Molecular Simulations for Adsorption-Based CO2 Separation Using Metal Organic Frameworks

Metal organic frameworks (MOFs) have received significant attention as a new family of nanoporous materials in the last decade. Variations in geometry, size, and chemical functionality of these materials have led to several thousands of different MOF structures. MOFs typically have high porosities, large surface areas, and reasonable thermal and mechanical stabilities. These properties make them ideal adsorbents for adsorption-based gas separations. It is not practically possible to test the adsorption-based gas separation potential of all available MOFs using purely experimental techniques. Molecular simulations can guide experimental studies by providing insights into the gas adsorption and separation mechanisms of MOFs. Several molecular simulation studies have examined adsorption-based CO2 separation using MOFs due to the importance of CO2 capture for clean energy applications. These simulations have been able to identify the MOF having the most promising CO2 separation properties prior to extensive experimental efforts. The aim of this chapter is to address current opportunities and challenges of molecular simulations of MOFs for adsorption-based CO2 separations and to provide an outlook for prospective simulation studies

Computational Screening of MOF-Based Mixed Matrix Membranes for CO 2

Atomically detailed simulations were used to examine CO2/N2 separation potential of metal organic framework- (MOF-) based mixed matrix membranes (MMMs) in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2 separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2 selectivities and higher CO2 permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2 permeabilities but high CO2 selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2 permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2 separation applications

Columba livia domestica’nın Bursa, Kelebek ve Bango ırklarının karyolojik özelliklerinin karşılaştırılması

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada Columbidae familyasına ait Columba livia domestica'nın Bursa, Kelebek ve Bango ırklarının karyolojik analizleri yapılmıştır. Analizler için bireylerin tüy kökü dokusundan elde edilen preparatlar kullanılmıştır. Columba livia domestica'nın Bango, Bursa ve Kelebek ırklarının diploid kromozom sayısı 2n=80 bulunmuştur. 9 kromozom çiftinin karyolojik ölçümleri yapılabilmiştir. Diğer kromozomlar (31 çift homolog kromozom) sadece sayılabilmiş olup, ölçümleri yapılamamıştır.Anahtar kelimeler: Columba livia domestica, Irk, Karyotip, SitogenetikIn this study, karyological analysises of Columba livia domestica?s Bursa, Kelebek and Bango breeds which are belong to Columbidae family were studied. Karyotype analysis was carried out feather pulp cells. Diploid chromosome number of Bursa, Kelebek and Bango breeds of Columba livia domestica was found 2n=80. It was that 9 pairs chromosomes were determined and chromosome measurements were made. Other chromosomes (31 homologous chromosome pair) only could be counted, and measurements couldn?t be made.Key Words: Columba livia domestica, Breed, Karyotype, Cytogeneti

