Photoacoustic spectroscopy of solids and surfaces

After briefly reviewing the theory and instrumentation, results from a variety of experiments carried out by the authors on the photoacoustic spectroscopy of solids and surfaces by employing an indigenous spectrometer are discussed in the light of the recent literature. Some of the important findings discussed are, phase angle spectroscopy, anomalous behaviour of monolayers, unusual frequency dependence in small cell volumes, spectra of a variety of solids including amorphous arsenic chalcogenides, photoacoustic detection of phase transitions and determination of surface areas and surface acidities of oxides. Recent developments such as piezoelectric photoacoustic spectroscopy, depth profiling and subsurface imaging are also presented.

Lewis Lichtenstein Strauss papers 1908-1973

Consists of correspondence, documents, speeches, reports and other writings, photographs, film and other records of Admiral Strauss' involvement with Jewish organizations and causes, as well as miscellaneous personal items.

Uniformity of film thickness on rotating planetary planar substrates

For the purposes of obtaining a number of components with nearly identical thickness distributions over the substrate area and of minimizing the inhomogeneities of the film, it is logical to presume that a substrate rotating on its own axis and revolving around another axis will give more uniformity in film thickness than a substrate only revolving around one axis. In relation to the practical applications, an investigation has been undertaken to study the refinement that can be achieved by using a planar planetary substrate holder. It is shown theoretically that the use of the planetary substrate holder under ideal conditions of source and geometry does not offer any further improvement in uniformity of thickness over the conventional rotary work-holder. It is also shown that the geometrical parameters alone have little influence over the uniformity achieved on a planetary substrate, because of the complex cyclidal motion of any point on it. However, for any given geometry, a non-integral speed ratio of the planetary substrate and the work-holder shows considerably less variation in thickness over the substrate area.

Harold Debrest papers 1905-1976

The collection contains miscellaneous writings, personal correspondence and memorabilia of Debrest, an American Jewish journalist, poet and business executive. Among the correspondents are Felix Adler and Harry Truman.

Congregation Beth Israel Hartford Connecticut collection, 1920-1999

Congregation Beth Israel was founded in 1843 and is Connecticut's oldest synagogue. Originally established as an Orthodox congregation, the synagogue eventually converted to Reform and was one of the founding members of the Union of American Hebrew Congregations (Union for Reform Judaism) in 1877. This collection includes event flyers, programs for services, sermons, anniversary books with historical information, and bulletins. Box 1: General/Miscellaneous Materials 1927-1970. 100th Anniversary /Programs and Invitations 1943. 125th Anniversary/Program 1968. Publications/Bulletins 1920-1959. Box 2: Publications/ Bulletings 1950-1969. Box 3: Publications/ Bulletins 1960-1989. Box 4: Publications/ Bulletin 1989-1999.

Upper Valley Jewish Community Hanover, New Hampshire collection, undated, 1984-1996

The Upper Valley Jewish Community (UVJC) is an egalitarian congregation on the campus of Dartmouth College. The congregation hosts a Hebrew School and publishes the newsletter, "The Jewish Connection." This collection consists of several issues of the publication, "The Jewish Connection," as well as other miscellaneous invitations and programs for a variety of events.

Studies on CNTs/DNA composite

The electrical and optical properties of MWCNTs/DNA composite were studied. Electrical conductivity studies reveal that, the increase in CNTs concentration in DNA increases the conductivity. Fourier transformed Infrared (FTIR) spectrum shows that the CNTs are bonded to DNA covalently at the ends and defects sites and the wrapping of DNA on the CNTs is due to van der Waals force.

On the Purity of Atmospheric Glow-Discharge Plasma

Purity of the glow-discharge plasma at atmospheric pressure for surface modification applications is always debatable, since it works at ambient atmosphere. We have demonstrated on the use of optical emission spectroscopy to test the purity of this kind of plasma. The effect of gas flow pattern, nature of gas, and its flow rate on the plasma chemistry was studied. The importance of proper system design in maintaining a uniform flow of heavy and inert gases as carrier gas in atmospheric glow-discharge plasma was confirmed. The surface of a plasma-treated PET sample was analyzed using X-ray photoelectron spectroscopy to verify the studies on plasma purity done using emission spectrum.

