection between RV and the small circle of blood circulation

고려말 새로운 정무 처결 모델의 등장: 공민왕의 報平廳 聽政

This paper traces the meaning of “handling matters of state(聽政)” discussions in Goryeo(高麗). From the reign of King Wu(禑王) onwards, the officials(官人) continuously petitioned the king for the implementation of 'handling matters of state'. Rather than being a generic term for the resolution of political affairs, the term came to refer to a specific form of political decision-making process: the king would receive a council of officials, report on their affairs, and make decisions regarding them. Where, then, did the officials' idea of a specific form of “handling matters of state” come from? How did the practice of this idea begin? Why did officials continue to petition for the implementation of handling matters of state? This paper attempts to answer these questions. First, where did the idea of “handling matters of state” come from and how was it implemented? I turned my attention to the Ming Emperor Taizu(太祖)'s letter sealed with an imperial seal(璽書), received in the 19th year of King Gongmin(恭愍王). In this letter, the emperor insisted that the King should have a fixed place to show dignity to his subjects. A few months later, the first “handling matters of state” was carried out at Bopyeongcheong(報平廳). The process of preparing for the “handling matters of state”, including the erection of the “no-frills” folding screen, is interpreted as a demonstration of the king's dignity. However, King Gongmin reduced the number of “handling matters of state” from the original plan, and even then, they seem to have been seldom executed. Subsequent kings also practiced “handling matters of state”, but only intermittently and sporadically. The reason why kings did not enforce “handling matters of state” is because, since the Yuan(元) Dynasty, they were able to handle most of their affairs through a small circle of entourage. King Chungryul(忠烈王)’s bītīkchī(必闍赤) and King Gongmin's inner cabinet(內宰樞) were symbolic institutions that represented aspects of such entourage politics. Under these circumstances, the officials were critical of the dominance of a small circle of officials and sought to change the political decision-making model of the time by expanding the contact between the king and the officials. They mobilized the “handling matters of state”, which they had done several times before, and petitioned for its implementation. The officials chose the “handling matters of state” model because it allowed them to report directly to the king and receive decisions from him, creating more contact between the king and officials.

Highly Sensitive Plasmon Refractive Index Sensor Based on MIM Waveguide.

This paper introduces a novel plasmon refractive index nanosensor structure based on Fano resonance. The structure comprises a metal-insulator-metal (MIM) waveguide with an inverted rectangular cavity and a circle minus a small internal circle plus a rectangular cavity (CMSICPRC). This study employs the finite element method (FEM) to analyze the sensing characteristics of the structure. The results demonstrate that the geometrical parameters of specific structures exert a considerable influence on the sensing characteristics. Simulated experimental data show that the maximum sensitivity of this structure is 3240 nm/RIU, with a figure of merit (FOM) of 52.25. Additionally, the sensor can be used in biology, for example, to detect the concentration of hemoglobin in blood. The sensitivity of the sensor in this application, according to our calculations, can be 0.82 nm∙g/L.

From "Small Circle" to "Popularity": The Generalization Phenomenon of Chinese Internet Language in the Perspective of Post-Subculture

Chinese Internet language was originated in the Internet space and has strong subcultural characteristics. Some of them have broken through the "small circle" and generalized into popular language used by all people. The generalization phenomenon of Chinese Internet language is primarily manifested in three aspects: semantic composition, usage scenes and cultural structure. From the perspective of post-subculture theory, the phenomenon is tightly associated with the transformation of media and commerce.

Relationship Between School Bullying Victimization and Social Attachment Patterns in Adulthood

Bullying has long-lasting consequences for mental and physical health as well as relationships, but little is known about how bullying experiences at school-age impact social behaviors–and particularly social attachment–in adulthood. This qualitative study investigates the relationship between experiencing school bullying and social attachment patterns in early adulthood. The analysis comprises a retrospective study of young adults in Poland (n = 20) who were interviewed to investigate possible connections between their peer bullying experiences and current social lives. The findings reveal three major social attachment patterns in adulthood: social cushioning, anxious withdrawal, and desperate friendship-seeking. In the first pattern, a person acquires emotional and social security through attachment to a small peer circle. In the second, a young adult prefers solitude or limited social contact to avoid further negative experiences. In the third, a person seeks to be socially recovered and approved despite multiple failures and rejections.

