Impingement Heat Transfer In The Leading Edge Cavity Of A Gas Turbine Vane

Jet Impingement Cooling is an internal cooling technique used in the leading edge cavities of Turbine Vanes. This involves a series of jets impinging onto the internal surfaces of a turbine vane/blade through the impingement plate. For the model tested here, the area around the blade/vane leading edge was studied for both heat transfer performance and aerodynamics losses. The performance of an Impingement cooling system depends on parameters like the spent flow effect on the downstream jet, film cooling configuration, and tip flow condition. The present study focuses on analyzing the effect of these parameters on a unique impingement cooling configuration. A Liquid Crystal based technique was used to obtain the heat transfer distribution on the target surface. A novel Camera-Endoscope combination was used to capture the liquid crystal images in a confined space. Heat Transfer Contours were obtained for a total of six different cases based on differing film cooling hole configurations and tip condition. Peak heat transfer values are observed in the impingement zone along with a characteristic reduction in heat transfer as we move away from the impingement zone. The results indicated that the cross flow had a negative impact on the peak heat transfer value but improved the uniformity of heat transfer distribution. The film cooling configuration was found to affect the amount of cross flow and the location of the impingement zone of the jet. The cross flow effect is found to have reduced effect with an increase in the available number of film cooling holes leading to an increase in the peak heat transfer. The tip condition was altered for the last case in which it adversely affected the extent of jet impingement. Line plots for all the contours showed the spent flow effect. A fluid dynamic analysis of all the above effects was presented

How Privacy-Enhanced Technologies (Pets) are Transforming Digital Healthcare Delivery

Privacy Enhancing Technologies (PETs) are playing a crucial role in maturing digital healthcare delivery for mainstream adaption from both a social and regulatory perspective. Different PETs are improving different aspects of digital healthcare delivery, and we have chosen seven of them to observe in the context of their influence on digital healthcare and their use cases. Homomorphic encryption can provide data security when healthcare data is being collected from individuals via IoT or IoMT devices. It’s also a key facilitator for large-scale healthcare data pooling from multiple sources for analytics without compromising privacy. Secure Multi-Party Computation (SMPC) facilitates safe data transfer between patients and healthcare professionals, and other relevant entities. Generative Adversarial Networks (GANs) can be used to generate larger data sets from smaller training data sets directly obtained from the patients, to train AI and ML algorithms. Differential Privacy (DP) focuses on combining multiple data sets for collective or individual processing without compromising privacy. However, its addition of noise to obscure data has some technical limitations. Zero-Knowledge Proof (ZKP) can facilitate safe verifications/validation protocols to establish connections between healthcare devices without straining their hardware capacities. Federated learning leans quite heavily towards training AI/ML algorithms on multiple data sets without margining or compromising the privacy of the constituents of any dataset. Obfuscation can be used in different stages of healthcare delivery to obscure healthcare data.

Web 3.0 and its Potential Impact on Privacy Shifting Left in the Development Process

The concept of Web 3.0 as the semantic web has been around since the early 2000s, and its decentralized interpretation gained more traction when the term was coined by Ethereum’s co-founder Gavin Wood. New programming languages were identified as the first enablers of Web 3.0, but under its new interpretation, other enabling technologies were identified. The three most significant of which are Artificial Intelligence (AI), Machine Learning (ML), and blockchain. IoT is both a concurrent technology and an enabler. Security and privacy-related challenges with the enabler technologies are already being identified and addressed. The privacy challenges associated with Web 3.0 as a whole are more difficult to identify due to multiple reasons, including the nascent form of the technology, the non-standardized definition of Web 3.0, and privacy (And compliance) concerns associated with decentralization. A decentralized version of the internet has the potential to evoke new, unprecedented privacy challenges, some of which may be addressed with further advances in blockchain (a key enabler). Other challenges and trends are associated with the other Web 3.0 enabler, i.e., artificial intelligence. Despite a wide variety of privacy challenges, there is a strong probability that Web 3.0 is highly likely to push privacy left in the development process. Many of the identified challenges with underlying Web 3.0 technologies can be better addressed at the early stages of the development process. Even though we have yet to see how development culture, our approach to privacy, and Web 3.0 as a tech will evolve, especially considering the myriad of new ethical concerns associated with AI, these factors may not impede privacy's shift to the left in Web 3.0

