bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical and tribological properties of 5A06 aluminum alloy at low temperature
Authors: Ye Tao , Jia Zhen-yuan , Ma Jian-wei , Yu Wu-jiang , Wang Jia-sen , Zhang Lian-wan , Tian Xue-bao , Wang Shuang
Published: January 2023

There are significant differences in the mechanical and tribological properties of 5A06 aluminum alloys subjected to a wide temperature range, and the related research has received very limited attention so far. In this paper, the mechanical properties of 5A06 aluminum alloy were obtained by tensile test at temperature as low as 77K, which laid a foundation for analyzing its tribological properties. Then, dry linear reciprocating sliding wear tests were performed on a ball-on-disc tribometer to explore the friction behavior and wear mechanism of 5A06 aluminum alloy at different temperatures from low temperature (173K) to room temperature (293K). Finally, the wear morphology and chemical composition of the worn surface were characterized by an optical 3D measurement system and a scanning electron microscope equipped with an energy dispersive spectroscopy. The results indicate that the ambient temperature affects the tribological properties of 5A06 aluminum alloy by changing its mechanical properties and the dissipation of friction heat. Compared with 293K, the coefficient of friction decreases by 14.66% and the wear rate decreases by 70.79% at 173K. The main wear mechanisms of 5A06 aluminum alloy are delamination wear and oxidation wear at 293K and 273K, and a combination of abrasive wear, adhesive wear and oxidation wear at 223K and 173K.
The effect of process temperature and powder composition on microstructure and mechanical characteristics of low-pressure cold spraying aluminum-based coatings
Authors: Shorinov Oleksandr , Dolmatov Anatolii , Polyviany Sergii
Published: January 2023

The effect of operating gas temperature and powder type on microstructure and mechanical characteristics of cold spraying coatings deposited on EZ33A-T5 magnesium alloy was studied. Three aluminum-based cold spraying powder mixtures Al + Zn, Al + Al2O3 and Al + Zn + Al2O3 were used for the investigation. Deposition was performed using D423 low-pressure cold spray system at operating gas pressure of 1.0 MPa and different temperatures –300 °C, 450 °C, and 600 °C. The coatings microstructure was investigated with optical and scanning electron microscopy. Mechanical properties of the coatings were characterized through standard test methods for adhesion and cohesion strength, and standard test methods for Vickers hardness of thermal spray coatings. The results demonstrate that with increasing initial gas temperature at spraying nozzle inlet from 300 °C to 600 °C, an increase in the porosity of the coatings of all investigated powder mixtures can be observed. Microstructure characterization showed an increase in porosity from 2.3% to 4.1% for Al + Zn powder mixture, from 2.1% to 3.5% for Al + Al2O3 powder mixture, and from 2.5% to 5.6% for Al + Zn + Al2O3 powder mixture. The minimum porosity was obtained at 450 °C for all investigated powder mixtures. Adhesion and cohesion strength and microhardness of coatings were reach their maximum value at 450 °C. The best performance was obtained for Al + Al2O3 powder mixture: coating adhesion—31.9 MPa (was limited by the bonding strength of the glue), cohesion—93.5 MPa, microhardness—81 HV0.15. The influence of Al2O3 particles in the powder mixture on the above-mentioned parameters was also established. The results show that the presence of ceramic particles in powder mixtures can positively effect porosity level and mechanical characteristics.
Study on optimization of surface processing technology of silicon nitride bearing ring
Authors: Songhua Li , Chao Wei , Xiangyu Li , Yonghua Wang , Zinan Wang
Published: January 2023

Based on the difficult machining characteristics of silicon nitride materials, this manuscript focuses on optimizing the precision machining process of silicon nitride bearing components and improving the machining efficiency and quality of silicon nitride bearing components. Firstly, the mechanism of crack formation and propagation in hard and brittle materials under the action of abrasive particles is discussed in this paper, and based on this, a kinematic model of single abrasive grain cutting on hard and brittle materials is established. The effect of workpiece linear velocity, grinding wheel linear velocity, grinding wheel oscillation velocity and feed velocity on inner surface roughness of Si3N4 ring was discussed through grinding test. The experimental results show that the surface roughness can reach about Ra0.20 ∼Ra0.33 μm through a large number of grinding experiments by adjusting the combination of process parameters μm. On this basis, use the optimized process parameters calculated by the surface quality prediction model constructed in this manuscript to conduct grinding test again, and the surface roughness value reaches about Ra0.19 ∼Ra0.23 μm. The purpose of optimizing the process parameters is realized. Finally, the surface roughness can be further reduced and maintained at Ra0.05 ∼Ra0.06 μm by further superfinishing the surface after the process optimization with an oilstone. The research work of this manuscript realized the optimization of precision machining process of silicon nitride bearing ring and the rapid optimization of machining process through the established prediction model, which improved the precision machining efficiency of ceramic bearing components. Through the study of this manuscript, a process route of controllable processing of inner surface quality of Si3N4 ring is formed, from preliminary selection of process parameters by optimization model to precision grinding and then to ultra-finishing of whetstone, which provides theoretical reference for efficient and precise manufacturing of practical bearing components.
Wear estimation of hip implants with varying chamfer geometry at the trunnion junction: a finite element analysis
Authors: Gutmann Celine , Shaikh Numa , Shenoy B Satish , Shaymasunder Bhat N , Keni Laxmikant G , K N Chethan
Published: January 2023

