On freezing resistance of borehole heat exchangers

info:eu-repo/semantics/publishe

Analysis of pre-service science teachers’ level of associating their chemistry knowledge with daily life and the relationship between these levels and their attitudes towards teaching science

The aim of this study is to determine science teacher candidates’ (PSTs) levels of associating their chemistry knowledge with daily life and to examine the relationship between these levels and their attitudes towards teaching science. The study is a descriptive study conducted through the survey method. This study was carried out with 30 PSTs in the part of science teacher education at the College of Education in their final semester. As the data collection tools, an open-ended questionnaire, which was developed by Kıyıcı and Aydoğdu (2011), was applied to determine the PSTs’ levels of associating their chemical knowledge with daily life. Also, the “Science Teaching Attitude Scale” developed by Thompson and Shringley (1986) and adapted into Turkish by Özkan, Tekkaya and Çakıroğlu (2002) was used to determine PSTs’ attitudes towards teaching science. The data obtained from the open-ended questionnaire analyzed based on the three categories that were used by Vazquez-Alanso and Manassero-Mas (1999). Findings obtained from the data showed that PSTs’ level of associating their chemistry knowledge with daily life was low. Results of the statistical analyses showed that there was a significant relations between level of associating their chemistry knowledge with daily and their attitudes towards teaching science

EFFECTS ON THE SURFACE QUALITY IN THE MACHINING PROCESSES OF THE TOOL VIBRATIONS

The problem of surface quality and cutting stability in the machining processes is very important and is strictly connected with the final quality of the product. Therefore, this paper describes a new theoretical model for the dynamic cutting forces of orthogonal cutting in turning. A specific advantage for the presented model is the convenience for vibration prediction. The presented dynamic force model is used to predict variable cutting forces with dynamic cutting between cutting tool and workpiece.  This model is considered two degree of freedom complex dynamic model of turning with orthogonal cutting system. The complex dynamic system consists of dynamic cutting system force model which is based on the shear angle (φ) oscillations and the penetration forces which are caused by the tool flank contact with the wavy surface

Nukleus Akumbens Bölgesine Uygulanan Topiramatın Morfin Yoksunluk Sendromuna Etkileri

Aim: Nucleus accumbens, one of the nuclei of the basal ganglia, and dopamine, the neurotransmitter play a critical role in opioiddependence and withdrawal. In opioid withdrawal, the importance of neurotransmitters such as glutamate and gamma aminobutyric acid(GABA), as well as dopamine, is known. In this study, we aimed to investigate the effects of local injections of topiramate, anantiepileptic agent affecting GABAergic and glutamatergic pathways, into the nucleus accumbens on withdrawal signs and locomotoractivity during naloxone-induced withdrawal in morphine-dependent rats.Materials and Methods: Twenty male Sprague-Dawley rats were divided in topiramate treatment and control groups. All animalsreceived morphine pellets and guide cannulas were placed bilaterally in the nucleus accumbens regions by stereotaxic surgery. On thelast day of the experiment, following the bilateral topiramate or saline (control group) microinjections, morphine withdrawal was triggeredby naloxone.Results: Topiramate microinjections into the nucleus accumbens region significantly suppressed the signs of naloxone-inducedmorphine withdrawal such as number of jumpings and weight loss. No significant difference was observed in wet dog shakes, one of thewithdrawal signs, after local topiramate treatment. Although topiramate microinjections increased stereotypical activity it did not changelocomotor activity behavior such as vertical and ambulatory activity, and total covered distance.Conclusion: These findings show that local microinjection of topiramate into the nucleus accumbens is effective in preventing opioiddeprivation symptoms without significant effect on locomotor activity.Amaç: Bazal gangliyon çekirdeklerinden biri olan nukleus akumbens ve nörotransmitter olan dopamin opioid bağımlılığı ve yoksunluğunda kritik rol oynamaktadır. Opioid yoksunluğunda dopaminin yanı sıra glutamat ve GABA gibi nörotransmitterlerin de önemi bilinmektedir. Biz bu çalışmada morfin bağımlılığı oluşturulan hayvanlarda GABAerjik ve glutamaterjik yolakları etkileyen antiepileptik ajan olan topiramatın nukleus akumbens bölgesine lokal uygulamasının naloksonla tetiklenen yoksunluk sendromunda yoksunluk bulguları ve lokomotor aktivite üzerine etkilerini araştırmayı amaçladık. Materyal ve Metot: Yirmi adet erkek Sprague-Dawley sıçanları topiramat tedavi grubu ve kontrol grubu olarak ikiye ayrıldı. Hayvanların hepsine morfin peletleri uygulandı, stereotaksik cerrahi işlemle nukleus akumbens bölgelerine kılavuz kanüller bilaretal yerleştirildi. Deneyin son gününde bilateral topiramat veya serum fizyolojik (kontrol grubu) mikroenjeksiyonlarını takiben nalokson uygulanarak morfin yoksunluğu tetiklendi. Bulgular: Nukleus akumbens bölgesine lokal uygulanan topiramat naloksonla tetiklenen morfin yoksunluk bulgularından sıçrama sayısını ve ağırlık kaybını anlamlı düzeyde baskıladı. Lokal topiramat uygulaması yoksunluk bulgularından ıslak köpek silkinmesinde ise anlamlı değişiklik yapmadı. Topiramat mikroenjeksiyonları stereotipik hareketleri artırdığı halde vertikal hareketler, ambulatuvar hareketler ve toplam kat edilen mesafe gibi lokomotor aktivite davranışlarını değiştirmedi. Sonuç: Bu bulgular antikonvülzan ilaç olan topiramatın nukleus akumbens bölgesine lokal uygulanmasının lokomotor aktivitede anlamlı baskılanma yapmadan opioid yoksunluk belirtilerinin önlenmesinde etkili olduğunu göstermektedir

