121 research outputs found
HELİS DİŞLİ POMPALARDA KIYASLAMA (BENCKMARKING) ANALİZİ İLE TASARIM VE ENERJİ TÜKETİMİNDE OPTİMİZASYON
No full textThe various types of helical gear pumps can be produced to transfer the gasoline, diesel, chemicals, and oil. Helical gear pumps are used by motor power in fuel selling and transfer points, and by gear shafts at mobile transfer trucks. These pumps are classified in three main groups as internal gear, pallet, and helical pumps. The common feature of them is sucking the liquid from the container placed under ground level and transferring it to the high levels. The lower flow rates, noisy working, and the quick corrosion of gear when the pump is running closing outlet valve are the disadvantages of these pumps produced in our country. The aim of this study is to design a new generation of helical gear pump which will eliminate or at least decrease these disadvantages. It is expected to minimize energy consumption, and to protect the corrosion of gears coming from the high pressure at this new design. The dimensions of this pump will be appropriated to the chassis of the truck and at minimum weight. The various types of helical gear pumps, both domestic production and imported, are evaluated in a study performed with the R&D department of the petroleum industrialist firm IPT (Ismet Pump Technology) on their energy consumptions, flow rates, dimensions, weights, and maximum pressure criteria. The reasons of the noiseless working and the high flow rates are explored at the end of this benchmarking analysis. Through the benchmarking, by-pass system, liquid clearance between the gears, and the faults at the inlet and outlet design of the domestic products are identified and a new design is proposed. In the new designed pump the number of teeth is decreased and the cavitation of the inlet and outlet is minimized. Besides these the transfer capacity of the pump is increased from 400 l/min to 600 l/min. The energy requirement for 1 liter of liquid is compared with the other products to measure its energy efficiency. The result is also positive at this point of view. Then, this new design is protected by patent registration.Benzin, mazot, kimyasal ve yağların aktarımı için farklı tipte dişli pompaların üretimi yapılabilmektedir. Dişli pompalar, transfer setlerinde ve akaryakıt dolum istasyonlarında motor bağlantısıyla, yakıt tankerlerinde ise “shaft” bağlantısıyla çalışmaktadırlar. İçten dişli, paletli ve helis dişli pompalar olmak üzere gruplandırılan pompaların genel özelliği, yerin altından akaryakıtı çekip yüksek metrajlara basabilmesidir. Ülkemizde üretimi yapılan helis dişli pompanın debi kapasitesinin düşüklüğü, çok sesli çalışması, pompa çıkış vanasının transfer sırasında kapatıldığında dişli ömrünü kısaltması gibi olumsuz sonuçları vardır. Bu çalışmada, söz konusu sonuçları azaltacak yeni bir tip ürün geliştirilmesi amaçlanmaktadır. Bu yeni üründe, minimum enerji tüketimi ve yüksek basınç oluşmasından kaynaklanan dişlilerde oluşabilecek zararların önlenmesi beklenmektedir. Pompa hacmi tanker şasesi bağlantısına sığacak ölçülerde ve montaj kolaylığı için minimum ağırlıkta olmalıdır. IPT (Ismet Pump Technology) Akaryakıt kuruluşunun Ar-Ge bölümü ile kıyaslama (benchmarking) çalışması yapılarak ülkemizde ve yurt dışında üretimi yapılan helis dişli pompalar debi, hacim, ağırlık, enerji tüketimi ve maksimum basınç kriterleri dikkate alınarak incelenmiştir. Kıyaslama çalışması sonunda ürünlerin sessiz çalışma özellikleri ve yüksek debilere ulaşma sebepleri ortaya çıkarılmıştır. Bu çalışmada hali hazırda üretimi yapılan pompaların “by pass” sistemi, dişler arasındaki akışkan boşluğu ve giriş-çıkış tasarımındaki hatalar gözlenmiş ve yeni bir tip tasarım önerilmiştir. Bu tasarım, diş sayısı azaltılarak ve giriş - çıkış kavitasyonu önlenecek şekilde yapılmıştır. Çalışmada yapılan analizlere göre, aynı enerji tüketimi ile dolum kapasitesi 400 litre/dk debiden 600 litre/dk debiye çıktığı gözlemlenmiştir. 1 litre yakıt transferi için gerekli olan enerji tüketimi, diğer ürünler ile karşılaştırmalı olarak incelenerek enerji verimliliği ölçülmüş ve sonuçlar alınmıştır. Bu yeni tasarım, patent ile koruma altına alınmıştır.
