A green chemical method for synthesis of bromine-containing “building blocks” for the production of photovoltaic polymers

Bromine-containing derivatives of aromatic and heteroaromatic compounds are the most important "building blocks" in the assembly of modern Photovoltaic Polymers (PV). While PV is being developed to produce "green" energy, converting sunlight to electricity, the reactions for producing brominated derivatives of building blocks described in the literature are examples of obsolete and environmentally dirty technologies. More environmentally harmful than bromination with molecular bromine [1] can only be bromination by molecular bromine in a concentrated hydrobromic acid medium [2]. Using 1,1'-diphenyl (1), 9H-diphenylcarbazole (2) and thiophene (3) as examples, we successfully tested the bromination of the above objects with a mixture of potassium bromide and bromate in acetic acid as outlined in the diagram

A New Method for the Synthesis of Bromine-Containing Heterocyclic Compounds for Photovoltaic Polymers

With the development and improvement of systems for converting sunlight into electric and thermal energy, more and more work is emerging on the development of the newest and most promising direction in solar energy, namely the creation of solar cells based on photosensitive polymers. Recently the power conversion efficiency of organic photovoltaic (OPV) devices has overcome the barrier of 17%, and thus we can expect a new wave of scientific interest in the development of new, more efficient OPV devices. Unfortunately, during searching for highly efficient chemical structures of OPV polymers, the researchers missed an important point: all photovoltaic polymers consist of aromatic and heteroaromatic «building blocks», which, in turn, are synthesized based on outdated techniques using highly toxic, dangerous for life and environment precursors. The development of «green», environmentally friendly, economically viable methods for the synthesis of photovoltaic polymers and building blocks for their production, will make the energy obtained from OPV truly «green». In this work, we present an alternative, «green» method for synthesizing halogen-containing aromatic and heteroaromatic, expensive building blocks most commonly used in the synthesis of photovoltaic polymers, which can be used to obtain photovoltaic polymers of various structures. We present the original methods for the synthesis of 4,4-dibromo-1,1- biphenyl (1), 4,7-dibromo-2,1,3-benzothiadiazole (2), 2-bromothiophene (3) and 2,5-dibromothiophene (4). All these methods differ from the previously described routes by their simplicity and convenience of their implementation, the absence of corrosive and irritant reagents, good yield and compliance with the principles of «Green Chemistry»

STRUCTURE AND PHASE TRANSFORMATIONS IN GRAPHENE-REINFORCED COMPOSITES TI/G

It has been shown that micro-and nanostructural hardening with the formation of specific deformation shear zones that cause a reduction in the fraction of the free volume and the formation of strengthening nanophase heterogeneities as a result of partial nanocrystallization transferring metal glasse.Работа выполнена по Государственному заданию ИМЕТ УрО РАН в рамках Программы фундаментальных исследований государственных академий (тема 19-2), регистрационный номер проекта № 0396-2019-0002

ОСОБЕННОСТИ РОСТА И РАЗВИТИЯ МОРКОВИ ПРИ РАЗЛИЧНЫХ СРОКАХ ПОСЕВА В УСЛОВИЯХ РАВНИННОГО ДАГЕСТАНА

Vegetable production in Dagestan is the one of the smallscale, where elementary techniques are used, therefore the vegetable commodity output does not reach a third from total volume produced. With appearance of new irrigation technologies the perspective occurred to raise the productivity of vegetable growing. The use of the drop irrigation improved the vegetable production and yield as well as carrot production. The influence of sowing terms and plant density on features in vegetation phases, photosynthesis activity and water consumption in drip irrigation was studied in carrot ‘Chantenay 2461’ grown on the meadowchestnut soils medium loamy soils of plain areas in Dagestan. Spring sowing time and summer sowing time with plant density of 0.6; 0.8 and 1.0 million plants per hectare have been studied in accordance with the two-factor experiment. In the course of experiment, it has been shown that not the plant density but sowing terms have essentially influenced upon interphase vegetation period in carrot. It has been also revealed that sowing terms have influenced upon photosynthetic activity, increasing the leaf area by 15.1%, while photosynthesis activety and dry matter content have increased by 7.5% and 4.2% respectively. The maximal parameters of photosynthetic activity were obtained when sowing in the second ten-day period of March with density of 0.8 million plants per hectare, and a yield of 42.2 t/ha. To produce such yield, there is a requirement of irrigation rate should be 2600-2700 m3/ha, on average with 18 watering at rates between 87-165 m3 /ha. Calculations of energy and economic efficiency have shown that when sown in the 2nd decade of March density of 0.8 million plants per hectare gave maximum energy efficiency 6.14, whereas the level of profitability of production expenses was equal to 73.5%.Овощеводство Республики Дагестан в основном мелкотоварное, базирующееся на применении примитивных технологий, отсюда и товарность выращиваемых овощей не превышает трети от производимого объема. С появлением новых технологий в орошении открываются хорошие перспективы повышения продуктивности овощеводства. Применение капельного орошения позволит поднять технологичность отрасли на новый уровень и повысить урожайность овощных культур, в том числе и столовой моркови. На лугово-каштановых среднесуглинистых почвах равниной зоны Дагестана изучено влияние сроков и густоты посевов столовой моркови сорта Шантенэ 2461 на особенности прохождения фаз вегетации, показатели фотосинтетической деятельности, водопотребление и режим орошения при капельном орошении. В соответствии с этим был заложен двухфакторный полевой опыт, в котором изучали весенние и летние сроки посева и густоту стояния 0,6; 0,8 и 1,0 млн шт./га. Результатами исследований установлено, что на продолжительность межфазных периодов наибольшее влияние оказывают сроки, а не густота посевов моркови. Выявлено, что сроки посева оказывают существенное влияние на фотосинтетическую деятельность посевов, увеличивая площадь листьев на 15,1%, фотосинтетический потенциал – на 7,5% и массу сухого вещества – на 4,2%. Максимальные показатели фотосинтетической деятельности получены при посеве во 2 декаде марта и густоте 0,8 млн шт./га, обеспечивая урожайность 42,2 т/га. Для формирования такого урожая в среднем требуется оросительная норма на уровне 2600…2700 м3/га при 18 поливах нормами 87 и 165 м3/га. Расчеты энергетической и экономической эффективности показали, что при посеве во 2 декаде марта густотой 0,8 млн шт./га обеспечивается максимальный коэффициент энергетической эффективности – 6,14 и уровень рентабельности производственных затрат 73,5%.