Cushing reflex: A sign of vessel perforation during mechanical thrombectomy performed under general anesthesia

We aimed to present the assessment of the Cushing reflex caused by intracranial haemorrhagia developing during mechanical thrombectomy in a case presenting with acute ischemic stroke. A 59-year old male patient was scanned by CT angio due to speaking disorder and right lateral weakness developing 5 hours earlier. Acute infarction was observed in the left MCA irrigation area with M1 segment occlusion observed in the left MCA. The decision was made to treat the patient with mechanical thrombectomy and he was transferred to the interventional neuroradiology unit. Under general anesthesia during navigation of the thromboaspiration catheter to the clot localization as the procedure was technically advancing routinely, with sudden development of bradycardia and hypertension the anesthesiology team was warned and 1 mg IV atropine was administered for bradycardia. Acute infarction has to be removed because it is understood as mechanical thrombectomy has been performed to a patient with an infarction. Simultaneously contrast material injection through the guide catheter showed the MCA M1 segment had ruptured and extravasation had developed. As conclusion, anesthesia and operation team must be alert for vessel perforation when Cushing triad develops during navigation of the thromboaspiration catheter

An analytical algorithm of porosity–permeability for porous and fractured media: extension to reactive transport conditions and fitting via flow-through experiments within limestone and dolomite

Accurate prediction of permeability evolution is essential for forecasting the long-term performance and lifetime of hydrothermal reservoirs, an important goal in the geothermal, ore, and petroleum industries. Erol et al. (Transp Porous Media 120(2):327–358, 2017. https://doi.org/10.1007/s11242-017-0923-z) introduced a general (non-empirical) analytical Kozeny–Carman type equation for predicting matrix and fracture permeability during single-phase, non-reactive flow. Here we incorporate the equation into an algorithm for addressing the influence on porous and fractured media permeability of the transient reactive processes of mineral dissolution and precipitation. Analytical algorithm predictions are identical to permeability values measured during fluid circulation through limestone and dolomite core samples from the Campine Basin deep geothermal system in Belgium. Benchmarking used identical values for initial hydraulic aperture dimension and porosity, measured during fluid circulation based on nondestructive micro-CT imaging. Analytical algorithm predictions of reactive surface area and fracture porosity are similar to results based on the TOUGHREACT reactive transport code. TOUGHREACT implements several well- established power-law models for predicting permeability, notably Civan (AIChE J 47(2):1167–1197, 2001. https://doi.org/10.1002/aic.690470206) and Verma and Pruess (J Geophys Res Solid Earth 93:1159–1173, 1988. https://doi.org/10.1029/jb093ib02p01159). However, these models rely on specification of empirical exponents, which are not straightforward to measure. Our results suggest that a more general, computationally inexpensive analytical method can lead to accurate permeability calculation

