A feasibility study of using Langley 0.3-m transonic cryogenic tunnel sidewall boundary-layer removal system for heavy gas testing

This report presents the results of a preliminary study for using the 0.3-m Transonic Cryogenic Tunnel sidewall boundary-layer removal system with heavy gas sulfur hexafluoride as the test medium. It is shown that the drive motor speed/power of the existing system and the additional heat load on the tunnel heat exchanger are the major problems limiting the boundary-layer removal system performance. Overcoming these problems can provide the capability to remove about 1.5 percent of the test section mass flow at Mach number M = 0.8 and about 5 percent at M = 0.25. Previous studies have shown that these boundary-layer mass flow removal rates can reduce the boundary-layer thickness by a factor of two at the model station. Also the effect of upstream boundary-layer removal on the airfoil test data is not likely to be significant under high lifting conditions. Near design conditions, corrections to the test Mach number may be necessary to account for sidewall boundary-layer effects

Performance of the active sidewall boundary-layer removal system for the Langley 0.3-meter Transonic Cryogenic Tunnel

A performance evaluation of an active sidewall boundary-layer removal system for the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) was evaluated in 1988. This system uses a compressor and two throttling digital valves to control the boundary-layer mass flow removal from the tunnel. The compressor operates near the maximum pressure ratio for all conditions. The system uses a surge prevention and flow recirculation scheme. A microprocessor based controller is used to provide the necessary mass flow and compressor pressure ratio control. Initial tests on the system indicated problems in realizing smooth mass flow control while running the compressor at high speed and high pressure ratios. An alternate method has been conceived to realize boundary-layer mass flow control which avoids the recirculation of the compressor mass flow and operation near the compressor surge point. This scheme is based on varying the speed of the compressor for a sufficient pressure ratio to provide needed mass flow removal. The system has a mass flow removal capability of about 10 percent of test section flow at M = 0.3 and 4 percent at M = 0.8. The system performance has been evaluated in the form of the compressor map, and compressor tunnel interface characteristics covering most of the 0.3-m TCT operational envelope

Evolution of 3D Boson Stars with Waveform Extraction

Numerical results from a study of boson stars under nonspherical perturbations using a fully general relativistic 3D code are presented together with the analysis of emitted gravitational radiation. We have constructed a simulation code suitable for the study of scalar fields in space-times of general symmetry by bringing together components for addressing the initial value problem, the full evolution system and the detection and analysis of gravitational waves. Within a series of numerical simulations, we explicitly extract the Zerilli and Newman-Penrose scalar $\Psi_4$ gravitational waveforms when the stars are subjected to different types of perturbations. Boson star systems have rapidly decaying nonradial quasinormal modes and thus the complete gravitational waveform could be extracted for all configurations studied. The gravitational waves emitted from stable, critical, and unstable boson star configurations are analyzed and the numerically observed quasinormal mode frequencies are compared with known linear perturbation results. The superposition of the high frequency nonspherical modes on the lower frequency spherical modes was observed in the metric oscillations when perturbations with radial and nonradial components were applied. The collapse of unstable boson stars to black holes was simulated. The apparent horizons were observed to be slightly nonspherical when initially detected and became spherical as the system evolved. The application of nonradial perturbations proportional to spherical harmonics is observed not to affect the collapse time. An unstable star subjected to a large perturbation was observed to migrate to a stable configuration.Comment: 26 pages, 12 figure

Implementation of optimal solution for network lifetime and energy consumption metrics using improved energy efficient LEACH protocol in MANET

In current scenarios MANET mainly focus on low power battery operated devices. Moreover in a MANET transmission of large data consumes more energy that affects the performance of network, energy consumption, throughput, end to end delay, and packet overhead. The sum of these parameter metrics measure must be taken into account to increase the life-time and network energy efficiency. The main constraint in WSN is due to the restricted power in a node, which cannot be substituted. The node senses the data and it is moved towards the sink. This action of data movement needs to be efficient and the usage of battery in the sensor node requires to be efficiently employed to improve the network lifetime. The development of the energy efficient algorithms is of primary concern in the research arena of MANET. In any network, most of the routing protocols are focused directly to collect and bifurcate the large data for long distance communication. The prime goal of this research focused to identifies and survey more suitable routing protocol for MANET. That consumed less energy and increase life time of network. In this paper the author made on attempt on improved energy efficient LEACH protocol for MANET to reduce the energy dissipation that to life time of the network during the data transmission between source nodes and destination nodes