Perception of optical illusions in ungulates: insights from goats, sheep, guanacos and llamas

Optical illusions have long been used in behavioural studies to investigate the perceptual mechanisms underlying vision in animals. So far, three studies have focused on ungulates, providing evidence that they may be susceptible to some optical illusions, in a way similar to humans. Here, we used two food-choice tasks to study susceptibility to the Müller-Lyer and Delboeuf illusions in 17 captive individuals belonging to four ungulate species (Lama guanicoe, Lama glama, Ovis aries, Capra hircus). At the group level, there was a significant preference for the longer/larger food over the shorter/smaller one in control trials. Additionally, the whole group significantly preferred the food stick between two inward arrowheads over an identical one between two outward arrowheads in experimental trials of the Müller-Lyer task, and also preferred the food on the smaller circle over an identical one on the larger circle in the experimental trials of the Delboeuf task. Group-level analyses further showed no significant differences across species, although at the individual level we found significant variation in performance. Our findings suggest that, in line with our predictions, ungulates are overall susceptible to the Müller-Lyer and the Delboeuf illusions, and indicate that the perceptual mechanisms underlying size estimation in artiodactyls might be similar to those of other species, including humans.

#1182 Arterial hypertension and chronic obstructive pulmonary disease—problems of choice of therapy

Abstract Background and Aims The development of hypertension in COPD is based on the early formation of endothelial dysfunction in the small and large circulatory circles, increased sympathetic activity with an imbalance in the synthesis of catecholamines, a violation of the role of the lungs in the metabolism of vasoactive substances, oxidative stress, chronic systemic inflammation, an imbalance in the renin-angiotensin-aldosterone system (RAAS). There are few studies confirming the role of RAAS components in the pathogenesis of cardiovascular changes in patients COPD. The activity of angiotensin converting enzyme (ACE) increases with hypoxia, which may play an important role in increasing the degree of systemic hypertension. An increase in the function of the RAAS is possible both under the direct influence of hypoxia and indirectly through activation of the sympathoadrenal system. To evaluate the efficacy and tolerability of the angiotensin II receptor antagonist valsartan (Nortivan) at a dose 80-160 mg per day in patients with hypertension of 1-2 degrees and COPD of stage II-IV. Method The study design is a local, open, incomparable study on the efficacy and safety of the drug Nortivan in patients with hypertension in combination with COPD. We examined 18 patients with stage II-IV in remission, suffering from grade I and II hypertension, determined in accordance with the generally accepted classification of blood pressure levels (VNOK, 2010). Results The criteria for exclusion from the study were the presence in patients of complications of hypertension, coronary heart disease, decompensated chronic pulmonary heart, endocrine diseases requiring drug correction, kidney pathology, chronic heart failure, oral steroid therapy. 10 days in the last 6 months before inclusion in the study, oncological diseases and any other conditions that could interfere with the interpretation and evaluation of the results of the study. Patients who had not previously received antihypertensive treatment were included in the study immediately, and the rest underwent a washing period for 2 weeks. Patients received Nortivan as antihypertensive therapy for 24 weeks. The effectiveness of therapy was controlled by daily monitoring blood pressure. The choice of quality criteria for the effectiveness of therapy parameters SMAD is associated with literature data and own observations on the prevalence of diurnal blood pressure profiles in patients with hypertension and COPD with no decrease or increase in blood pressure at night, when office blood pressure figures are to a lesser extent reflect the effectiveness of antihypertensive therapy. The initial dosage was 80 mg/day. With insufficient hypotensive effect, the dose of the drug was doubled at the 4th week of treatment. The basic COPD therapy did not change throughout the study period and included anticholinergic drugs (ipratropium bromide, tiotropium bromide), beta2-adrenomimetic (fe-noterol) or a combination thereof. Initially and after 24 weeks of treatment, a complete laboratory examination was performed: a clinical blood test, a biochemical blood test. The thickness of the intima-media complex of the carotid arteries and ECG was also studied. The criterion The safety of the therapy was assessed by the indicators of respiratory function, daily pulse oximetry. Conclusion The use of the drug Nortivan has shown high efficacy and safety in patients Grade I–II hypertension in combination with stage II-IV COPD. A statistically and clinically significant normalization of SMAD indicators with correction of pathological types of daily curves due to a decrease in the number of patients with an increase in or the absence of a decrease in blood pressure during the night period. The safety of using the drug in the clinical group with bronchial obstruction syndrome was confirmed by the dynamics of ventilation indicators according to spirometry and the results of daily pulse oximetry, which showed the absence of exacerbation of hypoxia during therapy.

