Пасивна система сонячного теплопостачання

The aim of our study is to calculate the passive solar heat supply of a building with the Trombe-Michel (TM) wall, which is located in Chernivtsi. The investigated building has the following parameters: heating area – 50 m2, heating volume – 150 m3. In the section, the TM wall has a trapezoidal profile with an inclination of the south side, with an area of 8×2.7 m2, to the plane of the horizon 67 ° and orientation to the south. From the south, the TM wall is separated from the outside air by double glazing. The arrival of radiation on the southern surface of the TM wall was determined for the following periods: October-November and March-April. In this case, the absorption coefficient of solar radiation by the surface of the TM wall is assumed to be 0.9. The loss of radiation when passing through the glazing is assumed to be 0.83. The average daily heat losses due to the radiation of the surface of the wall into an infinite space with an ambient temperature are determined. At night, the inner side of the glazing is covered with a shield made from a heat-insulating material to reduce heat loss. Being placed in the basement, a gravel battery accumulates about 2 GJ of heat at a temperature of 75 оС during the summer. The battery is charged by supplying hot air through it, which is heated by solar radiation in the gap between the TM wall and the glazing. In October-November period the air taken by the fan from the room passes through the battery and heated enters the room. This ensures a uniform supply of heat to the premises at a rate of 20 MJ per day for October and 48 MJ per day for November. Heat consumption for heating is determined by dissipative losses due to fencing building constructions and heat consumption during ventilation. The seasonal dependence of the total daily heat input taking into account radiation losses and the use of accumulated heat has been established. The replacement coefficient for heat supply f, as part of solar energy in the total required heat consumption for heating, was determined for different values of heat load γ (from 0.7 to 1.3 W/(m3 hail)) during the autumn and spring months. It has been established that when using the TM wall, replacement rate f of the heat supply of the building considered in Chernivtsi at the volum indicated above, the size of the TM wall and the heat capacity of the battery can be from 25 to 100 % for the autumn and spring months depending on the values of heat load γ.Досліджено розрахунковим способом пасивне сонячне теплопостачання енергоощадного будинку в Чернівцях з розташованою в ньому стіною Тромбе-Мішеля, південна поверхня якої площею 8×2,7 м2 нахилена до площини горизонту під кутом 67 о і відділена від навколишнього середовища подвійним склінням. Будівля є одноповерховим двокімнатним приміщенням з опалювальною площею 50 м2 і опалювальним об'ємом 150 м3. У підвалі будинку розташовано тепловий щебеневий акумулятор, який здатний зберігати до 2 ГДж теплоти за температури 75 оС. Влітку для зарядки акумулятора прогріте в проміжку між стіною Тромбе-Мішеля та склінням повітря відбирається вентилятором, продувається через акумулятор тепла, нагріваючи цим самим його теплоакумулятивну насадку. У жовтні-листопаді забране вентилятором з кімнати повітря проходить через акумулятор і нагріте повертається у приміщення. Встановлено сезонну залежність сумарного добового приходу тепла з урахуванням радіаційних втрат і використанням закумульованого тепла. Наведено розрахунок ефективності пасивної системи сонячного опалення розглянутої будівлі у Чернівцях за вказаних її об'єму, розміру стіни Тромбе-Мішеля і ємності теплового акумулятора, визначено коефіцієнти заміщення, з яких видно, що ступінь підтримки теплопостачання в осінні та весняні місяці може становити, залежно від значень теплового навантаження γ (Вт/(м3∙град)), від 25 до 100 %

In Pursuit of Prehistoric Caribou on Thandlät, Southern Yukon

In 1997, the first author noted a large concentration of caribou (Rangifer sp.) fecal pellets and a caribou antler on a permanent snow patch in the Kusawa Lake area of southern Yukon. Caribou are completely absent from this area today. Coring of the snow patch revealed continuous deposits of fecal pellets to depths of at least 160 cm. The proximal portion of a wooden dart or arrow shaft fragment recovered on the edge of the snow patch represents one of the few organic examples of mid-Holocene hunting technology ever found in Canada. An age of 2450 BP ± 50 years was obtained for the fecal material from approximately 1.6 m below the surface of the snow patch, and the dart was dated at 4360 BP ± 50 years. These dates indicate that aboriginal Yukon hunters have been harvesting caribou at this location for at least 4000 years. The Thandlät site offers a rare opportunity to explore a number of questions regarding the prehistoric ecology of large caribou populations, the implications of climate change for caribou populations, and human use of high-elevation hunting sites.En 1997, le premier auteur a découvert une concentration élevée de boulettes fécales (Rangifer sp.) et des bois de caribou sur une congère dans la région du lac Kusawa, dans le sud du Yukon. Il n'y a plus de caribous dans cette région. Le carottage de la congère a révélé des dépôts de boulettes jusqu'à une profondeur de 160 cm. Un fragment de dard ou de la flèche en bois trouvé sur le bord de la congère représente une des rares découvertes au Canada relatives à ce type d'arme. Il a été déterminé que les matières fécales prélevées dans la congère, à environ 1,6 m de profondeur, sont âgées de 2450 BP ± 50 ans, et que le dard aurait 4360 BP ± 50 ans. Ces dates montrent que les Autochtones du Yukon chassaient déjà le caribou à cet endroit il y a 4000 ans. Le site Thandlät est un des rares endroits où l'on peut observer divers aspects préhistoriques des grandes populations de caribou, des effets des changements climatiques sur les populations de caribous et des activités de chasse à grande altitude