The hip joint helps the upper body to transfer its weight to lower body. Along with age, there are various reasons for the degeneration of the hip joint. The artificial hip implant replaces the degenerated hip. Wear between the joints is the primary cause of the hip implant becoming loose. The wear can occur due to various reasons. Due to this revision surgery are most common in young and active patients. In the design phase of the implant if this is taken care then life expectancy of the implant can be improved. Small design changes can significantly enhance the implant’s life. In this work, elliptical-shaped hip implant stem is designed, and linear wear is estimated at trunnion junction. In this work, a 28 mm diameter femoral head with a 4 mm thick acetabular cup and a 2 mm thick backing cup is used. The top surface taper radiuses are changed. Solid works was used to create the models. Ansys was used to perform the analysis. It was found that as the radius of the TTR decreased, the wear rate decreased. The least wear rate was found in 12/14 mm taper with a value of 1.15E−02 mm year−1 for the first material combination and with a value of 1.23E −02 mm year−1 for the second material combination. In the comparison between the models with 1 mm chamfer and no chamfer, it was found that the wear rate was lower for the models with 1 mm chamfer. When the chamfer was increased (more than 1 mm), the linear wear increased. Wear is the main reason for the loosening of hip implants, which leads to a revision of an implant. It was found that with a decrease in TTR, there was a small increase in the linear wear rate. Overall, the implant with TTR 6 mm and a chamfer of 1 mm was found to have the least wear rate. To validate these results, the implant can be 3D printed and tested on a hip simulator.
In vitro magnetohydrodynamics system for modulating cell migration
Authors: Gebreyesus Eyerusalem A , Park Alice , Guldberg Robert E , Ong Keat Ghee
Published: January 2023

Fluid shear stress (FSS) is an important parameter that regulates various cell functions such as proliferation and migration. While there are a number of techniques to generate FSS in vitro, many of them require physical deformation or movement of solid objects to generate the fluid shear, making it difficult to decouple the effects of FSS and mechanical strains. This work describes the development of a non-mechanical means to generate fluid flow and FSS in a 2D in vitro setting. This was accomplished with a magnetohydrodynamic (MHD) pump, which creates liquid flow by generating a Lorentz force through the interaction between an electric field and an orthogonal magnetic field. The MHD pump system presented here consisted of trapezoidal prism-shaped magnets, a pair of platinum electrodes, and a modified petri dish. The system was validated and tested on an in vitro wound model, which is based on analyzing the migration of fibroblast cells through an artificially created scratch on a confluent cell culture surface. Experiments were performed to a control group, an electric field only group, and a group that was subject to fluid flow with the application of both electric field and magnetic field. Results show that fibroblast cells that experienced fluid shear have higher wound closure rate compared to the control group and the electric field only group. The data shows that the MHD pump can be a great tool to study FSS in vitro. Furthermore, due to its fluid flow generation without mechanical force, this system can be adapted and implemented to study the role of FSS and electric field on wound healing in vivo.
Enhanced RF response of 3D-printed wireless LC sensors using dielectrics with high permittivity
Authors: Kalhori Amirhossein Hassanpoor , Kim Taeil , Kim Woo Soo
Published: January 2023

The development of wireless sensing technologies paves the way for advances in the fields of wearable devices, prosthetics and robotics. Wireless communication between sensors and readers plays an important role in recent Internet of Things technologies. Among many types of wireless sensing devices, wireless passive radio frequency devices including inductor-capacitor (LC) resonators have been spotlighted. However, passive LC sensors suffer from short-range wireless detection, and their fabrication requires several processes. Here, we design a 3D integrated wireless compact LC location sensor fabricated using the 3D printing method for multi-layered devices. The fabricated wireless sensing system shows an increased wireless readout distance of up to 10 cm. In addition, a dielectric material with high dielectric permittivity has been applied to enhance the quality factor of the sensors by 2.5 times with improved wireless detection.
Parameters optimization of tungsten inert gas welding process on 304L stainless steel using grey based Taguchi method
Authors: Linger Muluken Alemu , Bogale Teshome Mulatie
Published: January 2023