Pareto’s legacy in the Italian tradition: the case of mathematical economics

Pareto’s personality had a great influence on the evolution of economic theory in the last century at least in the Italian context. At the beginning of the twentieth century a small but combative circle of followers aimed to defend and spread the new Paretian approach based on the idea of general economic equilibrium. Paretian scholars were well recognizable in the Italian context for their contributions to mathematical and statistical aspects. The purpose of this contribution is to outline the essential features of the Italian Paretian school in the field of pure economics or as we would say today of mathematical economics. This favorable position of the Italian tradition in the field of mathematical economics was basically due to two circumstances. The first was represented by the legacy of Pareto and his school while the second was to be found in the fact that among the students of Pareto there was a pure mathematician of great value Luigi Amoroso. We see then that an important voice even if poorly valued was that of Bruno de Finetti who published a remarkable series of articles on mathematical economics in the second half of the 1930s. After World War II the Paretian tradition in this field weakened considerably and effectively disappeared internationally.

Understanding the role of a ‘large’ family in the teaching of Pope Francis

Family is perceived as the most important environment in which humans develop and satisfy their basic needs. Therefore, the issues concerning the family are still current and of great interest for numerous theoreticians and researchers of various fields of science. Pope Francis also devoted a part of his apostolic exhortation Amoris Laetitia to the issue of the ‘larger’ family. In the teachings of Pope Francis spouses and parents should make a responsible use of their freedom, both with regard to procreation, taking into account the social and demographic reality, as well as to the possibility of bringing up their offspring. Conjugal love, which, in Catholic families, is expressed in fertility, is a reason for great joy for the Church. What is innovative in the Pope’s approach to the tasks of the ‘large’ family is mainly the help provided to the people who are victims or to those who are experiencing difficulties in their family homes. Another important issue concerns proper building relations and mutual respect between people creating a ‘large’ family. To achieve this, we must remember to provide mutual assistance and recognise the dignity of each of its members as persons.Contribution: This article holds that apart from the small circle formed by spouses and their children, there is also a ‘large’ family that cannot be ignored. It is necessary for the development of the society and it is a great opportunity for their future. In the teachings of Pope Francis, it is a family that is not afraid to take on current challenges. The basic task of a ‘large’ family is to provide support and love to the people who belong to it.

Multimaxima crystallographic fabrics (CPO) in warm, coarse-grained ice: New insights

Multimaxima crystallographic c-axis fabrics (CPOs) commonly observed in coarse-grained ice have been interpreted in several different ways but remain enigmatic. We review previous interpretations of these fabrics and present new data from Storglaciären, northern Sweden, for comparative purposes using both U-stage methods (c-axes only) and electron backscatter diffraction (EBSD) (both c-axis and a-axis orientations). Consistent with most previous studies, microstructures in our study indicate that all grains have been dynamically recrystallized with grain boundary migration as the dominant process. The CPO is characterized by grains oriented favorably for easy glide on the basal plane, given the local kinematics. When a representative sample is obtained, areas on the glacier margin undergoing non-coaxial deformation have a CPO generally consistent with simple shear. Multimaxima CPOs developed in the center of the glacier, which is associated with more coaxial deformation, likely represent a small circle girdle or partial girdle fabric associated with flow-parallel compression. In both locations, sampling bias, resulting from repeat measurements of single parent grains appearing several times as “island grains” in a 2D thin section, is likely responsible for the observed multiple maxima that, with bias removed, simplify to patterns expected for simple shear or coaxial deformation. An earlier study suggesting that multimaxima CPOs may result from twinning is not borne out from our data combining c-axes and a-axes that do not show the symmetry required of twinning.

Morphofunctional characteristics of the vessels of the small circle of blood circulation in those who died from severe and extremely severe forms of new coronavirus infection

BACKGROUND: An important feature of COVID-19 is the development of pronounced hypercoagulation with an increased risk of thrombotic damage to the pulmonary vascular bed, mainly the pulmonary arteries. Thrombosis of the pulmonary blood vessels causes a local violation of hemodynamics with the development of hyperemia, edema, which leads to a decrease in ventilation of the lung tissue area and serves as one of the causes of respiratory failure.
 AIM: This study aimed to conduct a morphological and morphometric analysis of the vascular bed of lung tissues in deceased with severe and extremely severe forms of new coronavirus infection who were on inpatient treatment in the period 2020-2022.
 METHODS: A pathomorphologic study of 129 autopsy cases with a confirmed diagnosis of a new coronavirus infection COVID-19 was performed. Morphometric analysis and statistical data processing of the pulmonary vascular system in histologic preparations stained with hematoxylin and eosin stain, orcein stain and Martius Scarlet Blue (MSB) stain was performed. The control group consisted of 14 patients who died of cardiovascular disease with bilateral focal confluent pneumonia.
 RESULTS: It was found that the proportion of thrombosed vessels in the lung tissues of the deceased was 27.6%. In 87.2% of cases, thrombosis develops in small arteries (lumen diameter 30-500 microns) and small veins (lumen diameter 40-500 microns). The vascular-functional indices of Kernogan and Vogenworth were statistically significantly increased in small arteries and small veins of the 4th order (p=0.001), small arteries (p=0.001) and small veins of the 5th order (p=0.014) compared with the control group.
 CONCLUSION: Diffuse involvement of small caliber blood vessels in the pathological process reflects the severity of specific hemocoagulopathic disorders in the lung tissue. Such disorders lead to the development of ventilation-perfusion disorders and entail an increase in right ventricular failure.

