Emission characteristics and dynamics of the stagnation layer in colliding laser produced plasmas

The expansion dynamics of ion and neutral species in laterally colliding laser produced aluminum plasmas have been investigated using time and space resolved optical emission spectroscopies and spectrally and angularly resolved fast imaging. The emission results highlight a difference in neutral atom and ion distributions in the stagnation layer where, at a time delay of 80 ns, the neutral atoms are localized in the vicinity of the target surface 1 mm from the target surface while singly and doubly charged ions lie predominantly at larger distances, 1.5 and 2 mm, respectively. The imaging results show that the ions were found to form a well defined, but compressed, stagnation layer at the collision front between the two seed plasmas at early times (Dt ~ 80 ns). On the other hand, the excited neutrals were observed to form a V-shaped emission feature at the outer regions of the collision front with enhanced neutral emission in the less dense, cooler regions of the stagnation layer

Functional outcome of surgical management in cases of fracture patella in a tertiary care hospital in Salem

Background: Fractures of the patella are serious injuries with a broad range of subtypes. These injuries account for about 1% of all skeletal injuries and are most prevalent within the age group of 20-50 years. The underlying mechanisms of open fractures are mostly high-velocity accidents. To assess the functional outcome of various surgical procedures done for fracture patella.Methods: A longitudinal study was conducted from the department of orthopedics, Vinayaka missions Kirupananda Variyar medical college and hospital, Salem for one year in August 2019 and July 2020. All the adult patients admitted with the diagnosis of patellar fracture were included in the study. A complete local examination was conducted and an X-ray of AP and the lateral view was taken for all the patients.Results: Transverse patella fracture is being the most common fracture and for that modified tension band wiring (TBW) was the most common procedure performed and for comminuted fracture partial patellectomy was the most common procedure and for 1 patient total patellectomy was performed.Conclusions: The study shows that the treatment of patella fractures with modified tension band wiring is a definitive treatment with minimal complications and excellent functional outcomes

He+ ion Irradiation on Tungsten Surface in Extreme Conditions

Higher melting point (3695K), lower sputtering yield and most importantly, lower in-bulk, and co-deposit retention at elevated temperature makes tungsten (W) as a potential candidate for plasma-facing component (PFC) in the international thermonuclear experimental reactor (ITER)-divertor. Helium ion (He+) bombardment on W can cause wide variety of microstructural evolution, such as dislocation loops, helium holes/bubbles and fibre-form nanostructures (Fuzz) etc. In this work, 100 eV He+ ion irradiation, at temperature ranges from 500°C to 1000°C, will be performed on mechanically polished mirror like W surfaces. The surface modification and compositional analysis, due to ion irradiation, will be studied using Scanning electron- (SEM) and Atomic force- (AFM) microscopy and X-ray photoelectron spectroscopy (XPS), respectively. The formation of fibre-form nanostructures was observed for temperatures in the range of 650°C to 1000°C. It was also noted that the incident ion energy and the fluence, that the material underwent, were crucial parameters for fibre-form nanostructure formation

Challenging the empire

This paper considers how Paul Gilroy transformed hitherto dominant understandings of the relationship between race and class by developing an innovative account that foregrounded questions of racist oppression and collective resistance amid the organic crisis of British capitalism. The returns from this rethinking were profound in that he was able to make transparent both the structuring power of racism within the working class, and the necessity for autonomous black resistance. At the same time, significant lacunae in his account are identified, including the neglect of the episodic emergence of working-class anti-racism and the part played by socialists, particularly those of racialized minority descent in fashioning a major anti-racist social movement. The paper concludes with a lament for the disappearance of such work informed by a ‘Marxism without guarantees’ in the contemporary field of racism studies, and asks readers to consider the gains to be derived from such a re-engagement

Impact of language-augmented human capital on foreign direct investment: a study of developing countries

Foreign direct investment is regarded as a key element in globalization and international economic integration. Being an additional source of investment funding, it plays an integral role in the economic development of countries. This study investigates the relationship between English language proficiency and foreign direct investment in developing countries. The study used macro and socio-economic variables of foreign direct investment, level of English language proficiency, income per capita and unemployment. A sample of forty-nine (49) developing countries is used. The model was regressed cross-sectionally and White standard error was employed to remove traces of heterogeneity. As expected, it is found that there are significant relationships between (1) English language proficiency and foreign direct investment; and (2) income per capita and foreign direct investment. The results confirmed the importance of English language proficiency in attracting foreign direct investment into developing countries. It also provides some insights to designing of policies mainly to raise the level of human resources capabilities in terms of improved language proficiency to facilitate sustainable flows of investment from abroad

Transplant ineligible multiple myeloma patients presenting as paraplegia/paraparesis a prospective single institution study

