RESUMO O objetivo desta pesquisa foi avaliar três métodos de determinação da densidade da madeira a 12 % e densidade básica. Os métodos usados foram: estereometria por imersão e por medição direta e ...o método de atenuação por radiação gama. Para tal, foram coletados discos de árvores de Pinus elliottii, oriundos de reflorestamento submetidas ou não ao processo de resinagem, com idade de 8, 15, 25 e 35, nas posições da base, DAP, 25%, 50%, 75% e 100% da altura comercial. Os resultados obtidos mostraram que os métodos empregados não apresentaram diferenças estatisticamente significativas. Entretanto, o método de atenuação da radiação gama permitiu determinar a densidade no sentido medulacasca, de milímetro em milímetro e transformar a densidade obtida na umidade de equilíbrio, em torno de 12% em densidade básica e densidade anidra, sem saturação e secagem total da amostra, respectivamente.
RESUMO A melhor utilização da madeira depende de suas propriedades químicas, físicas e anatômicas. Diversos fatores bióticos e abióticos podem interferir em maior ou menor magnitude nas propriedades ...da mesma e conseqüentemente, em sua qualidade. Esta pesquisa teve como objetivo o estudo da variação da densidade da madeira, visando obter subsídios face sua melhor aplicação. O material empregado, constituiu-se de amostras de madeira de 12 árvores de Pinus elliottii com diferentes idades de crescimento. Os Resultados obtidos mostraram haver variação da densidade nos sentidos longitudinal e radial e em função da idade de crescimento. A densidade aumentou da medula para a casca e com a idade de crescimento e diminuiu da base para o topo. Baseado nesta variação, foi possível distinguir regiões onde os valores de densidades são praticamente idênticos e regiões onde eles diferem entre si, permitindo assim, classificar a madeira em termos de densidade e sugerir seu melhor emprego.
Çalışmada, ardışık düşük doz gama () ışınlarının mono-kristal Silisyum (c-Si) güneş hücresi üzerine etkisi incelendi. ışını kaynağı olarak 60Co kullanılmıştır. c-Si güneş hücresinin performansı, ...radyasyon öncesi ve sonrası karanlık ve AM1.5G ışık koşullarında alınan akım-voltaj (I-V), dışsal kuantum verimlilik (EQE), kapasitans-voltaj (C-V) ve iletkenlik-voltaj (G/-V) ölçümleri ile belirlenmiştir. Deneysel sonuçlar, radyasyona maruz kaldıktan sonra hücrelerin idealite faktörlerinin arttığını göstermektedir. Doz miktarı arttıkça kısa devre akımı (Isc) ve verim () değerleri azalırken, açık devre voltajı (Voc) ve doluluk faktörü (FF) değerleri ise yaklaşık sabit kalmaktadır. Dışsal kuantum verimlilik (EQE) ölçümleri, güneş hücresinde oluşan hasarın taban katmanında oluştuğu gösterirken, hücrede oluşan bu hasarın azınlık yük taşıyıcısı yarı ömründe oluşan azalma ile ilişkilendirilmektedir. Ayrıca, aygıt performansındaki değişim C-V ve G/-V ölçümleri ile de doğrulanmıştır. Deneysel sonuçlar, radyasyon öncesi ve sonrası karşılaştırılarak tartışılmıştır.
In the study, the effect of sequential low-dose gamma () rays on mono-crystalline Silicon (c-Si) solar cells was investigated. 60Co was used as the ray source. Performance of c-Si solar cells was determined via dark and AM1.5G light current-voltage (I-V), external quantum efficiency (EQE), capacitance-voltage (C-V) and conductivity-voltage (G/-V) measurements before and after irradiation. Experimental results show that ideality factors of cells increase after exposure to radiation. As the dose increased, the short-circuit current (Isc) and efficiency () values decreased, while the open-circuit voltage (Voc) and fill factor (FF) values remained approximately constant. External quantum efficiency (EQE) measurements show that damage has occurred in base layer of the solar cell, while this damage is associated with a reduction in minority carrier lifetime. In addition, the change in device performance was confirmed by C-V and G/-V measurements. Experimental results are discussed by comparing before and after radiation.
•The GAMA aqueous homogeneous reactor (GAMA-AHR) is an AHR design developed by the Nuclear Reactor Research Team at the Department of Nuclear Engineering and Engineering Physics, Universitas Gadjah ...Mada.•Compared with other AHR designs, the GAMA-AHR utilizes light water as the reflector instead of graphite.•The standard GAMA-AHR design utilizes 3.0 % mole of uranyl nitrate as seed (fissile) fuel and 4 % mole of thorium nitrate as blanket (fertile) fuel, and both are dissolved in light water as solutions.•Criticality calculation and neutronic parameter analysis were performed utilizing SCALE6.2 and OpenMC computer codes with the ENDF/B-VII.1 neutron cross section library.