Indicators of intracardiac haemodynamics in patients with chronic coronary syndrome with concomitant coronavirus disease (COVID-19)

the nature of cardiovascular damage caused by SARS-CoV-2 coronavirus infection due to acute severe respiratory distress syndrome is associated with high mortality. However, the pathophysiological impact of COVID-19 (C19) on intracardiac haemodynamics remains unknown. The aim of our study was to evaluate intracardiac haemodynamics in patients with chronic coronary syndrome (CCS) in combination with coronavirus disease (COVID-19). The prospective study included: 30 patients with CAD with a negative PCR test for COVID-19 (1Agroup), 38 patients with CAD with a positive PCR test for COVID-19 (1Bgroup), of whom 12 were diagnosed with an increase in the level of troponin I (1B/T+), 26 patients had a normal level of troponin I (1B/T-). As a comparison, 30 patients with COVID-19 with PCR(+), without signs of CAD - group 2, as well as 30 healthy volunteers without signs of CAD and with negative PCR were studied. Clinical and laboratory data, treatment, and intracardiac haemodynamics were assessed by echocardiography in all groups. The left ventricular myocardial mass index, left ventricular end-diastolic volume, right ventricular size, and pulmonary artery systolic pressure were highest in the group of CAD with COVID-19 with a positive troponin test (1B/T+), compared with the (1B/T-) group, also in the (1B/T+) group, the ejection fraction and total longitudinal strain by speckle tracking were lower than in the (1B/T-) group. When compared with group 1A, LVEF was lower in the (1B/T+) group, and STla was higher in the (1B/T+) group. When comparing the indicators of group 1A and (1B/T-), a similar pattern of changes in intracardiac haemodynamics was noted: LV myocardial mass index, right ventricular diameter, systolic pressure in the pulmonary artery were higher, while longitudinal strain was slightly lower in (1B/T-) than in group 1A. When comparing the echocardiography parameters of patients in the (1B/T+) subgroup with group 2, larger left ventricular end-diastolic volume, left atrium, left ventricular myocardial mass index were found in (1B/T+), but the ejection fraction was lower in (1B/T+), while the right ventricular size and pulmonary artery systolic pressure were slightly higher than in group 2. In the subgroup (1B/T-), the nature of the changes was similar, but the size of the RV and PASP did not differ from those in group 2. The echocardiographic parameters of group 1A differed from those of group 2 by higher values of LVEF, LVEDV, LVMMS and lower EF, but the size of the RV and PASP were larger in patients with COVID-19. Cardiac damage associated with SARS-CoV-2 in patients with concomitant CAD has an effect on the myocardium, which is manifested in an increase in left ventricular EF due to increased preload, at the expense of a decrease in global strain and systolic function of the LV myocardium, due to the direct cytotoxic effect of SARS-CoV-2 on the one hand, and destabilisation of existing atherosclerotic plaques, as well as hypoxia and worsening of endothelial dysfunction on the other. An increase in the size of the right ventricle is associated with an increase in peripheral vascular resistance in the small circle as a consequence of increased systolic pressure in the pulmonary artery in covidassociated pneumonia. The impact of SARS-CoV-2 infection on the heart is associated with cardiovascular risk factors and the severity of the inflammatory process.

The Stonehenge bluestones did not come from Waun Mawn in West Wales

This paper examines the hypothesis that Waun Mawn in West Wales provided the bluestone monoliths that were used at Stonehenge. Some archaeologists believe that the site supports the last remains of a giant stone circle or ‘Proto Stonehenge’ which was dismantled and transported to Salisbury Plain around 5000 years ago. It was claimed, after three excavation seasons at Waun Mawn in 2017, 2018 and 2021, that there is firm evidence of some standing stones which were later removed or broken up, but it has still not been demonstrated that there ever was a small stone circle here, let alone a ‘giant’ one. Furthermore, there have been no control studies in the neighbourhood which might demonstrate that the speculative feature has any unique characteristics. There is nothing at Waun Mawn to link this site in any way to Stonehenge, and this is confirmed by recent cited research. No evidence has been brought forward in support of the claim that ‘this was one of the great religious and political centres of Neolithic Britain’. It is concluded that at Waun Mawn and elsewhere in West Wales there has been substantial ‘interpretative inflation’ driven by the desire to demonstrate a Stonehenge connection.