Fighting Cybercrime with Zero Trust

Zero Trust Architecture focuses on securing critical data and access paths by eliminating trust as much as possible by “assuming breach.” It establishes trust every time a user tries to access an asset in the system by questioning the premise that users, devices, and network components should be implicitly trusted based on their location within the network. We have chosen Zero Trust to help reduce the impact of cybercrime and establish baseline security practices. It is a dramatic paradigm shift in the philosophy of securing our infrastructure, networks, and data, from verifying once at the perimeter to continually verifying each user, device, application, and transaction. Trust in humans is essential to forming connections; however, trust in network connections can create dangers and potential security gaps in the digital world. In a hyper-connected world, anyone can launch an attack virtually and participate in cybercrime by violating the trust of systems or networks. The cost of not implementing good security practices is evident in the growing number of data breaches and ransomware attacks that erode consumers' trust in tech and online space. Considering Zero Trust and Zero Trust Architecture developed by the National Institute of Standards and Technology (NIST) should help reduce the impact of cybercrime and protect the crown jewels in cyberspace from a malicious insider or an external attacker

DevSecOps Services: A Study of the Most Common and Rarest DevSecOps Services Available in 2022

DevSecOps is an evolving set of practices within the prevalent DevOps paradigm that aims to include security at every stage of the development cycle. In order to understand how it has matured since its inception, we looked at a sample of 25 companies offering DevSecOps services to identify which services were most common and rarest. Multiple trends were identified, including a heavy lean towards DevSecOps services towards consultation and organizational adaptation. We also identified compliance to be a focus of many DevSecOps services. DevSecOps consultation and DevSecOps as a Service (DaaS) were identified as two of the most commonly available services in 2022, and isolation, SRE, SIEM, and orchestration were the rarest. Future studies on this subject might reveal different trends in the evolution of DevSecOps services, assuming DevSecOps hasn't been replaced by a more advanced paradigm

Generation of transgenic mouse models with expression of constitutively active STAT5A

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Multiscale modeling and characterization of additively manufactured materials

Ultrasonic nondestructive testing can be used to infer the elastic properties of additively manufactured (3D printed) materials. Fused deposition modeling 3D printing involves the layer-by-layer extrusion of a filament into a macroscale part that contains microscopic voids between the deposited lines of infill. This thesis presents a comparison of measured ultrasonic transmission through 3D-printed flat plates to model predictions that incorporate the part’s microgeometry. The experiment using a water-immersed point source and synthetic linear array to measure the plane-wave transmission coefficient, |T(f, θ)|, at 1–1000 kHz over a range of incidence angles. The model calculates the effective stiffness tensor of the plate using a finite element model of the infill and replicates the conditions of the experiment to calculate the transmission coefficient. This comparison is used to predict the Young’s modulus of the as-printed material as well as detect and identify the cause behind elastic anisotropy in 3D-printed parts. Contact transducer measurements of the stiffnesses at single frequencies are used to complement the predictive model. Minimizing the difference between the measured and simulated transmission coefficient by varying inputs to the model provides an improved understanding of the effects of print settings on the as-fabricated mechanical properties of 3D-printed materials.Mechanical Engineerin

Dengue Virus prM-Specific Human Monoclonal Antibodies with Virus Replication-Enhancing Properties Recognize a Single Immunodominant Antigenic Site