Vacuum Rabi splitting and strong coupling dynamics for surface plasmon polaritons and Rhodamine 6G molecules

We report on strong coupling between surface plasmon polaritons (SPP) and Rhodamine 6G (R6G) molecules, with double vacuum Rabi splitting energies up to 230 and 110 meV. In addition, we demonstrate the emission of all three energy branches of the strongly coupled SPP-exciton hybrid system, revealing features of system dynamics that are not visible in conventional reflectometry. Finally, in analogy to tunable-Q microcavities, we show that the Rabi splitting can be controlled by adjusting the interaction time between waveguided SPPs and R6G deposited on top of the waveguide. The interaction time can be controlled with sub-fs precision by adjusting the length of the R6G area with standard lithography methods.Comment: 4 pages, 4 figure

The Effect of Pre-Analytical Variability on the Measurement of MRM-MS-Based Mid- to High-Abundance Plasma Protein Biomarkers and a Panel of Cytokines

Blood sample processing and handling can have a significant impact on the stability and levels of proteins measured in biomarker studies. Such pre-analytical variability needs to be well understood in the context of the different proteomics platforms available for biomarker discovery and validation. In the present study we evaluated different types of blood collection tubes including the BD P100 tube containing protease inhibitors as well as CTAD tubes, which prevent platelet activation. We studied the effect of different processing protocols as well as delays in tube processing on the levels of 55 mid and high abundance plasma proteins using novel multiple-reaction monitoring-mass spectrometry (MRM-MS) assays as well as 27 low abundance cytokines using a commercially available multiplexed bead-based immunoassay. The use of P100 tubes containing protease inhibitors only conferred proteolytic protection for 4 cytokines and only one MRM-MS-measured peptide. Mid and high abundance proteins measured by MRM are highly stable in plasma left unprocessed for up to six hours although platelet activation can also impact the levels of these proteins. The levels of cytokines were elevated when tubes were centrifuged at cold temperature, while low levels were detected when samples were collected in CTAD tubes. Delays in centrifugation also had an impact on the levels of cytokines measured depending on the type of collection tube used. Our findings can help in the development of guidelines for blood collection and processing for proteomic biomarker studies

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress

The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex might be connected on a unique pathway essential for the safe expansion of neuronal cells. Here, we show that MYCN transcriptionally controls the expression of each component of the MRN complex. By genetic and pharmacological inhibition of the MRN complex in a MYCN overexpression model and in the more physiological context of the Hedgehog-dependent expansion of primary cerebellar granule progenitor cells, we also show that the MRN complex is required for MYCN-dependent proliferation. Indeed, its inhibition resulted in DNA damage, activation of a DNA damage response, and cell death in a MYCN- and replication-dependent manner. Our data indicate the MRN complex is essential to restrain MYCN-induced replication stress during neural cell proliferation and support the hypothesis that replication-born DNA damage is responsible for the neuronal defects associated with MRN dysfunctions.Cell Death and Differentiation advance online publication, 12 June 2015; doi:10.1038/cdd.2015.81

Current challenges in software solutions for mass spectrometry-based quantitative proteomics

This work was in part supported by the PRIME-XS project, grant agreement number 262067, funded by the European Union seventh Framework Programme; The Netherlands Proteomics Centre, embedded in The Netherlands Genomics Initiative; The Netherlands Bioinformatics Centre; and the Centre for Biomedical Genetics (to S.C., B.B. and A.J.R.H); by NIH grants NCRR RR001614 and RR019934 (to the UCSF Mass Spectrometry Facility, director: A.L. Burlingame, P.B.); and by grants from the MRC, CR-UK, BBSRC and Barts and the London Charity (to P.C.

Experimental demonstration of the microscopic origin of circular dichroism in two-dimensional metamaterials

Optical activity and circular dichroism are fascinating physical phenomena originating from the interaction of light with chiral molecules or other nano objects lacking mirror symmetries in three-dimensional (3D) space. While chiral optical properties are weak in most of naturally occurring materials, they can be engineered and significantly enhanced in synthetic optical media known as chiral metamaterials, where the spatial symmetry of their building blocks is broken on a nanoscale. Although originally discovered in 3D structures, circular dichroism can also emerge in a two-dimensional (2D) metasurface. The origin of the resulting circular dichroism is rather subtle, and is related to non-radiative (Ohmic) dissipation of the constituent metamolecules. Because such dissipation occurs on a nanoscale, this effect has never been experimentally probed and visualized. Using a suite of recently developed nanoscale-measurement tools, we establish that the circular dichroism in a nanostructured metasurface occurs due to handedness-dependent Ohmic heating.ope

Long-distance attachments and implications for tourism development: the case of the Western Ukrainian diaspora

This study analyzes the perspectives of roots tourism through the experiences of Western Ukrainian diaspora members. Their sense of attachment to the ancestral homeland and their visits to the places of origin are investigated, together with the views by tour operators specialized in roots tourism and public authorities dealing with tourism in the region, evaluating the actual or potential impact in terms of tourism development opportunities. The peculiar history of this territory makes it a distinct research target, with dynamics that are different from the rest of the country. The desire to turn Western Ukraine into a solid tourist destination and the aim of stimulating economic development in a region that is still struggling to re-emerge from its marginality are widespread and form a fertile basis for the growth of diaspora tourism as a solid asset. Lights and shadows emerge from the diaspora tourists’ experiences and perceptions. Specialized tour operators clearly see the enhancement of this form of tourism as an important business opportunity, while public authorities are not currently focusing on this segment, preferring general tourism promotion