Improving the Surface Quality and Mechanical Properties of Selective Laser Sintered PA2200 Components by the Vibratory Surface Finishing Process

This paper attempts to improve the physical and mechanical properties of selective laser sintered polyamide PA2200 components through a vibratory surface finishing process by inducing severe plastic deformation at the outer surface layers. The industrial target of additive manufacturing components is to obtain structures having surface roughness, hardness, and other mechanical properties equivalent to or better than those produced conventionally. Compared to the as-built SLS PA2200 samples, vibratory surface finishing treated specimens exhibited a smooth surface microstructure and more favorable roughness, hardness, and tensile strength. Also, the duration of the vibratory surface finishing process showed a further improvement in the surface roughness and hardness of the SLS samples. Compared to the asbuilt state, the roughness and hardness of the surface-treated samples improved by almost 90% and 15%, respectively. Consequently, microstructural analysis indicates that lower surface roughness and enhanced surface hardness is a crucial factor in influencing the overall tensile strength of SLS-PA2200 components. We consider that the combination of VSF and SLS processes can successfully handle a wide range of potential applications. This study also highlights the efficiency and applicability of the vibratory surface finishing process to other additive manufacturing processes and materials

Relativistic and Binding Energy Corrections to Direct Photon Production In Upsilon Decay

A systematic gauge-invariant method is used to calculate the rate for an upsilon meson to decay inclusively into a prompt photon. An expansion is made in the quark relative velocity v, which is a small natural parameter for heavy quark systems. Inclusion of these O(v^2) corrections tends to increase the photon rate in the middle z range and to lower it for larger z, a feature supported by the data.Comment: 13 pages, LateX, One figure (to be published in Phys. Rev. D, Sept. 1, 1996

Three-year follow-up and event rates in the international REduction of Atherothrombosis for Continued Health Registry

To determine 3-year event rates in outpatients with vascular disease enrolled in the REduction of Atherothrombosis for Continued Health (REACH) Registry. Methods and results REACH enrolled 67 888 outpatients with atherothrombosis [ established coronary artery disease (CAD), cerebrovascutar disease, or peripheral arterial disease (PAD)], or with at least three atherothrombotic risk factors, from 44 countries . Among the 55 499 patients at baseline with symptomatic disease, 39 675 were eligible for 3-year follow-up, and 32 247 had data available (81% retention rate). Among the symptomatic patients at 3 years, 92% were taking an antithrombotic agent, 91% an anti hypertensive, and 76% were on Upid- lowering therapy. For myocardial infarction (Ml)/ stroke/vascutar death, 1 - and 3-year event rates for all patients were 4.2 and 11.0%, respectively. Event rates (MI/ stroke/vascutar death) were significantly higher for patients with symptomatic disease vs. those with risk factors only at 1 year (4.7 vs. 2.3%, P < 0.001) and at 3 years (12.0 vs. 6.0%, P < 0.001). One and 3-year rates of MI /stroke/vascular cleath/ rehospitatization were 14.4 and 28.4 %, respectively, for patients with symptomatic disease. Rehospitalization for a vascular event other than Mi/ stroke/ vascular death was common at 3 years (19.0% overall; 33.6% for PAD ; 23.0% for CAD). For patients with symptomatic vascular disease in one vascular bed vs. multiple vascular beds, 3-year event rates for MI/stroke/ vascular death/ rehospitalization were 25.5 vs. 40.5% (P < 0.001). Conclusion Despite contemporary therapy, outpatients with symptomatic atherothrombotic vascular disease experience high rates of recurrent vascular events and rehospitalizations

Bridging the supply and demand gap for affordable home ownership in Malaysia: the roles of government and financial institutions

Promoting homeownership remains a conundrum in a developing economy in Malaysia. Despite significant initiatives pursued by the government, more needs to be done to promote affordable and sustainable homeownership further. Khazanah Report (2018) provides evidence that housing affordability in Malaysia is worsening compared to one reported in 2015.This study therefore aims to empirically assess the role of government in terms of designing policies to promote the supply of affordable homes and the role of financial institutions in terms of providing home financing. The finding reveals that existing housing policies and government programmes have a significant role in promoting homeownership. The finding further suggests that building and completing more units of affordable homes (as captured by housing stocks) and promoting innovative home financing products (both conventional and Islamic) are the most significant variables in promoting homeownership in Malaysia

COVID-19 pandemic:Nigerian University lecturers’ response to virtual orientation

The effect of the COVID-19 pandemic globally and the disruptions occasioned by it has far-reaching implications on societies in general and most especially the educational sector with governments across the globe ordering lockdowns including the closure of education institutions thereby necessitating alternative teaching and learning methods other than the usual face-to-face interaction to avoid a total collapse of the education sector. This study investigates Nigerian University lecturers’ perspective and response to virtual learning as an alternative to face-to-face teaching method during the pandemic. Relying on primary data source collected using questionnaires, a total number of 435 lecturers responded across both public and private universities and their responses analysed using SPSS. The study found that lecturers from private universities responded to virtual teaching than those from public universities; that the presence of infrastructural orientation influences virtual orientation; and that a negative relationship exists between the sociodemographic/occupational variables (gender, current position, years of experience) and virtual orientation of lecturers of Nigerian universities

Enhancement of mechanical and corrosion resistance properties of electrodeposited Ni–P–TiC composite coatings