Analysis of the Frequency and Structure of Congenital Heart Defects in Children

The article provides the frequency of their occurrence and the structure of congenital heart defects in 1,492 children according to the Scientific Research Institute of Heart Surgery and Organ Transplantation in Bishkek, Kyrgyz Republic. Among all forms of congenital heart defects in children, patients with enrichment of the small circle of blood circulation without cyanosis prevailed —1318 (88.3%) patients.

How childhood socioeconomic status (childhood SES) could influence scope of trust: The mediating role of neuroticism and uncertainty aversion

According to life history theory, trusting others is an investment where great benefits go with substantial risks. Then, choosing to trust a wide range of people or only a small circle of people could implicate different risk-and-benefit trade-offs, and have different influence on individuals' survival and development. Such trade-offs could be reflected by scope of trust, a well-studied concept in sociological research, being defined as “the width of one's circle of trusted people”. Integrating this concept into the life history framework, the current study explored the effects of childhood socioeconomic status (childhood SES) on scope of trust and the possible mediating mechanisms. Study1 found the associations between disadvantaged childhood SES and a narrower scope of trust with a large-scale nationally representative sample (N = 29,798) from China Family Panel Studies (CFPS). Study 2 (N = 437) further found that neuroticism traits and uncertainty aversion could mediate the proposed relationship between childhood SES and scope of trust. In conclusion, the current results showed that the relationship between childhood SES and one's scope of trust could be mediated by maladaptive personality traits. The current findings enriched our understandings of the effects of childhood resource availability on social trust from the perspective of life history theory.

Attentional Tunneling in Pilots During a Visual Tracking Task With a Head Mounted Display.

We examined whether active head aiming with a Helmet Mounted Display (HMD) can draw the pilot's attention away from a primary flight task. Furthermore, we examined whether visual clutter increases this effect. Head up display symbology can result in attentional tunneling, and clutter makes it difficult to identify objects. Eighteen military pilots had to simultaneously perform an attitude control task while flying in clouds and a head aiming task in a fixed-base flight simulator. The former consisted of manual compensation for roll disturbances of the aircraft, while the latter consisted of keeping a moving visual target inside a small or large head-referenced circle. A "no head aiming" condition served as a baseline. Furthermore, all conditions were performed with or without visual clutter. Head aiming led to deterioration of the attitude control task performance and an increase of the amount of roll-reversal errors (RREs). This was even the case when head aiming required minimal effort. Head aiming accuracy was significantly lower when the roll disturbances in the attitude control task were large compared to when they were small. Visual clutter had no effect on both tasks. We suggest that active head aiming of HMD symbology can cause attentional tunneling, as expressed by an increased number of RREs and less accuracy on a simultaneously performed attitude control task. This study improves our understanding in the perceptual and cognitive effects of (military) HMDs, and has implications for operational use and possibly (re)design of HMDs.

Wetting and spreading of bulk liquid and precursor film of molten AgCuTi on ultrafast laser structured surface of Ti

In order to reveal the influence of special surface structures on the wetting and spreading of Ag/Ti system and the precursor film, micro-bumps, micro-pits, micro-grooves and micro-thread surface structures were machined on a grade 2 commercially-pure Ti (TA2) surface by using ultrafast laser. In situ wetting experiments of AgCuTi filler metal on TA2 surfaces with different special structures were conducted. The results showed that the wetting morphology of AgCuTi over original TA2 surface is special double ring (small circle inside and ring outside). The special surface structures can effectively change the wetting characteristics of Ag/Ti system, including the spreading rate and the final spreading area. It also affects the structure and composition of the wetting interface. In Ag/Ti system, different components are affected to different degrees by the surface structures, resulting in uneven distribution of the bulk liquid region and the precursor film region of the wetting interface. The micro-bumps and micro-pits structures can effectively promote the wetting and spreading of AgCuTi on TA2, while micro-thread structures can inhibit its wetting spread. For the micro-grooves, the AgCuTi spreads rapidly and almost completely along the direction of the groove, while in the vertical direction, it is difficult for the AgCuTi to spread through the groove. By studying the wetting spreading process and interface behavior of molten filler metal on complex surfaces, it is expected to provide important guiding significance for using special surface microstructure to control the wetting spreading process and interface reaction of brazing system.