Affective Economies of Activism: Reimagining Anti-Lgbtq Hate Crime
No full text“Affective Economies of Activism: Reimagining Anti-LGBTQ Hate Crime” is a critique of racism and misogyny within the contemporary LGBTQ movement. I argue that the mainstream LGBTQ movement’s narrow focus on street crimes against white gay men has resulted in a hyperreality that distracts us not only from the effects of the actual racialized violence that takes place, but also denies meaningful discussion of structural violence. This dissertation traces the origins of this exclusive and harmful discourse since the late 1960s with each chapter describing different forms of active resistance and possibilities for finding solutions today. I analyze publications gathered from special collections across the country; oral histories I conducted with activists in the South; documentary films; and queer online culture. My scholarship combines theory with everyday lived experience in order to bring social justice to the center of our field of vision. I do not only discuss and theorize about social justice, but also practice what I preach by engaging in archive activism and contributing to a grassroots LGBTQ history.American StudiesDoctor of Philosophy (Ph.D.
Dual regulation of mitochondrial fusion by parkin–pink1 and oma1
No full textAdrienne Helis Malvin Medical Research Foundation Parkinsons Disease Program; Johns Hopkins University School of Medicine; Leonard and Madlyn Abramson Professor in Neurodegenerative Diseases; NIH [R35GM144103, R35GM131768, P20GM104320]; Human Aging Project; Adrienne Helis Malvin Medical Research Foundatio
Array of Cryogenic Calorimeters to Evaluate the Spectral Shape of forbidden -decays: the ACCESS project
No full textThe ACCESS (Array of Cryogenic Calorimeters to Evaluate Spectral Shapes)
project aims to establish a novel technique to perform precision measurements
of forbidden \b{eta}-decays, which can serve as an important benchmark for
nuclear physics calculations and represent a significant background in
astroparticle physics experiments. ACCESS will operate a pilot array of
cryogenic calorimeters based on natural and doped crystals containing
\b{eta}-emitting radionuclides. In this way, natural (e.g. 113 Cd and 115In)
and synthetic isotopes (e.g. 99Tc) will be simultaneously measured with a
common experimental technique. The array will also include further crystals
optimised to disentangle the different background sources, thus reducing the
systematic uncertainty. In this paper, we give an overview of the ACCESS
research program, discussing a detector design study and promising results of
115In.Comment: 12 pages, 12 figure
R3 de tan ml olan evolüt e rilerinin liftler yard m yla TR3 tanjant demetine ta nmas
No full textDiferansiyel Geometride önemli bir konu olan Riemannian manifoldunda tanjant
demetlerin diferansiyel geometrilerinin incelenmesi ilk olarak Sasaki (1958)
taraf ndan yap lm t r. Daha sonra Dombrowski (1962) tanjant demetteki
geometrilerin geli mesine katk da bulunmu tur. Tanjant demette liftler (1966)
çal lmaya ba lanm . lk çal ma Kobayashi ve Yano ya ait tanjant demette tensör
alanlar n n ve konneksiyonlar n tam, dikey, yatay liftleri olmu tur.
Bu tezin amac R3 üzerindeki evolüt e rileri liftler yard m yla tanjant demetine (TR3
)
ta d m zda nas l bir görünüme sahip oldu unu incelemektir. Bu dönü ünümü
incelerken Frenet Serret aparatlar , Dairesel Helis e risi, Salkowski e risi ve
Darboux birim vektörü ara t rmalar m za yol gösterecektir
Orientation effect in the neutron yield in deuterated Pd target bombarded by deuterium ion beam
No full textAt the ion accelerator HELIS at the LPI, the neutron yield is investigated from a deuteron-deuteron (DD) reaction in a deuterated Pd target, during an irradiation of its surface by a 20 keV deuterium (D) ion beam. The measurements of the neutron flux in the D beam direction are performed in dependence on the target angle β with respect to the D beam axis using a multichannel detector based on He^{3} counters. A significant anisotropy in the neutron yield is observed, and it was higher by a factor of 2 at β=0 compared to that at β=±30°. The possible reasons for the anisotropy, including D ion channeling, are discussed. The orientation effect of increasing the relative probability of the DD reaction in Pd due to channeling was investigated by computer simulations using the bcm-2.0 code. The numerically obtained 20 keV D trajectories allow calculating the flux density of channeled D in dependence on the penetration depth and angle of incidence. The enhanced D flux density between crystal planes at a zero incident angle with respect to (200) Pd planes allows a qualitative explanation of the increase of the neutron yield in the DD reaction
First measurement of Gallium Arsenide as a low-temperature calorimeter
No full textIn the quest for direct dark matter detection, innovative approaches to lower the detection threshold and explore the sub-GeV mass range, have gained high relevance in the last decade. This study presents the pioneering use of Gallium Arsenide (GaAs) as a low-temperature calorimeter for probing dark matter-electron interactions within the DAREDEVIL (DARk-mattEr DEVIces for Low energy detection) project. Our experimental setup features a GaAs crystal at an ultralow temperature of 15 mK, coupled with a Neutron Transmutation Doped Germanium (NTD-Ge) thermal sensor for precise energy estimation. This configuration is the first step towards detecting single electrons scattered by dark matter particles within the GaAs crystal, to improve the sensitivity to low-mass dark matter candidates significantly. Taking advantage of the production of optical phonons in polar materials such as GaAs gives the possibility to study the scattering of sub-MeV dark matter. This paper presents a detailed analysis of the detector’s response, using a calibration spectrum using particles and X-ray events. While the results do not meet the ambitious eV scale threshold yet, they establish a solid benchmark for assessing the detector’s current performance and sensitivity. This work not only highlights the detector’s potential but also sets the stage for future enhancements aimed at achieving the eV threshold, underscoring the promising direction of this detector technology. These findings demonstrate the feasibility of using GaAs as a cryogenic calorimeter and hence open new avenues for investigating the elusive nature of dark matter through innovative direct detection techniques
R3 de tan ml olan invalut e rilerinin liftler yard m yla TR3 tanjant demetine ta nmas
No full textDiferansiyel Geometride önemli bir konu olan Riemannian manifoldunda tanjant
demetlerin diferansiyel geometrilerinin incelenmesi ilk olarak Sasaki (1958)
taraf ndan yap lm t r. Daha sonra Dombrowski (1962) tanjant demetteki
geometrilerin geli mesine katk da bulunmu tur. Tanjant demette liftler (1966)
çal lmaya ba lanm . lk çal ma Kobayashi ve Yano ya ait tanjant demette tensör
alanlar n n ve konneksiyonlar n tam, dikey, yatay liftleri olmu tur.