Kalay ve çinko elementlerinin magnezyum metaline ilavesi ve özelliklerinin incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışma da, saf magnezyumun mikroyapı, mekanik ve korozyon özellikleri üzerinde kalay ilavesinin (ağ. % 1-3-5) etkisi incelenmiştir. Kalay ilavesine ek olarak, sabit değerde çinko (ağ. % 1), kalay içeren alaşımlara ilave edilmiştir. Alaşımlar, kontrollü atmosfer altında kokil döküm yapılarak üretilmiştir.Sonuçlarda, kalay ilavesinin mikroyapıyı modifiye etmiş ve tane boyutu azalmıştır. Çinko ilavesinde de daha küçük taneler gözlenmiştir. X ışınları difraktometresinde, tüm alaşımlarda ana fazların ?-Mg, Mg2Sn olduğu ortaya çıkmıştır. Ayrıca test edilen tüm alaşımlarda Zn esaslı intermetalikler gözlenmemiştir. Saf magnezyumun sertlik ve basma mukavemetleri, Sn ilavesinin ağırlıkça %5'e doğru artmasıyla artmıştır. Buna rağmen, saf magnezyumun çekme mukavemeti ağırlıkça %3 Sn ilavesine kadar artmıştır. Aynı durum ağırlıkça %1 Zn içeren alaşımlarda da gözlenmiştir, fakat Sn ilaveli alaşımlardan daha mukavemetlilerdir. En iyi uzama Mg-ağ.%3 Sn-ağ.%1 Zn alaşımında görülmüştür. Saf magnezyumun korozyon hızı, alaşım elementinin %5 Sn ilavesine doğru yükselmesiyle birlikte azalır. Zn ilavesinde, alaşımların korozyon direnci, Sn ilaveli alaşımlar ile kıyaslandığında artmıştır.In this study, the effect of tin (wt. % 1-3-5) on the microstructure, mechanical and corrosion properties of pure magnesium were investigated. In addition tin, a constant value of Zn (wt. % 1) was added to alloys with Sn. The alloys were produced under a controlled atmosphere by a gravity-casting process.The results show that the addition of Sn element modified the microstructure and decreased the grain size. In the case of Zn addition, the smaller grains were obtained. X-ray difractometry revealed that the main phases are ?-Mg, Mg2Sn in the all of alloys. Furthermore, it is not observed any Zn based intermetallics in all alloys tested. The hardness and compressive strength of pure-Mg increased by adding Sn up to 5wt.% however, the tensile strength of pure-Mg increased by adding Sn up to 3wt.%. A similar trend is also observed in the alloys containing 1wt% Zn, but more strong than with only Sn. The greatest elongation were exhibited by Mg-3wt.% Sn-1wt.% Zn. The corrosion rate of pure-Mg decreased with increasing alloying element up to 5wt.% Sn. In the case of Zn addition, the corrosion resistance of alloys increased when compared with only Sn alloys

Quality of Service in the Urban Bus System: Ankara EGO Example

The increasing global importance of the service sector in recent years requires planned improvements to be made in the quality of service in transportation systems, as well as in all service sectors. Studies to determine and improve the service quality of public transportation systems are of great importance, especially in terms of how to encourage the use of public transportation, rather than private vehicles, in urban transit. In this study, the service quality of Ankara Metropolitan Municipality EGO buses was measured using the modified Servqual model, which is the result of validity and reliability analysis conducted by researchers. After applying the Servqual questionnaire, which consists of four dimensions and twenty propositions, the relationship of the data obtained was calculated in terms of socio-demographic characteristics and the quality gaps of each proposition. Results show that the passengers evaluated all dimensions negatively, and a prioritization study was subsequently carried out with the help of Quadrant analysis

The effectiveness of electro-acupuncture in ovarian ischemia reperfusion injury

Electro-acupuncture is widely used in gynecology. Adnexal torsion is an important threat to ovarian reserves in women of reproductive age. This is the first study to investigate whether electro-acupuncture is beneficial in protecting ovarian reserves in case of adnexal torsion resulting in reperfusion injury. Thirty-two female Wistar Albino rats were randomized into four groups: the first group-sham operation, the second group-torsion/detorsion model, the third group-pre-acupunture + torsion/detorsion + post-acupuncture, and the fourth group-torsion/detorsion + post-acupuncture. The acupoints used were CV4 and bilateral SP6, Ex-CA1, Kid3, and ST36. In the third group, the acupoints were needled for two weeks before torsion, continuing for a further two weeks after torsion. In the fourth group, needling began after torsion and was maintained for two weeks. Both histological and biochemical parameters indicating ovarian reserves showed that electro-acupuncture applied to the above points exhibited an ameliorating effect on ovaries injured during ischemia/reperfusion. Electro-acupuncture may be capable of protecting against and preventing ischemia/reperfusion injury in case of ovarian torsion

Relationship of Lysosomal Storage Diseases (LSD) with Autophagy

Lysosomes are organelles that degrade damaged components or structures that have completed their functions and have roles in the last step of the autophagy pathway. Damage of the autophagy-lysosome pathway can cause vital problems for the cell. Lysosomal storage diseases (LSD) are one of the most common human genetic disorder caused by gene mutations. Up to now, more than 70 LSD were identified. LSD is mainly caused by functional disorders of enzymes in lysosomes or proteins associated with lysosomes. These disorders lead to the accumulation of undigested macromolecules in cells LSD can cause many systemic damages mainly in the nervous system, skeletal system, and reticuloendothelial system especially at early stages of the disease. Modulation and reactivation of autophagy is accepted as a new therapeutic approach for LSD. In this review, the general mechanisms of the relationship between lysosomal storage diseases and autophagy were evaluated together with the treatment approaches