ABSTRACT The proposed antibody-dependent enhancement (ADE) mechanism for severe dengue virus (DENV) disease suggests that non-neutralizing serotype cross-reactive antibodies generated during a primary infection facilitate entry into Fc receptor bearing cells during secondary infection, resulting in enhanced viral replication and severe disease. One group of cross-reactive antibodies that contributes considerably to this serum profile target the premembrane (prM) protein. We report here the isolation of a large panel of naturally occurring human monoclonal antibodies (MAbs) obtained from subjects following primary DENV serotype 1, 2, or 3 or secondary natural DENV infections or following primary DENV serotype 1 live attenuated virus vaccination to determine the antigenic landscape on the prM protein that is recognized by human antibodies. We isolated 25 prM-reactive human MAbs, encoded by diverse antibody-variable genes. Competition-binding studies revealed that all of the antibodies bound to a single major antigenic site on prM. Alanine scanning-based shotgun mutagenesis epitope mapping studies revealed diverse patterns of fine specificity of various clones, suggesting that different antibodies use varied binding poses to recognize several overlapping epitopes within the immunodominant site. Several of the antibodies interacted with epitopes on both prM and E protein residues. Despite the diverse genetic origins of the antibodies and differences in the fine specificity of their epitopes, each of these prM-reactive antibodies was capable of enhancing the DENV infection of Fc receptor-bearing cells. IMPORTANCE Antibodies may play a critical role in the pathogenesis of enhanced DENV infection and disease during secondary infections. A substantial proportion of enhancing antibodies generated in response to natural dengue infection are directed toward the prM protein. The fine specificity of human prM antibodies is not understood. Here, we isolated a panel of dengue prM-specific human monoclonal antibodies from individuals after infection in order to define the mode of molecular recognition by enhancing antibodies. We found that only a single antibody molecule can be bound to each prM protein at any given time. Distinct overlapping epitopes were mapped, but all of the epitopes lie within a single major antigenic site, suggesting that this antigenic domain forms an immunodominant region of the protein. Neutralization and antibody-dependent enhanced replication experiments showed that recognition of any of the epitopes within the major antigenic site on prM was sufficient to cause enhanced infection of target cells

Mapping the Human Memory B Cell and Serum Neutralizing Antibody Responses to Dengue Virus Serotype 4 Infection and Vaccination

ABSTRACT The four dengue virus (DENV) serotypes are mosquito-borne flaviviruses responsible for dengue fever and dengue hemorrhagic fever. People exposed to DENV develop antibodies (Abs) that strongly neutralize the serotype responsible for infection. Historically, infection with DENV serotype 4 (DENV4) has been less common and less studied than infections with the other three serotypes. However, DENV4 has been responsible for recent large and sustained epidemics in Asia and Latin America. The neutralizing antibody responses and the epitopes targeted against DENV4 have not been characterized in human infection. In this study, we mapped and characterized epitopes on DENV4 recognized by neutralizing antibodies in people previously exposed to DENV4 infections or to a live attenuated DENV4 vaccine. To study the fine specificity of DENV4 neutralizing human antibodies, B cells from two people exposed to DENV4 were immortalized and screened to identify DENV-specific clones. Two human monoclonal antibodies (MAbs) that neutralized DENV4 were isolated, and their epitopes were finely mapped using recombinant viruses and alanine scan mutation array techniques. Both antibodies bound to quaternary structure epitopes near the hinge region between envelope protein domain I (EDI) and EDII. In parallel, to characterize the serum neutralizing antibody responses, convalescence-phase serum samples from people previously exposed to primary DENV4 natural infections or a monovalent DENV4 vaccine were analyzed. Natural infection and vaccination also induced serum-neutralizing antibodies that targeted similar epitope domains at the EDI/II hinge region. These studies defined a target of neutralizing antigenic site on DENV4 targeted by human antibodies following natural infection or vaccination. IMPORTANCE The four serotypes of dengue virus are the causative agents of dengue fever and dengue hemorrhagic fever. People exposed to primary DENV infections develop long-term neutralizing antibody responses, but these principally recognize only the infecting serotype. An effective vaccine against dengue should elicit long-lasting protective antibody responses to all four serotypes simultaneously. We and others have defined antigenic sites on the envelope (E) protein of viruses of dengue virus serotypes 1, 2, and 3 targeted by human neutralizing antibodies. The epitopes on DENV4 E protein targeted by the human neutralizing antibodies and the mechanisms of serotype 4 neutralization are poorly understood. Here, we report the properties of human antibodies that neutralize dengue virus serotype 4. People exposed to serotype 4 infections or a live attenuated serotype 4 vaccine developed neutralizing antibodies that bound to similar sites on the viral E protein. These studies have provided a foundation for developing and evaluating DENV4 vaccines