Tungsten inert gas can be used to weld stainless steel due to its offering sound weld, narrow fusion zone, precise control weld’s shape and over penetration, spatter free, slagless, stable arc and low electrode wear. The goal of this study was to offer the best process parameters for improving the mechanical characteristics of the weld joint. The experimental analysis approach was applied in this work, and the experiment was carried out on 304L stainless steel using L16. The selected welding parameters were welding travel speed, current of welding, gas flow rate, arc length, and root gap. Rockwell hardness, tensile strength, and bending strength tests were the examined mechanical properties on the weld joint. Based on the grey based Taguchi method, the optimal level-settings of welding travel speed, current of welding, flow rate of gas, arc length, and root gap were obtained 2.7 mm s−1, 160 A, 14 l min−1, 3 mm, and 1 mm, respectively. The analysis result of ANOVA showed that the current has the greatest impact and it was followed by travel speed and root gap on weld joint quality with percentage contribution of 80.77%, 10.86%, and 5.98%, respectively. According to confirmation results, the average grey relational grade of 0.863 which was found between the confidence interval of 0.800 to 1.082 for the 95% confidence level, and the maximum Rockwell hardness, tensile strength and bending strength were obtained 101.38 HRB, 1425.8 MPa and 1648.6 MPa, respectively.
Independent Associations Between Trait-Anger, Depressive Symptoms and Preclinical Atherosclerotic Progression
Authors: Eckerle William , Koldhekar Amol , Muldoon Matthew , Stewart Jesse , Kamarck Tom
Published: January 2023

Background

Previous research from our group found that recent depressive symptoms were associated with 3-year change in carotid intima-media thickness (CA-IMT), a biomarker of cardiovascular disease risk, in an initially healthy sample of older adults. Trait measures of anxiety, anger, and hostility did not predict 3-year CA-IMT progression in that report.

Purpose

The current study sought to reexamine these associations at a 6-year follow-up point.

Methods

Two-hundred seventy-eight participants (151 males, mean age = 60.68 years) from the original sample completed an additional IMT reading 6 years following the initial baseline assessment.

Results

Though not significant at 3-years, trait-anger emerged as a predictor of IMT progression at the 6-year point. When examined in separate regression models, both depression and trait-anger (but not anxiety or hostility) predicted 6-year IMT change (b = .017, p = .002; b = .029, p = .01, respectively). When examined concurrently, both depression and anger were independently associated with 6-year IMT progression (b = .016, p = .010, b = .028, p = .022, respectively). Exploratory analyses suggest that the relative contributions of anger and depression may differ for males and females.

Conclusions

The use of sequential follow-ups is relatively unique in this literature, and our results suggest a need for further research on the timing and duration of psychosocial risk exposures in early stages of cardiovascular disease.
Russian Modernist Theater
Authors: Lin Alisa Ballard
Published: January 2023

Few theatrical epochs have had the lasting international impact of Russian modernist theater. The two most influential theater directors to emerge from this era, Konstantin Stanislavsky and Vsevolod Meyerhold, continue to provide rich fodder in their acting theories and performance practices for contemporary theater creators worldwide. Meanwhile, the early 20th century in Russian theater was a time of fierce theoretical and practice-based polemics, rapid technological development, and monumental shifts in theatrical practice as actors were trained in specific internal and external (bodily) techniques and directors took on increasingly more importance for the creative design of a production. At the same time, popular theater was a major avenue of theatrical development in the era, with cabaret and other minor forms enjoying great popularity in Russia and on tours abroad, while avant-garde artists like the Russian futurists created shocking street-based performance art that capitalized on the modernist sense of newness and rejection of the past. Points of debate in studies of Russian modernist theater include disagreement over the definition of what counts as modernist and how seriously to take the polarization and polemics that these theater artists themselves espoused. While modernist theater in Europe is known for its emphasis on closet drama, on grand experiments that were ultimately unperformable, and on mistrust of language and representation, performance practice took a related but different path in Russian culture in the first decades of the 20th century. Despite a great diversity of performance styles, venues, and audiences, theater in the age of Russian modernism unifies around a few key points. First, it placed great emphasis on honing and highlighting the various physical and mental skills of the actor. Second, Russian modernist theater generally valued language and the literary tradition, both Russian and global, despite some efforts to break with literature in theater. Third, theater of this era presented a tone of irony, self-consciousness, and theatricalism. In all its manifestations, it was experimental and self-reflexive, interrogating theater’s relationship to the world and boldly devising new forms. Fourth, Russian modernist theater was richly integrated into its artistic, intellectual, and political context, with ties to science, philosophy, psychology, visual arts, music, dance, film, and literature. Theater came to serve the political ends of the young Soviet nation in the 1920s, though politics were not a predominant force in theater throughout Russian modernism. Theater was not immediately strongly affected by the Russian Revolution of 1917, but by the end of the 1920s, theater was forced to bend to the strong will of Soviet censors, and by the mid-1930s, theatrical innovation was greatly diminished under Stalin-era censorship and its insistence on the style of socialist realism, as well as the general threat of the Stalinist Terror.
Pride in Organizations
Authors: Wu Yuen Lam , Brosi Prisca , Shaw Jason D.
Published: January 2023