Investigation of theileria equi, babesia caballi, neospora spp. and toxoplasma gondii by serological methods in horse breed for touristic purpose in Nevşehir province

Protozoal hastalıklar atlarda ölümlere ve ciddi ekonomik kayıplara neden olur. Bazılarının zoonotik potansiyelleri ise halk sağlığı açısından önem arz eder. Bu çalışmanın amacı Nevşehir ilinde turistik amaçlarla yetiştirilen atlarda doku (Neospora spp. ve Toxoplasma gondii) ve kan (Theileria equi ve Babesia caballi) protozoonlarının yaygınlığını belirlemektir. Bu amaçla yaşları 3-24 arasındaki 105 dişi attan kan alınarak serumları çıkarılmıştır. Elde edilen serumlar Neospora spp., T.equi ve B.caballi antikorlarına karşı c-ELISA ve T.gondii antikorlarına karşı da Sabin-Feldman Dye testleri ile incelenmiştir. Çalışma sonucunda 105 atın ikisinde (%1,90) anti-Neospora spp., dokuzunda (%8.57) anti-T.gondii, ikisinde (%1,90) anti-B.caballi ve 77 (%73,33)’sinde de anti-T.equi antikorları tespit edilmiştir. Atlardan birinde (%0,95) T.equi, B.caballi ve T.gondii, birinde (%0,95) T.equi ve B.caballi, ikisinde (%1,90) Neospora spp. ve T.equi ve altısında (%5,71) ise T.gondii ve T.equi’nin neden olduğu miks enfeksiyonlar belirlenmiştir. Ki-kare testi ile ≤ 7 ve >7 yaş grupları ile Neospora spp., T.gondii ve B.caballi seroprevalansları arasında istatistiksel açıdan önemli bir fark bulunmazken, 7 yaş üzerindeki atlarda yüksek T.equi seroprevalansının önemli olduğu görülmüştür. Bu çalışma ile İç Anadolu bölgesinde Nevşehir ilinde atlarda T.equi’ye maruziyet oranının oldukça yüksek olduğu, prevalansın yaşla birlikte arttığı, ayrıca protozoon kaynaklı miks enfeksiyonların görülebileceği ve bunun tedavide göz ardı edilmemesi gereken bir durum olduğu ortaya konmuştur.Protozoan diseases cause deaths in horses and serious economic losses. Some of them have zoonotic potential and are important for public health. The aim of this study was to determine the seroprevalence of tissue (Neospora spp. and Toxoplasma gondii) and blood (Theileria equi and Babesia caballi) protozoa of horses, raised for touristic purposes, in the Nevşehir provice Central Anatolia Region of Turkey. For this aim, a total of 105 blood samples were collected from female horses from various breeds between the ages of 3-24 in Nevşehir province. Sera samples were tested against anti-Neospora spp., T.equi and B.caballi antibodies with c-ELISA method, while Sabin Feldman Dye Test was used for the detection of anti-T.gondii antibodies. At the end of the serologic examination, it was determined that two of 105 (1.90%) horses had anti-Neospora spp.; nine (8.57%) had anti-T.gondii; two (1.90%) had anti-B.caballi and 77 (73.33%) had anti-T.equi antibodies. Mixed infections were also detected in one horse (0.95%) caused by T.equi, B.caballi and T.gondii, one (0.95%) by T.equi and B.caballi, two (1.90%) by Neospora spp. and T.equi and in six horses (5.71%) by T.gondii and T.equi. There was no statistically significant difference between the age groups and Neospora spp., T. gondii and B.caballi seropositivity, while high T.equi seroprevalence was found to be significant in horses over 7 years old with the chi-square test. With this study, it was set forth that the exposure rate to T.equi in horses in Nevşehir province in the Central Anatolia region is quite high; also the prevalence increases with age, and protozoal mixed infections are likely to occur, which should not be ignored in treatment

Interview with Marjorie Harkins Buchanan Kiewit

In this interview with Julia Stringfellow, Marjorie Harkins Buchanan Kiewit, LU class of 1943, discusses her time as a student as well as her time on the Board of Trustees.https://lux.lawrence.edu/oralhistories/1036/thumbnail.jp

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe