180 research outputs found
Effect of Lyophilization on Stability of PEG-Protein Conjugate: A Case Study with Peginterferon alfa-2b
The purpose of the present study was to develop stable lyophilized formulation of peginterferon alfa-2b which is acquiescent to the short lyophilization process. The present study evaluates the effect of buffering components and cryoprotectant(s) on depegylation of the peginterferon alfa-2b in combination with lyophilization process. Finally, a short lyophilization process was identified which can produce a stable pharmaceutical form of peginterferon alfa-2b without any depegylation during long-term storage. Formulations were analyzed mainly for depegylation by HP-size exclusion chromatography and in-vitro antiviral activity. Residual moisture content in the lyophilized product was also used as a key indicating parameter to check its role with respect to depegylation upon storage under various temperature conditions. It was observed that the peginterferon alfa-2b when formulated in presence of cryoprotectant like sucrose requires longer lyophilization process of about 5 days, irrespective of the buffering components used, to reduce the level of residual moisture content and thereby to produce the stable formulation without depegylation. A stable formulation in presence of high concentration of lactose as a cryoprotectant was developed which can withstand stresses exerted to protein-polymer conjugate during lyophilization phases without any significant depegylation. A short lyophilization process of about 48 hours can be utilized for peginterferon alfa-2b when formulated in presence of lactose as a cryoprotectant through which a stable lyophilized formulation can be produced as against longer process required when sucrose is used a cryoprotectant, which is essential from commercial point of view as lyophilization is a costly process
Identifying and Mitigating Pack Rust in Steel Bridges
Pack rust, or crevice corrosion, is a type of localized corrosion. When steel surfaces are in contact, or even when a steel surface is in contact with a non-metal, corrosion can initiate and rust starts to pack between the surfaces. This study involves understanding the parameters involved in the initiation process, analyzing pack rust in Indiana bridges, and reviewing existing DOT mitigation strategies and repair procedures. Join us for a discussion
Pack Rust Identification and Mitigation Strategies for Steel Bridges
Pack rust or crevice corrosion is a type of localized corrosion. When a metal is in contact with a metal, or even non-metal, the metal starts to corrode, and rust starts to pack in between the surfaces. When significant development of pack rust occurs, it can cause overstressing of bolts and rivets causing them to fail, and it can bend connecting plates and member elements thus reducing their buckling capacity. Thus it is important to mitigate the formation and growth of pack rust in bridges. This study was conducted to determine if pack rust occurs frequently and thereby may pose a problem in the state of Indiana. The study is divided into three primary tasks. The first part of the study involves understanding the parameters involved in the initiation process of crevice corrosion and post-initiation crevice corrosion process. The second part of the study involves reviewing existing mitigation strategies and repair procedures used by state DOTs. The third part of the study involves identifying steel bridges with pack rust in Indiana. Analyses were performed on the data collected from Indiana bridges that have pack rust. This involved finding the components and members of bridges which are most affected by pack rust and finding parameters which influence the formation of pack rust. Pack rust in the steel bridges were identified using the INDOT inspection reports available through BIAS system. The study revealed that good maintenance practices helped in reducing pack rust formation. The study identified locations on steel bridges which have a high probability towards pack rust formation. A mitigating strategy possessing qualities which can show promising results is identified
The Perils of Using Social Media Data to Predict the Spread of Diseases
The data produced by social media engagement is of interest to various organizations and has been used in different applications like marketing, finance and healthcare. Though the potential of mining this data is high, standard data mining processes do not address the peculiarities of social media data. In this paper, we explore the perils of using social media data in predicting the spread of an infectious disease; perils that are mostly related to data quality, textual analysis and location information. We synthesize findings from a literature review and a data mining exercise to develop an adapted data mining process. This process has been designed to minimize the effects of the perils identified and is thus more aligned with the requirements of predicting disease spread using social media data. The process should be useful to data miners and health institution
Energy Audit in Residential Building
This paper deals with the study of energy audit of residential building at Trumbull, CT (USA). Worldwide,30-40% of all primary energy is used for buildings and they are held responsible for 40-50% of green house gas emissions. Sustainable development is essential for the residential building construction. It has various benefits such as low environmental impact, high economical and social gains. An energy audit is an assessment of how much energy is used and identifying where it is used. We can get a detail idea about energy consumption, identifying, enumerating and evaluating possible energy saving opportunity
Resilient Risk based Adaptive Authentication and Authorization (RAD-AA) Framework
In recent cyber attacks, credential theft has emerged as one of the primary
vectors of gaining entry into the system. Once attacker(s) have a foothold in