Pride is a self-conscious emotion evoked when individuals perceive themselves attaining an outcome that is congruent with their goals and being responsible for achieving a socially valued outcome. The experience of pride can influence one’s own behaviors but the accompanying expressions can also elicit behavioral changes in observers. Although pride is a positive emotion and provides individuals with psychological rewards and pleasant feelings, accumulated empirical findings show a broad range of consequences in response to both the experience and expression of pride in organizations. In attempts to explain the various outcomes, pride researchers have conceptualized the construct in different ways. Some researchers examine pride as a unified emotion that arises from the attainment of positive outcomes; others adopt a multifaceted view to explain its divergent consequences. The multifaceted view suggests that pride can be authentic or hubristic depending on whether the achievement is assumed to arise from one’s efforts or abilities, and promotive or preventive depending on whether the achievement is assumed to result from promotion-related eagerness or prevention-related vigilance. Pride may also be differentiated into specific facets based on whether it is elicited by the achievement of performance or moral standards. Furthermore, as the individual self is embedded in social contexts, pride can arise from group belongingness. Thus, the conceptualization of pride can extend beyond the individual level to cover group and organizational pride. This article concludes that pride is an important source of motivation for both individuals who experience it and those who express it in organizations. Yet, what outcomes or behaviors result depends crucially on the source of pride because pride leads individuals to repeat behaviors attributed as the original cause of the positive feeling. Although pride is commonly engendered by achievements and socially desirable outcomes, it can also arise from immoral behaviors when those behaviors are assumed to benefit the organization. The outcomes of pride experience and expression are also contingent on individual and contextual boundary conditions.
Parenting of Queer Offspring
Authors: Lannutti Pamela J. , Butauski Maria
Published: January 2023

Over recent decades, a growing body of research has consistently emphasized the importance of parental support of one’s queer (lesbian, gay, bisexual, transgender, nonbinary, etc.) identity to their mental health and overall well-being. Parent–queer child relationships have increasingly drawn scholarly attention, with particular interest in children’s coming out (i.e., disclosing their queer identity) to their parents. Scholars have also focused on understanding parents’ experiences. Although researchers emphasize the importance of parents’ responses to their children coming out, as well as the importance of how people communicate and make sense of queer identities, the nature of parent–child communication beyond the initial coming out event is also central to the personal and relational well-being of parents and their queer children.
Plasticity of Information Processing in the Auditory System
Authors: King Andrew J.
Published: January 2023

Information processing in the auditory system shows considerable adaptive plasticity across different timescales. This ranges from very rapid changes in neuronal response properties—on the order of hundreds of milliseconds when the statistics of sounds vary or seconds to minutes when their behavioral relevance is altered—to more gradual changes that are shaped by experience and learning. Many aspects of auditory processing and perception are sculpted by sensory experience during sensitive or critical periods of development. This developmental plasticity underpins the acquisition of language and musical skills, matches neural representations in the brain to the statistics of the acoustic environment, and enables the neural circuits underlying the ability to localize sound to be calibrated by the acoustic consequences of growth-related changes in the anatomy of the body. Although the length of these critical periods depends on the aspect of auditory processing under consideration, varies across species and brain level, and may be extended by experience and other factors, it is generally accepted that the potential for plasticity declines with age. Nevertheless, a substantial degree of plasticity is exhibited in adulthood. This is important for the acquisition of new perceptual skills; facilitates improvements in the detection or discrimination of fine differences in sound properties; and enables the brain to compensate for changes in inputs, including those resulting from hearing loss. In contrast to the plasticity that shapes the developing brain, perceptual learning normally requires the sound attribute in question to be behaviorally relevant and is driven by practice or training on specific tasks. Progress has recently been made in identifying the brain circuits involved and the role of neuromodulators in controlling plasticity, and an understanding of plasticity in the central auditory system is playing an increasingly important role in the treatment of hearing disorders.
Black Feminism and Black Women’s Interactions With Faculty in Higher Education
Authors: Allen Monica , Smith April , Dika Sandra
Published: January 2023

The legacies of slavery and exploitation continue to shape the opportunities and experiences of contemporary Black women in the United States. While college access and attainment has increased over the past few decades, Black women contend with negative stereotypes, experiences, and inequitable outcomes associated with the intersectionality of their race and gender. Feminist standpoint theory and Black feminist thought can be used as lenses to centralize Black women’s experiences and thoughts when aiming to understand how their interactions with faculty and other institutional agents can function as barriers to and facilitators of their educational persistence. When Black women feel acknowledged by faculty as competent individuals rather than stereotypes, their engagement, sense of belonging, and persistence are positively affected. Listening to and valuing the stories of Black women students is an essential step to bringing about necessary changes for educational equity on historically White campuses across the country.
Systemic Supports for Antiracist Practice in Montessori Classrooms
Authors: Hegseth Whitney M.
Published: January 2023

When considering how to (re)build educational systems for equity, one might explore the potential of a system’s supports to facilitate changes in perceptions and pedagogy in classrooms, so that both become increasingly antiracist. A disciplinary incident in a Montessori elementary classroom in Washington, DC helps illustrate how the Montessori system’s educational infrastructure supports teachers in (re)framing problems and solutions in their classrooms. The infrastructure that supports such (re)framing includes (a) teacher training; (b) system standards around class size and composition; and (c) system guidance around community relations, paired with standards around the structure of the school day. Though the Montessori system is not yet an antiracist system, its highly elaborate infrastructure already supports a transformation in perception and pedagogy for Montessori teachers. This existing infrastructure, then, has potential to help Montessori teachers and schools move toward increasingly antiracist practice. Exploring such synergy between infrastructure and antiracist practice may help the Montessori system, and other educational systems, in their efforts to (re)design system supports to redress long-standing inequities in schools and society.
Immigrant Teachers in Israel as Newcomers and Educators (1949–1966)
Authors: Tadmor-Shimony Tali
Published: January 2023

Most research on education and the migration question assumes that schools function as the social agents of the host society. Teachers are supposed to disseminate their society’s dominant norms to influence future generations. Ever since the implementation of compulsory education laws, teachers have been asked to function as social agents of two major processes: nation-building and the integration of new immigrants. An interesting situation arises when the teachers are newcomers, as was the case during the nearly two decades of compulsory education law in Israel (1949–1966). Immigrant teachers comprised more than a fifth of the teachers during the 1950s. They worked in an educational system where over two-fifths of the students were immigrants who had arrived during the mass migration. Due to the need to address the shortage of teachers, the Ministry of Education lowered the professional standards and employed a lower proportion of certified teachers. The teachers’ training program was drastically shortened, and its level of standards was reduced to crash courses, which the Ministry of Education initiated in the early 1950s, as it was necessary to recruit many teachers in a short time.

The entry of immigrants into the ranks of teachers slowed down the process of feminization in primary education for a few years because the male share among the immigrant teachers was almost twice that of old-time teachers already there. The teaching profession assisted the immigrants in improving their economic status compared to their immigrant colleagues. The immigrant teachers were placed in a unique situation. On the one hand, they were newcomers who struggled with the difficulties of integration, while on the other hand, they were supposed to serve—as did their colleagues—as representatives of the state.

Many studies have shown the cultural conflict between society and immigrant students through the curricula. In the Israeli case, some of the immigrant teachers shared this conflict too. The immigrant teachers had to deal with the experiences of immigrating, just like other immigrants, while teaching in a language that was not their mother tongue, as many were not fluent in Hebrew. The lack of social workers and consultants resulted in many immigrant teachers working as social workers. These teachers had to impart knowledge and provide support for their students’ families. One way to understand the immigrant teachers’ activities is by applying the analytical tool of teacher empowerment. This empowerment, the appreciation of their functioning by their surroundings, in some way compensated for their difficulties. The research argues that the teaching profession was a key element in the social mobility of immigrant teachers and enabled them to become a part of the host society.
Early Food Production in the Congo Basin
Authors: Seidensticker Dirk H. , Jungnickel Katharina V. M.
Published: January 2023

The introduction of food production into a specific region is among the most influential transitions in human history. It is frequently connected to other changes such as sedentism and population growth. Though most communities living in the Congo Basin today follow a relatively sedentary lifestyle with a slash-and-burn agri- or horticulture, hunting and fishing still contribute in large part to their subsistence. The lifestyle of historic forager communities and their sedentary neighbours changed significantly through colonialism. When and how food production started in the region is essentially not solved yet.

Studies suggest that the introduction of food production dates back to the 1st millennium bce. However, empirical data are sparsely available, and Central African research is still marked significantly by its lack of physical evidence. Postcolonial archaeological research started earlier in other parts of Central Africa, while the Congo Basin saw large-scale, systematic research on its prehistory from the late 1970s. Investigations focused predominantly on the chrono-typological sequences, as ceramics are an easily encountered find category in the region. Archaeobotanical samples often underwent no further scrutiny or are still awaiting processing. Political instability in the Democratic Republic of the Congo in the 1990s and 2000s halted research in the Congo Basin. The western parts of Central Africa are among the better-researched areas. However, even there, only limited evidence of early food production has been uncovered. For a more concise picture, one should nonetheless discuss these two bodies of evidence in conjunction.