Background: Multiple myeloma a plasma cell neoplasm characterized by heterogeneous myriad of presentation with paraparesis or paraplegia in 20% cases due to spinal cord compression by vertebral collapse, compression or fracture.Methods: This is a prospective observational study of thirty transplant ineligible multiple myeloma patients with paraplegia/paraparesis. Pretreatment evaluation done as per standard protocol including MRI whole spine. Involved spine XRT 8Gy single fraction followed by BLD (Bortezomib 1.3mg/m2 weekly once, Lenalidomide 10mg/m2 for 21 days, oral dexamethasone 40 mg weekly once). Neurological parameters, time to neurological and tumor response at 6 months assessed. Patients in very good partial response or complete response were maintained on Lenalidomide and bisphosphonate therapy for a period of two years. The duration of symptoms and time to response were analyzed with Mann Whitney Cox test.Results: 15 patients were grade 0 power and others grade 1 or 2. Median time to any neurological response was 2.97 weeks. 63.3% of patients achieved power of grade 5, 30% grade 4 and 6.7% grade 3 powers. 23.3% patients received complete response while 63.3% patient’s very good partial response.Conclusions: Bedridden myeloma patients had an excellent improvement in quality of life and tumor control with this treatment schedule.

Racism, anti-racist practice and social work: articulating the teaching and learning experiences of Black social workers

In the mid 1990s a Black practice teacher programme was established in Manchester and Merseyside with the primary aim to increase the number of Black practice teachers in social work organisations, and in turn provide a supportive and encouraging learning environment for Black student social workers whilst on placement. In the north‐west of England research has been undertaken, to establish the quality of the practice teaching and student learning taking place with Black practice teachers and students. This paper is an exploration of the ideas generated within the placement process that particularly focused on the discourse of racism and ant‐racist practice. Black students and practice teachers explain their understanding of racism and anti‐racist practice within social work. From the research, the paper will critique some of the ideas concerning anti‐racism. In particular, it will question whether anti‐racist social work practice needs to be re‐evaluated in the light of a context with new migrants, asylum seekers and refugees. It will concluded, by arguing that whilst the terms anti‐racism, Black and Minority Ethnic have resonance as a form of political strategic essentialism, it is important to develop more positive representations in the future

Doube-pulse Laser-induced Breakdown Spectroscopy of Multi-element Sample Containing Low- And High-Z Analytes

Laser-induced breakdown spectroscopy (LIBS) is a portable, remote, non-invasive analytical technique which effectively distinguishes neutral and ionic species for a range of low- to high-Z elements in a multi-element target. Subsequently, LIBS holds potential in special nuclear material (SNM) sensing and nuclear forensics requiring minimal sample preparation and detecting isotopic shifts which allows for differentiation in SNM (namely U) enrichment levels. Feasible applications include not only nonproliferation and homeland security but also nuclear fuel prospecting and industrial safeguard endorsement. Elements of higher mass with complex atomic structures, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. Preliminary research suggests double-pulse LIBS (DPLIBS) improves signal sensitivity for analytes of lower atomic mass over conventional single-pulse LIBS (SPLIBS). This study investigates signal sensitivity for low- and high-Z analytes in a glass matrix containing U (1.3%) comparing DPLIBS to SPLIBS. DPLIBS involves sequential firing of 1064 Nd: YAG (FWHM 9 ns) pre-pulse and 10.6 µm TEA CO2 (FWHM 50-100 ns) heating pulse in near collinear geometry; SPLIBS entails only the Nd:YAG laser. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines for bulk analytes Ca, Na, and Si and trace analyte U for both DPLIBS and SPLIBS. Temporally-integrated excitation temperature and electron density as well as neutral-to-ionic species ratio constitute relative figures of merit for both DPLIBS and SPLIBS plasma characterization. Temporally-resolved studies provide insight into high-Z U analyte persistence and signal enhancement with DPLIBS as compared to low-Z bulk analytes. The study predicts and discusses optimal emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS

Critical Race Theory and Education: racism and anti-racism in educational theory and praxis

What is Critical Race Theory (CRT) and what does it offer educational researchers and practitioners outside the US? This paper addresses these questions by examining the recent history of antiracist research and policy in the UK. In particular, the paper argues that conventional forms of antiracism have proven unable to keep pace with the development of increasingly racist and exclusionary education polices that operate beneath a veneer of professed tolerance and diversity. In particular, contemporary antiracism lacks clear statements of principle and theory that risk reinventing the wheel with each new study; it is increasingly reduced to a meaningless slogan; and it risks appropriation within a reformist “can do” perspective dominated by the de-politicized and managerialist language of school effectiveness and improvement. In contrast, CRT offers a genuinely radical and coherent set of approaches that could revitalize critical research in education across a range of inquiries, not only in self-consciously "multicultural" studies. The paper reviews the developing terrain of CRT in education, identifying its key defining elements and the conceptual tools that characterise the work. CRT in education is a fast changing and incomplete project but it can no longer be ignored by the academy beyond North America