Bu tezin amac R3 üzerindeki involüt e rileri lifler yard m yla tanjant demetine (TR3
)
ta d m zda nas l bir görünüme sahip oldu unu incelemektir. Bu dönü ünümü
incelerken Frenet Serret aparatlar , Dairesel Helis e risi, Salkowski e risi ve
Darboux birim vektörü ara t rmalar m za yol gösterecektir
Radiopurity of a kg-scale PbWO
No full textRES-NOVA is a newly proposed experiment for detecting neutrinos from astrophysical sources, mainly Supernovae, using an array of cryogenic detectors made of PbWO crystals produced from archaeological Pb. This unconventional material, characterized by intrinsic high radiopurity, enables low-background levels in the region of interest for the neutrino detection via Coherent Elastic neutrino-Nucleus Scattering (CENS). This signal lies at the detector energy threshold, O(1 keV), and it is expected to be hidden by naturally occurring radioactive contaminants of the crystal absorber. Here, we present the results of a radiopurity assay on a 0.84 kg PbWO crystal produced from archaeological Pb operated as a cryogenic detector. The crystal internal radioactive contaminations are: Th <40 \upmu Bq/kg, U <30 \upmu Bq/kg, Ra 1.3 mBq/kg and Pb 22.5 mBq/kg. We also present a background projection for the final experiment and possible mitigation strategies for further background suppression. The achieved results demonstrate the feasibility of realizing this new class of detectors
Calibration du taux d'épimérisation de l'isoleucine par le 14C: exemple du Maroc.
No full textThe lithostratigraphic and archeological framework of the units of the upper part of the last climatic cycle froim sites along the northern Atlantic coast of Morocco, from Tangier to Casablanca, is established with the classical and AMS 14C and amino acids dating methods. Due to the intermediate high thermal history of this part of Morocco, racemization ratios in the molluscs are sufficiently high to establish a good regional aminochronological sacle. Measurement of the D-alloisoleucine/L-isoleucine (Aile/Ile) ratios of the hydrolisate of total amino acids is applied to marine shells Patella, Monodonta, Mytilus, and continental gastropods Helix and Rumina. Sites sampled belong to supratidal and infratidal beach deposits, eolianites and deposits. Results for shells from all the sites indicate statistically significant differences and increasing values of the ratios conformable to the stratigraphic position and to the 14C dates. Ratios for Helis from caves, as compared to 14C dates, seem to indicate a linear increase of values until at least 25 Ka.Le cadre lithostratigraphique et culturel de la partie supérieure du dernier cycle climatique du littoral atlantique du Maroc, entre Casablanca et Tanger, est précisé par des données croisées entre des datations par le 14C conventionnelle ou par accélérateur et par les acides aminés. Les conditions thermiques le long des côtes marocaines sont restées favorables à la différenciation d'une échelle aminochronologique régionale. La mesure des rapports D-allosioleucine/L-isoleucine (Aile/Ile) de l'hydrolisat total des acides aminés mesurés par chromatographie liquide a été appliquée à plusieurs types de tests dont les taux d'épimérisation peuvent varier du simple au double selon le genre : gastéropodes et pélécypodes marins, Patella, Monodonta, Mytilus et gastéropodes continentaux, Helix et Rumina. Les sites échantillonnés, grottes, abris sous roche, paléorivages, dunes littorales, nappes continentales, représentent des milieux de conditions thermiques et de fossilisation variées. Dans les conditions thermiques stables d'abris sous roche et de grottes, le taux d'épimérisation de Helix suit une courbe linéaire au moins jusque vers 25 000 BP, concordante avec les âges 14C
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