The available evidence suggests that during the 1st millennium bce, pearl millet, originating from West Africa, was used in southern Cameroon and the Congo Basin, but presumably not in quantities that constituted a staple crop. The evidence for the use of cooking bananas is incomplete. Archaeobotanical remains are dominated by charred oil palm or wild Canarium, both equally unsuited as a staple food. Thus, the composition of the subsistence base and the reliance on food production of the ceramic-producing communities living in the Congo Basin during the 1st millennium bce and the 1st millennium ce remain uncertain.
Slavery and the Slave Trade in Ethiopia and Eritrea
Authors: Bonacci Giulia , Meckelburg Alexander
Published: January 2023

Slavery and the slave trade were persistent features of the cultural, social, and economic fabric of the Ethiopian-Eritrean region, which is historically constituted by various polities and societies across the Christian, Semitic-speaking highlands and the Rift Valley with its surrounding lowland regions, bordered by the Nile Valley on the west and the Red Sea coast to the east. The connectedness of this vast region through long-distance trade routes reaching the Mediterranean, the Red Sea, and the Indian Ocean world is attested in sources since antiquity. There were multiple ways into enslavement: wars, raids, debt, birth, or trade, which involved various actors, be they shifta (bandits), soldiers, traders, or kings. Slave markets dotted the region along the general trade routes, and slaves were distributed into various social categories and labor occupations. While the expansion of the Ethiopian empire turned an increasing number of peasants into servants of the feudal class, the 19th century saw both a growth in the volume of slaves traded in the region and a growth in sources related to slavery thanks to increasing international attention. Despite a pronounced commitment to abolition by Ethiopian rulers since the late 19th century, abolition happened late and slowly. Legacies of slavery play a role in the continuing exclusion and marginalization of persons of slave descent in the 21st century.
Archaeology of Slavery in Atlantic West Africa, 1450–1900
Authors: Reid Sean H.
Published: January 2023

Archaeological examination of the transatlantic slave trade in West Africa largely began with investigations of European trade posts and forts on the coast and on major West African rivers. The predominant focus of subsequent work has been on African states and societies affected by or involved in Atlantic commerce and the slave trade. Major themes of research include African–European interactions and trade, political and economic effects in African societies, and the integration and consumption of Atlantic goods in daily life. Work has also expanded geographically beyond West African towns and states into hinterland and frontier landscapes far from the coast. Archaeological investigations of Atlantic era slavery developed in dialogue with the archaeology of the African diaspora in the Americas, yet their foci and objectives have not always been completely aligned. Slavery is more of a central theme in African diaspora archaeology—being the primary formative historical force in the creation of the diaspora—than it is in West African archaeology, where it is more often examined as a major feature of social, political, and economic life with uneven regional and societal effects. Archaeologists are also involved in the study, interpretation, and politics of African diaspora heritage tourism. Emerging approaches to the archaeology of Atlantic era slavery in West Africa include maritime archaeology and the archaeology of the formerly enslaved that returned to West Africa.
Sugar Plantation Slavery
Authors: Rönnbäck Klas
Published: January 2023

Sugar and slavery became intimately connected in the Americas during the early modern era. Once the cultivation of sugar cane had been transplanted to the Americas in the early 16th century, Spanish and Portuguese planters turned to exploiting slaves as laborers on the plantations. The first slaves were taken from among Indigenous populations in the Americas. In the 17th century, English and French planters tried to recruit indentured servants from Europe. Both these sources of labor would, for several reasons, turn out to be insufficient to meet the great demand for laborers on the American sugar plantations. Planters throughout the Americas therefore came to import slaves from Africa, particularly following the so-called “sugar revolution” during the late 17th century. As sugar henceforth became the preferred crop of cultivation throughout most of the Caribbean and Brazil, it also became the main driver of the transatlantic slave trade. The particular demography of sugar planting—with a natural population decline as a consequence of hard labor, a brutal labor regime, and insufficient diet—did furthermore exacerbate the demand for slave imports even further. The cultivation of sugar, and all economic activities associated with the slave plantation complex, would be of great economic importance for investors, merchants and producers in Europe. The political decision to abolish the slave trade would therefore have large economic consequences both in the Americas, Africa, and Europe.
The Intersection of Disability With Substance Use and Addiction
Authors: Reif Sharon , Lee Margaret T. , Ledingham Emily
Published: January 2023

