Effect of dead space on avalanche speed

The effects of dead space (the minimum distance travelled by a carrier before acquiring enough energy to impact ionize) on the current impulse response and bandwidth of an avalanche multiplication process are obtained from a numerical model that maintains a constant carrier velocity but allows for a random distribution of impact ionization path lengths. The results show that the main mechanism responsible for the increase in response time with dead space is the increase in the number of carrier groups, which qualitatively describes the length of multiplication chains. When the dead space is negligible, the bandwidth follows the behavior predicted by Emmons but decreases as dead space increase

Assessment innovation and student experience: a new assessment challenge and call for a multi-perspective approach to assessment research

The impact of innovative assessment on student experience in higher education is a neglected research topic. This represents an important gap in the literature given debate around the marketization of higher education, international focus on student satisfaction measurement tools and political calls to put students at the heart of higher education in the UK. This paper reports on qualitative findings from a research project examining the impact of assessment preferences and familiarity on student attainment and experience. It argues that innovation is defined by the student, shaped by diverse assessment experiences and preferences and therefore its impact is difficult to predict. It proposes that future innovations must explore assessment choice mechanisms which allow students to shape their own assessments. Cultural change and staff development will be required to achieve this. To be accepted, assessment for student experience must be viewed as a complementary layer within a complex multi perspective model of assessment which also embraces assessment of learning, assessment for learning and assessment for life long learning. Further research is required to build a meta theory of assessment to enhance the synergies between these alternative approaches and to minimise tensions between them

Buildings behaving badly:A behavioral experiment on how different motivational frames influence residential energy label adoption in the Netherlands

Heating buildings contributes to approximately 36% of Europe’s energy demand and several EU member states have adopted mandatory energy labels to improve energy efficiency by promoting home weatherization investments. This paper focuses on the perception of the energy label for residential buildings in the Netherlands and the role of different frames (egoistic, biospheric and social norms and neutral frames) in motivating adoption of energy labels for housing. We used a behavioral email experiment and an online survey to investigate these motivational factors. We find that biospheric frames are weaker than the other three motivational frames in terms of engaging interest in the energy label, but that the biospheric frame results in higher willingness to pay (WTP) for the energy label. We also find that age (rather than income) correlates with higher willingness to pay for home energy labels

Instructional leadership in centralised systems: evidence from Greek high-performing secondary schools

This paper examines the enactment of instructional leadership (IL) in high-performing secondary schools (HPSS), and the relationship between leadership and learning in raising student outcomes and encouraging teachers’ professional learning in the highly centralised context of Greece. It reports part of a comparative research study focused on whether, and to what extent, IL has been embraced by Greek school leaders. The study is exploratory, using a qualitative multiple case design to examine two HPSS in Athens. The research design involved a qualitative approach using several different methods, including semi-structured interviews with school principals, deputy heads, subject teachers and subject advisers, plus observation of leadership practice and meetings and scrutiny of relevant policy documents. The findings show that IL is conceptualised as an informal collaborative leadership practice, interwoven with the official multi-dimension role of Greek principals and their ‘semi-IL’ role. In the absence of official IL ‘actors’, teachers’ leadership has been expanding

SYNTHESIS OF POTASSIUM-S-1,2- DIHYDROXYPROPYLSULPHONATE AND ITS INCORPORATION TO SYNTHESISE POLYESTER IONOMER

ABSTRACT: An anionic diol, potassium-S-1,2-dihydroxyprppylsulphonate, (SDOL) has been synthesised by using phase transfer catalyst, benzyltriethylammonium chloride and subsequently used for the preparation of polyester ionomer. A series of polyester were successfully synthesised by using different molar ratio of the ionic diol and propane diol. The monomer (ionic diol) and polyester were characterised by FTIR, 1 H NMR, TGA and DTG. The inherent viscosities of polyesters were in the range 0.38-1.21 dL/g. Key words: Polyester ionomer, benzyltriethylammonium chloride, ionic diol, potassium-S-1,2-dihydroxypropylsulphonate . I.INTRODUCTION Polyesters are a highly versatile class of polymers synthesized generally from a diacid and a diol. During the last 30 years, scientists have been fascinated by a class of polymers known as ionomers.Ionomers are normally defined as ion-containing polymers with a maximum content of ionic groups of about 15mol% or less along the backbone chains or as pendent groups. The modification and control of polymer properties through the use of ionic functional groups have received a considerable amount of attention in recent years. The common thread in most of the research efforts to date was the knowledge that the presence of even a small amount of covalently bonded ionic moieties in organic polymers is known to exert a profound effect on their physical and rheological properties. In fact ionomers have been shown to exhibit considerably higher moduli, and higher glass transition temperatures compared to their non-ionic analogues. Our research effort is directed towards the development of new polymer structures by introducing ionic groups (SDOL) into the polyester backbone. The first fibre-forming polyesters were prepared by Carothers and Hill in the late 1920s using the melt condensation of dicarboxylic acids and aliphatic diols. 1 Ionomers are materials of great technological interest due to the fact that the ionic groups can interact with each other disturbing the supramolecular structure and modifying their physical and chemical properties