In the present study, the effect of concentration of titanium carbide (TiC) particles on the structural, mechanical, and electrochemical properties of Ni–P composite coatings was investigated. Various amounts of TiC particles (0, 0.5, 1.0, 1.5, and 2.0 g L−1) were co-electrodeposited in the Ni–P matrix under optimized conditions and then characterized by employing various techniques. The structural analysis of prepared coatings indicates uniform, compact, and nodular structured coatings without any noticeable defects. Vickers microhardness and nanoindentation results demonstrate the increase in the hardness with an increasing amount of TiC particles attaining its terminal value (593HV100) at the concentration of 1.5 g L−1. Further increase in the concentration of TiC particles results in a decrease in hardness, which can be ascribed to their accumulation in the Ni–P matrix. The electrochemical results indicate the improvement in corrosion protection efficiency of coatings with an increasing amount of TiC particles reaching to ~ 92% at 2.0 g L−1, which can be ascribed to a reduction in the active area of the Ni–P matrix by the presence of inactive ceramic particles. The favorable structural, mechanical, and corrosion protection characteristics of Ni–P–TiC composite coatings suggest their potential applications in many industrial applications

Adenovirus-prime and baculovirus-boost heterologous immunization achieves sterile protection against malaria sporozoite challenge in a murine model.

With the increasing prevalence of artemisinin-resistant malaria parasites, a highly efficacious and durable vaccine for malaria is urgently required. We have developed an experimental virus-vectored vaccine platform based on an envelope-modified baculovirus dual-expression system (emBDES). Here, we show a conceptually new vaccine platform based on an adenovirus-prime/emBDES-boost heterologous immunization regimen expressing the Plasmodium falciparum circumsporozoite protein (PfCSP). A human adenovirus 5-prime/emBDES-boost heterologous immunization regimen consistently achieved higher sterile protection against transgenic P. berghei sporozoites expressing PfCSP after a mosquito-bite challenge than reverse-ordered or homologous immunization. This high protective efficacy was also achieved with a chimpanzee adenovirus 63-prime/emBDES-boost heterologous immunization regimen against an intravenous sporozoite challenge. Thus, we show that the adenovirus-prime/emBDES-boost heterologous immunization regimen confers sterile protection against sporozoite challenge by two individual routes, providing a promising new malaria vaccine platform for future clinical use

Sister Mary Joseph's Nodule at a University Teaching Hospital in Northwestern Tanzania: A Retrospective Review of 34 cases.

Sister Mary Joseph's nodule is a metastatic tumor deposit in the umbilicus and often represents advanced intra-abdominal malignancy with dismal prognosis. There is a paucity of published data on this subject in our setting. This study was conducted to describe the clinicopathological presentation and treatment outcome of this condition in our environment and highlight challenges associated with the care of these patients, and to proffer solutions for improved outcome. This was a retrospective study of histologically confirmed cases of Sister Mary Joseph's nodule seen at Bugando Medical Centre between March 2003 and February 2013. Data collected were analyzed using descriptive statistics. A total of 34 patients were enrolled in the study. Males outnumbered females by a ratio of 1.4:1. The vast majority of patients (70.6%) presented with large umbilical nodule > 2 cm in size. The stomach (41.1%) was the most common location of the primary tumor. Adenocarcinoma (88.2%) was the most frequent histopathological type. Most of the primary tumors (52.9%) were poorly differentiated. As the disease was advanced and metastatic in all patients, only palliative therapy was offered. Out of 34 patients, 11 patients died in the hospital giving a mortality rate of 32.4%. Patients were followed up for 24 months. At the end of the follow-up period, 14(60.9%) patients were lost to follow-up and the remaining 9 (39.1%) patients died. Patients survived for a median period of 28 weeks (range, 2 to 64 weeks). The nodule recurred in 6 (26.1%) patients after complete excision. Sister Mary Joseph's nodule of the umbilicus is not rare in our environment and often represents manifestation of a variety of advanced intra-abdominal malignancies. The majority of the patients present at a late stage and many with distant metastases. The patient's survival is very short leading to a poor outcome. Early detection of primary cancer at an early stage may improve the prognosis

An interdisciplinary framework for Islamic cognitive theories

The Islamic psychology (IP) community in Europe has recently witnessed a heated debate about the credentials required to participate in the theoretical substantiation of IP and Islamically integrated psychotherapy and counseling. This debate has provided convenient circumstances for Muslim psychologists and Islamic scholars alike to rethink their roles within the flourishing movement. Specifically, the discussions hint toward the importance of adopting a collaborative research methodology for IP, in particular for basic research. The methodology of choice will need to define the necessary qualifications and responsibilities of scholars and psychologists in a collaborative research process (personal collaboration) and evince its capability to appropriately marry knowledge and data, diverging research methods, and perspectives, concepts, and theories from Islamic studies and contemporary psychology (content-related collaboration). Here, we devise and offer a case illustration of an Islamic Psychology Basic Research Framework (coined the SALAAM Framework). This framework uses the Institute for Interdisciplinary Studies (IIS) Model of Interdisciplinary Research, developed by the IIS at the University of Amsterdam. Our first aim is to appropriate the IIS model for the IP literature by applying the model's research process phases and technique for the integration of disparate bodies of knowledge—that is, the identification of common ground—to methodological approaches in the contemporary IP literature. Our second aim is to exemplify the devised SALAAM Framework using the relatively unexplored area of Islamic cognitive theories (ICTs), which remain underdeveloped in contemporary psychological literature, primarily because of a lack of commensurability with the nomenclature of contemporary psychology. We thus provide a primer on the potential scope of ICTs. Toward the end of this article, we discuss the potential of the project of interdisciplinary construction of Islamic psychological theory, and the ability of the SALAAM Framework to establish a research program in IP that centers on cognition. We finally offer our reflections on the distinctiveness of Islamic psychologies in comparison to mainstream and Christian psychology.Q4WOS:0004589189000062-s2.0-8506156876