LPG Gas-Sensing System With SnO2 Thin-Film Transducer and 0.7-mu m CMOS Signal Conditioning ASIC

The design and implementation of a complete gas sensor system for liquified petroleum gas (LPG) gas sensing are presented. The system consists of a SnO2 transducer, a lowcost heater, an application specific integrated circuit (ASIC) with front-end interface circuitry, and a microcontroller interface for data logging. The ASIC includes a relaxation-oscillator-based heater driver circuit that is capable of controlling the sensor operating temperature from 100degC to 425degC. The sensor readout circuit in the ASIC, which is based on the resistance to time conversion technique, has been designed to measure the gas sensor response over three orders of resistance change during its interaction with gases.

Nanoindentation study on germania-doped silica glass preforms: evidence for the compaction-densification model of photosensitivity

Nanoindentation technique was employed to measure the changes in mechanical properties of a glass preform subjected to different levels of UV exposure. The results reveal that short-term exposure leads to an appreciable increase in the Young's modulus (E), suggesting the densification of the glass, confirming the compaction-densification model. However, on prolonged exposure, E decreases, which provides what we believe to be the first direct evidence of dilation in the glass leading into the Type IIA regime. The present results rule out the hypothesis that continued exposure leads to an irreversible compaction and prove that index modulation regimes are intrinsic to the glass matrix.

Influence of rapid thermal annealing (RTA) on the structural and electrical properties of SnS films

The performance of optoelectronic devices critically depends on the quality of active layer. An effective way to obtain a high quality layers is by creating excess of metal atoms through various heat treatments. Recently, rapid thermal annealing (RTA) has proved a versatile technique for the post-treatment of semiconductor materials as compared to other techniques due to its precise control over the resources. Thus, we carried out a set of experiments on SnS films to explore the influence of RTA treatment on their properties. From these experiments we noticed that the films treated at 400 °C for 1 min in N2 atmosphere have a low electrical resistivity of ~5 Ωcm with relatively high Hall mobility and carrier density of 99 cm2/Vs and 1.3 × 1016 cm−3, respectively. The observed results, therefore, emphasise that it is possible to obtain good quality SnS films through RTA treatment without disturbing their crystal structure.

The determination of the refractive index of a photoelastic specimen by immersion technique

Conventional methods for determining the refractive index demand specimens of optical quality, the preparation of which is often very difficult. An indirect determination by matching the refractive indices of specimen and immersion liquid is a practical alternative for photoelastic specimen of nonoptical quality. An experimental arrangement used for this technique and observations made while matching the refractive indices of three different specimens are presented.

Ennaltamäärätty kääntymys: Predestinaatio ja vapaan tahdon ongelma Jonathan Edwardsin teologiassa