Non-neoplastic lesions of the ovary review

Abstract Ovary is an important organ as it is concerned with the production of progeny. commonest site of neoplastic and non age group and accounts for the most prevalent cause of hospital admissions. lesions are classified as inflammatory (infectious and non non-cystic) and pregnancy related disorders

Online Signature Verification Using Energy, Angle and Directional Gradient Feature With Neural Network

Abstract: Signature used as a biometric is implemented in various systems as well as every signature signed by each person is distinct at the same time. It is very important to have anonline computerized signature Verification system differentiate digital signature. Hand written signature used every day at various places (Bank, Office etc) for the authentication of a person, but a signature of a person may not be same at different time or it may be generated by some fraud way. So therobust system is required for verification of the signature. The signature verification can be done either online or offline, here we are using online signature verification network. In the proposed system the signatures is taking as a image by the signature pad and apply image processing technique before the feature extraction to make the system effective. The angle, energy and chain code features are used in this paper to differentiate the signature. Neural network is used as a classifier for this system. The studies of online signature verification are given in this paper

Clinicopathological study of viral skin lesions

Abstract Introduction: Many viral infections have prominent skin manifestations. simplex, molluscum contagiosum and human papilloma virus which causes verruca vulgaris, condyloma acuminatum, deep palmoplantar wart and verucca plana. They are of increased significance in immunocompromised patients. the viral lesions are diagnosed clinically and serologically, some require biopsy confirmation. identify the specific histological changes in individual viral lesions. To differentiate the lesions that can clinically mimi as bullous lesion or soft tissue mass. SMVMCH for a period of 3 years from 2011 to 2013 were taken for this study. studied, 31 patients were diagnosed to have skin manifestations of various viral infections. The most commonly encountered entity was Verruca molluscum contagiosum (4), herpes (2) and verucca plana the diagnosis were, intranuclear inclusions in herpes; cytoplasmic viral inclusion bodies in MC, deep palmoplantar wart; koilocytes in Verruca and condyloma .These were also associated with o produce warty, bullous and mass like lesions which can mimic non infectious conditions. Histopathological evaluation serves as a valuable tool for identification of virus induced skin changes and aids in approp lesions. In our study most common infection was HPV

Talking Assistance about Location Finding both Indoor and Outdoor for Blind People

Abstract: God gifted sense to human being which is an important aspect in our life is vision. We are able to see the beauty of nature, things which happen in day-to-day life with the help of our eyes. But there are some people who lack this ability of visualizing these things. They face many difficulties to move on with their daily life. The problem gets worse when they move to an unfamiliar location. Visually impaired people face many challenges when moving in unfamiliar public places. Only few of the navigation systems for visually impaired people can provide dynamic interactions. None of these systems work perfectly both indoors and outdoors. Current navigation device for the visually impaired focus on travelling from one location to another. This focuses on designing a device for visually impaired people that help them to travelling independently also it must be comfortable to use. The proposed device is used for guiding individuals who are blind or partially sighted. The device is used to help blind people to move with the same ease and confidence as a sighted people. The device is linked with a GPS to identify the location of the blind person. Moreover, it provides the voice alert to avoid obstacles based on ultrasonic sensors. An emergency button is also added to the system. A RFID can be installed into public building and it is also integrated into blind persons walking stick .The whole device is designed to be small and is used in conjunction with the white cane

Detection of Black Hole Attack With Improved AODV Protocol in Manet

ABSTRACT:Ad-hoc network is a collection of dynamic nodes it means any node can join the network and leave the network any time. Wireless communication is less secure than wired communication and that's why it is the vulnerability of mobile ad-hoc network and any threat can easily affect the communication. Many types of attacks are developed today which badly crash the network and make the communication performance degrade. So for avoid these vulnerabilities and make network secure we propose the technique on SECURITY of mobile ad-hoc network. To provide the security of mobile ad-hoc network we generate new techniques for detection of black hole attack. Black hole attack is type of malicious node who drops the packet instead to send that packet to their destination