As many as one in four adults have a disability and up to one in 12 have addiction to alcohol or drugs yet little is known about their intersection or more broadly about substance use among people with disabilities. The complex interplay of social, economic, and health factors associated with disability are also risk factors for substance use, unhealthy use, and addiction. Disability stigma and stereotypes are common around substance use by disabled people and their ability to engage in treatment and recovery. Many people with disabilities abstain from alcohol and drug use yet rates of addiction are higher across most disabilities than among the nondisabled, with the notable exception of alcohol. Despite this, disabled people are less likely to enter addiction treatment than nondisabled people. Stigma and other barriers to treatment are common for all people with substance use problems and more so for people with disabilities. Attitudes, discriminatory policies or practices, communications, and physical constraints reflect ableism and affect the ability of people with disabilities to enter addiction treatment. Once treatment is initiated, success can be maximized by meeting specific disability-related needs. For people with physical and sensory disabilities, if physical accessibility and communications accommodations are met, success in addiction treatment presumably should parallel that of people without these disabilities. For people with intellectual, developmental, and cognitive disabilities, success may require additional adaptations. Promising approaches exist but cross-systems training and collaboration is essential. By reducing ableism, misbeliefs, and stigma and offering flexible treatment approaches along with the required accommodations, people with disabilities who also have addiction should be supported in reducing unhealthy substance use and in their paths to recovery.
International Law Developed Through the European Union
Authors: Barrett Kathie
Published: January 2023

The European Union (EU) was created through treaties and thus is a product of international law. In the Van Gend en Loos decision, the European Court of Justice (CJEU) stated that the EU was a “new order of international law” and reiterated this in subsequent decisions. This perspective is consistent with the way that the EU influences international law to drive integration as well as its foreign policy goals to become a global leader in the rule of law, protection of human rights, and environmental stability while at the same time decreasing the sovereignty of Member States without their agreement. The CJEU is adjudicating a supranational constitution and empowering national courts to ensure the consistency of EU law. The EU has demonstrated that a unique international system can be driven through cooperation and confidence in international law. While creating possibilities for both international and the EU, it also creates challenges for the national court as well as EU and international law development.
Nonhuman, More-Than-Human, and Post-Human International Relations and International Studies
Authors: Mitchell Audra
Published: January 2023

In international studies, the field of non-, more-than-, and post-human approaches to international relations and associated subfields (e.g., international security and global studies) has burgeoned in recent years. Within the field are works that challenge mainstream ideas of “the human” or “humanity” and highlight their exclusions. It also examines terms and frameworks such as rights, agency, ethical status, sovereignty, security, and survival from the perspectives of three main streams: nonhuman, more-than-human, and post-human and inhuman thought. Examined also are the broader contexts on which such arguments draw, including currently marginalized knowledge systems (e.g., Indigenous, Black, Global Majority, queer, and disabled approaches), to ultimately guide further study in this rapidly growing subfield.
Great-Power Competition
Authors: DiCicco Jonathan M. , Onea Tudor A.
Published: January 2023

Great-power competition (GPC) is a touchstone for strategists and policymakers. Its popularity stems from perceptions of China’s rise, Russia’s resurgence, and the United States’ relative decline. The term’s notoriety in policy circles is related to its use in U.S. national defense and strategy guidance documents. Sometimes GPC is dismissed as a buzzword, but it is a distinctive phenomenon that deserves scholarly investigation.

GPC is a classic feature of modern international relations grounded in a traditional power politics approach. Specifically, GPC is a permanent, compulsory, comprehensive, and exclusive contest for supremacy in a region or domain among those states considered to be the major players in the international system. The contest varies in intensity over time and space but remains a persistent aspect of the international system of sovereign states.

Great powers field uncommonly large, sophisticated, and diversified capabilities and compete for high stakes; their competitive behavior is endemic to a stratified system in which select states are recognized as having special status. That status imparts to members of the great-power club privileges and responsibilities, including collective action to address system-wide problems. However, the competition over power, security, and status among the great powers is always present.

GPC is often parsed into analytically separable dimensions (military, economic, scientific–technological, and so on), but in practice such dimensions are interrelated. Together with the great powers’ extraordinary capabilities and interests, the interdependence of these dimensions of competition tends to push GPC to be comprehensive. GPC is sometimes treated as something other than war, but when GPC intensifies, the possibility of major war looms.

