Two new benzoxazine monomers with aliphatic and aromatic substituents, as well as azobenzene moieties were synthesized and characterized by spectroscopic methods. Their thermal curing behavior in the absence of any catalyst was investigated by differential scanning calorimetry. The thermal properties of the crosslinked structures were also studied by thermogravimetric analysis. While the monomeric forms gave some indication of thermally-induced isomerization, the azo groups were shown to be fixed in the disordered form in the densely cross-linked matrix.

Land use/cover changes (LUCCs) in megacities can be rapid and extensive and lead to unintended consequences in sustainable watershed management. The aim of this study was to investigate effects of LUCC on hydrological components using Soil & Water Assessment Tool (SWAT) model in Terkos Basin, Turkey. Four LUCC scenarios (deforestation, urbanization, decrease in agricultural land and expansion in agricultural land) were set up regarding possible future land use changes in the watershed. Surface runoff was the main hydrological component that was impacted by LUCCs. Urbanization and conversion into agricultural lands scenarios resulted in considerable increases in surface runoff. Annual change of surface runoff for urbanization and conversion into agricultural lands scenarios was over 45% when compared to the baseline scenario. More remarkable changes were seen in dry months among the scenarios. Controlling the overall response of the hydrological systems to LUCC depends on better understanding of surface runoff processes. LUCC scenarios were also assessed based on freshwater availability components blue water and green water. The average annual total blue water potential, annual total green water flow and average green water storage of studied sub‐basin were 537, 584 and 108 mm/year for the baseline scenario, respectively. The trends of the blue water flow and green water storage were similar for each scenario, in that they were closely related to precipitation. This study provides valuable insight into hydrological impacts of possible land use changes on forested watersheds.

Pestisitler, yeterli miktarda ve kalitede tarımsal üretim gerçekleştirmek için modern tarımının vazgeçilmezi olmuşlardır. Kontrolsüz ve aşırı pestisit kullanımı, doğal kaynaklar, insanlar ve diğer canlılar için tehlike oluşturmaktadır. Özellikle su kaynaklarındaki pestisit kirliliğinin kontrolü için, pestisit kullanım ve satışına dair verilerin sağlıklı tutulması, pestisit uygulaması birlikte pestisitlerin taşınım ve dönüşüm mekanizmalarının bilinmesi, izleme çalışmaları ile pestisit varlığının tespit edilmesi gerekmektedir. Matematiksel modeller vasıtası ile de pestisit kirliğinin yönetiminde zaman ve ekonomik açıdan tasarruf sağlanabilecektir. Ayrıca En İyi Yönetim Uygulamaları (EİYU) gibi doğal arıtım yöntemlerinin ve alternatif kontrol tedbirlerinin havzada uygulanabilirliği araştıralabilecektir. Bazı çalışmalarda EİYU kapsamında uygulanan bitkilendirilmiş filtre şeritler ile su kaynaklarında %40 üzerinde pestisit giderimi sağlandığı görülmüştür. EİYU'ların verimliliğini araştırmak için karar destek sistemleri (KDS) önemli bir araç olup, pestisit türlerine ve havza yapısına göre giderim oranları değişmektedir. Bir metre uzunluğundaki bir bitkilendirilmiş şerit uygulamasının etkinliğini KDS ile ölçen bir çalışmada Kaliforniya'daki domates tarlalarında %40-60 oranında pestisit giderimi sağlanırken aynı uygulama Oregon'daki buğday tarlalarında %15-20 oranında giderim sağlamaktadır. Bu tarz çalışmaların ulusal düzeyde artması ile yoğun pestisit kullanımı olan tarımsal havzalarda pestisit kirliliğinin kontrolü kolaylaşacak, alınabilecek tedbirler kolayca belirlenebilecektir. Pesticide use is essential for sufficient quality and quantity production in modern agriculture. Uncontrolled and excessive pesticide use poses serious danger for human health, other living things and natural resources. It is necessary to keep track of pesticide sale and consumption data, to determine pesticide fate and transport mechanisms in the environment after application and monitoring pesticides in water sources for sustain efficient pesticide pollution control. Mathematical models are useful for the pesticide pollution control by time and money saving. It will also possible to investigate the applicability of natural treatment and alternative control methods in the basins such as Best Management Practices (BMP). As mentioned in this study, vegetated filter strip application as BMP reduces pesticide load over 40% in water sources. Decision Support Systems (DSS) are promising tool for assess the efficiency of BMPs. DSS are able to predict pesticide concentrations in the watershed that depends on pesticide types and watershed properties. In a DSS study, 1 meter vegetated filter strip application in tomato fields removes 40-60% pesticide concentration in receiving water bodies while reduces 15-20% pesticide pollution in the wheat fields in Oregon. With the increase of such studies at the national level, the control of pesticide pollution in agricultural basins with intensive pesticide use will be easier.

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