the system, they use various techniques including token manipulation to elevate
the privileges and access protected resources. This makes authentication and
token based authorization a critical component for a secure and resilient cyber
system. In this paper we discuss the design considerations for such a secure
and resilient authentication and authorization framework capable of
self-adapting based on the risk scores and trust profiles. We compare this
design with the existing standards such as OAuth 2.0, OpenID Connect and SAML
2.0. We then study popular threat models such as STRIDE and PASTA and summarize
the resilience of the proposed architecture against common and relevant threat
vectors. We call this framework as Resilient Risk based Adaptive Authentication
and Authorization (RAD-AA). The proposed framework excessively increases the
cost for an adversary to launch and sustain any cyber attack and provides
much-needed strength to critical infrastructure. We also discuss the machine
learning (ML) approach for the adaptive engine to accurately classify
transactions and arrive at risk scores
Model predictive control for a dual active bridge inverter with a floating bridge
This paper presents a Model Predictive Control technique applied to a dual active bridge inverter where one of the bridges is floating. The proposed floating bridge topology eliminates the need for isolation transformer in a dual inverter system and therefore reduces the size, weight and losses in the system. To achieve multilevel output voltage waveforms the floating inverter DC link capacitor is charged to the half of the main DC link voltage. A finite-set Model Predictive Control technique is used to control the load current of the converter as well as the floating capacitor voltage. Model predictive control does not require any switching sequence design or complex switching time calculations as used for SVM, thus the technique has some advantages in this application. A detailed analysis of the converter as well as the predictive control strategy is given in this paper. Simulation and experimental results to validate the approach are also presented
A Level Dependent Authentication for IoT Paradigm
The Internet of Things (IoT) based services are getting a widespread expansion in all
the directions and dimensions of the 21st century. The IoT based deployment involves
an internet-connected sensor, mobiles, laptops, and other networking and computing de-
vices. In most IoT based applications, the sensor collects the data and communicates
it to the end-user via gateway device or fog device over a precarious internet channel.
The attacker can use this open channel to capture the sensing device or the gateway
device to collect the IoT data or control the IoT system. For a long time, numerous
researchers are working towards designing the authentication mechanism for the sen-
sor network to achieve reliable and computationally feasible security. For the resource
constraint environment of the IoT, it is essential to design reliable, ecient, and secure
authentication protocol. In this paper, we propose a novel approach of authentication in
the IoT paradigm called a Level-Dependent Authentication(LDA). In the LDA protocol,
we propose a security reliable and resource ecient key sharing mechanism in which users
at level li can communicate with the sensor at level lj if and only if the level of user in
the organizational hierarchy is lower or equal to the level of sensor deployment. We pro-
vide a security analysis for the proposed LDA protocol using random oracle based games
& widely accepted AVISPA tools. We prove mutual authentication for the proposed
protocol using BAN logic. In this paper, we also discuss a comparative analysis of the
proposed protocol with other existing IoT authentication systems based on communica-
tion cost, computation cost, and security index. We provide an implementation for the
proposed protocol using a globally adopted IoT protocol called MQTT protocol. Finally,
we present the collected data related to the networking parameters like throughput and
round trip delay
Functional and radiological outcome of proximal femoral nailing versus dynamic hip screw in unstable intertrochanteric femur fractures
Background: Intertrochanteric femur fractures account half of the hip fractures in elderly, the other majority being neck of femur fracture. 35-40% of intertrochanteric are unstable (Tronzoâs classification type 3, 4 and 5). The dynamic hip screw (DHS) has achieved widespread acclaim in the last few years and is currently considered to be the standard device for outcome assessment. Though, the DHS has been shown to produce good results, but complications are frequent, particularly in unstable inter-trochanteric fracture. The advantage of Proximal Femur Nailing fixation is that it provides a more biomechanically stable construct by reducing the distance between hip joint and implant. The goal of this study is to assess the clinical and radiographical outcomes of the DHS (load bearing implant) and PFN (load sharing implant) for the treatment of Intertrochanteric hip fractures.Methods: We assessed the same in 52 cases of unstable femur fracture 26 operated with DHS and 26 with PFN and followed up with sequential radiographs for radiological union and sequential interview with Harris hip score calculation for functional outcome assessment.Results: Patients operated for unstable intertrochanteric femur fracture with Proximal femoral nailing had better Harris hip scores (excellent 4, good 14) compared to dynamic hip screw group (Excellent 6, good 5) and earlier weight bearing (At 18 weeks, 100% in PFN compared to 65.5% in DHS). PFN has lesser incidence of postoperative complications (15% in PFN compared to 38% in DHS).Conclusions:The proximal femoral nail has better functional outcome in terms of Harris hip score and early radiologic union in unstable intertrochanteric fractures of femur.Â
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