High fidelity sorting of remarkably similar components via metal-mediated assembly.

Subtle differences in ligand coordination angle and rigidity lead to high fidelity sorting between individual components displaying identical coordination motifs upon metal-mediated self-assembly. Narcissistic self-sorting can be achieved between highly similar ligands that vary minimally in rigidity and internal coordination angle upon combination with Fe(ii) ions and 2-formylpyridine. Selective, sequential cage formation can be precisely controlled in a single flask from a mix of three different core ligands (and 33 total components) differing only in the hybridization of one group that is uninvolved in the metal coordination process

Substrate-Integrated Folded Waveguide Slot Antenna

In recent years a number of researchers have proposed novel techniques for fabricating rectangular waveguide using microwave integrated circuit techniques. These so-called substrate integrated guides have been fabricated using multilayer LTCC, multi- and single-layer microwave laminates and photoimageable thick films. All of these structures result in dielectric filled rectangular waveguide and as such have a width reduction of 1/square root of the relative permittivity over conventional waveguide. Furthermore, by their very nature they are easily integrated with planar transmission lines and circuits, allowing hybrid waveguide/microstrip systems to be fabricated on a single substrate. Several researchers have investigated slot antennas and arrays in substrate-integrated guide. In this paper we show a slot antenna in a folded substrate-integrated waveguide. These waveguides have half the width of the other types of substrate-integrated waveguide. As such the present structure allows arrays of slot antennas to be more highly integrated

Microwave characterization of slotline on high resistivity silicon for antenna feed network

Conventional silicon wafers have low resistivity and consequently unacceptably high value of dielectric attenuation constant. Microwave circuits for phased array antenna systems fabricated on these wafers therefore have low efficiency. By choosing a silicon substrate with sufficiently high resistivity it is possible to make the dielectric attenuation constant of the interconnecting microwave transmission lines approach those of GaAs or InP. In order for this to be possible, the transmission lines must be characterized. In this presentation, the effective dielectric constant (epsilon sub eff) and attenuation constant (alpha) of a slotline on high resistivity (5000 to 10 000 ohm-cm) silicon wafer will be discussed. The epsilon sub eff and alpha are determined from the measured resonant frequencies and the corresponding insertion loss of a slotline ring resonator. The results for slotline will be compared with microstrip line and coplanar waveguide

Rodent Populations and Crop Damage in Minimum Tillage Corn Fields

No-till and disked cornfields were examined in southwest Iowa to determine small mammal population densities, movements, and impacts of rodent depredations on corn seedlings. Two replicates of the treatments corn planted into. corn stubble, corn planted into chemically treated sod, and corn planted into spring-disked fields were studied during the 1982 and 1983 growing seasons. Grids of 100 Sherman live traps were established at the edge and middle of each field to determine rodent densities and document possible encroachment of small mammals from nearby habitats. Trapping experiments were conducted for 6 consecutive days during May, August, and November. To assess crop damage, 5 164 ft. (50 m) transects were established in the edge and middle of each field. Corn seedlings were examined every other day for the first 10 days post-emergence

Rodent Populations and Crop Damage in Minimum Tillage Corn Fields

No-till and disked cornfields were examined in southwest Iowa to determine small mammal population densities, movements, and impacts of rodent depredations on corn seedlings. Two replicates of the treatments corn planted into. corn stubble, corn planted into chemically treated sod, and corn planted into spring-disked fields were studied during the 1982 and 1983 growing seasons. Grids of 100 Sherman live traps were established at the edge and middle of each field to determine rodent densities and document possible encroachment of small mammals from nearby habitats. Trapping experiments were conducted for 6 consecutive days during May, August, and November. To assess crop damage, 5 164 ft. (50 m) transects were established in the edge and middle of each field. Corn seedlings were examined every other day for the first 10 days post-emergence

Decoupling Crossover in Asymmetric Broadside Coupled Split Ring Resonators at Terahertz Frequencies

We investigate the electromagnetic response of asymmetric broadside coupled split ring resonators (ABC-SRRs) as a function of the relative in-plane displacement between the two component SRRs. The asymmetry is defined as the difference in the capacitive gap widths (\Delta g) between the two resonators comprising a coupled unit. We characterize the response of ABC-SRRs both numerically and experimentally via terahertz time-domain spectroscopy. As with symmetric BC-SRRs (\Delta g=0 \mu m), a large redshift in the LC resonance is observed with increasing displacement, resulting from changes in the capacitive and inductive coupling. However, for ABC-SRRs, in-plane shifting between the two resonators by more than 0.375Lo (Lo=SRR sidelength) results in a transition to a response with two resonant modes, associated with decoupling in the ABC-SRRs. For increasing \Delta g, the decoupling transition begins at the same relative shift (0.375Lo), though with an increase in the oscillator strength of the new mode. This strongly contrasts with symmetric BC-SRRs which present only one resonance for shifts up to 0.75Lo. Since all BC-SRRs are effectively asymmetric when placed on a substrate, an understanding of ABC-SRR behavior is essential for a complete understanding of BC-SRR based metamaterials

The effectiveness of ER on reading proficiency: A meta-analysis

A meta-analysis was performed to investigate the impact of extensive reading (ER) on reading proficiency. This study gathered 71 unique samples from 49 primary studies published from 1980 to 2014 involving a total of 5,919 participants. Effect sizes were generated separately according to two different study designs: experimental-versus-control contrasts and pre-to-post-test contrasts. Small to medium effect was found in both study designs. Moderator analysis showed growing interest in ER in the field over the last 30 years. Also, a higher effect was found in the adults than in the children and adolescents group. English as a foreign language (EFL) settings showed a higher effect than English as a second language (ESL) settings; and web-based stories had a higher effect than paper books. Finally, ER as a part of curriculum showed the highest mean effect among ER types. Suggestions are made on how to implement ER in ESL and EFL settings effectively

Cutter Assembly for Microscope and Related Method

A low-profile cutter assembly for use on a microscope and related cutting method are provided. The cutter assembly includes a support subassembly having a mounting ring for receiving and engaging the objective of a microscope. A cutter subassembly carried by the support subassembly is displaceable between a home and a forward position in response to actuation. Upon reaching the forward position, additional actuation causes the front end of the cutter subassembly to pivot toward the stage, thereby placing a cutter adjacent to or in contact with the specimen. By selectively actuating the cutter subassembly, multiple cuts may be performed, as necessary or desired for cutting a spore or isolating a particular specimen