Patterns of GPC are identified through the lens of competing schools of thought on power politics: balance of power and hegemonic–power transition. Each provides a general framework in which GPC may be located. Scholars, however, should not confine their investigations to such frameworks; novel scholarship is warranted to further develop the concept of GPC, to characterize it and theorize about its dynamics, to further study it empirically, and to scrutinize it through critical lenses.
Human Rights in Latin America
Authors: Franklin James C.
Published: January 2023

The systematic study of human rights came into its own in the 1980s on the heels of expanded efforts by human rights organizations, the U.S. Congress, and the Carter administration to respond to human rights abuses. Latin America was a primary target of these efforts and many of the early studies on human rights focused on this region. Here, an early literature on human rights formed around the practical question of whether U.S. foreign aid allocations were steered away from human rights violators, as the law required. The literature brought some of the first attempts to measure human rights violations systematically, and several of these scholars moved on to broader questions about what caused human rights abuses and on global efforts to stop them. This included analyses of threat perceptions, human rights movements, foreign policy, naming and shaming, and transitional justice. Some of the key theories in this literature were developed, at least in part, by Latin Americanists and a lot of early empirical application of the theories focused on this region. Over time, this literature has become increasingly global, and thus earlier research on Latin America greatly influenced the broader literature on human rights. Alongside the evolution of the scholarly literature, the nature of human rights abuses in Latin America has also changed. After the widespread democratization of the region, abuses shifted from those primarily targeted at political opposition to actions targeted at socially marginalized individuals. This suggests an important new topic for researchers.
Household Archaeology in South Asia
Authors: Menon Jaya
Published: January 2023

The house has stood proxy for the household in South Asian archaeology. Houses belonging to various periods in South Asia’s past have been cleared and excavated since the early 20th century. Urban centers such as Mohenjodaro (Bronze Age), Bhita, Sirkap, and Indor Khera (early historic), as well as Vijayanagara and Sultan Ghari (medieval and early modern) have revealed a variety of patterns of house forms and settlement layouts. The form of the dwelling provides information about familial, household, and community precepts on housing, while access to and within houses tell us about those who used these spaces. In turn, house forms give hints toward less tangible aspects, such as inequality or privacy. Archaeologists have also used artifacts associated with these houses to understand the range of activities undertaken by the occupants of domestic spaces.

The spatial disposition of houses in relation to one another has enabled archaeologists to explore specific sociospatial entities such as neighborhoods. A distinct morphological type, at Mohenjodaro, Bhir, and Sirkap, were blocks, comprising houses built up against each other, which were separated from other similarly constituted blocks. These blocks were interpreted as neighborhoods, composed of close kin or those of similar ethnic origins, or may have constituted large, multiroomed, elite residences. Resources and infrastructure, such as shrines, wells, and drains, can be understood as provided, built, and shared at multiple levels of the household, the neighborhood, and the settlement.

Overwhelmingly, discussions of house forms at Mohenjodaro, and artifacts in context, have contributed toward an analysis of households and neighborhoods. The potential of this site arose from the extensive archaeological exposures of structures, labeled as houses, in the 1920s. The kind of archaeological work that has been undertaken at this site since the 1980s, using older excavated data, should point the way to investigating other sites. However, an archaeology of households and neighborhoods in South Asia requires the identification of hitherto untouched sites where focused work through horizontal exposures can enable comparisons between domestic spaces. It also needs multidisciplinary work that allows the site to be understood within a larger context. More important, the framing of new projects explicitly conceived within social archaeology is required, by posing new questions about communities, group identity, membership, and spatial location, as well as access to resources. Perhaps only then can it be said that South Asian archaeology has progressed to understanding critical social concerns of past communities.
Bioarchaeology in the Nile Valley
Authors: Marshall Jenail H. , Buzon Michele
Published: January 2023

Bioarchaeology is the study of human remains within their archaeological and mortuary contexts. Bioarchaeologists use skeletal biology, mortuary practices, and the archaeological record to answer questions about past populations’ lives and lifestyles. The term Nile Valley defines a geographic region of Egypt and Nubia, the latter encompassing the region between the First Cataract at Aswan, Egypt, and the Sixth Cataract just north of Khartoum, Sudan. Spanning the Nile River area, it is sometimes referred to in its two parts, according to the river’s flow, from south to north, Lower Nubia in the north and Upper Nubia in the south. In Egypt, that is Upper Egypt in the south and Lower Egypt in the north. For over a century, the region has had many campaigns and salvage projects that have led to the excavation of thousands of skeletal remains from ancient Nile Valley sites.

Analyses of these collections have provided important information about the people and their health, patterning disease and trauma, diet, and biological relationships. Early morphological research on the skeletal remains of the people who once lived in ancient Nubia was dominated by biased interpretations stemming from racist paradigms in the early 19th century that included racial typologies. Moving beyond these perspectives, contemporary research on the ancient Nile Valley has expanded methodological and theoretical advancements in bioarchaeology more broadly.

The integration of bioarchaeology in the larger context of archaeological projects provides a wealth of information that includes but is not limited to health, disease, identity, nutrition, life experiences, and demographic patterns. Likewise, how archaeology is conducted in the region is shifting and highlights a move toward decolonial and ethical practices within the discipline, including involvement with the local communities.