The GAMA aqueous homogeneous reactor (GAMA-AHR) is an AHR design developed by the Nuclear Reactor Research Team at the Department of Nuclear Engineering and Engineering Physics, Universitas Gadjah Mada. This nonpower reactor produces valuable radioisotopes, mostly molybdenum-99, that are intended for medical purposes. The standard GAMA-AHR design utilizes 3.0 % mole of uranyl nitrate as seed (fissile) fuel and 4 % mole of thorium nitrate as blanket (fertile) fuel, and both are dissolved in light water as solutions. Compared with other AHR designs, the GAMA-AHR utilizes light water as the reflector instead of graphite. This design allows the use of a completely passive post-shutdown cooling system. Criticality calculation and neutronic parameter analysis were performed utilizing SCALE6.2 and OpenMC computer codes with the ENDF/B-VII.1 neutron cross section library, respectively. The analyzed parameters comprised power distribution, excess reactivity, shutdown margin, shutdown capability using a fuel drain tank, control-rod worth, temperature reactivity coefficient, and void reactivity coefficient (αθ). From the calculation results, the GAMA-AHR exhibited an excess reactivity of 0.07843 Δk/k at zero burn-up in 3.0 % mole of uranyl nitrate solution. The excess reactivity at zero burn-up increased with the increase in the mole fraction of uranyl nitrate until the maximum value of 0.215 Δk/k at 15 % mole of uranyl nitrate. The GAMA-AHR exhibited the control-rod shutdown margin of −0.03072 Δk/k at a normal operation temperature (80 °C) and −0.01958 Δk/k at 40 °C. Draining of the seed-fuel solution shut down the reactor with a shutdown reactivity of −1.40385 Δk/k. The GAMA-AHR showed a negative feedback for temperature and αθ, with values of −0.000155 Δk/(k.°C) and −0.00353 Δk/(k.%), respectively. These results prove the inherent safety characteristic of the GAMA-AHR. The GAMA-AHR with the thermal power of 200 kWth capable to produce 2500 six day Ci per week of Mo-99.
Background: Diabetes mellitus (DM) is a clinical syndrome characterized by hyperglycemia due to absolute or relative deficiency of insulin. It is a leading cause of mortality and morbidity in adults ...worldwide, posing serious medical, socioeconomic, and rehabilitation problems. Rapid diagnosis plays an important role in the management of DM. Gama glutamyl transferase (GGT) is an example of one of these biomarkers.
Aims and Objectives: The aim of the study was to study the correlation of GGT in Type 2 DM patients.
Materials and Methods: The present cross-sectional study was carried out in the Department of Biochemistry, B.J. government Medical College and Sassoon General Hospital Pune, Maharashtra. The study period was from December 2015 to June 2017. A total of 70 newly diagnosed Type 2 DM patient aged between 40 and 60 years with blood glucose level more than 126 mg/dL in fasting and more than 200 mg/dL post-prandial were included in the study.
Results: The mean GGT in control group was 26.5 U/L and in diabetic group was 58.5 U/L. The GGT values were significantly raised in diabetic (case group) as compared to control group (P<0.0017).
Conclusion: GGT can be considered as an important biomarker in monitoring and preventing complication associated with Type 2 DM.
In order to determine the presence and spatial distribution of gully erosion on the Pag Island (Croatia), a gully erosion susceptibility model was developed using GIS-based multicriteria decision ...analysis (GIS-MCDA). To simplify the GIS-MCDA modelling process, we developed automated multicriteria GIS analysis - GAMA method that is applicable to other karstic areas. The analytic hierarchy process (AHP) was used to assign specific weight coefficients to each criterion in regard to its importance for gully erosion occurrence. In total four different gully erosion susceptibility models were created, based on different criteria weight coefficients. The final GIS-MCDA model (3) was chosen based on the quality validation. Validation of GIS-MCDA model quality was done using ROC curves that were made based on two reference gully datasets. Validation confirmed the consistency of created models and proved that existing gullies are within high gully erosion susceptibility areas. The entire Pag Island was divided, through generated gully erosion susceptibility model into areas of: very low susceptibility, low susceptibility, medium susceptibility, high susceptibility and very high susceptibility. High and very high gully erosion susceptibility areas cover around 30% of the total area of Pag Island. Developed GAMA method allows easier and faster application of GIS-MCDA methodology in gully erosion susceptibility modelling, as well as in various other research areas.
•Gully erosion susceptibility model is created through GIS-MCDA based on 10 predisposing and one Boolean criteria.•ROC curve quality validation confirmed the consistency of created gully erosion susceptibility model (AUC = 0,8965).•Final model has shown that high and very high gully erosion susceptibility areas cover around 30% of Pag island.•GAMA method makes GIS-MCDA process more direct, practical and applicable in various susceptibility modelling purposes.