Evaluation of the effect of frozen ejaculate and frozenTesticular sperm results on inrtacytoplasmic sperm injection (ICSI) parameters

Amaç: Çalışmamızda, dondurulmuş ejekülat ve dondurulmuş testiküler spermin İntrasitoplaz - mik Sperm Enjeksiyonu (ICSI) sonuçları üzerine etkisinin araştırılması amaçlanmıştır. Gereç ve Yöntemler: Çalışmamızda 11.10.2016- 12.09.2017 tarihleri arasında infertilite nedeniyle ICSI tedavisine alınan ve spermleri dondurulan 36 çift çalışmaya alınmıştır. Hastaların 14 tanesine ejekülat sperm kriyoprezervasyonu, 22 tanesine de micro testiküler sperm ekstraksiyonu (TESE) sperm kriyoprezervasyonu gerçekleştirilmiştir. İki grubun ICSI sonuçları (fertilizasyon oranı, embriyo gelişme oranı ve gebelik oranları) karşılaştırılmıştır. Bulgular: Sperm parametreleri değerlendirildi- ğinde ejekülat ve TESE spermlerinde dondurma ön- cesi ve dondurma sonrası toplam motilite ve canlılık oranları arasında istatistiksel bir fark belirlenme - miştir (>0.05). Fertilizasyon oranları, implantasyon oranları ve embriyo gelişme oranları arasında ista - tistiksel olarak anlamlı bir fark gözlemlenmemiştir (>0.05). Gebelik oranları ise dondurulmuş ejekülat grubunda dondurulmuş testiküler sperm grubuna oranla istatistiksel olarak anlamlı derecede yüksek bulunmuştur ( 0.05). When ICSI parameteres were compared nostatistically signifi - cant difference were observed between fertilization rates, implantation rates and embryo development rates (> 0.05). But pregnancy rates were found sta - tistically significantly higher in frozen ejaculate group than frozen testicular sperm group (<0.05). Conclusion: Although sperm cryopreservation has been used in ICSI treatments for many years, re- search and debate on the effectiveness of the method continues. According to our results frozen testicular sperm had no adverse effect on ICSI parameteres but we analyzed a significant decrease in pregnancy rates. This may be partially explained by the role of sperm in the implantation process. In order to dem- onstrate this effect and to elucidate the mechanisms involved in the implantation process, molecular studies with larger patient groups are needed

Database for CO2 separation performances of MOFs based on computational materials screening

Metal-organic frameworks (MOFs) are potential adsorbents for CO2 capture. Because thousands of MOFs exist, computational studies become very useful in identifying the top performing materials for target applications in a time-effective manner. In this study, molecular simulations were performed to screen the MOF database to identify the best materials for CO2 separation from flue gas (CO2/N-2) and landfill gas (CO2/CH4) under realistic operating conditions. We validated the accuracy of our computational approach by comparing the simulation results for the CO2 uptakes, CO2/N-2 and CO2/CH4 selectivities of various types of MOFs with the available experimental data. Binary CO2/N-2 and CO2/CH4 mixture adsorption data were then calculated for the entire MOF database. These data were then used to predict selectivity, working capacity, regenerability, and separation potential of MOFs. The top performing MOF adsorbents that can separate CO2/N-2 and CO2/CH4 with high performance were identified. Molecular simulations for the adsorption of a ternary CO2/N-2/CH4 mixture were performed for these top materials to provide a more realistic performance assessment of MOF adsorbents. The structure-performance analysis showed that MOFs with Delta Q(st)(0) > 30 kJ/mol, 3.8 angstrom 1 g/cm(3) are the best candidates for selective separation of CO2 from flue gas and landfill gas. This information will be very useful to design novel MOFs exhibiting high CO2 separation potentials. Finally, an online, freely accessible database https://cosmoserc.ku.edu.tr was established, for the first time in the literature, which reports all of the computed adsorbent metrics of 3816 MOFs for CO2/N-2, CO2/CH4, and CO2/N-2/CH4 separations in addition to various structural properties of MOFs.European Research Counci