Corporate Portal Management System

Web Portal Software Systems have become a very effective communication medium for sharing. Our Portal Management System dramatically simplifies the creation and management of portals. A corporate portal is a web-based platform to access with security a broad range of information, services, applications and expertise. The corporate portal management system platform offers a flexible and robust content management solution that allows employees, customers and partners to safely collaborate on, contribute to and manage business content anywhere around the world. It can be utilised as an extranet that serves both internal and external users or as an intranet for internal communication in an organisation. Corporate portals can also provide single sign-on capabilities between their users and various other systems. The focus of our software is on presenting documents and content in an effective manner to individuals, groups, customers, partners and vendors. Portal content, services and applications can be customized and personalized to the need of different users or user groups. Content will be published on portal by a content management tool. Before publishing the content, it will be approved by management by using workflow. The basic and the most important function of the Corporate Portal Management System is the routing of data using the concept of workflow along with the various features like scheduling, commenting module and other similar features which make the software using service highly interactive and communicative. The use of this software can result in a reduction in the number of man hours spent in moderating the content on any portal. It also provides an easy to understand and intuitive interface for users which greatly helps in adapting to the use of this software

1mb{1\over m_b} and 1mt{1\over m_t} Expansion of the Weak Mixing Matrix

We perform a $1/m_b$ and $1/m_t$ expansion of the Cabibbo-Kobayashi- Maskawa mixing matrix. Data suggest that the dominant parts of the Yukawa couplings are factorizable into sets of numbers $\vert r>$, $\vert s>$, and $\vert s'>$, associated, respectively, with the left-handed doublets, the right-handed up singlets, and the right- handed down singlets. The first order expansion is consistent with Wolfenstein parameterization, which is an expansion in $sin \theta _c$ to third order. The mixing matrix elements in the present approach are partitioned into factors determined by the relative orientations of $\vert r>$, $\vert s>$, and $\vert s'>$ and the dynamics provided by the subdominant mass matrices. A short discussion is given of some experimental support and a generalized Fritzsch model is used to contrast our approach.Comment: A set of references has been added to ealier related wor

Constraints and strategies of smallholder farmers for successful protected cultivation of capsicum: A critical appraisal

The study was framed to assess the challenges/constraints in protected cultivation of capsicum by small holder farmers in Karnataka state, India and provide strategies for sustained profitability. Ex-post-facto research design was followed for conducting study in three districts (Bangalore Rural, Bangalore Urban and Chickballapur) of Karnataka. From each district, 50 smallholders capsicum cultivation farmers under protected cultivation were selected through purposive random sampling, constituting 150 respondents. Garrett’s ranking technique was adopted to analyse the constraints faced by the farmers in the study area. The various constraints experienced by the farmers were broadly grouped in to production constraints, market constraints, financial constraints, technological constraints, institutional constraints, weather-based constraints, health and labour constraints. These finding demonstrated urgent need to intervene towards the constraints experienced by the smallholder capsicum grows under protected cultivation, which not only ensures to get stable income but also sustain their livelihoods

Acne in South African black adults: A retrospective study in the private sector

Background. Acne vulgaris is the most common skin disorder affecting teenagers and young adults, and is becoming increasingly common in middle-aged women. It affects all skin types and ethnic groups, but dark-skinned individuals are burdened by post-inflammatory hyperpigmentation (PIH) as a sequela. PIH causes distress in acne patients even after the inflammatory lesions have resolved.Objective. To describe the characteristics of acne in black South African adults in the private health sector in Durban, KwaZulu-Natal Province.Methods. A retrospective study of records of patients attending two large private dermatology clinics in central Durban, mainly catering for black patients, was performed. Data were collected for the period January - December 2014. Records with acne as a diagnosis were retrieved and analysed with regard to age, demographics, type and severity of acne, therapy, HIV status and outcomes.Results. Of a total of ~3 000 charts available for the 12-month period, 242 had acne as a diagnosis and were retrieved and analysed. Of these patients, 204 (84.3%) were female and the remainder were male. The mean age was 28.5 years (under-18s were excluded from the study). Inflammatory acne was the most frequently encountered form (58.6%). Fifteen patients (6.2%) were on topical treatment only, and 226 (93.4%) were on topical plus systemic treatment. PIH was the most common sequela (81.0% of patients).Conclusions. The majority of the patients were young females with inflammatory acne, and PIH was the most common sequela. Early and vigorous treatment of acne may minimise its complications, including those seen mainly in black patients