This research aims to study the quantitative structure and activity relationship (QSAR) of gamma-carboline derivative compounds as anti-BVDV agents to get an equation that can predict the value of ...the anti-BVDV activity of gamma-carboline derived compounds. The research material is experimental EC50 data that convert to anti-BVDB activity. 14 gamma-carboline derivative compounds are divided into 2 groups, namely, 11 fitting compounds and 3 test compounds. QSAR analysis is based on multilinear regression calculations of the fitting compound by plotting the EC50 log as the dependent variable and the descriptor as the independent variable. The used descriptors are atomic net charge (q) and dipole moment (µ), which are involved in calculations using the AM1 semiempirical quantum mechanics method. In addition, the partition coefficient of n-octanol/water (Log P), molecular polarizability (α), molecular weight (BM), Van Der Waals surface area (A vdw), Van Der Waals volume (V vdw), and index of refraction (RD) are obtained from QSAR properties. The resulting QSAR equation is: Log pEC50 = -48.670 – 124.801 (qC11) – 12.661 (α) – 0.918 (µ) – 0.876 (RD) – 0.999 (Log P) + 1.863 (BM) + 0.043 (V vdw) with n = 14; r = 0.937; r2 = 0.878; SD = 0.244; Fcount/Ftable = 1.466; PRESS = 0.749; Sig. = 0.02 This equation can be used as an initial guide for designing the structure of new compounds of the gamma-carboline class by considering some of the most influential descriptors. Consequentially, new compounds can be designed that have a smaller predicted EC50 value than the known compounds derived from gamma-carboline.
Numerous computational tools for the simulation and design of emergency evacuation and egress are now available. Many evacuation models have been studied at different scales, from micro to macro ...models. To examine the problem in detail, the popular approach solicited is that of agent-based models (ABMs). ABMs take into account the heterogeneity of pedestrian behaviors and the unspecified conditions of the road network. However, the computational cost is enormous when applied to numerous evacuees. Coupled with ABM, the available Shapefile data can be used to develop simulation models to improve the analysis of spatial data and spatial processes. One such application concerns the evacuation of buildings in hazardous situations, where ABM is integrated with geographic information system (GIS) Shapefiles indoor spatial data to model humans during evacuation events and to simulate evacuation scenarios visualized in the Shapefiles. The research presented in this paper develops a multi-agent geosimulation model for building evacuation, integrating a Shapefile dataset of the case study building as input to ABM through the GAMA simulation platform. This model is intended to complement and enhance traditional approaches to building evacuation planning and management, such as earthquake and fire drills. The framework has been elaborated in such a way that it works for a wide range of scenarios, both in terms of hazards, geographical configurations, individual behaviors and crisis management. To demonstrate its adaptability, a real-life case study is presented concerning the evacuation of the Station NightClub from a fire.
Among the myriad of constants that appear in mathematics,p,e, andiare the most familiar. Following closely behind isg, or gamma, a constant that arises in many mathematical areas yet maintains a ...profound sense of mystery.
In a tantalizing blend of history and mathematics, Julian Havil takes the reader on a journey through logarithms and the harmonic series, the two defining elements of gamma, toward the first account of gamma's place in mathematics.
Introduced by the Swiss mathematician Leonhard Euler (1707-1783), who figures prominently in this book, gamma is defined as the limit of the sum of 1 + 1/2 + 1/3 + . . . up to 1/n, minus the natural logarithm ofn--the numerical value being 0.5772156. . .. But unlike its more celebrated colleaguespande, the exact nature of gamma remains a mystery--we don't even know if gamma can be expressed as a fraction.
Among the numerous topics that arise during this historical odyssey into fundamental mathematical ideas are the Prime Number Theorem and the most important open problem in mathematics today--the Riemann Hypothesis (though no proof of either is offered!).
Sure to be popular with not only students and instructors but all math aficionados,Gammatakes us through countries, centuries, lives, and works, unfolding along the way the stories of some remarkable mathematics from some remarkable mathematicians.
The field of glassy studies has long speculated about the existence of liquid-like regions within solid amorphous states. However, limited evidence from indirect investigations has left the question ...of their presence unanswered. In this study, we propose a computational approach to analyze dissipation characteristics at the atomic level. Our findings reveal the actual existence of localized liquid-like dissipation clusters in the glassy state, demonstrating a damping factor similar to liquids and a vanishing shear modulus. Surprisingly, these clusters are only observed at low temperatures and do not involve diffusive motions, unlike typical liquids. This unique state of condensed matter is dissipative but non-diffusive. In metallic glasses, we show that these clusters are responsible for the recently discovered β' relaxation. Our results provide a solid basis for the longstanding concept of liquid-like region in glassy materials and provide a new perspective on establishing structure-property correlations.