Tämän tutkielman tehtävänä on ollut selvittää onko ihmisellä vapaata tahtoa Jonathan Edwardsin mukaan. Lähteenäni minulla on ollut Edwardsin Freedom of the Will -teos sekä Miscellaneous- sarjasta Concerning the Divine Degrees -kirjoitus. Metodina minulla on ollut systemaattinen analyysi. Edwardsin taustana oli puritanismi. Esimerkiksi sakramenteilla ei ollut puritanismin piirissä samaa ratkaisevaa merkitystä uskon synnyttäjänä ja ylläpitäjänä kuin perinteisissä kristillisissä kirkoissa oli ollut. Puritanistien keskeinen armonväline oli saarna. Saarnalla pyrittiin vaikuttamaan ihmisen tahtoon antamalla rationaalisia perusteita Raamatun pelastustapahtumasta. Tämä on nähtävissä myös Jonathan Edwardsin teologiassa. Deismi ja valistus vaikuttivat myös Edwardsin aikaiseen ajatteluun voimakkaasti. Edwardsin Berkeleytä muistuttava idealismi kuitenkin takasi sen, että Jumala ei irronnut maailmasta vaan oli kaikessa koko ajan läsnä. Erityisesti Locke Newtonin luonnontieteiden filosofina vaikutti Edwardsin filosofiseen ajatteluun tahdon vapaus -kysymyksen osalta. Edwards pyrki Locken ja Newtonin avulla puolustamaan perinteistä kalvinistista kristillisyyttä. Tämän kilpailijaksi puritanismin piirissä oli tullut ajan henkeen sopiva järkiperäinen arminiolaisuus, joka edusti myös anti-revivalismia. Tähän arminiolaisuuteen liittyi perinteisistä kristillisistä opeista luopuminen. Tämä arminiolaisuus oli kehittynyt antropologisempaan suuntaan Remonstranssin ajoista korostaen ihmisen vapaita tahdon akteja. Näin ihminen pystyi päättämään uskoiko hän vai ei. Edwardsille usko ja pelastuminen perustuivat Jumalan valintaan, jossa kolmiyhteinen Jumala otti ihmisen yhteyteensä. Tämä kääntymys ilmeni kommuuniona ja uniona Kristuksen kanssa. Edwardsin ajattelua tahdon vapauden osalta avaa kompatibilismi. Kompatibilismin mukaan ennaltamäärääminen ei ole ristiriidassa vapaan tahdon kanssa, vaan päinvastoin sen lähtökohta ja perusta. Kääntymissä olemme eri näkökulmista täysin passivisia ja täysin aktiivisia. Kompatibilismin myötä Edwardsin kirjoitusten pohjalta pystytään johtamaan ennalta määrätty uskonratkaisu. Myöhemmin Edwardsin seuraajat New Lights harppasivat ironisesti arminiolaiseen suuntaan korostaen juuri uskonratkaisua. Vaikka Jumalalla on sanan varsinaisessa merkityksessä vapaa tahto, niin silti Hän toimii välttämättä pyhästi. Samoin Jeesus Kristus on linkkinä ihmisten välttämättömälle, mutta vastuulliselle toiminnalle. Jeesuksen valinta on kaikkien pyhien valinnan perusta. Ne, jotka Jumala hylkää helvettiin saavat oikeudenmukaisen rangaistuksen, koska Jumala rankaisee heissä itsessään olevaa pahaa. Se, miksi Jumala valitsee toiset ja hylkää toiset, kuuluu Jumalan salattuun tahtoon. Jumalan ilmoitetun tahdon mukaan Hän tahtoo kaikkien pelastuvan. Arminiolaiset hylkäävät ennaltamääräämisen, mutta hyväksyvät ennalta tietämisen. Edwardsille nämä ovat sama asia. Edwardsin mukaan välttämättömyys ei ole ristiriidassa vapauden kanssa. Luonnollisella ja moraalisella välttämättömyydellä on yhteys. Arkikielessä moraalista välttämättömyyttä ei oleteta. Koko tahdon vapaus -kysymys on pitkälti kielellinen. Arkikielessä ja filosofisessa kielessä on ero. Tahto ei ole agentti, joka voi valita itsenäisesti. Vapaus on ihmisen, ei tahdon ominaisuus. Siksi kysymys tahdon vapaudesta tulisi esittää onko ihminen vapaa. Edwards ja arminiolaiset ymmärtävät vapauden eri tavoin. Edwardsin mukaan tahdolla on oltava alku, eikä tahto voi koskaan arminiolaisten tavoin neutraali. Arminiolaiset hylkäävät perisyntiopin klassisessa merkityksessä, mistä seuraa erilainen lähtökohta. Sellaisena kuin arminiolaiset esittävät vapaan tahdon, meillä ei sitä Edwardsin mukaan ole. Vaikka kaikki tapahtuu Edwardsin mukaan välttämättä, niin silti olemme vastuullisia moraalisia agentteja.

A Novel Opto Electro Mechanical Interrogation System for Measuring Wavelength Shifts in Fiber Bragg Grating (FBG) Sensors

Here, we describe a novel FBG interrogation system in which FBGs are used as both sensing and reference elements. The reference FBGs is bonded to a mechanical flexure system having a linear amplification of 1:3.5, which is actuated using a piezo-actuator by applying a 0-150V ramp. The lengths of the reference gratings decide the maximum strain that can be applied to the reference grating, which in turn decides that strain range which can be interrogated. The main advantages of the present system are the on-line measurement of the wavelength shifts, small size, good sensitivity, multiplexing capability and low cost.

A Nonmoving-Part Fluidic Display Using Photoelastic Effect

Digital fluidic and pneumatic systems incorporate displays for the presentation of information to the operator. Displays reported so far for such systems use moving pistons, tapes, and other mechanisms leading to lower reliability. This paper describes a nonmoving part fluidic display employing the photoelastic effect. The display is pressure actuated and has a long life. When fabricated from compatible materials, this device can withstand hostile environments like nuclear radiation, vibrations, etc. The display is compact, economical and is virtually maintenance free. The display unit has been tested in the laboratory for reliability and speed of response.