Shuttle/GPSPAC experimentation study

The utilization is discussed of the GPSPAC, which is presently being developed to be used on the low altitude host vehicle (LAHV), for possible use in the shuttle avionics system to evaluate shuttle/GPS navigation performance. Analysis and tradeoffs of the shuttle/GPS link, shuttle signal interface requirements, oscillator tradeoffs and GPSPAC mechanical modifications for shuttle are included. Only the on-orbit utilization of GPSPAC for the shuttle is discussed. Other phases are briefly touched upon. Recommendations are provided for using the present GPSPAC and the changes required to perform shuttle on-orbit navigation

1,3,5,7-Tetra­kis(4-iodo­phen­yl)adamantane benzene tetra­solvate

The title mol­ecule, C34H28I4·4C6H6, has crystallographic symmetry and crystallizes with four symmetry-related benzene solvent mol­ecules. The phenyl group is eclipsed with one of the adamantane C—C bonds. The tetra­phenyl­adamantane units and the benzene solvent mol­ecules are connected by weak inter­molecular phen­yl–benzene C—H⋯π and benzene–benzene C—H⋯π inter­actions. In the crystal, mol­ecules are linked along the c-axis direction via the iodo­phenyl groups by a combination of weak inter­molecular I⋯I [3.944 (1) Å] and I⋯π(phen­yl) [3.608 (6) and 3.692 (5) Å] inter­actions

catena-Poly[zinc-tris­(μ-dimethyl­carbamato-κ2 O:O′)-zinc-μ-(2-phenyl­benzimidazolido-κ2 N:N′]

The crystal structure of the title compound, [Zn2(C13H9N2)(C3H6NO2)3]n, displays a long chiral chain. This is composed of zinc-dimer clusters capped by dimethyl­carbamate ligands, which lie on crystallographic twofold rotation axes and are polymerically linked in one dimension by 2-phenyl­benzimidadole (2–PBImi) organic ligands. The two Zn2+ ions defining the dimetal cluster are crystallographically independent, but display very similar coordination modes and tetra­hedral geometry. As such, each Zn2+ ion is coordinated on one side by the N-donor imidazole linker, while the other three available coordination sites are fully occupied by the O atoms from the capping dimethyl­carbamates. The chirality of the chain extends along the c axis, generating a rather long 52.470 (11) Å cell axis. Inter­estingly, the chiral material crystallizes from completely achiral precursors. A twofold axis and 31 screw axis serve to generate the long asymmetric unit

Student reactions to traumatic material in literature: Implications for trigger warnings

Introduction While trigger warnings have garnered significant debate, few studies have investigated how students typically respond to potentially triggering material. Method In this study, three hundred and fifty-five undergraduate students from four universities read a passage describing incidences of both physical and sexual assault. Longitudinal mea- sures of subjective distress, PTSD symptoms, and emotional reactivity were taken. Results Greater than 96% of participants read the triggering passage even when given a non-trig- gering alternative to read. Of those who read the triggering passage, those with triggering traumas did not report more distress although those with higher PTSD scores did. Two weeks later, those with trigger traumas and/or PTSD did not report an increase in trauma symptoms as a result of reading the triggering passage. Conclusions Students with relevant traumas do not avoid triggering material and the effects appear to be brief. Students with PTSD do not report an exacerbation of symptoms two weeks later as a function of reading the passage

N,N′,N′′-Tricyclo­hexyl­guanidinium iodide

In the title compound, C19H36N3 +·I−, the orientation of the cyclo­hexyl rings around the planar (sum of N—C—N angles = 360°) CN3 + unit produces steric hindrance around the N—H groups. As a consequence of this particular orientation of the tricyclo­hexyl­guanidinium cation (hereafter denoted CHGH+), hydrogen bonding is restricted to classical N—H⋯I and non-clasical (cyclo­hex­yl)C—H⋯I hydrogen bonds. The propeller CHGH+ cation and the oriented hydrogen-bonding interactions lead to a three-dimensional supra­molecular structure

Surveys of experiences of sexual violence and harassment in higher education: reports and findings

In April 2021, the Minister for Further and Higher Education, Research, Innovation and Science, Simon Harris, asked the Higher Education Authority (HEA) to conduct national surveys to track students\u27 and staff\u27s experiences of sexual violence and harassment. Working with an expert advisory group, the HEA Centre of Excellence for Equality Diversity and Inclusion ran surveys of staff and students in April 2021. 7,901 students and 3,516 staff answered the surveys (11,417 responses in total). The department will use the results of these surveys to make policy and funding decisions to tackle sexual violence and harassment in higher education institutions (HEIs)

tert-Butyl (2S)-2-{3-[(R)-bis­(tert-but­oxy­carbon­yl)amino]-2-oxopiperidin-1-yl}-3-methyl­butano­ate1

The title compound, C24H42N2O7, is a chiral lactam-constrained amino acid with a six-membered ring backbone and isopropyl and tert-butyl ester side chains. The conformation of the six-membered ring can be described as a half chair, with two CH2 C atoms lying 0.443 (1) and −0.310 (1) Å out of the best plane of the other four atoms (mean deviation = 0.042 Å). Both N atoms are sp 2 hybridized, lying 0.0413 (9) and 0.067 (1) Å out of the planes defined by the three C atoms bonded to them. The absolute configuration was determined, based on resonant scattering of light atoms in Cu Kα radiation

(1S,2E,6R,7aR)-1,6-Dihy­droxy-2-(4-nitro­benzyl­idene)-2,3,5,6,7,7a-hexa­hydro-1H-pyrrolizin-3-one

The crystal structure of the title compound, C14H14N2O5, contains two distinct conformers in the asymmetric unit. The compound has three defined stereocenters, two of them contiguous, and a C=C double bond with an E conformation. The stereocenters exhibit the same chirality in both conformers, with significant differences in the conformation of the five-membered rings of the pyrrolizine unit (both either in a twist or in an envelope form) and in the dihedral angles between the corresponding mean planes and the benzene rings. A prominent feature is a change from almost coplanar rings in one conformer to a new conformation in the second conformer, in which the mean plane of a five-membered ring is almost perpendicular to the benzene ring, with a dihedral angle 87.19 (8)°; the corresponding angle in the first conformer is 14.02 (10)°. In the crystal, molecules are linked by O—H⋯O and C—H⋯O hydrogen bonds. Crystallographic data were essential to confirm the configuration of the double bond, which was unclear from the available two-dimensional NMR data. In addition, reliable Flack and Hooft parameters were obtained, allowing for the correct absolute structure to be determined