Epidemiology and etiological factors of the risk of development of urinary disease in Dagestan

То clarify the clinical epidemiology of IBC in RD given site 12123 inpatient and outpatient cards of patients with ICD were analyzed. The average annual indicators of the quality of drinking water in various climatic and geographical zones of the region were studied. The incidence of ICD uneven, with high incidence among residents of planar zones 83,08%, it revealed the highest hardness of the water. The number of ICD patients living in the highlands is much less than USD 11.8%. It is established that increased consumption of animal protein is directly proportional to the increase in the number of ICD patients in the RD. Revealed that the incidence of IBC is higher among women (66,3%) than in men (33.7 per cent).С целью выяснения клинической эпидемиологии МКБ в РД с учетом территории проанализировано 12123 амбулаторных и стационарных карт больных с МКБ. Изучены среднегодовые показатели качества питьевой воды в различных климатогеографических зонах региона. Установлено, что заболеваемость МКБ неравномерна, высокая заболеваемость отмечена у жителей плоскостной зоны 83,08%, здесь выявлены самые высокие показатели жесткости воды. Число больных МКБ проживающих в горных районах намного меньше -11,8%. Установлено, что увеличение потребления животного белка прямо пропорционально увеличению количества больных МКБ вРД. Выявлено, что заболеваемость МКБ у женщин выше (66,3%), чем у мужчин (33,7%)

THERMOSTABILITY OF ATOMIC AND ELECTRONIC STRUCTURE WITH THE INTERFACE FORMATION OF GRAPHENE AND SILICON ON A SUBSTRATES METALS

Analyzing MD simulation data on the thermic evolution of G/M, Si/M interface there are have been established the specificities and criteria of functional stability of atomic, electron (conserving Dirac cone) structures, as main condition of exelant electronic properties (superconductivity including)

Nutritional assessment foradolescents attending urban and rural schools of the Sverdlovsk region

The article presents the results of a pilot questionnaire-based survey of adolescents attending urban and rural schools of the Sverdlovsk Region and their parents conducted for the purposes of nutritional assessment within the framework of the Federal Public Health Promotion Project.В статье представлены результаты пилотного анкетирования родителей и старшеклассников по вопросам оценки питания в образовательных учреждениях в городских и сельских территориях Свердловской области в рамках реализации Федерального проекта «Укрепление общественного здоровья»

Antimony-Doped Tin(II) Sulfide Thin Films

Thin-film solar cells made from earth-abundant, inexpensive, and nontoxic materials are needed to replace the current technologies whose widespread use is limited by their use of scarce, costly, and toxic elements. Tin monosulfide (SnS) is a promising candidate for making absorber layers in scalable, inexpensive, and nontoxic solar cells. SnS has always been observed to be a p-type semiconductor. Doping SnS to form an n-type semiconductor would permit the construction of solar cells with p-n homojunctions. This paper reports doping SnS films with antimony, a potential n-type dopant. Small amounts of antimony (1%) were found to greatly increase the electrical resistance of the SnS. The resulting intrinsic SnS(Sb) films could be used for the insulating layer in a p-i-n design for solar cells. Higher concentrations (5%) of antimony did not convert the SnS(Sb) to low-resistivity n-type conductivity, but instead the films retain such a high resistance that the conductivity type could not be determined. Extended X-ray absorption fine structure analysis reveals that the highly doped films contain precipitates of a secondary phase that has chemical bonds characteristic of metallic antimony, rather than the antimony–sulfur bonds found in films with lower concentrations of antimony.United States. Dept. of Energy. Sunshot Initiative (Contract DE-EE0005329)National Science Foundation (U.S.) (Grant CBET-1032955